The Web of Life – Glossary



2nd messenger: a molecule that relays a signal from a cell surface receptor to a target molecule inside the cell.

4d (aka spacetime): the 4 dimensions of everyday experience: 3 of space (3d) + 1 of time. See hd and ed.


α-helix (aka alpha helix): a common secondary structure of proteins that is a right-handed spiral conformation.

abalone: a sea snail in the Haliotidae family of mollusks.

abstraction: a thought stream involving symbolic representations. Compare concept, idea.

abyssal: the bottom waters (benthic zone) of the ocean.

acacia (aka thorntree, wattle, whistling thorn): a genus of shrubs and trees with 1,300 species, 960 of which are endemic to Australia. While many non-Australian species are thorny, most Australian acacias are not.

acetylcholine: a neurotransmitter in many organisms.

acid (chemistry): a proton donor. Contrast base.

acidophile: an organism that lives in a highly acidic habitat.

acorn woodpecker (Melanerpes formicivorus): a medium-sized woodpecker native to the western Americas, fond of acorns for food.

actin: a globular, multi-functional protein found in all eukaryotic cells except roundworm sperm. Actin participates in many cell processes, including communication, motility, and mitosis. Actin has equivalent cousins (homologs) in prokaryotes.

actinobacteria: a group of bacteria common in soil and water (freshwater and marine). Actinobacteria are ecologically important as decomposers of organic materials, including cellulose and chitin.

actinomycin: a class of antibiotic isolated from Streptomyces bacteria.

action potential: a quick excitation and release of the electrical membrane potential of a cell. Several types of such excitable cells are found in animals, including neurons, muscle, and endocrine cells. Some plant cells ply their trade on action potential, facilitating rapid movement.

activator (chemistry): an enzyme that increases reaction rate. Contrast inhibitor.

active margin: an active area of tectonic plates colliding. Contrast passive margin.

active site (organic chemistry): the position on a protein where substrates bind and undergo a chemical reaction.

adaptation (evolutionary biology): the teleological process of adjusting to ecological circumstance.

adaptive immune system (aka acquired immune system): the portion of the immune system that learns to recognize specific pathogens. Compare innate immune system.

adder (Vipera berus): a viper endemic to Europe.

Adélie penguin (Pygoscelis adeliae): a penguin common along the Antarctic coast.

adenine (A) (C5H5N5): a nucleobase of DNA & RNA, complementary to thymine in DNA or uracil in RNA.

adenovirus: a nonenveloped with a double-stranded DNA genome. Adenoviruses have a broad vertebrate host range.

adenylyl cyclase (AC): an enzyme family with key regulatory roles in almost all cells. Six classes of AC are known. All catalyze the conversion of ATP to cAMP and pyrophosphate.

adiabatic: occurring without gain or loss of heat; the opposite of diabatic).

ADP (adenosine diphosphate (C10H15N5O10P2)): the product of ATP dephosphorylation, which provides energy for a cell. See ATP.

adult: a fully developed organism. Sexual maturity is an aspect of adulthood for sexually reproducing life forms.

adventitious: not innate, and so arising or occurring out of the ordinary.

aerenchyma: channels that allow gas exchange between plant roots and shoots.

aerobic: living with oxygen. Contrast anaerobic.

aerobic respiration: cellular respiration which employs oxygen. Contrast anaerobic respiration.

aerosol: a suspension of fine liquid or solid particles in gas. Aerosol particles are less than 1 micrometer in diameter.

African termite (Macrotermes natalensis): a termite species in the African savanna that makes colonial mounds up to 3 meters high, built for ideal ventilation and constant internal temperature.

African wild dog (aka painted dog/wolf, Lycaon pictus): a canid endemic to Africa, especially savannas and lightly wooded areas.

agama: a small, long-tailed, insectivorous lizard that lives in Africa, of 37 species.

age (geology): a duration in the geological time scale, typically millions of years; shorter than an epoch.

agouti: a rodent native to the Neotropics, related to guinea pigs.

Agrodiaetus: a genus of butterfly in the Lycaenidae family (the 2nd-largest family of butterflies), found throughout the Palearctic ecozone.

Agulhas Current: a swift Indian Ocean gyral current, carrying warm water clockwise.

aka: “also known as.”

alanine (C3H7NO2): an amino acid employed in the biosynthesis of proteins.

albatross: a large seabird of 21 species in the Diomedeidae family, endemic to the Southern Ocean and north Pacific Ocean.

albedo: the ratio of light reflected by a surface to that received by it.

Aleutian Islands: a chain of 14 large volcanic islands and 55 smaller ones off the southwest coast of Alaska.

alevin: a juvenile fish.

alga (plural: algae): a eukaryotic protist that photosynthesizes via chloroplasts. Algae are usually unicellular or colonial.

aliphatic compound: the group of hydrocarbons that do not link together to form a ring.

alkaline: a substance with a pH ▫ 7.0.

alkaliphile: an organism that lives in a highly alkaline habitat.

alkaloid: a chemical compound containing mostly basic nitrogen atoms. Many organisms, including bacteria, fungi, plants, and animals, produce alkaloids.

alkene: a hydrocarbon with double bonds between carbon atoms.

allatostatin: a neuropeptide hormone in insects and crustaceans, employed in growth control.

allele (aka allelomorph): one of multiple forms of a gene; a variation of a gene at the same locus. Selfsame alleles at a locus are homozygous; if different, heterozygous.

allelopathy: the process of an organism producing biochemicals that affect the survival, growth, or reproduction of other organisms. Allelochemicals are employed by plants to fend off other plant species and herbivory.

allergen: a substance which can cause an allergic reaction.

alligator: a freshwater crocodilian in the Alligator genus which first appeared 37 MYA.

allogrooming: social grooming.

allometry: growth of a body part relative to the entire organism; also, the study thereof.

allomyces: a chytrid freshwater mold.

alloparenting: individuals other than biological parents acting as youngling caretakers.

allopatric speciation: evolution of a single species into 2 distinct species owing to populations being isolated from each other. Contrast parapatric speciation and sympatric speciation.

allosteric activator: an enzyme that enhances activity at an allosteric site. Contrast allosteric inhibitor.

allosteric inhibitor: an enzyme that lessens activity at an allosteric site. Contrast allosteric activator.

allosteric site: a site on a protein other than its active site.

allostery: regulation of an enzyme or other protein by binding an effector molecule at the protein’s allosteric site.

allotrope: a molecular structure of the same atomic species that may take various forms; that is, where element atoms may be bonded together in different ways.

allotropy: the property of an element existing as an allotrope (structural variations).

Aloe (aka Aloë): a genus of over 500 species of flowering succulent plants. The best-known species is Aloe vera (“true aloe”), so-called for its use as a moisturizing skin treatment.

aloe vera: a tropical succulent plant valued for its soothing medicinal effects. Scientific evidence of the medicinal benefits of aloe vera is spotty, yet aloe vera is a popular ingredient in skin creams and is touted for its healing properties when ingested as well, despite concerns about toxicity.

alpaca (Vicugna pacos): a South American camelid (member of the camel family).

alpha (sociality): the apex of a social hierarchy.

alphasatellite: a single-stranded DNA satellite virus dependent upon another virus for transmission.

alternation of generations (AoG): alternate asexual and sexual reproductive modes during a multicellular organism’s life cycle. For algae, plants, fungi, and slime molds, AoG also involves different genetic forms at different stages of life: haploid and diploid.

altricial: animals that are relatively immature and immobile at birth or hatching and so require parental care. Many mammals are altricial. Contrast precocial.

altruism: unselfish behavior.

aluminum (Al): the element with the atomic number 13; a soft, ductile, silvery-white, nonmagnetic metal; the 3rd-most abundant element in Earth’s crust (after oxygen and silicon (silica)), and the most abundant metal.

Amanita muscaria (aka fly agaric): a psychotropic mushroom.

Amazonian ant-plant (Hirtella physophora): a plant that hosts the arboreal ant species (Allomerus decemarticulatus) in honeycombed gallery structures that the ants construct.

amensalism: an interaction an organism negatively impacts another while immediately gaining nothing or being harmed.

American slave-maker ant (Protomognathus americanus): an ant that makes slaves of Temnothorax longispinosus ants, endemic to the woodlands of the northeastern United States and nearby Canada.

ametabolous: a type of metamorphosis in which physical development proceeds largely as growth in size. Compare hemimetabolous, holometabolous.

amiability: the tendency to be agreeable.

amine: a derivative of ammonia.

amino acid: an organic molecule comprising a carboxylic acid group, an amine group, and a side chain specific to the specific amino acid.

ammonia (NH3; aka azane): a toxic colorless gas with a pungent smell that figures in biology because of its nitrogen content. In certain microbes, atmospheric nitrogen is converted into ammonia by enzymes termed nitrogenases, in a process called nitrogen fixation. Mammals have a mechanism to prevent the buildup of ammonia toxicity in the bloodstream. Fish and amphibians lack this mechanism, as they can eliminate ammonia by excretions. For other aquatic animals, even dilute concentrations of ammonia are highly toxic.

amnion: a thin, membranous, fluid-filled sac surrounding an animal embryo. An amnion is filled with amniotic fluid. The vertebrate clade Amniota, distinguished by employing an amnion, comprises reptiles, birds, and mammals. In reptiles, birds, and monotremes, the amnion is enclosed in a shell. In marsupials and placental mammals, the amnion is enclosed in a uterus. Fish and amphibians do not employ an amnion (non-amniotic).

amoeba (plural: amoebas or amoebae): a protozoan with flexible form.

amoebozoa: an amoeboid protist, with ~2,400 species.

amphibian: a class of ectothermic tetrapod vertebrates that lay non-amniotic eggs; includes frogs, salamanders, and newts.

amphidromous: fish that migrate from the sea to fresh water to spawn. Contrast catadromous.

amphisbaenian (aka worm lizard, Amphisbaenia): a group of squamates, usually legless, of over 180 extant species. Although similar to snakes, they are most closely related to lizards.

amygdalin (C20H27NO11): a glycoside.

amyloplast: a non-pigmented plant organelle that synthesizes and/or stores starch granules by polymerizing glucose. Amyloplasts also convert starch back into sugar when a plant needs energy. Amyloplasts are abundant in fruit and in underground storage organs, such as potato tubers.

anabolism: the metabolic pathways for constructing biopolymers. See biosynthesis. Contrast catabolism.

anaconda: a large, nonvenomous snake of tropical South America.

anacoustic zone: an area where sound does not carry.

anadromous: ascending rivers from the sea for breeding.

anaerobe: an organism that does not require oxygen.

anaerobic (aka anerobic): living without oxygen. Contrast aerobic.

anaerobic respiration: cellular respiration without oxygen. Anaerobic respiration is less efficient than aerobic respiration.

anaerobiosis: living without free oxygen.

anaphase: the stage of cell division where replicated chromosomes split, and 2 daughter chromatids migrate to opposite poles of a cell. See interphase, telophase.

Anatidae: the family of aquatic birds that includes ducks, geese, and swans. Anatidae are generally herbivorous, and monogamous breeders. Numerous species are migratory.

anchovy: a small fish of 140 species in 17 genera, found in the Atlantic, Indian, and Pacific Oceans, and in the Mediterranean and Black Sea. Most anchovies are marine, but several species are okay with brackish water, and some in South America are freshwater.

Andes (aka Andean Mountains): a 7,000 km continuous range of highlands along the western coast of South America; the longest continental mountain range in the world. The Andes include the world’s highest volcanoes.

Anelosimus studiosus: a comb-foot spider native to the Americas. A. studiosus are solitary at less than 30° latitude, but increasingly become colonial in biomes with pronounced seasons.

anemone: see sea anemone.

angiosperm: a flowering plant; over 254,000 species are extant.

anguid: a diverse family of insectivorous or carnivorous lizards that live in the northern hemisphere.

anhydrobiosis: desiccation tolerance in an organism (typically aquatic) or life form, such as a plant seed.

ani (biology): a tropical New World cuckoo in the genus Crotophaga, with 3 species.

animal: a kingdom of eukaryotic heterotrophs. Most animals are motile. The other kingdoms of eukaryotes are fungi, plants, and protists.

animism: the doctrine that that there is no separation between the physical and spiritual world, and that a vital force is inherent in all matter. Contrast vitalism.

anion: a negatively charged ion (indicating a surplus of electrons). Contrast cation.

Anno Domini (AD): Medieval Latin for “in the year of the Lord.” A Julian and Gregorian calendar designation for the era traditionally reckoned as starting with the conception or birth of Jesus of Nazareth. There is no year zero in this scheme: 1 BC (“before Christ”) is followed by 1 AD.

annual (botany): an angiosperm that lives 1 year. Crabgrass and watermelon are exemplary summer annuals. Henbit and deadnettle are winter annuals. Winter annuals are ecologically important for providing vegetative cover that feeds animals during the winter, as well as preventing soil erosion when other plants are not around. Winter annuals are sometimes considered a pest in commercial agriculture, as they can host fungal diseases or insect pests. Ironically, keeping the soil relatively moist and preventing soil erosion during the winter can be problematic under many commercial agriculture regimes. Many food plants are annuals, or grown as such, including all domesticated grains. Root crops, such as carrots, celery, and parsley are biennials that are grown as annuals to harvest their edible roots, petioles, and leaves respectively. Bell peppers, sweet potatoes, and tomatoes are perennials that are typically grown as annuals. Compare biennial, perennial. See herbaceous.

anoxia: oxygen depleted; hypoxia of such severity to cause permanent bodily damage.

anoxic (adjective): oxygen depleted.

anoxybiosis: a cryptobiotic response to lack of oxygen.

ant: a colonial eusocial insect of ~22,000 extant species.

ant (verb): to dab and or other insect juices on the body.

Antarctica: Earth’s southernmost continent, 14 million km2, the 5th largest continent. Antarctica is the coldest, driest, and windiest continent, as well as averaging the highest elevation.

Antarctic Circumpolar Current (ACC): an ocean current that flows clockwise, from west to east, around Antarctica. The ACC is the dominant circulation pattern of the Southern Ocean, and the largest ocean current. The ACC is circumpolar because no landmass connects with Antarctica. This keeps warm seawater away from Antarctica, enabling the massive continental ice sheet.

The ACC presents the Antarctic Convergence, where cold and warm waters meet, creating an upwelling rich with nutrients. The Antarctic Convergence nurtures phytoplankton, copepods, and krill, which form the bottom of the oceanic food chain; thus, supporting fish, cetaceans, seals, seabirds, and a host of seafaring animal life.

antelope: an even-toed bovid native to Africa and Eurasia.

anther: the pollen-carrying portion of a stamen.

anthocyanin (aka anthocyan): a water-soluble pigment that may appear red, purple, or blue, depending upon pH.

anthropoid: a monkey or ape. Compare hominid.

anthropology: the study of human cultures and societies.

antibiosis: an antagonistic biological interaction, where an organism produces an antibiotic against an infectious microbe.

antibiotic: a substance toxic to certain microbes.

antibody: a large, Y-shape protein employed by the immune system to identify pathogens by recognizing a chemical signature on a specific region (antigen) on the surface of a pathogen.

anticipate: to make some preparation for an expectation.

antigen (aka antibody generator): a substance that specifically binds to a certain antibody, provoking an immune system response.

antioxidant: a molecule that inhibits oxidation of other molecules.

antlion (aka ant lion, doodlebug (US) (for the markings they leave in the sand)): the larva of an insect in the Myrmeleontidae family that traps ants and other small prey in funnel-shaped pits dug in the sand. Adult antlions look like damselflies.

ape (aka great ape): a tailless primate, not a monkey.

apex predator: a predator that is not preyed upon by another species, excluding pathogens.

aphid (aka plant lice): an extraordinarily successful herbivorous insect comprising 4,400 species in 10 families. Aphids exist worldwide but are most populous in temperate zones. Aphids can migrate great distances by riding the winds. Their success has labeled them as one of the most destructive crop pests in temperate climes. Many aphid species are monophagous. Others forage on hundreds of plant species across many families.

apophallation: deliberate penis amputation by a hermaphroditic terrestrial gastropod mollusk after mating, if entwined penises cannot get untangled. The amputated penis does not grow back, but the slug may have sex in the future as a female.

apical meristem: the growing tip of a plant from undifferentiated cells.

apoplast: the diffusional space outside a plant cell’s plasma membrane.

apoptosis: programmed cell death. Compare necrosis.

aposematism: coloration that warns potential predators of toxicity. Contrast crypsis.

appropriate: suitable to circumstance; fitting.

aquifer: a water-bearing geological bed or stratum capable of supplying water to wells or springs.

arachnid: the Arachnida class of invertebrates, with 8 jointed legs. There are over 100,000 named species, including spiders, harvestmen (aka opiliones, daddy longlegs), scorpions, solifuges (aka camel spiders, wind spiders), ticks, and mites.

arachnology: the study of spiders and other arachnids.

arbitrium (plural: arbitria):

arboreal: inhabiting trees.

arborescent (plant): a plant with wood / tree-like. Contrast herbaceous.

arbovirus (an acronym for arthropod-borne virus): a virus transmitted via arthropods.

archaea (singular: archaeon): the group of prokaryotes from which eukaryotes arose; a taxonomic domain of life alongside bacteria and viruses. Archaea may account for 20% of Earth’s biomass. Archaea are an extremely robust and versatile life form, with both extremophiles and ubiquity in their favor. Archaea are plentiful in the oceans. The archaea in plankton make them among the most abundant organisms on the planet. Archaea play roles in the carbon cycle and nitrogen cycle. Typically gregarious, archaea are commonly mutualists or commensals. No archaeal pathogens or parasites are known.

Archean (3.9–2.5 BYA): the eon when life first appeared on Earth, following the Hadean eon.

archerfish (aka archer fish, spinner fish): a fish in the Toxotidae family with the habit of shooting down insects on nearby vegetation by targeted spits of water. Archerfish inhabit the brackish waters of mangroves swamps and estuaries, but can also be found in the open ocean, as well as far upstream in fresh water. Archerfish are found from India to Polynesia.

archipelago (aka island chain): a clustered group of islands.

Arcobacter: a genus of Proteobacteria that commonly colonize animal intestinal tracts. Many Arcobacter have mastered the trick of nitrogen fixation.

Arctic: the northern polar region, comprising a vast frozen ocean.

Arctic tern (Sterna paradisaea): a mid-sized, piscivorous, migratory seabird in the tern family.

arenavirus: a genus of virus that infects rodents and humans.

Argentine ant: a small ant native to southern South America.

arginine: an amino acid employed in the biosynthesis of proteins; a precursor for the biosynthesis of nitric oxide.

arms race: (the idea of) 2 parties escalating their advantage in interacting with or competing against each other.

army ant: an ant of over 200 species that aggressively forages in predatory groups, known as raids, in which enormous numbers roam over an area. Unlike most other ant species, army ants do not construct residential nests. Instead they nomadically march, forming bivouacs as they travel.

armyworm: the caterpillar of various moths.

aromaticity: a molecule that is cyclic (ring-shaped) and planar (flat), with a ring of resonance bonds that has more stability than other geometric or connective arrangements with the same set of atoms. Aromatic molecules are stable. Organic compounds that are not aromatic are classed as aliphatic; they may be cyclic, but only aromatic rings have low reactivity (stability).

arthropod: an invertebrate with an exoskeleton, a segmented body, and jointed appendages. Arachnids, crustaceans, and insects are arthropods. There are over 6 million distinct arthropods. Arthropods comprise over 75% of animal species. Their collective biomass far outweighs that of vertebrates.

ascaroside: a glycolipid signaling molecule used by nematodes for communication, both internally and with conspecifics. The sugar in the glycolipid is ascarylose (C15H25N3O14P2).

asexual reproduction: biological reproduction from a single parent.

assassin bug: a predatory insect that lures its prey via subterfuge.

Assyria (~25th century BCE – ~599 BCE): a kingdom in the Near East and Levant.

Asteraceae (aka aster, daisy, composite, sunflower, Compositae): a large, widespread family of flowering plants with over 33,000 species in at least 1,911 genera.

asteroid: a small rocky body orbiting the Sun. Most asteroids emerge from the asteroid belt between Mars and Jupiter.

asthenosphere: the layer of Earth’s upper mantle just below the lithosphere.

atelid: a typically large New World monkey in the family Atelidae, which includes howler, spider, woolly and woolly spider monkeys.

atmosphere: the layer of gases that surround a body of sufficient mass. The atmosphere is held in place by the gravity of the body.

atmospheric circulation: the distribution of thermal energy throughout the troposphere.

atmospheric tide: analogous to ocean tides, the flow of air in the atmosphere based upon diurnal heating.

atom: the smallest particle of an element, comprising at the simplest a proton and an electron (hydrogen).

atomic decay: particulate radiation by subatomic particles from atomic nuclei.

atomic number: the number of protons an atom has.

atomic species: atoms of the same type (same number of protons).

atomic spectral line: a spectral measurement of an electron changing energy level.

ATP (adenosine triphosphate (C10H16N5O13P3)): the universal cellular energy storage and source molecule. ATP acts like a battery for cellular power. See ADP.

atropine (C17H23NO3): an alkaloid extracted from plants in the Solanaceae family, with simulative effects on the parasympathetic nervous systems of animals.

attine: a fungus-growing ant in the Attini tribe.

attojoule: a unit of energy equal to 10–18 joules.

attosecond: 10–18 seconds.

audience effect: an animal altering behavior because it suspects or perceives a conspecific eavesdropping or observing.

auk (aka alcid): a seabird related to terns and gulls. Auks can “fly” underwater as well as in the air. Though agile swimmers and divers, auks walk clumsily.

Australasia: a region of Oceania comprising New Guinea, Australia, New Zealand, and neighboring islands.

Australian golden orb weaver (Nephila edulis): a large web-building spider native to Australia, parts of New Guinea, and New Caledonia.

Australopithecus (4.2–1.8 MYA): a relatively long-lived genus of largely vegan hominins with considerable species diversity.

Australopithecus africanus: a hominin that lived 3.7–3.0 MYA.

autolysis: (cellular) self-digestion.

autonomic: involuntary; automatic behavior in an organism. Animal reflexes are autonomic.

autophagy (aka autophagocytosis): the catabolic process of recycling and waste disposal in cells. See lysosome and vacuole.

autopoiesis: a dynamic of self-sustaining activity; a system capable of maintaining and reproducing itself. A biological cell maintaining itself is an example of autopoiesis. Compare homeostasis.

autotomy: the ability of an animal to shed an appendage, usually as a defense against predation, to escape. In some instances, the lost body part, typically a tail, may regenerate.

autotroph: an organism that makes its own food. Autotrophs are lithotrophs or photoautotrophs. Lithotrophs consume electrons from inorganic chemicals for energy. Phototrophs take light as their primary energy source. Contrast heterotroph.

auxin: a class of plant hormones instrumental in numerous growth and behavioral processes.

avian: relating to birds.

awareness: the quality of being conscious in the present. See consciousness.

axon: a long, slender nerve fiber connecting neurons. A neuron has at most 1 axon. Some neurons do not have an axon.

Ayurveda: a system of Hindu traditional health care.

Azotobacter: a genus of soil bacteria, some of which have a symbiotic relationship with Cellulomonas, another soil bacterium.

Azteca ant: a large arboreal ant indigenous to the tropical forests of South America.


B cell: a lymphocyte of the adaptive immune system that makes antibodies against antigens. Compare T cell.

β-sheet (aka beta sheet): a secondary structure of proteins that is less common than α-helix. β-sheets comprise β-strands (beta strands) connected laterally by a backbone hydrogen bonds, forming a twisted, pleated sheet.

babbler: a small to medium-sized passerine.

baboon: a large African and Arabian monkey in the genus Papio, with 5 species, all having pronounced sexual dimorphisms. Baboons possess the innate ability for literacy (orthographic processing skills).

Babylonia (~18th century–6th century BCE): an ancient civilization in central-southern Mesopotamia.

bacillus (plural: bacilli) a rod-shaped bacterium. Compare coccus, spirillum.

background extinction: extinction limited to relatively few species. Contrast mass extinction.

bacteria (singular: bacterium): a taxonomic domain of single-celled prokaryotes, abundant in most ecosystems. Bacteria play vital roles in various facets of the biosphere.

bacteriophage (aka phage): a virus that infects bacteria.

bacteriorhodopsin: a light-sensitive protein used by archaea, notably halobacteria (a misnomer, as they are not bacteria). Bacteriorhodopsin works as a proton pump: pushing protons across the cell membrane. The resultant proton gradient is used to create a biochemical signal.

baculovirus: a family of invertebrate viruses.

badger: a short-legged omnivore in the Mustelidae family. There are 11 badger species.

baleen whale (aka great whale): a whale which feeds by filtering water through comb-like baleen plates rather than having teeth.

balling: a mass of entwined snakes, with multiple males trying to copulate with a female.

bananaquit (aka sugar bird, Coereba flaveola): a small, active nectarivore bird found in warmer biomes of the Americas.

banded mongoose (Mungos mungo): a colonial mongoose native to central and eastern African savannas, fond of eating beetles and millipedes.

bandy-bandy snake (Vermicella annulata): a black-and-white banded snake native to northern and eastern Australia that, when feeling threatened, tries to confuse by creating loops with its body.

banksia (aka acorn banksia, orange banksia, Banksia prionotes): a shrub native to southwest Australia, with serrated green leaves and large, bright flower spikes, which are pollinated by birds. Banksia grows exclusively in sandy soil and is typically a dominant plant in scrubland. Banksia is an important food source for many animals in the autumn and winter months.

baobab (Adansonia): a genus of trees adapted to aridity, of 8 species: 6 indigenous to Madagascar, 1 to Africa and the Arabian Peninsula, and 1 to Australia. Baobabs grow to 5–30 meters, with trunk diameters 7–11 m. Baobabs may live for thousands of years.

Barbary macaque (Macaca sylvanus): a macaque with a vestigial tail, unique for its distribution outside Asia.

barbeled dragonfish: a deep-sea dragonfish in the Stomiidae family that uses fanged teeth to snag prey. Barbeled dragonfish have bioluminescent photophores.

barberry (aka European barberry, Berberis vulgaris): a deciduous shrub that grows to 4 m high, producing acidic berries; native to central and southern Europe, northwest Africa, and western Asia. With a tart flavor and high in vitamin C, barberry berries are tailored for small birds, which disperse the seeds in their droppings. The barberry is thorny, and the plant itself is poisonous, thus effectively thwarting herbivores.

barbet: a tropical bird of 80 species, named for the bristles at the base of its stout, sharp bill. Weak fliers, none are migratory.

bark (botany): the outermost layer of a woody plant. Bark is a nontechnical term for the various tissues outside the vascular cambium. On older stems, inner bark is living tissue, whereas outer bark is dead tissue.

barnacle goose (Branta leucopsis): a goose with largely black plumage, native to the Arctic islands in the North Atlantic.

barophile (aka piezophile): an organism that thrives at high pressures, such as deep-sea archaea and bacteria.

basalt: a volcanic rock, typically rich in magnesium oxide and calcium oxide, and low in silicon dioxide and alkali oxides.

base (chemistry): a proton acceptor. Contrast acid.

basement (rock): a rock below a sedimentary platform. Basement rock is igneous or metamorphic in origin.

bat: a mammal with forelimbs forming webbed wings. Bats are the only mammal capable of sustained flight. 1,240 bat species are known; 70% are insectivores.

batfish: a coral reef dwelling fish in the genus Platax.

bay: a large body of water connected to the sea formed by an inlet of land which blocks some waves.

BCE (acronym for Before the Common Era): a semi-secular alternative designation for the calendar scheme introduced by Dionysius Exiguus, who respectively used BC (before Christ) and AD (anno Domini) to indicate times before and after the life of Jesus of Nazareth. Year zero is unused in both systems. Dates before 1 CE (common era) are indicated as BCE. CE dates are typically not denoted.

bean bug (Riptortus pedestris): a rice and bean plant consumer, native to east Asia; considered an agricultural pest.

bearcat (binturong, Arctictis binturong): an omnivorous viverrid endemic to the tall forests of South and Southeast Asia. Neither bear nor cat, binturongs are long and heavy, with short, stout legs, thick, black fur, a thick, long tail, and a short, pointed muzzle.

beaver: a large, primarily nocturnal, semiaquatic rodent. The beaver is best known for its dam-building skills, which provide still, deep water as protection against predators, and for floating food and building materials to construct homestead lodges.

bee: a flying insect of 20,000 species in the superfamily Apoidea. Bees, like ants, are a specialized form of wasp. Bees are best known for their product from pollinating flowering plants: honey. Bee sociality varies from solitary to eusocial. Bee eusociality evolved independently in different species.

bee bread: the brood food of older worker larvae.

bee killer (Pristhesancus papuensis): an assassin bug that waits on flowers to grab bees as prey, using collected sticky plant resin which helps hold the victim.

bee milk: a milky-white glandular secretion from the honeybee head which is fed to larvae.

bee-eater: a group (26 species) of near passerine birds with slender bodies, colorful plumage, and typically enlonged central tail feathers.

beet armyworm (aka small mottled willow moth, asparagus fern caterpillar, Spodoptera exigua): a moth native to Asia, but now found worldwide where any of its many host crops are grown; a pest of global proportions. The wide host range of these worms includes asparagus, beans and peas, beets and sugarcane, celery, cereals, leafy vegetables, potatoes, tomatoes, cotton, oilseeds, and tobacco.

beetle: an insect with wings and shell-like body protection, in the order Coleoptera.

behavior: an attributable state of action or inaction by a living entity.

bends (aka decompression sickness (DCS)): dissolved gases in tissues at depth creating painful air bubbles when surfacing quickly. DCS may produce various symptoms, including rashes, joint pain, breathing problems, neurological damage, paralysis, even death.

Benguela Current: a counterclockwise oceanic gyre in the Atlantic Ocean which carries cool water.

benthic zone (benthos): the ecological region at the bottom of the ocean or other water body, including the sediment surface and subsurface layers.

benzene (C6H6): a plant secondary metabolite which is carcinogenic in animals.

benzoxazinoid (BX): a class of plant secondary metabolites used against pests aboveground and below. BX is also used for intra-plant communication. Benzene is part of BX nastiness.

Beringia: the episodic Bering land bridge between Siberia and Alaska.

beta oxidation: the cellular process by which fatty acid molecules are broken down for energy.

biennial (botany): an angiosperm that takes 2 years to complete its life cycle. A biennial grows vegetative structures – roots, stems, and leaves – in its 1st year, before going dormant during the colder months. Typically, biennials grow close to the ground, with leaves forming a rosette. Many biennials require vernalization before they will flower. Onions, carrots, and parsley are biennials. Contrast annual, perennial. See herbaceous.

bicosoecid: a group of free-living unicellular flagellates.

bighorn sheep (Ovis canadensis): a sheep native to North America, named for its large horns.

binocular vision: the vision capability in an animal with 2 eyes to perceive a 3d image. See peripheral vision.

biochemical: an organic chemical with biological import.

biodiversity: the diversity of life at every level. Compare species diversity.

bioelement: a planetary ecological element. The bioelements include the atmosphere, lithosphere, hydrosphere, and biota.

biofilm: a colony of prokaryotes encased in a stabilizing polymer matrix; commonly known as slime.

biogenesis: the birth of the biosphere.

biogenic (substance) (aka biomolecule): a compound produced via an organic process.

biologic: biological logic; the reason for a biological trait.

biology: the science of life.

bioluminescence: production and emission of light by a living organism.

biome: an area where organisms live with similar conditions, both geographically and climatically.

biomechanics: biological mechanics.

Biophytum: a genus of 50 herbaceous plants in the wood sorrel (Oxalidaceae) family.

biopolymer: a polymer produced by a cell.

bioproduct: a biologically synthesized chemical compound.

biosonar: a synonym for echolocation.

biosphere: the global summation of the Earth’s ecosystems.

biosynthesis: the cellular construction process of converting substrates into more complex bioproducts. See anabolism.

biota: the organisms in an environment.

biotroph: an organism dependent upon another as a nutrient source. Contrast necrotroph.

bioturbation: displacement and mixing of sediment by fauna or flora.

bird: a feathered, bipedal, endothermic, egg-laying vertebrate in the class Aves. Birds descended from maniraptoran theropod dinosaurs. 10,000 living species are known.

bird of prey (aka raptor): a carnivorous bird.

bird-dung crab spider (Phrynarachne): a southeast Asian spider that looks and smells like feces to attract flies for food.

bitter leaf plant (Veronia amygdalina): a small medicinal shrub native to tropical Africa.

bitterbrush (Purshia tridentata): a shrub native to the mountainous western North America.

bivalve (Bivalvia): a class of marine and freshwater mollusks which includes clams, oysters, mussels, scallops, and many other families.

Black Death: a plague in the 14th century, caused by an airborne bacterium (Yersinia pestis).

black dragonfish (Idiacanthus atlanticus): a barbeled dragonfish, endemic to southern subtropical and temperate oceans, at depths down to 2,000 meters.

black egret (aka black heron): a sub-Saharan African heron, known for its habit of using its wings as a canopy for fishing.

black kite (aka fire hawk, Milvus migrans): a medium-sized bird of prey endemic to tropical and temperate biomes in Eurasia, Australasia, and Oceania. Temperate region black kites tend to be migratory.

black walnut (Juglans nigra): a flowering walnut tree native to Eastern North America that grows in riparian zones.

blackbird: a black bird in the Turdus genus.

blackpoll warbler (Setophaga striata): a migratory New World warbler. New World warblers (aka wood-warblers) are a group of small, often colorful, passerines.

bladderwort: a freshwater, carnivorous, flowering plant in the genus Utricularia, with 233 species; found in wet soil or in the water; extant worldwide except Antarctica.

blanketflower: a flowering plant in the genus Gaillardia, in the sunflower family.

blood: an animal body fluid employed to transport nutrients to and waste products from cells.

blowing a raspberry: putting the tongue between closed lips and producing a flatulent sound.

blue tit (Cyanistes caeruleus): a small passerine in the tit family, native to Eurasia.

blue wren (aka superb fairywren, Malurus cyaneus): a sedentary, territorial, passerine bird of southeastern Australia.

blue-footed booby (Sula nebouxii): a seabird native to the tropical and subtropical eastern Pacific Ocean; named for its bright blue feet. An adult blue-footed booby averages 81 cm long and 1.5 kg. The female is slightly larger than the male.

bluethroat (Luscinia svecica): a small, migratory, insectivorous passerine of Eurasia and North Africa. Male bluethroats are creative and imitative singers.

blunt-leaved orchid (aka small northern bog orchid, Platanthera obtusata): a small orchid, widespread in the colder forests of the northern hemisphere.

boa (snake): a nonvenomous constricting snake found through much of the world in the Boidae family.

bobwhite quail (aka northern bobwhite, Virginia quail, Colinus virginianus): a ground-dwelling bird native to the United States, Mexico, and the Caribbean.

bog beacon (aka swamp beacon (US)): an aquatic mushroom; the fruiting body of Mitrula paludosa.

Borderea chouardi: a small, slow-growing Spanish Pyrenees plant that can live over 300 years and has mutualist relations with 3 ant species.

bolas spider (aka angling spider, fishing spider) a spider that hunts by swinging a silk bolas to snag its prey.

bone: a rigid organ of connective tissue in vertebrates which forms a skeleton. Bone is mostly a fibrous matrix of composite material: inorganic calcium phosphate for rigidity and ossein (an elastic protein (collagen)) for fracture resistance.

bonnet macaque (aka zati, Macaca radiata): a macaque endemic to southern India.

bonobo (Pan paniscus): a peaceable ape, closely related to chimpanzees and humans. Bonobos have a matriarchal society. Bonobos are notably fond of sexual behaviors.

booby: a seabird of 6–7 species in the Sula genus, closely related to gannets.

boreal (aka taiga forest): a biome characterized by coniferous forest. Boreal is the Earth’s largest land biome, comprising 29% of the world’s forest cover.

Borneo: the 3rd-largest island in the world, and the oldest rainforest, located north of Java, Indonesia.

botany: the study of plants.

boundary (of tectonic plates): an intercourse between tectonic plates. A boundary is either divergent, convergent, or a transform-fault. At a divergent boundary, plates move apart, increasing plate area. At a convergent boundary, plates come together, decreasing plate area, as part of one plate is subducted. At a transform boundary, 2 plates rub, in the same or opposite directions; plate area is unchanged.

bovid: a cloven-footed ruminant ungulate in the Bovidae family, including antelopes, bison, African buffalo, water buffalo, (domestic) cattle, gazelles, goats, impala, muskoxen, sheep, and wildebeest. Bovids emerged 20 MYA.

bower: an attractive architectural display.

bowerbird: a medium-sized passerine of 20 species, found in the Pacific region. Male bowerbirds construct bowers to attract and seduce mates.

boxer crab: a small crab in the Lybia genus that holds up its claws for defense.

brachiate: to progress by swinging from one arm hold to another.

brackish water: water with more salinity than fresh water, but not as salty as seawater.

Bradfield’s Namib day gecko (Rhoptropus bradfieldi): a diurnal gecko with low metabolism, endemic to Namibia.

brain: an animal organ central to nervous systems, located within the head.

brassinosteroid: a class of steroidal plant hormones critical to differentiation of cells into organs, as well as contributing to other processes, including stress response (cold, drought).

Brazilian owl butterfly (Caligo): a large South American butterfly with eye-like camouflage.

bread mold (Rhizopus stolonifer): a black fungal mold commonly found on bread surfaces. Bread mold is heterothallic.

bread palm: a cycad in the genus Encephalartos, native to central and southern Africa.

breadcrumb sponge (Halichondria panicea): a hardy marine sponge abundant in the North Atlantic Ocean and Mediterrean Sea, especially coastal areas.

Breviatea: a group of unicellular, anaerobic, flagellate, amoeboid protists.

bristle worm (aka polychaete): a segmented (annelid) worm, generally marine, where each body segment has fleshy bristles.

British thief ant (Solenopsis fugax): a kleptomaniacal ant indigenous to the British Isles.

bromeliad: a monocot in the Bromeliaceae family, native mainly to the tropical Americas, with 3,170 species.

brood: a young offspring of an animal.

brood parasitism: passing one’s own eggs off on another species to raise. Avian cuckoos are typical brood parasites.

brown hoplo (aka armored catfish, curito, cascadu, atipa, hassa, Hoplosternum littorale): a catfish native to tropical eastern South America with plate-like armor on its sides.

brown snake (Storeria dekayi): a small ovoviviparous snake in the western hemisphere known to play dead in distress.

brushtail possum: a nocturnal, semi-arboreal marsupial in the Trichosurus genus, native to Australia. Brushtails are inventive and determined foragers.

Bryde’s whale (Balaenoptera brydei): a small rorqual whale which prefers warmer waters over the polar seas that other baleen whales frequent. Bryde’s are largely coastal rather than pelagic.

bryophyte: a plant that lacks vascular tissue. Mosses, hornworts, and liverworts are bryophytes.

buckhorn (aka ribleaf, English plantain, narrowleaf plantain, ribwort plantain, lamb’s tongue, Plantago lanceolata): a flowering plant in the plantain family; a common weed on cultivated land in the British Isles. Buckhorn was introduced in the Americas and Australia and is now widespread there.

budding: a mother asexually creating a smaller daughter. Baker’s yeast reproduces by budding.

budgie (aka budgerigar, pet parakeet, Melopsittacus undulatus): a small, long-tailed seed-eating parrot, native to the drier regions of Australia.

bugleweed: a mint plant of 40–50 species in the genus Ajuga.

bulb: a plant food storage organ for dormancy.

bulbul: a medium-sized passerine in the Pycnonotidae family, found in Africa, the Middle East, and tropical Asia to Indonesia and Japan.

bur cucumber (aka bur gherkin, cackrey, gooseberry gourd, maroon cucumber, Cucumis anguria): a vine indigenous to Africa with ovoid to oblong fruit.

Burkholderia: a genus of bacteria, some species pathogenic.

burying beetle (aka sexton beetle): a beetle in the Nicrophorus genus which buries a small vertebrate as a larder for its larvae.

bushbaby (formally: galago): a small, slow-moving nocturnal prosimian in the family Galagidae, native to continental Africa.

butterfly: a flying diurnal insect of 17,500 extant species. Compare moth.

butterfly effect: a sensitive dependence on initial conditions, where an incremental change at one place in a nonlinear system creates a cascade that results in large changes.

button mushroom (Agaricus bisporus; also known by a host of other provincial names): the most commonly and widely consumed mushroom in the world.

buzz pollination (aka sonication): a technique by pollinating bees to release pollen by vibrating their bodies near the anther.

BYA: billions of years ago. by as an acronym for “billion years” is deprecated in modern geophysics in favor of Ga, shorthand for gigaannum. Sometimes the old ways are the best.


C3 plant: a plant that produces phosphoglyceric acid, with 3 carbon atoms, as its 1st-stage photosynthetic product. C3 plants are adapted to cool, wet environments. Compare C4, CAM.

C4 plant: a plant that produces oxaloacetic acid, with 4 carbon atoms, as its 1st-stage photosynthetic product. C4 plants are adapted to hot, sunny environments. Compare C3, CAM.

cabbage (Brassica oleracea and variants): a leafy, green or red/purple biennial, grown as an annual vegetable crop for its dense-leaved heads.

caddisfly (aka sedge-fly, rail-fly): a small moth-like insect with 2 pairs of hairy membranous wings; of 12,000 species in the order Trichoptera, closely related to moths and butterflies. The aquatic larvae of many species construct protective cases from available materials.

caffeine (C8H10N4O2): a bitter crystalline alkaloid and stimulant. Plants employ caffeine in their seeds, leaves, and fruit as a pesticide. Found in minute measure in nectar, caffeine enhances the reward memory of pollinators.

Cafeteria roenbergensis: a tiny, bacterivorous, marine, flagellate zooplankton. C. roenbergensis is a rather flat, kidney-shaped bicosoecid, 3–10 µm long.

caiman: a smallish alligatorid crocodilian native to Central and South America, living in marshes, swamps, mangrove rivers, and lakes. Caimans eat primarily fish.

Cairo spiny mouse (Acomys chairinus): a nocturnal rodent endemic to the rocky hills and hot deserts of north Africa.

calcium (Ca): the element with atomic number 20. Calcium is a soft, gray, alkaline, earth metal. Calcium plays vital roles in biochemistry and physiology. See calcium channel.

calcium channel: a calcium ion (Ca2+) channel. Calcium channels are a ubiquitous cellular communication means.

callitrichid (Callitrichidae, aka Arctopitheci, Hapalidae): the family of arboreal New World monkeys that includes marmosets and tamarins.

CAM plant: a plant with a variation of the C4 pathway, using crassulacean acid metabolism (CAM) to fix atmospheric CO2. By minimizing photorespiration, CAM plants adapted to hot, dry environments. Most succulents are CAM plants. Compare C3, C4.

cambium: a thin formative layer between the xylem and phloem of vascular plants that gives rise to new cells.

Cambrian (542–485 MYA): the 1st period of 6 in the Palaeozoic era, when the fossil record evidences a vast proliferation of complex life. The name derives from Latin for the area in Wales where the best Cambrian rocks in Britain are exposed.

camouflage: obscuring concealment through appearance and/or in/action.

cAMP: see cyclic adenosine monophosphate.

campion: a plant in the carnation family.

Canary Islands: an archipelago just off the northwest coast of northwest Africa.

cancer: a disease characterized by uncontrolled cell growth.

cane toad (aka marine toad, Rhinella marina): an opportunistic toxic toad native to Central and South America.

canid (aka canine): a carnivorous and omnivorous mammal in the family Canidae that includes wolves, dogs, foxes, jackals, coyotes, and other such mammals.

Candida albicans: a microscopic fungus found in yeast and filamentous cells.

cannibalism: consumption of conspecifics. Cannibalism is selectively practiced by many animals, including humans.

canopy (botany): the uppermost cover of a forest, formed by the leafy upper branches of trees.

cape gannet (Morus capensis): a large seabird, known for their elaborate greeting rituals at their nests.

Cape sumach (aka Pruimbos, Osyris compressa): a woody parasitic plant, native to South Africa.

capillary action: the ability of a liquid to readily flow when narrowly confined in a solid tube, essentially ignoring gravity.

capsid: a viral protein protective coat.

capuchin: an omnivorous New World monkey.

capybara (Hydrochoerus hydrochaeris): the largest extant rodent in the world; a gregarious native South American living near bodies of water.

carbohydrate: a macromolecule containing carbon, hydrogen, and oxygen. Carbohydrates are sugars of varying complexities. See saccharide.

carbon (C): the element with atomic number 6; a gregarious element, with 4 electrons available to form covalent bonds. Life is based upon molecules made with a carbon backbone.

carbon cycle: the gaseous cycling of carbon exchange among the geosphere, pedosphere, hydrosphere, atmosphere, and biosphere.

carbon dioxide (CO2): a colorless gas that has fluctuated in concentration in Earth’s atmosphere through geologic time. Plants breathe CO2. Animals exhale it. CO2 is a greenhouse gas.

carbon fixation (aka carbon assimilation): conversion of inorganic carbon (CO2) into organic carbon compounds.

Carboniferous (359–299 MYA): the 5th period of 6 in the Palaeozoic era, following the Devonian period and preceding the Permian. Vast forests covered the land. Their demise produced the coal beds which came to characterize the geology of the period, and after which the period is named. Amphibians were dominant. Arthropods were quite common.

carbonyl (CO): an organic functional group in aldehydes, ketones, carboxylic acids, esters, and their derivatives, comprising a carbon atom double-bonded to an oxygen atom (C=O).

carboxylic acid: a polar molecule (–CO2H) connected to a hydrocarbon. A carboxylic acid completes itself with a side chain.

cardinal (bird): a passerine of the Americas.

cardinal (number): a number indicating quantity. Compare ordinal number.

caribou: see reindeer.

carnation: a flowering plant in the Caryophyllaceae family, also called the pink family, with 81 genera and 2,625 known species. Carnation (aka clove pink) is also used for Dianthus caryophyllus, an herbaceous perennial native to the Mediterranean region.

carnivore (aka predator): a meat eater. Compare herbivore, omnivore, saprovore.

carotenoid: a tetraterpenoid organic pigment occurring in photosynthetic organelles of plants (e.g., chloroplasts).

carp: a large group of freshwater fish native to Eurasia.

carpel (aka pistil): the female part of a flower, acting as a pollen receptor.

carpenter ant: a large eusocial ant in the genus Camponotus, found in much of the world. Carpenter ants like to build their nests in damp, dead wood.

carrying capacity: the (idea of a) maximum population size of a species given the constraints imposed by the environment.

castor bean (aka castor oil plant, Ricinus communis): a flowering perennial in the spurge family.

cat (Felis catus): a small, typically furry carnivorous mammal which domesticated itself 10 millennia ago.

cat’s claw (Schrankia uncinata): a semi-woody vine with leaves that fold up when disturbed, exposing recurved thorns. Cat’s claw blooms bright pink star-burst flowers in congested bunches.

catabolism: the controlled cellular process (metabolic pathway) of breaking down organic matter to harvest energy via cellular respiration. Compare anabolism.

catadromous: fish that migrate from fresh water into the sea to spawn. Contrast amphidromous.

catastrophism: a theory that Earth has been episodically affected by sudden violent events. Contrast uniformitarianism.

catbird: a bird that may belong to several unrelated groups of songbirds. The 3 species of catbirds in the genus Ailuroedus are bowerbirds that do not build bowers.

catechin: a phenol plant secondary metabolite, typically employed to hinder the growth of neighbors (allelopathy). Catechin constitutes 25% of the weight of tea leaves, as well as being present in cocoa (chocolate), and other fruits and vegetables. As an antioxidant, catechin is a healthy chemical for humans.

caterpillar: a larva of a butterfly or moth.

cation: a positively charged ion (indicating a deficit of electrons). Contrast anion.

cattle egret (Bubulcus ibis): an egret with an affinity for cattle, from which it cleans ticks and flies as a dietary mainstay, with considerable tolerance by the client grazer.

caudex: a plant stem from which new growth arises. The term caudex is usually used with plants with an atypical stem morphology, such as cycads, ferns, and palms.

causal reasoning: the mental ability to infer an unperceived mechanism for an effect that is detectable.

cebid (Cebidae): a family of arboreal New World monkeys that includes the capuchin and squirrel monkeys.

cecum: a pouch at the beginning of the large intestine. Herbivores have an especially active cecum, full of digestive bacteria cohorts.

cell (biology): the basic physical unit of living organisms.

cell signaling: a protocol for cellular communication, whether intracellular or intercellular.

cell wall: a flexible membrane holding the contents of the cell and providing an interface to the outside environment.

Cellulomonas: a genus of soil bacteria that feed on cellulose. Cellulomonas have a symbiosis with Azotobacter, another bacterium.

cellulose ((C6H10O5)n): a polysaccharide employed as a primary component of plant cell walls.

Celsius (aka centigrade): a standard temperature scale, where 100° C is the boiling point of water, and 0° C its freezing point.

Cenozoic (65.5 MYA–now): the geological era from the demise of the dinosaurs to present day.

centipede: an arthropod with an awful lot of legs; metameric animals with a pair of legs for each body segment. Of the estimated 8,000 species, leg pairs vary have from under 20 to over 300, but always an odd pair number (e.g., 15 or 17 pairs), never even.

central nervous system: the brain and nervous system associated with it. In vertebrates, the central nervous system includes the spinal cord.

cephalopod: a class of marine animals in the mollusk phylum, including squid, octopuses, cuttlefish, and nautilus among the over 800 extant species.

Ceratozamia: a genus of New World cycads with 26 extant species, endemic to the mountains of Mexico and nearby regions.

cercopithecid (aka Cercopithecidae): a group of Old World monkeys that include baboons, guenons, macaques, mandrills, mangabeys, patas monkeys, and vervets.

cercus (plural: cerci): one of the paired whisker-like appendages protruding from the rear of a cockroach’s or earwig’s abdomen. Cerci are covered in hairs which are sensitive to air movements.

cerebral cortex: the outermost layer of neural tissue in the cerebrum in mammals.

cerebrum (aka forebrain): the part of the mammalian brain comprising the cerebral cortex and several subcortical structures, including the basal ganglia, hippocampus, and olfactory bulb.

cestode: a parasitic flatworm, most of which are tapeworms.

Cerrado: a vast tropical savanna in Brazil.

Cetacea: a clade of aquatic mammals of ~89 species, commonly called whales, dolphins, and porpoises. Most cetacean species prefer colder waters. Cetaceans are adapted to stay under water for extended periods: 7 to 30 minutes – much longer than most other mammals.

chacma baboon (aka Cape baboon, Papio ursinus): the largest of all monkeys, native to southern Africa.

chaffinch (Fringilla coelebs): a small finch.

chalcid wasp: one of the largest groups of wasps, with an estimated 60,000–500,000 species. Most chalcid wasps are parasitoids of other insects.

chameleon: a distinctive and highly specialized clade of Old World lizards, with over 200 species. Many chameleons can change color at will.

chamois (Rupicapra rupicapra): a goat-antelope of 2 species, endemic to the mountains of Europe.

Chantek: a male orangutan born in captivity and reared like a human child, providing a demonstration of how close apes and humans are in their capabilities.

characin: a ray-finned fish in the Characiformes order, with a few thousand species, including the well-known piranha.

chaulmoogra: the oil from the kalaw tree. Chaulmoogra is sometimes itself called the tree. Chaulmoogra is a traditional Chinese and Indian medicine for treating leprosy.

cheetah (Acinonyx jubatus): a large feline indigenous to Africa and part of the Middle East. The cheetah is the absolute fastest land animal: able to accelerate from 0 to 100 km/h in 3 seconds; and able to sustain 115 km/h for short distances (500 m). The cheetah’s agility, and its ability to anticipate the escape maneuvers of its specific quarry, gives it the hunting edge it needs.

chelicerae: the mouthparts (“jaws”) of chelicerates.

chelicerate: a subphylum (Chelicerata) of arthropod which includes arachnids, sea spiders, and horseshoe crabs.

chemistry: the science of matter, especially chemical reactions.

chemo-communication: chemical communication.

chemobiosis: a cryptobiotic response to environmental toxins.

chemoreception: reception of a chemical signal.

chemosynthesis: employing chemical reactions to generate usable energy.

chemotherapy: a chemical treatment regime to kill cancer cells; often combined with radiation, surgery, and/or hyperthermia (raising the body temperature) therapy.

chemotropism: plant movement in response to chemical stimulus.

chickadee: see tit.

chicken: a domesticated subspecies of the red junglefowl.

chimeric: an organism of diverse genomic constitution.

chimpanzee (Pan troglodytes): a medium-sized ape, closely related to bonobos and humans.

chipmunk: a small, striped North American rodent in the family Sciuridae, excepting the Asian-native Siberian chipmunk.

chinook (salmon): the largest species of the Pacific salmon family. Chinook spend one to 8 years in the ocean (3–4 years average) before returning to the home river to spawn.

chiroptology: the study of bats.

chitin ((C8H13O5N)n): a long-chain polysaccharide that includes proteins, lipids, and catecholamine. Chitin serves as the main component of the cell walls of fungi, the exoskeletons of animals such as insects and arthropods, and the beaks of cephalopods, including octopi and squid. Compare keratin. Also see lignin.

Chlamydia (aka chlamydia): a genus of obligate intracellular bacteria parasites. Chlamydia depend the cytoplasm of a eukaryotic host cell for growth and replication. The 3 chlamydia species respectively infect mice and hamsters, swine, and humans.

Chlamydomonas reinhardtii: a tiny (10 µm), single-cell, photosynthetic, green alga, found worldwide in soil and fresh water; the only known vegetation capable of consuming cellulose.

chlorenchyma: plant tissue of parenchyma cells that contain chloroplasts.

Chlorobium aggregatum: a symbiosis of 2 different bacteria species that feed each other.

chlorophyll: the green biomolecule in cyanobacteria and the chloroplasts of algae and plants that absorbs light for photosynthesis.

chlorophyll c: a golden form of chlorophyll that is an accessory pigment to chlorophyll a, which is the green primary photosynthetic pigment. Chlorophyll c has light absorption in the 500–600 nm region. Chlorophyll c has a chemical structure distinct from other chlorophylls commonly found in algae and plants.

chloroplast: the photosynthetic plastid in algae and plant cells.

chloroplast capture: obtaining the genome of another plant by uptake of an organelle.

chordate: an animal in one of the following groups: fish, amphibian, reptile, bird, tunicate, lancelet, or mammal; an animal with tadpole characteristics (a notochord, a hollow dorsal nerve cord, pharyngeal slits, an endostyle, and a post-anal tail) during some period of its life cycle; a member of the phylum Chordata.

chough: a lifelong monogamous corvid that lives in the mountains of southern Eurasia and North Africa. Choughs are in the Pyrrhocorax genus, with 2 species.

chromatic aberration: variation of focal length at different light wavelengths, with resultant prismatic coloring.

chromatin: the combination of proteins and DNA that comprise genetic information storage in the nucleus of a eukaryotic cell.

Chromista (biological classification): a eukaryotic kingdom under some taxonomy schemes with various definitions, albeit typically including algae; introduced by Tom Cavalier-Smith in 1981.

chromophore: the moiety that causes a conformational change of a photosensitive molecule when hit by light.

chromosome: an elaborately coiled package of genetic material in a eukaryotic cell, comprising DNA, regulatory elements such as histones, and other nucleotide sequences. Compare genophore.

chum (salmon) (aka dog salmon, Keta salmon): a Pacific salmon. Chum travel up the Yukon river more than 3,200 km to spawn. They spend 1 to 3 years traversing the Pacific Ocean over long distances. Chum live 6–7 years.

chytrid: a primitive fungus.

cicada: a flying insect of 3,000+ species in the Cicadoidea family. Cicada live most of their life underground, coming to the surface as adults to make a racket and mate for a few weeks or months. Individually defenseless, cicada numerically overwhelm predators by emerging en masse; a phenomenon called predator satiation.

cichlid: a freshwater fish in the large, diverse family Cichlidae, with ~3,000 species; found in the tropics of Africa, Madagascar, southern Asia, and America. The most varied speciation occurs in Africa and South America. Cichlid diets range from vegetarian to carnivorous. Cichlids have complex mating and parental care behaviors. All cichlids practice parental care for their eggs and fry.

ciliate: a group of protozoans characterized by cilia.

cilium (plural: cilia): a slender protuberance projecting from a cell, capable of undulating wave motion.

circadian: daily cycle.

circadian rhythm: a biological process entrained to an endogenous oscillation of about 24 hours.

circulatory system (aka cardiovascular system, vascular system): an organ system for circulating nutrients via blood cells.

circumnutation: recurring spiral oscillation by a plant part.

circumstance: the situational sum of essential and environmental factors.

cirrus cloud: a genus of atmospheric cloud characterized by thin, wispy strands at altitudes of at least 5,000 m.

citrus greening disease: a fatal plant disease caused by Liberibacter bacteria that begins with yellowing leaf veins and adjacent tissue.

clade (biological classification): a group of biological taxa, such as genus, which includes all descendants of a common ancestor.

cladism (evolutionary biology): (aka phylogenetic nomenclature, cladistics): biological classification based upon clade, reliant upon branching.

clam: a bivalve which consumes plankton by filter feeding.

class (biological classification): the taxon above order and below phylum. Though the taxon was introduced by Joseph de Tournefort in 1694, botanists nowadays typically don’t use class. See family.

Claviceps purpurea: a poisonous ergot fungus that grows on the ears of rye and related plants.

cleaner fish: a fish that provides a cleaning service to other species by removing ectoparasites and dead skin.

cliff-rose (Cowania stansburiana): a genus of 5–8 species of flowering plants native to western North America.

climate: a characterization of tropospheric activity in an area over ~30 years, accounting for seasonal variations. The standard of 30 years is often adjusted to suit reportage. Compare weather.

climax vegetation: dominant plants in a biome.

cloaca: the shared portal for the digestive and reproductive tracts in amphibians, reptiles, birds, and monotremes.

clone: an organism that is genetically selfsame to its parent.

cloud: a visible mass of liquid droplets or frozen crystals in the atmosphere.

cloud condensation nuclei: water particles 1–1,000 micrometers in diameter.

clownfish: a small marine fish best known for its mutualist relations with sea anemone.

clutch: a group of laid eggs.

clutch coordination: the practice of some colonial birds to contemporaneously time their egg-laying.

Cnidaria: a phylum of early-evolved jelly-like aquatic animals which includes jellyfish and anthozoa. There are now over 10,000 species. The distinguishing feature of cnidarians is cnidocytes. Cnidarian bodies are made of mesoglea. Jellyfish are exemplary cnidara, though coral too are cnidarians. Compare Ctenophora. See Coelenterata.

cnidocyte (aka cnidoblast, nematocyte): an explosive cell containing 1 giant secretory organelle (cnida). Cnidae are used to capture prey and defend against predation.

coal: a blackish combustible sedimentary rock from compressed vegetation millennia old. Compare petroleum.

coalition: 2 or more individuals joining forces against one or more conspecific rivals. Many birds and mammals are known to form coalitions, either for resource access (typically food sharing), or for social reasons, such as grooming, or help in a conflict.

coast redwood (aka coastal redwood, Sequoia sempervirens): an evergreen conifer tree, the tallest in the world (115 m). Coast redwoods, which require a humid climate, are endemic to the northern California and southern Oregon coast, within 60 km of the ocean. Though commonly confused, the coast redwood is a different species than the sequoia, which is the most massive tree, albeit reaching 95 m in height. Sequoia may live 3,200 years, whereas coast redwoods survive only 2 millennia or so.

coati (aka coatimundi and other local names): a diurnal mammal in the racoon family, native to southwestern North America, Central America, and South America.

cobra: a venomous snake that can expand its neck ribs to form a widened hood. Various cobras are found throughout the world.

cobweb (spider): see theridiid.

cocaine (C17H21NO4): an alkaloid derived from the coca plant, used medicinally and recreationally as a stimulant.

coccolithophore: a unicellular, eukaryotic alga.

cochlea: a spiral-shaped cavity, forming a division of the internal ear in birds and mammals.

cockatoo: an Australasian parrot in the Cacatuidae family, of 21 species.

cockle: a small marine clam.

cocklebur: a flowering plant in the genus Xanthium, native to eastern Asia and the Americas.

cockroach: a typically large insect with a broad, flattened body and relatively small head. 30 of the 4,500 species are considered pests, as they are inclined to live in human habitats. The largest and heaviest cockroach is the Australian giant burrowing cockroach, which can reach 9 cm and weigh more than 30 g. The giant cockroach native to Central America is as big, though not quite as heavy. Cockroaches are in the order Blattodea, which also includes termites.

coccus (plural: cocci) a spherical bacterium. Compare bacillus, spirillum.

coevolution: intertwined adaptation among species inspired by their interaction.

Coelenterata: an archaic phylum containing Cnidaria and Ctenophora.

cognition: the process of understanding, involving both awareness and judgment.

coherence: the intelligent interaction behind Nature. Like Ĉonsciousness, coherence localizes.

cohesion-transport theory: the dominant theory as to how plant sap can defy gravity, which is by pressure variations.

coho (salmon): a salmon species, with a traditional range along both sides of the Pacific Ocean, from Hokkaidō, Japan around the Bering Sea to mainland Alaska, extending as far south as Monterey Bay, California. Coho are easily fished, and so have suffered precipitous decline due to ravenous human harvesting.

coleoid: the group of cephalopods that includes squid, cuttlefish, and octopi. Their sister group, the nautiloids, have a rigid outer shell for protection. In contrast, coleoids have at most an internal shell, bone or cartilage used for buoyancy or support.

Collective: people who follow their biological urges as natural imperative. The Collective believe emotions and beliefs are valuable. The Collective comprise the bulk of human populations.

colobine: an Old World monkey in the group Colobinae, which includes colobus, douc, langur, lutung, surili, snub-nosed, and proboscis monkeys.

colobus: a monkey native to equatorial Africa, of 2 genera: one is the black-and-white colobus (Colobus), the other the red colobus (Procolobus).

colony: a population of tolerant individuals.

colpus (plural: culpi): a furrow in a pollen grain.

colubrid: a snake in the largest snake family (Colubridae), with 304 genera and 1,938 species, which comprises 2/3rds of snake species. The earliest colubrids date to the Oligocene. Colubrids live on every continent except Antarctica.

comb (fungal): a fungus garden.

commensalism: a relationship of between 2 organisms where one benefits without affecting the other.

common ancestor: the hypothesis that all life somehow arose from a single life form.

common clubhook squid (Onychoteuthis banksii): an oegopsid squid that may grow to 14 cm, native to the central and northern Atlantic Ocean and the Gulf of Mexico.

common house spider (aka American house spider, Parasteatoda tepidariorum): a cobweb spider indigenous to the New World.

common murre (aka common guillemot, thin-billed murre, Uria aalge): a diving seabird living in the chilly waters of the northern oceans. The murre lives largely at sea, coming to land only to breed.

common poorwill (Phalaenoptilus nuttallii): a nocturnal bird native to western North America. Common poorwills inhabit dry, open areas. Many, but not all, migrate to warmer climes for the winter. Those that stay hibernate, which is rare for birds.

communication: emitted ecological information by an organism.

communication substitution: signaling in a way that relies upon a strong innate pre-existing reception.

compass plant (aka pilotweed, polarplant, Silphium laciniatum): an angiosperm in the aster family, native to North America.

complementation (genetics): the instance of genetic combination via various mutations.

compound (chemistry): a combination of elements bonded into a molecule.

concept (aka idea): an abstract mental construct involving discriminatory categorization.

conceptualize, conceptualization: mentally resolving perceptions into a concept.

conifer: a woody, cone-bearing, seed plant. Most conifers are trees, with a few shrubs. Conifers dominate the forests in the northern hemisphere.

coniine (C8H17N): a poisonous alkaloid in hemlock.

conjugation (microbes, particularly bacteria): a term used for horizontal gene transfer (HGT) by researchers in 1946, who analogized HGT process to sex.

conscientiousness: the tendency to moral integrity; also, the tendency to be careful, meticulous.

consciousness: the platform for awareness in an individual life constituent (e.g., organism, cell). Compare Ĉonsciousness.

Ĉonsciousness: the unified field of consciousness. Compare consciousness.

conservation (evolutionary genetics): preservation of a trait through generations (of cells or offspring).

consortship: a mating partnership, typically referring to apes.

conspecific: of the same species. Contrast interspecific.

consumer (biology) (aka heterotroph): an organism unable to sustain itself by inorganic means. Animals are consumers. Contrast producer.

continent: a gigantic landmass, 7 of which are currently extant on Earth: Africa, Antarctica, Asia, Australia, Europe, North America, and South America.

continental drift: the movement of tectonic plates that causes continental masses to move about.

continental shelf: a relatively shallow submarine plain at the edge of a continent.

continental slope: the steep slope from a continental shelf to oceanic abyss.

convection: the concerted, collective movement of fluids (liquids, gases) and rheids (solids deformed by viscous flow).

convergent boundary: a boundary where tectonic plates come together, with one plate subducting under another. Contrast divergent, transform.

convergent evolution (aka parallel evolution): the independent evolution of similar traits in organisms of separate species which are usually not closely-related.

convict cichlid (aka zebra cichlid, Amatitlania nigrofasciata): a small cichlid known for its aggressiveness when breeding; so named for their vertical black stripes which are reminiscent of the striped prison uniforms of British convicts.

coordination complex (chemistry): a molecular binding configuration, typically based upon covalent bonds. Coordination complexes are ubiquitous in chemical structures and reactions.

copepod: a group of small (1–2 mm) crustaceans that live in the sea and nearly every freshwater habitat. 13,000 species are known, of which 2,800 are freshwater dwellers.

copper shark (aka narrowtooth shark, bronze whaler): a species of requiem shark, the only species of its genus that favors temperate latitudes. Copper sharks are found in brackish estuaries and rivers, shallow bays, and offshore waters to 100 meters or more.

coral: a colonial marine invertebrate comprising numerous identical polyps.

coral snake: a large group of typically small venomous snakes found in temperate to tropical regions throughout much of the world, with ~81 species in 6 genera.

coral trout (aka leopard coral grouper, Plectropomus leopardus): a marine piscivore native to the western Pacific Ocean.

corbicula (plural: corbiculae): a pollinating-insect pollen basket.

corella: a white cockatoo of 6 species native to Australasia.

Coriolis effect: generally, a deflection of moving objects when viewed from a rotating reference frame. In meteorology, the rotation of Earth and inertia of its mass cause a Coriolis effect that manifests as a pronounced atmospheric circulation.

cork cambium: the secondary tissue in vascular plants that replaces the epidermis in stems and roots.

cormorant (aka shag): a medium-to-large coastal, aquatic, piscivorous bird of ~40 species, native to Eurasia, parts of Africa, North America, Australia, and New Zealand. Most are seabirds, though some cormorants ply inland waters. Cormorants are excellent divers. The classification of cormorants is contentious.

corn (aka maize, Zea mays): a large grain plant domesticated by Mesoamericans in prehistoric times; commonly considered a vegetable.

cornea: the transparent front cover of the eye.

cornflower (aka bachelor’s button, bluebottle): an annual angiosperm in the family Asteraceae.

coronatine (C18H25NO4): a toxin produced by the phytopathogenic bacterium Pseudomonas syringae. Coronatine is instrumental in causing stomata to reopen after they close in response to recognizing invasion, as well as interfering with post-infection responses mediated by salicylic acid.

cortex: the outermost layer of an organ. See cerebral cortex.

corvid: a cosmopolitan bird family (the crow family) of over 120 species, including choughs, crows, jackdaws, jays, magpies, nutcrackers, ravens, rooks, and treepies.

corybantic: wild; frenzied; in the spirit of a Corybant. The Corybants were priests devoted to Cybele, known for their wildly emotional rites. Cybele was a Nature goddess to the ancient peoples of Asia Minor.

cosmic rays: radiation from outer space.

cosmopolitan (biogeography): a taxon with species in a broad range of biomes.

cosmotrophic: an organism that can survive in space.

Cotesia: a genus of a parasitoid wasps that harbor polydnaviruses to effect their parasitism.

cottonmouth (aka water moccasin, Agkistrodon piscivorus): a venomous snake native to the southeastern United States; the only semiaquatic viper, usually found near or in slow-moving water bodies.

cotyledon: an embryonic leaf in an angiosperm seed. See dicot, monocot.

coumarin (C9H6O2): a phytochemical with a vanilla-like flavor.

cowbird: an insectivorous New World brood parasitic passerine of 5 species in the Molothrus genus.

coyote (aka American jackal, prairie wolf, Canis latrans): an omnivorous canine species native to Central and North America. The coyote evolved separately from jackals, which occupy a similar ecological niche in Eurasia and Africa.

coyote tobacco (Nicotina attenuata): a species of tobacco native to western North America.

crab: a 10-footed (decapoda) crustacean, typically with a thick exoskeleton and a pair of claws on its front legs.

craton: the stable part of a continental plate, generally in the interior, built upon basement rock.

crèche: a nursery.

creeping daisy (aka creeping-oxeye, wedelia, Sphagneticola trilobata): a flowering plant with wide ecological tolerance, originally native to Central America and the Caribbean, though now with and expanded range throughout the Neotropics. The creeping daisy is widely cultivated as an ornamental groundcover, and so has been taken around the world, with dismay for its prolific success. It rapidly spreads vegetatively. The creeping daisy is damned as one of the worst invasive species by International Union for Conservation of Nature, which absentmindedly makes no mention of humans as a horrific invasive species.

creeping dogwood (aka Canadian dwarf cornel, Canadian bunchberry, crackerberry, quatre-temps, Cornus canadensis): a species of creeping, rhizomatous perennial, growing to ~20 cm tall.

crepuscular (biology): an animal active primarily during twilight (dawn and dusk), as contrasted to diurnal or nocturnal. As a legacy from their time underfoot of dinosaurs, many mammals are crepuscular, as are most moths, many beetles and flies, and some birds. For temperature reasons, desert squamates tend to be crepuscular.

Cretaceous (145–66 MYA): the 3rd and last period in the Mesozoic era, following the Jurassic and preceding the Paleogene. The name derives from the Latin for chalk, and is abbreviated as K. The Cretaceous ended with the major mass extinction event that killed all non-avian dinosaurs.

cricket (aka true cricket): an insect with a somewhat flattened body and long antennae. 900 cricket species are known. Crickets are related to katydids; more distantly related to grasshoppers, with which they are often confused.

crocodile: a large, semiaquatic reptile which first evolved 83.5 MYA. Birds are their closest living relative.

Cromwell Current (aka Pacific Equatorial Undercurrent): an eastward-flowing subsurface current that runs the length of the equator in the Pacific Ocean; named after its 1952 discoverer, Townsend Cromwell.

crossbill: a finch in the genus Loxia, with 6 species. Crossbills are conifer cone specialists, with an odd bill shape that enables them to extract seeds from cones.

CroV: a giant virus that preys upon the zooplankton Cafeteria roenbergensis.

crow: a clever corvid in the Corvus genus, known for their mischievous ways. 40 species are known.

crust (geology): the outermost solid slab of a rocky planet.

crustacean: a large group of arthropods, including barnacles, krill, crabs, crayfish, shrimp, and lobster. There are at least 67,000 species, ranging from 0.1 mm to 3.8 meters in size. Most crustaceans are aquatic, but some, such as woodlice, are terrestrial.

cryobiosis: a cryptobiotic response to extreme cold.

Cryogenian (720–635 MYA): the middle period of 3 in the Neoproterozoic era, following the Tonian and preceding the Ediacaran. A period of global glaciation (Snowball Earth), to which the name refers.

crypsis: the ability of an organism to avoid detection or observation. Contrast aposematism.

cryptobiosis: an ametabolic state of life that an organism enters in response to adverse environmental conditions. See anhydrobiosis, anoxybiosis, chemobiosis, cryobiosis, osmobiosis.

cryptochrome: a photoreceptive protein sensitive to blue light, found in both plants and animals. Cryptochrome is employed for circadian rhythms and sensing magnetic fields.

crystal: a solid characterized by an orderly, repeating 3d pattern. A lattice is a typical crystalline pattern.

crystal violet: a blue-violet dye used in Gram staining.

Ctenophora: a phylum of marine animals that use groups of cilia for swimming. Ctenophores have soft, gelatinous bodies. Compare Cnidaria. See Coelenterata.

cuckoo: a near passerine with distribution ranging across all continents except Antarctica. A large minority of cuckoos practice brood parasitism.

cuckoo bee: a kleptoparasitic egg-laying bee.

cuckoo-finch (Anomalospiza imberbis): a parasitic weaver or cuckoo weaver, native to sub-Saharan Africa.

cuckoo wasp: a parasitoid or kleptoparasitic wasp in the Chrysididae family, which has over 3,000 species.

cucumber: a creeping vine in the gourd family that bears cylindrical fruit.

cucumber mosaic virus: a plant-pathogenic virus with worldwide distribution and very wide host range.

cucurbitacin: a phytosteroid as defense against herbivores. Pumpkins and gourds employ cucurbitacin. Cucurbitacins are among the bitterest tastes to humans.

culture (biology): the transfer of knowledge among conspecifics, and from one generation to the next.

cumulonimbus: a towering cloud that extends to 9 km or more.

cumulus: a puffy cloud with a flat base and cauliflower top.

curlew: a wading bird with a long, slender, down-curved bill and mottled brown plumage, of 8 species in the genus Numenius.

Curtuteria australis: a parasitic fluke common in New Zealand that is fond of clams.

cuticle: a multi-layered shell on the outside of many invertebrates, employed as an exoskeleton. The main ingredient of cuticle is chitin. Cuticle also refers to protective layers of organisms in other kingdoms, including fungi and plants.

cuttlefish (aka cuttles): a marine cephalopod. Cuttlefish have a unique internal shell: a cuttlebone. Cuttlefish are mollusks, not fish.

cyanide: a compound employing the monovalent group CN (carbon–nitrogen), where a carbon atom is triple-bonded to a nitrogen atom. Organic cyanides are usually called nitriles.

Cyanobacteria (aka Cyanophyta): a phylum of photosynthesizing eubacteria; the only prokaryote that produces oxygen as a respiratory waste product; often called blue-green algae, though they are not in the same group as algae.

cyanophage: a virus that infects cyanobacteria.

cycad: a gymnosperm with a stout, woody trunk and a crown of large, stiff evergreen leaves. Cycads vary in size from a few centimeters to several meters. Cycads typically grow very slowly, with a longevity over 1,000 years.

cyclic adenosine monophosphate (cAMP): a 2nd messenger which is significant in many biological processes.

cycloalkane: a hydrocarbon with 1 or more rings of carbon atoms.

cypress: a long-lived conifer in the Cupressaceae family.

cytokine: a small cell signaling protein.

cytokinesis: the process by which the cytoplasm of a eukaryotic cell divides.

cytology: the study of living cells.

cytolysis (osmotic lysis): an osmotic imbalance from excess water inside a cell, causing the cell to burst.

cytomegalovirus: a virus in the herpes family that infects mammals. In humans, cytomegalovirus raises the risk of schizophrenia in offspring that inherit the virus from their mothers.

cytoneme: a long, thin filopodia specialized for intercellular communication.

cytoplasm: the watery gel that holds a cell’s organelles within a cytoplasmic membrane.

cytoplasmic membrane: the membrane holding a cell’s cytoplasm and other contents within.

cytoplasmic streaming: the flow of cytosol through plant cells.

cytosine (C) (C4H5N3O): a nucleobase of DNA and RNA. Cytosine is complementary to guanine. Cytosine is inherently unstable and can spontaneously change into uracil (spontaneous deamination). If not repaired, spontaneous deamination results in a point mutation.

cytoskeleton: filaments of protein within a cell, providing cellular scaffolding.

cytosol (aka cytoplasmic matrix or intracellular fluid): cytoplasmic fluid (the liquid within cells), comprising mostly water, along with dissolved ions and various molecules, including proteins.


D’Arnaud’s barbet (Trachyphonus darnaudii): an east African barbet that grows to 20 cm, eats insects, fruits, and seeds, and is equally at home on the ground or in the trees.

daisy: a widespread and extensive family of flowering plants; also known as the aster, composite, or sunflower family.

Damara mole rat (aka Damaraland mole rat, Damaraland blesmol, Fukomys damarensis): a burrowing rodent native to southern Africa. The Damara mole rat and the sand puppy are the only known eusocial mammals.

damselfish: a fish in the Pomacentridae family. Most damselfish live in tropical coral reefs. Many are brightly colored. There are a relative few freshwater damselfish that live in rivers.

damselfly: a predatory insect like dragonflies, albeit more gracile. Damselfly nymphs are freshwater aquatic. Emerging over 250 million years ago, damselflies now live on every continent except Antarctica.

darter: a small, perch-like fish native to North American freshwater streams.

Darwin’s bark spider (Caerostris darwini): an orb-weaver spider endemic to Madagascar that weaves a large web across water bodies to snare flying insects.

Darwinism (aka natural selection): the disproven hypothesis of Charles Darwin that evolution transpires only over millions of years by random rearrangements of matter that create species which endure or are eliminated via competition with other species (“natural selection” via “survival of the fittest”).

Natural Selection almost inevitably cause much Extinction of the less improved forms of life. ~ Charles Darwin

Dasypeltis: a nonvenomous egg-eating snake native to Africa, favoring forests that are also home to many birds.

daughter cell: a cell formed from a mother cell.

Dawsonia: the genus of the largest moss, which may reach 65 cm in length, found in Oceania.

dayflower (aka widow’s tears, Commelina): a flowering, fruit-bearing herbal plant.

death adder: a most venomous snake, native to Australia, New Guinea, and nearby islands, in the genus Acanthophis.

deception: the act of presenting a false impression. Contrast honesty.

deciduous: a tree or shrub that loses its leaves seasonally. The term is also used with animals, for parts that are seasonally or developmentally lost, such as deer antlers and baby teeth.

decomposer: see saprovore.

decorator crab: a generic name given to various crabs which are fond of using materials to guise themselves.

deep-water formation: ocean current sinking because it contains cold, dense seawater.

deer: an even-toed ungulate ruminant in the Cervidae family.

deictic: indicating identity or location.

Deinococcus: the most extremophilic bacterium known. Having a thick cell wall helps. Whereas other bacteria change their structure, such as forming endospores, to avoid damage from radiation, Deinococcus tough it out.

demography: statistical characterization of the size, density, and distribution of a population.

denitrification: the process of nitrogen compound reduction; often used to signify releasing waterborne or soil nitrogen into the atmosphere. Contrast nitrification.

dental plaque: a biofilm that inhabits teeth. The bacteria that form dental plaque benefit the host by inhibiting occupancy of pathogenic cousins (a little-known fact).

descent (evolutionary biology): evolution from; derivation from an ancestor; lineage.

desert bitterbrush (Purshia glandulosa): a hybrid of the bitterbrush and the cliff-rose.

determinism: belief in cause and effect, from which emanates the doctrine that all facts and events exemplify natural laws.

detrivore: see saprovore.

Devonian (416–359 MYA): the 4th of 6 periods in the Palaeozoic era, following the Silurian and preceding the Carboniferous. The Devonian experienced the first radiation of terrestrial life. The name derives from Devon, England, where rocks of the period were first studied.

dew point: the temperature at which water vapor condenses into a liquid (dew). When air cools to its dew point via contact with a surface, water condenses on the surface. When the ambient temperature is below the freezing point of water, the dew point is a frost point, as frost is formed rather than dew. Dew point is related to humidity: a higher dew point indicates more moisture in the air.

dialogue: interactive communication between 2 or more parties. Contrast monologue.

Diana monkey: an arboreal monkey native to the rainforests in the southern coastal region of West Africa.

diapause: an animal physiological state of dormancy or delay in development to survive periodic, unfavorable habitat conditions, such as temperature, drought, or diminished food resources. Diapause is common among arthropods, especially insects, and in embryonic development of many oviparous toothcarp fish.

diapir: a geologic intrusion in which deformable material is forced into overlying brittle rocks. Lava lamps illustrate diapirs.

diapsid: a reptile with 2 holes on each side of its skull. Diapsids evolved 300 MYA. All lizards, crocodiles, snakes, and tuatara are diapsids.

diaspore: a spore or seed with attached tissue that abets dispersal.

diatom: an alga; one of the most common phytoplankton.

diatomaceous earth: a soft, siliceous sedimentary rock, easily crumbled into a fine whitish powder. Diatomaceous earth comprises fossilized diatoms.

dichromacy: having 2 types of color vision receptors. Dichromats typically see in the blue-green color spectrum but cannot detect red. Dichromats can distinguish 10,000 distinct colors. Most mammals are dichromats. Compare monochromacy, trichromacy, tetrachromacy.

dicot (dicotyledon): an angiosperm with 2 embryonic leaves (cotyledons) in its seed. Compare monocot.

Dictyostelium discoideum (aka slime mold): a common soil amoeba that feeds on bacteria which it cultivates.

diet: habitual nourishment.

diffusion (chemistry): the passage of molecules between chemical species.

digitalis (aka floxglove): a flowering plant in the Digitalis genus, with ~20 species, native to western Europe, northwestern Africa, western and central Asia, and Australasia. Digitalis extracts are used medicinally for heart problems.

dimorphism: the existence of 2 different forms; typically refers to a size difference between sexes.

dinoflagellate: a diverse group of flagellate protists. Most are marine plankton.

dinosaur: a diverse clade of largely extinct reptiles, excepting birds, which descended from dinosaurs (yet are excluded from the clade).

dinosaur ant (aka dawn ant, Nothomyrmecia macrops): an early-evolved ant, native to Australia.

dioecious: separate sexes; especially a plant reproductive morphology of separate female and male plants.

diopter (aka dioptre): a unit of magnifying power measurement.

diploid: an organism having 2 sets of chromosomes. Most eukaryotes are diploid: 2 sets, 1 from each parent, typically twined through sexual reproduction. Humans are diploid. Compare haploid.

dipodid: a northern hemisphere rodent in the Dipodidae family, with over 50 species in 16 genera.

dipole (physical chemistry): a polar molecule.

dirt: see soil.

dispersal (evolution): speciation when a subpopulation migrates outside the range of the main population, adapting to a new species over time. Compare vicariance.

dissolved organic matter (aka marine snow): the slowly sinking remains of oceanic life.

dissonance: divergence between signal and reception.

diuretic: something that tends to increase the production of urine.

diurnal (biology): active during the day. Contrast nocturnal. See crepuscular.

diurnal temperature variation: the temperature extremes between night and day.

divergence (geometry): the angle of succession in a geometric sequence.

divergent boundary: a boundary where tectonic plates move apart. Contrast convergent, transform.

diversity loss: a measure of the number of species lost during a mass extinction event.

DNA (deoxyribonucleic acid): a long, double-stranded molecular chain employed as a physical template for biomolecular production.

Doctrine of Signatures: a nonsensical philosophy of herbalists from antiquity (~70 ce) which stated that herbs which resemble human body parts are able to treat ailments of that part of the body.

dodder: a parasitic plant in the genus Cuscuta, with 100–170 species.

dog: a domesticated subspecies of the gray wolf.

doldrums: a maritime colloquial expression for the low-pressure area around the equator where the prevailing winds are calm.

Dolichoderinae: a subfamily of ants, distinguished by a having a single petiole (narrow waist) and a slit-like orifice for chemical release (as contrasted to a round acidopore (formic acid outlet)).

dolphin: a notably intelligent, gregarious marine mammal, closely related to porpoises and whales (altogether: Cetacea). There are ~40 species of dolphin, varying in size from 1.2 m and 40 kg (Maui’s dolphin) to 9.5 m and 10 tonnes (orca whale).

domain (biological classification) (aka empire): the 2nd highest taxon (below life), with 3 classes: archaea, bacteria, and viruses.

dominant (trait): a genetic trait (allele) that masks a recessive trait.

dopamine (C8H11NO2): a hormone and neurotransmitter with various effects in different species.

Doppler shift: a change in frequency of a wave relative to an observer.

Dorcas gazelle (aka Ariel gazelle, Gazella dorcas): a small gazelle adapted to the arid regions of Africa and Arabia.

dorsal: the back or upper side of an organism. Contrast ventral.

douc: a monkey of 3 species in the genus Pygathrix, native to Southeast Asia, with a striking, high-contrast, appearance. Doucs live in small family groups headed by a single adult male and several adult females. Unattached late adolescent males may form their own group.

dragonfly: a flying insect predator, with over 5,900 extant species. Dragonfly hindwings are broader than their forewings. Adult dragonflies differ from otherwise similar damselflies by their holding their wings perpendicular to their bodies at rest, whereas damselflies tuck their wings in toward their bodies.

drone comb: brood cells for male honeybees.

drongo: a small insectivorous passerine of 29 species which resides in the Old World tropics, noted for its deceptive mimicry to snatch another species’ food. Most drongos are black or dark grey, sometimes with metallic tints. Drongos have short legs and long forked tails. They sit very upright while perched.

duck: an aquatic bird in the Anatidae family.

dugong (aka sea cow): a large marine mammal in the same order (Sirenia) as manatees.

dung beetle: a group of beetles that feed on feces. Many dung beetles – rollers – roll their finds into round balls, which they porter to their brooding chambers for extended dining. Others, termed tunnelers, bury the good stool where they find it. In contrast, dwellers neither roll nor burrow. They simply live in manure.

dunnock (aka hedge sparrow, Prunella modularis): a small passerine found throughout temperate Eurasia. Dunnocks were introduced into New Zealand in the 19th century.

dwarf mongoose (Helogale parvula): a small mongoose endemic to grasslands, bush lands, and open forests in Africa.

dyad: a group of 2; a couple/pair.

dynein: a motor protein. Dynein transports cellular cargo along cytoskeletal microtubules.

dysentery: an inflammatory disease of the intestine, especially the colon, causing abdominal pain and severe diarrhea. Several infectious pathogens, including viruses, bacteria, and parasites, can cause dysentery.


E.(Escherichia) coli: a rod-shaped enterobacteria commonly found in the lower intestine of endothermic organisms. E. coli normally colonize an infant’s gut within 40 hours of birth, delivered by food, water, or mere handling.

eagle: a large, powerful bird of prey in the Accipitridae family.

Earth: the 3rd planet from the Sun; the densest and 5th largest.

earwig: an insect with cerci (forceps-like pincers on their abdomen) and membranous wings folded under short, rarely-used forewings. There are ~2,000 species in 12 families.

ecdysis: the process of molting an outer layer. Invertebrates in the clade Ecdysozoa molt various cuticles. Snakes shed their keratin skin.

Ecdysozoa: the group of animals with exoskeletons or tough outer skin, including arthropods and nematodes.

echinoderm: a phylum of marine invertebrates comprising 7,000 species, including sea stars, sea urchins, sand dollars, and sea cucumbers. Echinoderms live at every ocean depth.

Echis (aka saw-scaled vipers, carpet vipers): a genus of venomous vipers found in dry biomes from Africa to India and Sri Lanka. All 8 species have a distinctive threat display of stridulation.

echolocation: sensation via echoes of self-emitted ultrasonic sounds.

eclosion: the act of hatching from an egg (by a larva) or emerging from a pupal case (by an adult).

ecology: an interactive interface; patterns of relations among entities; as a subdiscipline of biology, patterns of interrelations between life forms (e.g., cells, organisms) and their environment (including other organisms); more broadly, the relations between bioelements.

ecosystem: the community of biota in a biome, and the abiotic (non-living) elements within the area.

ectomycorrhiza: where a fungus symbiotically enters a plant root, but not root cells. Contrast endomycorrhiza.

ectoparasite: an external parasite. Contrast endoparasite.

ectotherm: an animal without internal means to maintain thermal homeostasis. Ectotherms practice behaviors to regulate body temperature, like lying in the Sun to warm themselves. Commonly misnamed cold-blooded, ectotherms’ blood is just as warm as endotherms. Compare endotherm.

ed: extra dimensions (or extra-dimensionality); the spatial dimensions of existence beyond the 3 that are perceptible and measurable. See 4d and hd.

Ediacaran (635–542 MYA): the 3rd and last period of the Neoproterozoic era, preceding the Cambrian period. Named after fossils found in the Ediacara Hills in south Australia in 1946.

eel: an elongated fish in the order Anguilliformes, with 20 families, 111 genera, and around 800 species. Most eels are predatory, living in the shallows of the sea, burrowing, or hiding among rocks. Most eel species are nocturnal. Only 1 family of eels inhabit freshwater (Anguillidae). Even these freshwater eels return to the sea to spawn.

egg: an organic vessel in which an embryo first begins development. See sperm.

egret: a white or buff colored bird, often preferring watery areas, practically synonymous with heron.

Egyptian (civilization) (3150 – 30 BCE): an ancient civilization in northeastern Africa, concentrated along the lower Nile River.

Egyptian cotton leafworm (aka African cotton leafworm, Mediterranean brocade, Spodoptera littoralis): a noctuid (owlet) moth native to Africa and Mediterranean Europe.

El Niño: a quasi-periodic climate pattern that forms in the tropical Pacific Ocean, roughly every 5 years. The most notable facets are the warm ocean surface current in the tropical eastern Pacific Ocean, coupled with high surface air pressure in the western Pacific. El Niño is Spanish for “the little boy,” an oblique reference to Christ as a child, specifically referring to the ocean warming in the Pacific near South America, usually noticed around Christmas.

La Niña (“little girl”) is the opposite oscillation to El Niño: cold water and low air pressure. Contrary to El Niño, La Niña lacks religious connotation.

elaiosome: a fleshy structure attached to some seeds that typically contains nutritious lipids and proteins, as an inducement for ant seed dispersal. See myrmecochory.

elater: a hygroscopic cell or cell structure that responsively changes shape with humidity variation.

electric fish: a fish that can generate an electric field (electrogenic). A fish that can detect electric fields is electroreceptive. Most electric fish are also electroreceptive. Electric fish are found in the sea, and in freshwater rivers of South America and Africa. Sharks, rays, and catfishes are electroreceptive, but cannot generate an electric field.

electron microscope: a high-powered microscope that employs accelerated electrons for illumination; capable of 10 million times magnification and resolution better than 50 picometers (5 x 10–13 m). In contrast, the best light microscopes resolve to 200 nm (2 x 10–11), with magnification below 2,000 times.

Elements of Physiology (1883–1840): a landmark work on human and comparative anatomy by Johannes Peter Müller.

elephant: a large terrestrial mammal native to Africa and India.

elephant seal: a large oceangoing seal. Elephant seals spend 80% of their lives in the ocean. They can hold their breath for longer (100 minutes) and dive deeper (1,550 meters) than any other noncetacean mammal.

elephant yam (aka konjac, devil’s tongue, voodoo lily, snake palm): a plant in the genus Amorphophallus, endemic from Indonesia to tropical eastern Asia, including Japan and China. Konnyaku (yam cake) is a food made from the root.

elytron (plural: elytra; aka shard): the hardened forewing of beetles and a few true bugs.

embryo: an early stage of development in multicellular diploid eukaryotes (e.g., plants and animals that sexually reproduce).

embryonic diapause (aka delayed implantation): a reproductive strategy employed by ~100 different mammals, where implantation of an embryo into the uterus is willfully delayed. Rodents, marsupials, mustelids, sea otters, and bears practice delayed implantation.

embryophyte: a land plant, including mosses, liverworts, ferns, and other seedless plants (pteridophytes), gymnosperms, and angiosperms.

Emery’s Rule: a 1909 observation by Carlo Emery that insect social parasites select as victims closely related organisms.

emochemical: an organic compound active in an organism experiencing an emotion.

emotion: a feeling evolved by cognition into a sustained mental state.

emotive cognition: appraisal of the ambiance of a situation based upon one’s empathic temperament and experience.

empathy: an imaginative projection of another’s mental state.

emperor penguin (Aptenodytes forsteri): the largest and heaviest penguin, endemic to Antarctica.

empiricism (epistemology): the presumption that knowledge derives solely from sensory experience.

empiricism (philosophy of science): the belief that Nature may be entirely explained by physical forces.

emu (Dromaius novaehollandiae): the largest Australian bird and 2nd only to the ostrich. Like ostriches, emu are flightless. Emu have incredibly strong legs.

encyst: to become enclosed in a cyst.

endemic: restricted to a circumscribed environment or area, such as an island. Compare indigenous, native.

endocrine: a secretion from a gland into the circulatory system. Many endocrines are hormones.

endocrine gland: a ductless animal gland that secretes hormones directly into the bloodstream, thereby regulating a body function. Contrast exocrine gland.

endocrine signaling: intercellular communication over a long distance. Compare paracrine signaling, juxtacrine signaling.

endodermis: the inner tissue layer in some land plants.

endolithic: living within or deeply penetrating stony surfaces.

endomycorrhiza: where a fungus symbiotically colonizes a host plant’s root cells. Contrast ectomycorrhiza.

endoparasite: a parasite residing within a host. Contrast ectoparasite.

endophyte: a plant endosymbiont.

endoplasmic reticulum (ER): an organelle connected to the nuclear membrane; a membranous network of sac-like structures (cisternae) held together by the cytoskeleton. ER has a role in various functions, including carbohydrate metabolism, lipid synthesis, glycoprotein production, and cell membrane manufacture. ER also plays a critical role in assisting mitochondrial division and replication.

endoreduplication: replication of a cell’s nuclear genome without cell division. Endoreduplication is common in plants, whereas limited to certain cell types in animals.

endorheic basin: a closed drainage basin: no outflow to another body of water.

endoskeleton: an internal animal support structure composed of mineralized tissue, such as bone. Vertebrates have an endoskeleton. Contrast exoskeleton.

endosperm: the tissue inside an angiosperm seed that provides nutrition to a growing embryo until it can establish roots.

endosymbiont: an organism living within the body or cells of another organism, forming a mutually advantageous arrangement.

endotherm: an animal with internal means to maintain thermal homeostasis. Birds and mammals are endotherms. Endothermy raises an animal’s metabolic needs compared to ectothermic animals. Compare ectotherm.

energy (physics): the idea of an immaterial force acting upon or producing matter. Energy is characterized relatively and by type (how it affects matter). Energy manifests only through its effect on matter. Though the foundational construct of existence, energy itself does not exist. As matter is made of energy, this fact tidily proves energyism.

energyism (aka (philosophical) immaterialism): the monistic doctrine that Nature is a figment of the mind. Energyism differentiates between actuality and reality. Whereas actuality is phenomenal, reality has a noumenal substrate, emergently spawning a shared actuality (showtivity) via a unified Ĉonsciousness. Contrast matterism.

entanglement (physics): distinct phenomena behaving synchronously. Entanglement defies locality.

enterobacteria: a large family of bacteria that make their living inside eukaryotes, either symbiotically or as a pathogen.

entomology: the study of insects.

entomopathogen: an insect-killing pathogen.

entropy (physics, particularly thermodynamics): the tendency of energy to dissipate and equilibrate (dissipate to equilibrium); the natural physical tendency toward disorder.

environment: a designated spatial region or conceptual realm.

enzyme: a protein that facilitates the activities of other proteins or substrates. Enzymes typically act as catalysts.

eocyte (aka Crenarchaeota): the kingdom of Archaea from which eukaryotes evolved.

eon (geology): a duration in the geological time scale, half a billion years or more; longer than an era.

Ephedra: an evolutionarily isolated genus of low, straggling, or climbing gymnospermous desert shrubs.

Ephedra sinica: a gymnosperm shrub that is used as a traditional Chinese medicine for a variety of ailments. Other Ephedra species were used medicinally by Native Americans.

epidermis: the outermost tissue layer of a plant or animal (in animals, the skin).

epigenetic: mechanisms for gene regulation and physical heredity without changing the structure of the gene involved – that is, without genetic mutation.

epigenome: the conceptual sum of instructions in a cell affecting access and expression of genes.

epilithon (bacteria): aquatic transformation.

epiparasite (aka hyperparasite): a parasite of a parasite.

epiphyte: a plant that grows harmlessly on another plant, typically a tree. Epiphytes grow on other plants for physical support.

epithelium (plural: epithelia): animal tissue that acts as lining.

epitoky: the process in marine bristle worms of a sexually immature worm (an atoke) transforming into sexual maturity (an epitoke).

epoch (geology): a duration in the geological time scale, tens of millions of years; shorter than a period, longer than an age.

equid: an odd-toed (perissodactyl) ungulate in the Equidae family, with horses, asses, and zebras extant.

era (geology): a duration in the geological time scale, several hundred million years; shorter than an eon, longer than a period.

ergot: a fungus of 50 species in the genus Claviceps.

erythrocyte (aka red blood cell): a vertebrate blood cell that transports oxygen.

esophagus (aka gullet): a vertebrate organ that is a muscular tube through which food passes from the pharynx to the essential amino acid: an amino acid necessary for health that cannot be synthesized by the human body, and so must be obtained via diet.

Escherichia coli: see E. coli.

essential amino acid: an amino acid necessary for health that cannot be synthesized by the human body, and so must be obtained via diet.

essential oil: a colloquial term for any of various volatile aromatic compounds produced by plants.

ester: a compound produced by a reaction between an acid and an alcohol, with the elimination of a molecule of water; an organic compound comprising a carbonyl adjacent to an ether.

estrogen: a group of female animal sex hormones.

estrus (aka in heat): sexual receptivity in a female.

estuary: a partly enclosed coastal body of water connected to the sea which has at least 1 river or stream flowing into it.

ether: a class of organic compounds characterized by an oxygen atom bonded to 2 carbon atoms (C-O-C).

ethnography: the study of culture.

ethology: the study of animal behavior, often with an eye toward evolutionary implications.

ethylene (C2H4 or H2C=CH2): a hydrocarbon; the simplest alkene. Ethylene hastens fruit ripening and floral senescence.

eucalyptol (C10H18O): a colorless liquid terpene, produced by eucalyptus trees for pest control.

eucalyptus: a diverse genus (Eucalyptus) of flowering trees and shrubs in the myrtle family comprising over 700 species. Eucalyptus dominate the tree flora of Australia.

eudicot (aka eudicotledon, tricolpate, Eudicotidae): a clade of flowering plants with pollen grains having 3 colpi (grooves) paralleling the polar axis. Eudicots and monocots are the 2 largest clades of angiosperms, constituting over 70% of flowering plants.

Eugenia: a genus of angiosperms in the myrtle family. The fruit of E. nesiotica has anti-parasite properties.

Euglena: a genus of unicellular flagellate protists.

eukaryote: an organism with internal cell structures (organelles). All multicellular life is eukaryotic. Compare prokaryote.

euphotic zone: the layer of water with sufficient sunlight for photosynthesis.

Euplotes: a genus of single-celled, transparent, ciliate, freshwater and marine protozoan.

Eurasia: the continental landmass of Europe and Asia, including Borneo and other nearby islands. Compare Australasia.

European earwig (aka common earwig, Forficula auricularia): a flattish, brown, nocturnal earwig that grows to 12–15 mm long, native to the temperate regions of Europe, western Asia, and North Africa, and in North America, where it was introduced by humans in 1907. An omnivore, the common earwig is considered a pest, owing to the damage it may do to crops, its frightening appearance, foul odor, and its too-frequent household appearances, where an earwig may find comfortable crevices and tasty foodstuffs. See earwig.

European robin (aka robin, robin redbreast, Erithacus rubecula): an insectivorous Old World flycatcher native to Europe, northwestern Asia, and North Africa. See robin.

European toad (aka common toad, Bufo bufo): a common toad found throughout most of Europe, excepting islands, in part of northwest Asia, and a small region of northwest Africa.

European turtle beetle (Amphotis marginata): a highwayman of the shining black ant.

eusocial: an animal that has: 1) overlapping generations, 2) cooperative care of the young, and 3) reproductive division of labor. Contrast presocial.

eutely: an organism with a fixed number of somatic cells upon reaching maturity, with the exact number a constant for any eutelic species. Development proceeds via cell division until maturity, whereupon growth transpires only by cell enlargement (hypertrophy). Nematodes are eutelic.

evaporation: conversion of water into vapor.

evening primrose (aka suncups, sundrops): an herbaceous angiosperm native to the Americas, in the Oenothera genus, with 145 species.

Everglades: the tropical wetlands in southern Florida.

evergreen: a plant with green leaves year-round.

evolution (evolutionary biology): the process of adaptation, most apparently seen as a distinctive change across successive generations of a population.

existence: corporeality, including both matter and energy. See Nature.

exocrine gland: a gland that secretes its product into ducts that lead directly to an external environment. Contrast endocrine gland.

exocytosis: the cellular process of secreting proteins outside the cell.

exon: a polynucleotide sequence in a nucleic acid that codes for protein synthesis. An exon is copied and spliced together with other such sequences to form messenger RNA. Compare intron.

exoskeleton: an external skeleton. Arthropods have exoskeletons. Contrast endoskeleton.

exosome: a saucer-shaped vesicle, produced by most eukaryotic cells for intercellular communication.

exosphere: the outermost layer of the atmosphere, reaching halfway to the Moon (190,000 km).

expect: to think that a certain event will occur. See anticipate.

extinction: the demise of a species. See background extinction, mass extinction.

extinction event: an episode of mass extinction.

external fertilization: a form of fertilization by which a sperm unites with an egg cell external to the bodies of the reproducing individuals. Contrast internal fertilization, where a female is inseminated via copulation.

extra dimensions: see ed.

extremophile: an organism that thrives in an environment adverse to most life. See acidophile, alkaliphile, anaerobe, barophile, halophile, hyperthermophile, osmophile, piezophile, psychrophile, thermoacidophile, thermophile, xerophile. The preceding is an exemplary, but incomplete listing of extremophile types.

external fertilization: a form of fertilization by which a sperm unites with an egg cell external to the bodies of the reproducing individuals. Contrast internal fertilization, where a female is inseminated via copulation.

exudate: exuded matter. Tree gum or sap is an exemplary exudate.

exudativore: an organism that eats exudate.


fact: recall of an experienced event.

facultative parasitism: an organism that may resort to parasitism but does not rely upon its host for completion of its life cycle. Contrast obligate parasitism. Compare hemiparasitism.

fairy cichlid (Neolamprologus brichardi): a cichlid endemic to the alkaline waters of Lake Tanganyika in East Africa.

fairy wasp (aka fairyfly): a parasitoid chalcid wasp in the family Mymaridae, found in tropical and temperate regions throughout the world; the smallest insect in the world.

fairywren: a family (Maluridae) of small, insectivorous passerines, with 15 species, endemic to Australia.

family (biological classification): a major biological group of shared morphological similarities. In the generally accepted taxonomy system, family is above genus and below order. For example, maple trees (family) are hardwoods (order), angiosperms (class), vascular plants (phylum), plants (kingdom). Pierre Magnol introduced family for plant groups in 1689, identifying 76 families. Carl Linnaeus incorporated family into his classification schema in 1751.

fascicle: a small muscle bundle.

fat (chemistry): a broad group of compounds comprising carbon, hydrogen, and oxygen; a subgroup of lipids. See saturated fat, unsaturated fat.

fatty acid: a carboxylic acid with a long aliphatic tail (chain).

fauna (plural: faunas or faunae): animals (metazoa). Compare flora.

feeling: a perceptual reaction that may develop into an emotion via emotive cognition. Compare emotion.

feldspar: a silicate-based mineral that makes up as much as 60% of the Earth’s crust.

felid (aka feline): an animal in the cat family (Felidae). Cats emerged ~25 MYA.

felsic: rocks, magma, and silicate materials enriched with aluminium, potassium, and/or sodium. Granite is the most common felsic mineral. Felsic is a portmanteau of “feldspar” and “silica.” Felsic rocks over 65% silica. Contrast mafic.

fennel (Foeniculum vulgare): a hardy, perennial herb with a bulbous base, yellow flowers, and feathery leaves.

Fermat’s principle (aka principle of least time): a 1658 optics principle by Pierre de Fermat that light always travels most efficiently: from one point to another in the least time.

fermentation (biochemistry): a metabolic process by microbes and oxygen-starved muscle cells of converting sugar to alcohol, acids, and/or gases.

fern (aka Pteridophyta): the first pteridophyte, emerging 360 MYA.

Fernandina Island: the youngest and 3rd-largest Galápagos Island; named after King Ferdinand of Spain, who sponsored the voyages of Christopher Columbus.

Ferrel cell: an atmospheric circulation belt between 30° and 60° latitude. See Hadley cell and Polar cell. The Ferrel cell is named after William Ferrel, who explained in 1856 mid-latitude atmospheric circulation.

ferret: a mustelid.

fetus: an unborn nascent vertebrate after passing through the earliest developmental stages, having attained its basic body structural plan. See embryo.

fibroin: an insoluble protein comprising specifically layered amino acid sheets.

fiddler crab: a small semi-terrestrial crab of ~100 species with asymmetric claws. Fiddler crabs communicate via gestures.

field: an energy associated with a spacetime point or region.

fight-or-flight response: reflexive reaction to a perceived threat.

filament (botany): the stalk with the anther at one end that comprises the stamen.

filefish (aka foolfish): a diverse family of subtropical fish that live in the Atlantic, Indian and Pacific Oceans. There are 27 genera, and 102 species of filefish. Like their close relatives, triggerfish, filefish are rhomboid-shaped and display beautifully elaborate cryptic patterns.

filopodia: a slender cytoplasmic projection, employed for sensing, cell-to-cell interactions, and migration.

finch: a small to medium-sized songbird in the Fringillidae family that primarily eats seeds. Many birds in other families are commonly called finches.

fingerling: a small fish, typically used to characterize a developmental stage to becoming a larger fish.

fire ant (aka red ant, ginger ant): a stinging ant in one of several species in the genus Solenopsis.

fire coral: a colonial marine organism that looks like coral but is more closely related to jellyfish and other stinging anemones.

firefly: a winged beetle notable for its production of bioluminescence, commonly in the tail. 2,000 species are known, found in tropical and temperate zones, particularly marshlands and wet woods. A larva is a glowworm.

fish: a gill-bearing, aquatic animal lacking limbs with digits. 32,000 species are known. Most fish are endothermic.

fission-fusion sociality: a dynamic social group comprising a larger community with sub-groups, including families and close friendships. This awkward term refers to the dynamics of group fusion (merging), such as for sleeping together for safety, and fission (splitting up), such as foraging in small groups during the day. Various social animals have fission-fusion sociality, including fish (guppies), cetaceans (dolphins), ungulates (deer), elephants, most mammalian carnivores (lions, hyenas), and primates.

flagellate: an organism or gamete with a whip-like organelle for propulsion.

flagellum (plural: flagella): a whip-like appendage protruding from a cell, employed for sensation and locomotion. Compare cilium.

flamingo: a wading bird in the Phoenicopteridae family, with 6 species.

flatworm (aka platyhelminth): a relatively simple unsegmented, bilateral (head and tail), soft-bodied worm. Flatworms have no specialized respiratory or circulatory organs. Their flatness lets oxygen and nutrients diffuse through them. Over half of the 15,000+ known flatworm species are parasitic.

flavonal: a flavonoid with a 3-hydroxyflavone backbone (signified by specific arrangement of oxygen and hydrogen).

flavonoid (aka bioflavonoid): a plant secondary metabolite used to color flowers, filter UV, and symbiotically fix nitrogen.

flora (plural: florae or floras): plants. Compare fauna.

floret: one of the small buds clustered together in a flower.

florigen: a plant signaling molecule that initiates flowering; also known as the protein flowering locus t (ft).

flower (aka bloom, blossom): the reproductive structure of an angiosperm.

flower constancy: the practice of a foraging bee to specialize in harvesting from a certain flower species through a single trip or for days at a time.

fluid: a substance that deforms (flows) under an applied shear stress. Gases, plasmas, and liquids are fluids. Contrast rheid, solid.

fluke (aka trematode): a parasitic flatworm.

fly: a small flying insect with a single pair of wings.

flycatcher: a perching bird (passerine) that darts out to capture insects on the wing.

fog: a low-lying cloud.

foliage: a mass of leaves as a plant feature.

folic acid (C19H19N7O6, aka vitamin M, vitamin B9): a water-soluble B vitamin essential in plants and animals for the synthesis of nucleic acids.

folkway: a traditional behavior that is a norm. Compare more.

food chain: a hierarchy of organism consumption, from autotroph through herbivore(s) to predator(s).

food web: the energy production and consumption interrelations between biota in an ecosystem.

forage: search for food.

foraminifera: a large phylum of amoeboid protists; among the most common marine plankton species.

Forelius pruinosus: a small ant fond of sweets and warm weather, endemic to the United States and Mexico. The catalpa tree hires F. pruinosus as bodyguards: oozing nectar on their branches when caterpillars come to gobble their leaves. The ants dispatch what they perceive as a potential rival to their food supply.

formic acid (CH2O2) (aka methanoic acid): a simple carboxylic acid, produced by ants and meliponines for defense. Formica is the Latin word for ant.

Formica polyctena: a eusocial northern European red wood ant with a distinctive caste system.

fossil fuel: a fuel formed from dead organisms. Coal, natural gas, and petroleum are fossil fuels.

fovea: the portion of the eye with sharpest vision, as it has the highest concentration of photoreceptors.

fractal: a scale-invariant self-similar set of patterns.

fragmentation (biology): a form of asexual reproduction, where a new organism grows from a fragment of the parent. Some plants are capable of fragmentation.

frankfish: (aka aba, African nightfish, Gymnarchus niloticus): a freshwater electric fish, endemic to African swamps and the edges of waterways with vegetation. Frankfish grow to 1.6 m and 19 kg.

Franklin’s gull (aka prairie rose gull, Leucophaeus pipixcan): a small migratory gull native to the western hemisphere.

freeloader fly (aka jackal fly): a small, dark fly in the Milichiidae family that is a kleptoparasite of predatory invertebrates.

freshet: a stream of freshwater flowing to the sea.

frigatebird (aka pirate bird): a pelagic piscivore, with food most often obtained on the wing. Frigatebirds occasionally rob other seabirds and snatch seabird chicks; behaviors which bestowed the family name.

frog: a largely carnivorous group of tailless amphibians with short, stout bodies. With ~5,000 species, frogs are one of the most diverse vertebrate orders. Most frogs live in tropical rainforests. Warty frogs tend to be termed toads. This is an informal convention, not based on evolutionary descent or taxonomy.

frog lung fluke (aka Haematoloechus medioplexus): a parasitic flatworm (trematode) that lives its adult life stage in the lungs of frogs.

frugivore: an animal that prefers a fruit-based diet.

fruit (botany): a plant ovary containing seeds that is a sweet-tasting gift to animals by a flowering plant in a gambit to disseminate its progeny.

fruit fly: a fly in the Tephritidae family that primarily feeds on unripe or ripe fruit. Sometimes called a “true” fruit fly, as contrasted to vinegar flies that are also called “fruit flies.” Compare vinegar fly.

fry: a recently hatched fish.

fumarolic (vent): a hole in a volcanic region from which hot gases and vapors issue.

fungiculture: culturing fungi for food.

fungivore: a fungus eater.

fungus (plural: fungi): a group of eukaryotes that includes microorganisms such as yeast and molds, as well as macroscopic mushrooms.

funnel ant: a non-aggressive ant in the Aphaenogaster genus, with over 200 species found throughout much of the world, southern Africa and South America excepted. Much of funnel ants’ food comes from tended aphids that live on plant roots. Hence, they are rarely seen on the surface. The funnel-shaped openings they construct are traps for the arthropods upon which they feed.

fur: the hair of animals, especially mammals.


GABA (gamma-Aminobutyric acid): a neurotransmitter which is inhibitory in humans.

Gaia: a theory by English environmentalist James Lovelock that Earth acts as “a single physiological system.”

Evolution is a tightly coupled dance, with life and the material environment as partners. From the dance emerges the entity Gaia. ~ James Lovelock

Galápagos Islands: an archipelago of 18 large and 3 small volcanic islands in the Pacific Ocean near the equator, 972 km west of Ecuador.

Galápagos marine iguana: a marine iguana found only on the Galápagos Islands, capable of diving 9 meters to graze on algae and seaweed.

gall aphid: an aphid which causes galls on poplars and other trees.

gallery forest: a forest forming a corridor along rivers or wetlands, bordered by a biome sparsely treed.

gallfly (aka gall wasp): a small wasp of ~1,300 species of wasps, named after the galls they induce on plants for larval development. The larvae of most gall wasps develop in plant galls which they induce. Oak is the wood of choice for many gall wasps.

Gallionella: an aquatic iron-oxidizing bacterium.

game bird: a bird often eaten by humans.

gamete: a cell or cell nucleus that undergoes sexual fusion to form a zygote. In animals, gametes are eggs and sperm cells. Plant germ cells produce ovules and pollen.

gametangia: an organ or cell in which gametes are produced.

gametophyte: the haploid, gamete-producing phase of plants and algae that undergo alternation of generations; the prothallus in ferns, and the embryo sac in angiosperms. Compare sporophyte.

gamma ray: electromagnetic radiation above 10 exahertz (>1019 Hz); very high energy/frequency radiation.

ganglion (plural: ganglia): a mass of neuronal tissue.

gannet (Morus genus): a large seabird in that hunts by diving into the sea from height. Gannets can dive from 30 meters up, achieving speeds of 100 km/h as they strike the water. This lets them catch fish much deeper than other diving birds.

garlic (Allium sativum): the bulb of a plant in the onion genus.

gas: a fluid that may be airborne.

gaster: the abdomen of a hymenopterous insect, such as an ant, bee, or wasp.

gazelle: an antelope of 13 species in the genus Gazella.

gecko: a lizard in the Gekkota group, fond of warm climate. Geckos are unique among lizards for their gregarious vocalizations. There are 1,500 gecko species; the most speciose group of lizards.

gelada baboon (aka bleeding-heart monkey, as the top of their chest is a bright red patch of skin): a monkey in the genus Theropithecus, endemic to the high-elevation grasslands on the central Ethiopian plateau. Geladas are closely related to baboons.

gender: designation of female or male of a species. See sex.

gene: the idea that nucleic acids provide instructions for producing an organic molecule, typically a protein. Genes do not exist; they are merely a construal. The actuality of genetics is more intricate than supposed by matterist geneticists, as heritable bioproduct information is stored energetically, with organic molecules as illusory material substrates.

gene expression: employment of a gene; the conceptual process by which genetic information is used to synthesize a bioproduct.

gene regulation: control of gene expression, including stifling gene expression.

generalist (ecology): a species with considerable tolerances to environmental changes. Contrast specialist.

genetic code: the conceptual rulebook by which information is encoded in genetic material (DNA or RNA sequences).

genetic drift: a difference in genome between species in a hereditary lineage.

genetics: the study of heredity and variation in life forms at the molecular level. The 4 major subdisciplines of genetics are transmission genetics (heredity), molecular genetics (chemistry), population genetics (traits in populations), and epigenetics (influences of living on inheritance).

genome: the (idea of the) entire set of genes within an organism. Like genes, a genome is merely a concept, not phenomenal.

genophore: a package of DNA in a prokaryote’s nucleoid. Compare chromosome.

genotype: the energetic constitution of an organism, as artifactually represented by its genome. The gen in genotype refers to genesis (not genetics).

genus (plural: genera): a category of organisms, more generic than species.

geographic harmonic (aka geoharmonic): the energetic resonance of a biome (affecting biota).

geoid: the geometric figure formed by an imaginary surface that coincides with mean sea level and its extension through continents.

geology: the science of the solid matter that comprises Earth, especially in the crust.

geophagy: eating soil or rock.

geosphere: within Earth, including the crust and mantle. Compare pedosphere.

geosmin (C12H22O): an organic compound with the scent of rich earth, produced by Streptomyces soil bacteria. Geosmin gives beets their earthy taste. Geosmin contributes to the scent in the air when rain falls after a dry spell, or when soil is disturbed.

Geranium (aka cranesbills): a genus of 422 species of flowering plants.

germ: see pathogen.

germinate: to begin growth or development.

germline: the line (sequence) of gene cells within the gene set that may be passed to offspring.

giant otter (aka giant river otter, Pteronura brasiliensis): a carnivorous, aquatic South American otter. Adults are 1–1.7 meters long, 22–32 kg. Males are ~17% larger than females.

giant water bug: a large insect fond of water, in the family Begiant siphonophore (Praya dubia): a deep-sea siphonophore, with a body length of 40–50 meters; native to the Atlantic Ocean, between the Gulf of Mexico and Europe.

gibberellin: a plant hormone that regulates growth.

ginkgo: a long-lived large tree, sometimes reaching 50 meters. Ginkgo have unique fan-shaped leaves.

giraffe: an African even-toed ungulate ruminant with an exceedingly long neck, making it the tallest living terrestrial animal.

glacial period (aka glaciation): a period of glaciers, typically thousands of years, within an ice age, marked by colder temperatures and glacial advances. By contrast, interglacials are periods of warmer climate within an ice age. The last glacial period ended 15,000 years ago. The present epoch, the Holocene, is the current interglacial.

gland: a group of cells in an animal that synthesizes substances for release inside or on the body.

glia: the predominant cell type in animal brains. Neurons (nerve cells) support glial cells via their interfaces outside the brain.

globe skimmer dragonfly (aka wandering glider, Pantala flavescens): one of the most widespread dragonflies throughout the tropical and temperate biomes of world, noted for their extensive migratory tendencies.

globin: a family of heme-containing globular proteins involved in binding and/or transporting oxygen.

glowworm: a larva of a firefly.

glucose (C6H12O6): a simple sugar used in glycolysis to form ATP.

glucosinolate: an organic compound containing sulfur and nitrogen, derived from glucose and an amino acid. Glucosinolate is toxic to animals at high doses. Some insects, including specialized sawflies and aphids, sequester glucosinolates to render themselves inedible.

glutamate: an amino acid that acts as a neurotransmitter.

glycan: ostensibly a synonym for polysaccharide, but commonly used to refer to the carbohydrate bonded to a protein or other glycoconjugate.

glycerol: a simple alcohol compound comprising 3 hydroxyl groups (3 molecules of hydrogen and oxygen).

glycocalyx: an extracellular glycoprotein produced by some bacteria, epithelia, and other cells.

glycolysis: a metabolic pathway of 10 reactions that results in free energy; often used to form ATP.

glycoprotein: a protein containing a carbohydrate (oligosaccharide chain (glycan)) attached to a polypeptide side chain.

glycosidase (aka glycoside hydrolase): an enzyme that hydrolyzes a glycoside.

glycoside: a sugar bound to another functional group (moiety) via covalent bond.

glycosidic bond: a covalent bond that joins a sugar to another group (carbohydrate or not).

glycosylation: the process of adding a carbohydrate (glycosyl group) to another functional group (a glycosyl acceptor). Glycosylation typically refers to adding a glycosyl group (glycan) to a protein to form a glycoprotein.

gnetophyte: a group of gymnosperms which differs from others by having the water-transport vessel elements found in flowering plants.

Gnetum: a genus of gymnospermous tropical trees, shrubs, and lianas which may have been the first plants to be insect pollinated.

goat: an even-toed bovid, closely related to sheep.

goby: a fish in one of the most specious families of fish (Gobiidae), with more than 2,000 species in over 200 genera.

golden algae (aka chrysophytes): a group of algae found mostly in fresh water. Though a green algae, the name derives from the golden sheen given by accessory pigments. The designation is sometimes applied to the species Prymnesium parvum.

goldenrod: an angiosperm in the Solidago genus, with 100–200 species; most are herbaceous and found in North America.

gomphothere: a family of elephant-like animals that lived 12–0.7 MYA, before being hunted to extinction by humans.

Gondwana (510–200 MYA): a supercontinent prior to Pangea (300 MYA); later becoming the southernmost of 2 supercontinents (Laurasia to the north) 200 MYA. Gondwana was the progenitor of the landmasses in today’s southern hemisphere: Antarctica; Australia; the Arabian Peninsula and Indian subcontinent, both now part of the northern hemisphere; Madagascar, Africa; and South America.

goose (plural: geese): a large waterfowl. Some other birds have “goose” as part of their names. Distantly related birds include the generally larger swans and smaller ducks.

gorilla: a large, ground-dwelling ape that lives in the African forest, in the genus Gorilla, with 2 species: one in the mountains, the other in lowlands.

gourd (aka cucurbit): a flowering vine in the Cucurbitaceae family, with ~965 species in ~95 genera. Squash, pumpkin, cucumber, and watermelon are exemplary gourds.

gossamer: a lightweight film.

grade (biological classification): a taxon designating a level of morphological or physiological complexity. Compare clade.

Gram staining: a technique using dyes to classify bacteria.

Hans Christian Gram and Carl Friedländer worked together in Berlin’s city morgue. In 1882, they devised a technique of staining lung tissue to look for bacteria. Gram’s 1884 published report noted that the typhus bacillus did not retain the stain, rendering it Gram-negative.

Whether a bacterium holds a purple dye determines whether it is Gram-positive or Gram-negative. Stain retention is based upon a bacterium’s cell wall.

Murein (aka peptidoglycan) is a polymer of amino acids and sugars, in a mesh as part a bacterium’s cell wall, giving the wall rigidity and structural strength.

Gram-positive bacteria have a thick (20–80 nm) cell wall, mostly made of murein (50–90%). Gram-negative bacteria have a much thinner (7–8 nm) cell wall; only 10% peptidoglycan.

Instead of much murein, Gram-negative bacteria have an extra layer of lipopolysaccharide. This lipid layer does not contribute strength but does act as a selective barrier that keeps unwanted large molecules away from the plasma membrane. Both wall types have their advantages.

In contrast to bacterial cell wall constructions, archaeal cell walls lack a peptidoglycan component. Thus, they are immune to antibiotics that interfere with bacterial cell wall synthesis. Drugs that inhibit ribosomes and protein synthesis in bacteria have no effect on archaeans.

Crystal violet is the blue-violet triarylmethane ((C6H5)3CH) dye used in the 1st step of Gram staining, which is a 4-step process. The dye is a topical antiseptic, with antibacterial, antifungal, and anthelmintic (anti-parasitic) properties.

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The Gram staining process:

1) Apply crystal violet (the primary stain) to a heat-fixed smear of bacteria on a slide. Heat-fixing affixes the bacteria to the slide, at the cost of killing some.

2) Add a mordant (Gram’s iodine) that binds to the stain and traps it within bacterial cells.

3) Decolorize with a quick rinse in alcohol (CH3CH2OH) or acetone (((CH3)2CO).

4) Counterstain with safranin (C20H19ClN4), a red dye.

After decolorization, a Gram-positive bacterium holds its purple, while a Gram-negative does not. Applying safranin gives Gram-negative bacteria a pink or reddish hue.

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Gram staining does not always work. Some bacteria yield a Gram-variable pattern after Gram staining: a mix of pink and purple cells. This may reflect cell division in some of the Gram-positive bacteria, at a time when cell walls are sensitive to breakage.

Some bacteria are Gram-indeterminate, as they don’t respond to Gram staining. This includes various Gram-variable bacteria, as well as acid-fast bacteria, which resist the decolorization step. Mycobacterium, the genus which include tuberculosis, are acid-fast.

Further, the age of the culture may influence the results of a Gram stain.

grandmother hypothesis: the 1957 surmise by George Williams that menopause evolved so that grandmothers could help rear offspring of a succeeding generation.

granellare: a base from which a xenophyophore builds a shell-like stercomare.

granite: a course-grained igneous rock, at least 20% quartz by volume.

granivore: a specialized seed eater.

grass: a large, versatile, ubiquitous monocot that grows on all continents, in the family Poaceae. Grasses have small flowers and sheathing leaves covering hollow stems. They include cereals and bamboo, but not other plants commonly called grasses, such as seagrasses, rushes, and sedges (though rushes and sedges are related to grass).

grass snake (aka ringed snake, water snake, Natrix natrix): a Eurasian nonvenomous snake that lives near water, feeding almost exclusively on amphibians.

grasshopper: a predominantly tropical, ground-dwelling insect with powerful hind legs for leaping; extant for 250 MYA, now with 11,000 known species. Grasshoppers are herbivorous. Only 1 is monophagous. The others have various dietary preferences (polyphagous). Many grasshoppers maintain a rounded diet: eating from different plant species every day. To distinguish from crickets and katydids, grasshoppers are sometimes called short-horned. Species that change color and aggregate in huge populations are called locusts.

gravitropism: plant movement in response to gravity.

gravity: a spacetime distortion caused by mass.

Great American Interchange: the period of intercontinental species migration between North and South America 3 MYA. See Nearctic and Neotropic.

great desert skink (aka Kintore’s egernia, Liopholis kintorei): a medium-sized skink native to western Australia. Adults may grow to ~19 cm. The great desert skink is unusual in building elaborate underground mansions for its family, and that males are mostly monogamous.

great reed warbler (Acrocephalus arundinaceus): a Eurasian passerine that is the largest of the European warblers.

Great Rift Valley: a geographic trench in East Africa, best known for fossils found of early hominids. The Great Rift Valley runs from Afar Triple Junction: 3 plates – the Nubian, Somalian, and Arabian – that intersect where the Gulf of Aden and the Red Sea meet, to central Mozambique.

great tit (Parus major): a small, common passerine resident in woodlands throughout North Africa, the Middle East, Europe, and central and northern Asia.

grebe: a freshwater diving bird of 6 genera and 22 species in the Podicipediformes order. Grebes live in temperate biomes around the world.

green darner (aka common green darner, Anax junius): a large, abundant migrating dragonfly, named for its resemblance to a darning needle. The green darner is native to North America, the Caribbean, Tahiti, and East Asia.

green scale (aka coffee scale, Coccus viridis): a soft scale insect endemic to Brazil, but now found worldwide. The green scale is considered a major pest by coffee growers.

green tree frog: a common name for several distinct green tree frogs.

greenhouse (climate): see hothouse.

greenhouse effect: the process by which radiation from the atmosphere warms a planet’s surface.

greenhouse gas: a gas in the atmosphere that absorbs and emits radiation within the infrared range. The primary greenhouse gases in Earth’s atmosphere are carbon dioxide, methane, nitrous oxide, and ozone. Water vapor acts as a greenhouse gas.

gregarious: highly social.

grooming: the practice of keeping the body clean by removing foreign objects from the fur. Grooming plays a major role in primate social relations.

grosbeak: a seed-eating passerine with a pronounced beak.

ground meristem: the primary meristem that produces various ground tissues, used for structural support, leaf energy production, and would repair.

ground tissue: plant tissue that manufactures and stores nutrients.

groundwater: water within the crust, the upper surface of which forms the water table.

grouse: a heavily-built herbivorous bird that inhabits temperate and subarctic biomes in the northern hemisphere.

guanine (G) (C5H5N5O): a nucleobase of DNA and RNA. Guanine is complementary to cytosine.

guenon: an arboreal forest-dwelling monkey in the Cercopithecus genus, endemic to sub-Saharan Africa; characterized by bold markings of white and/or bright color. Guenons live in nuclear families of 1 adult male and 2 or 3 adult females, along with youngsters.

guild (botany): a group of plants interlinked through a common mycorrhizal network.

Guinea baboon (aka western baboon, red baboon, Papio papio): the smallest species of baboon, endemic to a small range in westernmost Africa, inhabiting dry forests, gallery forests, steppes, and savannas. The Guinea baboon is diurnal and terrestrial, though it sleeps in trees at night for safety. The number of suitable trees for sleeping limits its group size and range. Troops are up to 200 members. Guinea baboons are highly communicative. Socially a troop comprises a complex multilevel society. Unlike other baboons, adult male Guineas are tolerant and cooperative, forming social bonds with other males regardless of kin relation.

(The) Guinness Book of World Records: a reference book of world records; both human achievements and extremes in the natural world. The book itself holds its own world record as the best-selling copyrighted book series of all time. The book is one of those most frequently stolen books from American public libraries.

Gulf Stream: a swift, powerful, and warm Atlantic Ocean current that runs from the Gulf of Mexico up the Atlantic seaboard to Newfoundland before crossing to the west coast of Europe; named by Benjamin Franklin.

gull (aka seagull): a medium-to-large assertive seabird that is an opportunistic eater.

guppy (aka million fish, rainbow fish, Poecilia reticulata): a freshwater tropical fish native to northeast South America.

gymnosperm: a group of seed-producing plants, including conifers (e.g., pine, fir), cycads, ginkgo, and gnetophytes.

gyne: the primary reproductive caste in social insects (ants, bees, wasps, termites). Whereas the typical female worker is sterile, gynes are destined to become queens. A colony with a single queen is monogyne (e.g., honeybees), whereas a colony with multiple queens (e.g., ants) is polygyne.

gynoecium: the female part of a flower that produces ovules which develop into fruit and seeds.

gypsy moth: a moth found in Europe, Africa and North America. Gypsy moth larvae eat the leaves of over 300 different trees.

gyre: a conceptual framework treating a physical system as a dynamic vortex. A gyre is characterized by its structure, qualities, thermodynamics, and interactions.


habitat: the relevant aspects of an environment in which a species population lives.

Hadean (4.55–3.9 BYA): the 1st geologic eon, originally thought to be before life originated on Earth (but life started 4.1 BYA).

Hadley cell: an atmospheric circulation belt between the equator and latitude 30° (the Horse Latitudes). The Hadley cell is named after George Hadley, who was intrigued by the trade winds having a pronounced westerly flow, rather than blowing straight north. In generally explaining the gyre of the trade winds in 1735, Hadley’s explanation accounted for the Coriolis effect. See Ferrel cell and Polar cell.

hairworm (aka nematomorpha, horsehair worm, Gordian worm): a phylum of water-loving parasitoid worms, superficially similar to nematodes.

halfbeak (aka Buffon’s river garfish, Zenarchopterus buffonis): a smallish fish found near the surface of rivers, estuaries, and coastal waters ranging from southern China to northern Australia. Halfbeaks may grow to 23 cm.

haloarchaean: a salt-loving archaean.

halophile: an organism that lives in a salty habitat.

halophyte: a plant that grows in saltwater. Salt marsh grasses and mangrove trees are halophytes.

hamadryas baboon (Papio hamadryas): the northernmost of baboons, native to the Horn of Africa and the southwestern tip of the Arabian Peninsula. Hamadryas have a pronounced sexual dimorphism. Males are often twice the size of females. This coincides with a strict patriarchal society. The hamadryas baboon was sacred to the ancient Egyptians.

hammer-headed bat (aka big-lipped bat, Hypsignathus monstrosus): a megabat common in equatorial Africa.

haplodiploidy: a sex-determination system where the sex of offspring is determined by the number of sets of chromosomes received. Female eusocial (Hymenopteran) insects, such as bees, wasps, and ants, are diploid, but males are haploid because they develop from unfertilized, haploid egg cells.

haploid: an organism having 1 set of chromosomes.

Harris’s hawk (aka bay-winged hawk, dusky hawk, Parabuteo unicinctus): a medium-large hawk found in the southwestern United States south to Chile, central Argentina, and Brazil. Harris’s hawk is notable for its pack hunting.

harvest mouse: a small rodent in the Micromys genus, native to Eurasia.

harvester ant: an ant that collects seeds and stores them in a communal granary. A Southeast Asian species – Euprenolepis procera – harvests mushrooms.

haustorium: a hook used by parasitic fungi and plants to attach and draw nutrients from their chosen host. A haustorium may be shaped like a balloon or glove, or spiral-shaped.

Hawaiian bobtail squid (Euprymna scolopes): a bioluminescent squid, courtesy of the bacteria Vibrio fischeri. The Hawaiian bobtail squid is native to the central Pacific Ocean, living in shallow coastal waters.

Hawaiian Islands: an archipelago of 8 major volcanic islands in the North Pacific Ocean. The islands are the exposed peaks of an extensive undersea mountain range, formed over a volcanic hotspot.

hawk: a bird of prey, of various sizes and genera, in the Accipitridae family.

hawkmoth: a moderate- to large-sized moth in the Sphingidae family, with 1,450 species, found mostly in the tropics, but represented in many biomes. As moths, hawkmoths are distinguished for their rapid, sustained flying ability, adaptively equipped with narrow wings and streamlined abdomens.

hazel grouse (aka hazel hen, Tetrastes bonasia): a relatively small (~37 cm), shy, terrestrial, sedentary grouse endemic to woodlands throughout northern Eurasia.

HD (holistic dimensionality): the totality of dimensions in existence. HD refers to the universe having more than 4 dimensions (4D) (3 spatial and 1 temporal vector). HD = 4D + ED, where ED = extra spatial dimensions.

heath: a low evergreen shrub of over 700 species in the Erica genus; related to heather (Calluna); both genera are in the Ericaceae family.

hectocotylus (plural: hectocotyli): a tentacle of male cephalopods that is specialized to store and transfer spermatophores to a female.

hedgehog: a spiny omnivorous mammal endemic to parts of Europe, Asia, and Africa, of 17 species in 5 genera.

Helicobacter pylori: a bacterium that lives in the stomach. Over 50% of the world human population harbor H. pylori. The bacterium instigates gastritis or ulcers in less than 20% of those that carry it.

heliobacteria: phototrophic bacteria.

Heliconia: a genus of 100– 200 flowering plant species, native to the tropical Americas and Pacific Ocean islands west to Indonesia.

hellebore: an herbaceous or evergreen perennial of ~20 species in the Helleborus genus. Many species are poisonous.

hematophagy: feeding on blood.

heme (aka haem): a deep red, iron-containing pigment (C34H32N4O4Fe) which readily oxidizes.

hemicellulose: a polysaccharide matrix in plant cell walls. In contrast to stiff cellulose, hemicellulose has little rigidity.

hemimetabolous: a type of metamorphosis in which physical development proceeds from egg to nymph to adult. Compare ametabolous, holometabolous.

hemiparasitism: a plant that is parasitic by inclination, but able to live on its own. Contrast obligate parasitism. Compare facultative parasitism.

hemlock (Conium maculatum): an herb native to Europe and the Mediterranean, notorious for producing the toxic alkaloid coniine.

hemlock: a genus (Tsuga) of pines.

hemipenis (plural: hemipenes): 1 of a pair of intromittent organs of male squamates. Hemipenis is a portmanteau of hemi (meaning half) and penis. Only 1 hemipenis is used at a time for sex. Males tend to alternate their hemipenes for successive copulations. Hemipenes are usually held within the body, inverted. They are everted for sex via erectile tissue. As hemipenes are inverted and everted, there is no closed sperm channel; instead, a seminal groove which seals closes as the erectile tissue expands. Hemipenis shape varies by species. Hemipenes often have spines or hooks to better anchor the male in the female.

hemocoel: interconnected body cavity spaces between tissues through which blood freely flows, unconfined by blood vessels. Several invertebrate groups, including arthropods and mollusks, have hemocoel.

hemocyanin: the copper-based protein that transports oxygen in most mollusks, some arthropods, and a few cephalopods. Hemocyanins are suspended directly in hemolymph. Compare hemoglobin.

hemoglobin (aka haemoglobin; abbreviated Hb or Hgb): the iron-containing oxygen-transport protein in red blood cells of almost all vertebrates except crocodile icefish. See icefish.

hemolymph (aka haemolymph): the fluid in the circulatory system of arthropods that is functionally analogous to blood and tissue fluid in vertebrates.

Hepatica (aka liverleaf, liverwort): a genus of herbaceous perennials in the buttercup family, native to central and northern Europe, Asia, and eastern North America. Hepatica was named for its leaves, which resemble the human liver in having 3 lobes. Owing to the Doctrine of Signatures, the plant was once wrongly thought to be an effective treatment for liver disorders. Although poisonous in large doses, the leaves and flowers are astringent, make for a salve for slow-healing injuries, and act as a diuretic.

herb: an herbaceous plant. Also used to refer to a leafy plant part employed as a food flavoring, medicinally, or in perfume. Compare spice.

herbaceous: an angiosperm that has leaves and stems which die down to the ground at the end of the growing season. Herbaceous plants have no persistent woody stem above ground. Herbaceous plants may be annuals, biennials, or perennials. Contrast arborescent.

herbivore: a heterotrophic organism that primarily eats plant-based foods. Compare omnivore, carnivore, and saprovore.

hermaphrodite: a sexually reproducing organism with both male and female reproductive organs at some point in its life. Hermaphroditism is a normal condition for most invertebrates, which do not have separate sexes.

hermit crab: a crab of 1,100 species that salvages empty seashells for a protective lodging.

heron: a long-legged freshwater and coastal bird of 64 species, some of which are called egrets or bitterns.

herpes: an ancient virus that causes disease in animals.

herring: a coastal, schooling, marine fish in the Clupeidae family.

heterofertilization: plant fertilization by sperms from different plants.

heterogamy (reproductive biology): sexual reproduction, as contrasted to parthenogenetic generation.

heterokaryon: a special form of syncytium, in which a life form, such as a plasmodium, has multiple nuclei of different genetic origin.

heterokaryosis: the process of forming a heterokaryon.

Heterorhabditis bacteriophora: an entomopathogenic endoparasitic nematode that harbors Photorhabdus luminescens.

heterothallism: a species with individuals having a single sex and practicing sexual reproduction only when opposite mating types come into contact. Heterothallic organisms are otherwise capable of asexual reproduction. The term is used to distinguish between fungi which require 2 compatible partners to sexually produce spores from homothallic ones which can sexually reproduce spores from a single organism. Contrast homothallism.

heterotroph: an organism that cannot make its own food. All animals are heterotrophs. Compare autotroph.

heuristic (psychology): a simple, efficient rule employed to form judgments or make decisions.

heywood (Moricandia moricandioides): an herb in the Brassica genus, native to Spain.

Himalayas: a young mountain range formed by the Indian subcontinent moving north and slamming into Eurasia. 9 of the 10 highest peaks on Earth are in the Himalayas.

hippopotamus: a large, mostly herbivorous even-toed ungulate of sub-Saharan Africa. Hippos are semiaquatic: inhabiting lakes, shallow rivers, and mangrove swamps. Despite resembling oversized pigs, their closest are cetaceans, from which they diverged 55 MYA.

histology (aka microanatomy): the study of cell and tissue anatomy via microscopy.

hive: a bee nest.

hoatzin (pronounced: wot-seen) (aka stinkbird, Opisthocomus hoazin): a pheasant-sized tropical bird found in swamps and riparian forest of the Amazon and Orinoco delta of South America. Hoatzin evolved in the Old World but made their way to the South America via floating on a raft of vegetation millions of years ago. European hoatzin died out when the climate became too cold.

hognose snake: a snake with an upturned snout, known for playing dead. There are 3 distantly related genera of hognose snake: in the United States and northern Mexico (Heterodon), South America (Lystrophis), and Madagascar (Leioheterodon).

Holocene (11,700 years ago–1940): the interglacial epoch during icehouse before Earth headed into hothouse from manmade pollution. The current hothouse epoch has yet to be recognized. The Pleistocene preceded the Holocene.

homeostasis (biology): a regulatory process by which an organism strives for holistic health. Compare autopoiesis.

holometabolous: a type of metamorphosis with 4 stages: egg, larva, pupa, adult. Compare ametabolous, hemimetabolous.

homeostasis (biology): a regulatory process by which an organism strives for holistic health. Compare autopoiesis.

homeostasis (physics): a tendency toward stability within a system.

hominid: an ape descendant, some of which became hominin. Compare anthropoid.

hominin: the hypothesized clade that descended into humans.

homogeneous: the same at all locations. Compare isotropic.

homoplasy: the seemingly same trait in organisms of different species, but the trait did not evolve from a common ancestor; instead, developed via parallel or convergent evolution.

homosexuality: proclivity for sexual activity with another of the same sex.

homothallism: a species where a single organism can sexually reproduce, as it has female and male reproductive structures on the same thallus. The term is commonly applied to fungi. Contrast heterothallism.

honesty: giving a candid impression. Contrast deception.

honey: a viscid sugar made by bees from nectar.

honey badger (aka ratel, Mellivora capensis): a weasel-looking mustelid native to Africa, southwest Asia, and the Indian subcontinent.

honey crop (aka honey stomach, honey sack): a specialized organ in the foregut of honeybees used to store and transport liquid food.

honey fungus (aka openky): a parasitic macroscopic fungus of woody plants in the genus Armillaria.

honeybee: a bee in 7 of 20,000 species of bees, in a subset of the genus Apis; best known for making honey via foraged pollen collection.

honeydew (secretion): a sticky, sugary liquid secreted by aphids and some scale insects.

honeyguide (aka honey bird): a near passerine brood parasite.

honeypot: an ant species where select workers are gorged with food by other workers. These engorged ants are then used as a larder by their sisters. A honeypot is solicited by stroking its antennae, whereupon it regurgitates some stored liquid. While many insects cache food, honeypot ants are unique in using their own bodies as a food store.

Honshū: the largest and most populous island of Japan.

hooded seal (Cystophora cristata): a large seal endemic to the central and western North Atlantic Ocean.

hookworm: a parasitic nematode that lives in the small intestine of its mammalian host.

horizon (pedology): a soil layer.

horizontal gene transfer (HGT): sharing of genetic material between organisms. Contrast vertical gene exchange.

hormone: an organic compound intended for long-distance intercellular communication; from the Greek word for impetus.

Horn of Africa: a peninsula in easternmost central Africa which juts into the Guardafui Channel, the oceanic strait which connects the Gulf of Aden to the north with the Indian Ocean to the south. The tip of the Horn of Africa is Cape Guardafui.

hornbill: a tropical or subtropical bird in the Bucerotidae family, found in Africa, Asia, and Melanesia. Hornbills have a large, long, downward curving bill, sometimes with a casque (protrusion) on the upper mandible.

horned frog: a frog with a flap/horn of skin above each eye.

hornwort: a group of bryophytes that evolved during the Devonian, now of 100–150 species, found worldwide in moist soils.

horse (Equus ferus caballus): an odd-toed ungulate. Men began to domesticate horses ~4,000 BCE. See equid.

Horse Latitudes (aka Subtropical High): subtropical latitudes between 30°–35° north and south, characterized by a ridge of high pressure.

horsetail (aka snake grass, puzzlegrass, Equisetum): a vascular plant that produces spores.

host (biology): a cell, virus, or organism in/on/to which another organism has an interest or relationship.

host cell: a cell hosting an endosymbiont. Eukaryotes arose from an archaean hosting bacterial endosymbionts.

host range: the cell type(s) that a pathogen infects.

hothouse (aka greenhouse): a duration lasting millions of years where Earth is hot and typically humid, completely lacking continental glaciers. Contrast icehouse.

hotspot: a volcanic region fed by hot mantle plumes.

house mouse (Mus musculus): a mouse that mainly lives in association with humans.

housefly (Musca domestica): a fly that is one of the most widely distributed insects, found all over the world. Adult houseflies are 5–8 mm long. Houseflies live up to their name: most flies found in human domiciles are houseflies. The ones not in the house want in. The housefly evolved 50 MYA on the steppes of central Asia and spread worldwide as a human commensal.

howler monkey: a large New World monkey of 15 species in the Alouatta genus, known for its loud howl, which can carry 5 km through dense forest.

human: a bipedal, largely furless primate in the Homo genus. Humans are ironically unintelligent in thinking that they are smarter than other organisms while having proved the opposite with their self-destructive and environmentally devastating behaviors.

Humboldt Current (aka Peru Current): a cold, low-salinity deep-water ocean current flowing northwestward along the west coast of South America, from the southern tip of Chile to northern Peru. The current ends its flow going east near the equator, extending to 1,000 km offshore (the Galápagos Islands). The Humboldt Current provides for the most productive marine ecosystem in the world, as well as being the largest upwelling current. It also cools the lands that it runs by: Chile, Peru, and Ecuador. Through fog and clouds are produced, marine air cooled by the Humboldt Current is not conducive to generating rain, which so accounts for the aridity in the coastal areas where it flows.

Humboldt squid (aka jumbo squid, pota, diablo rojo, Dosidicus gigas): a large, bioluminescent predatory squid living in the depths of the Humboldt Current in the eastern Pacific Ocean.

hummingbird: a bird in the Trochilidae family. Hummingbirds are among the smallest of birds, including the smallest: the 5 cm Bee Hummingbird.

humus: the organic portion of soil, formed from partial decomposition of plant and animal matter.

hybrid: an organism that is a combination of 2 species.

hydra: a small, freshwater invertebrate in the genus Hydra, of ~25 species. The hydra body is a thin, usually translucent tube up to 2 centimeters long, but capable of great contraction.

hydrocarbon: an organic compound entirely comprising hydrogen and carbon. Methane (CH4) is an exemplary hydrocarbon.

hydrogen (H): the element with atomic number 1, constituting in its simplest form a single proton and solitary electron (protium, 1H); the lightest element, and the most abundant chemical in the universe, comprising 75% of cosmic baryonic mass. Hydrogen plays an especial role in acid-base chemistry and is a proton donor in many reactions between soluble molecules.

hydrogen sulfide (H2S): a colorless gas with the foul odor of rotten eggs. H2S is poisonous, corrosive, and flammable.

hydrological cycle (aka water cycle): the cycling of water in the biosphere.

hydrolysis: the cleavage of chemical bonds by adding water.

hydrophilic: having a high affinity for water. Contrast hydrophobic.

hydrophobic: having a low affinity for water. Contrast hydrophilic.

hydrophyte: a plant adapted to living in waterlogged soil or in water.

hydrosphere: the bioelement of water, including the participants in the water cycle.

hydrostatic pressure: positive pressure exerted by a fluid at equilibrium due to the force of gravity.

hydrothermal vent: a fissure, usually on the seabed at a volcanically active location, from which geothermally heated water issues.

hydrozoan (plural: hydrozoa): a diverse group of tiny, predatory, mostly marine animals, found worldwide. Different hydrozoa live solitary or colonial lives.

hyena: a dog-like carnivorous mammal in the Hyaenidae family, endemic to Africa.

hylomorphism: the belief that all things are a combination of matter and form. The form of life is in the soul. Aristotle concocted hylomorphism.

Hymenoptera: one of the largest orders of insects, including ants, bees, wasps, and sawflies; derived from the Greek word for wing. Hymenoptera range in size from tiny to quite large. They have large compound eyes. Their mouths are adapted for chewing. Hymenoptera typically have 2 pairs of wings. The sex of almost all hymenopterans is decided by the number of chromosomes an individual has. Fertilized eggs get 2 sets of chromosomes (from mother and father), developing into diploid females. Unfertilized eggs, with only the mother’s chromosomes, develop into haploid males. Fertilization is volitionally controlled by the egg-laying female. This is known as haplodiploidy.

hyperpallium (aka hyperstriatum): the portion of an avian brain analogous to the mammalian cerebral cortex.

hyperphagia: intensive feeding; one way migratory animals prepare themselves for their journey.

hyperplasia: growth in a tissue or organ by cell proliferation. Contrast hypertrophy.

hyperthermophile: an organism that can survive at 80 °C or greater.

hypertrophy: growth in a tissue or organ by cell enlargement. Contrast hyperplasia.

hypha (plural: hyphae): a threadlike fungal filament.

hypothalamus: the part of the brain that links the nervous and endocrine systems. The hypothalamus regulates autonomic functions.

hypothesis: a guess gussied up in scientific garb. Under the scientific method, hypotheses are ripe for falsifiability testing. Compare theory.

hypoxia: a deficiency of oxygen reaching body tissues. Compare anoxia.

hyrax (aka dassie): a small, thickset, herbivorous mammal, endemic to sub-Saharan Africa and the Middle East. Adults weigh 2–5 kg and are 30–70 cm long. Hyraxes retain a number of early mammalian characteristics. They are barely endothermic: needing to huddle together for warmth, or bask in the Sun. Like rodents, hyrax teeth constantly grow, but they do not use their front incisors for biting. Instead, they use their side molars. Although not ruminants, their digestive tract is like those of ungulates, as hyraxes have complex, multi-chambered stomachs which allow symbiotic bacteria to break down fibrous plant matter. Though they bear no resemblance, the hyrax is a close relative to the elephant.


icefish (aka notothenioid): a fish which lives mainly in the Southern Ocean. While most animals have 45% hemoglobin in their blood, crocodile icefish (aka white-blooded fish) have only 1%. Icefish flourish because of the high oxygen content of the cold Southern Ocean waters, and partly because oxygen is absorbed and distributed directly by their blood plasma. Oxygen solubility greatly increases when cold. The cost is that crocodile icefish expend twice as much energy in cardiac output as other icefish with higher hemoglobin concentration.

icehouse (aka ice age): a span of millions of years where the world has continental ice sheets, tending toward cool and arid climate. Contrast hothouse.

ichthyology: the study of fishes.

idea: the representation of a concept.

Idotea: a genus of isopod crustaceans which mostly inhabit cold temperate waters.

igneous (rock): rock formed by cooling and solidification of magma or lava. Compare sedimentary and metamorphic. See basement.

ignorance: a state of unknowing. There are 2 types of ignorance: fact-ignorance (fignorance) and perspective-ignorance (pignorance). Fignorance is not knowing the salient facts of a subject. Pignorance arises from incognizance of reality.

iguana: an herbivorous tropical lizard.

immune system: a biological system that protects against disease, especially infection. For macrobes, an immune system acts as a microbiome management system.

inclusive fitness: the hypothesis of an evolutionary strategy whereby conspecifics altruistically help one another. See kin selection.

Indian pipe (aka ghost plant, corpse plant, Monotropa uniflora): a mycoheterotrophic plant native to the temperate regions of North America and eastern Asia. The Indian pipe is white, as it lacks chlorophyll.

Indian snakeroot (aka devil pepper, serpentine wood, Rauvolfia serpentine): a flowering plant in the milkweed family, native to the Indian subcontinent and East Asia to Indonesia.

indigenous: naturally occurring in an environment or biome. Compare native, endemic.

indigobird: a brood parasitic finch native to sub-Saharan Africa.

indole (C8H7N): an aromatic biocompound produced by bacteria as a degradation product of the amino acid tryptophan (C11H12N2O2).

inference: the process of deriving a conclusion from premises known or assumed true.

inflorescence: a cluster of flowers on a stem.

inflorescence meristem: meristematic cells that produce floral meristem, from which flower parts develop: sepals, petals, stamens, and carpels.

infrared (IR): electromagnetic radiation between 1 and 400 THz (terahertz). Most thermal radiation at room temperature is infrared. Infrared is emitted or absorbed by molecules when they change their rotational or vibrational mode.

infrasound: sound at a frequency lower than can be heard by human ears.

inhibitor (chemistry): an enzyme that decreases reaction rate. Contrast activator.

innate immune system: the non-learning portion of the immune system. Compare adaptive immune system.

inquiline: an animal that lives commensally in the dwelling of another species. The most diverse types of inquiline are found in the nests of social insects, especially ants and termites, where a single colony may support dozens of different inquilines. Inquiline is a somewhat slippery term. Parasites are by definition deleterious to their hosts. In contrast, inquilines gain from their host association, by taking advantage of host services and facilities, but do not necessarily bring their hosts down.

insect: an arthropod with a tripartite body (head, thorax, and abdomen), a chitinous exoskeleton, 3 pairs of jointed legs, a pair of compound eyes, and a pair of antennae. Insects are among the most diverse groups of animals, with over a million known species.

insectivore: an insect eater.

instinct: precocious knowledge.

integrase (retroviral integrase): an enzyme made by a retrovirus that enables its genetic material to be incorporated into the DNA of an infected cell.

intelligence: an attribution for behaving appropriately; the process of gathering and analyzing information.

intent: volition; willfulness.

interconnection: mutual connection.

interdependence: a system where one feature dynamic may affect another.

interglacial: a period of warmer climate within an ice age (icehouse). Compare glacial period.

internode (botany): growth between an established plant and its nascent offspring during vegetative reproduction.

interphase: the period of the cell cycle during which a cell lives its everyday existence. Interphase is 90% of a cell’s life cycle. See anaphase, telophase.

interspecies: between species. Contrast conspecific.

interspecific: occurring between distinct species. Contrast conspecific.

intron: a polynucleotide sequence in a nucleic acid that does not code for protein synthesis. Introns are removed before translation of messenger RNA. Compare exon.

introspection (aka metacognition): awareness of cognition; (the capability of) reflectively examining one’s own thoughts, feelings, and emotions.

invasive species: a non-native species introduced into a new ecosystem.

invertase: an enzyme that catalyzes the hydrolysis (breakdown) of sucrose (C12H22O11) into fructose and glucose (both C6H12O6). Bees biosynthesize invertase, as do yeast.

invertebrate: an animal that is not a vertebrate. Arthropods are the best-known invertebrates.

iridescence (aka goniochromism): a change of color appearance in a material based upon angle of view or illumination. Iridescence is often created via structural coloration (microstructures which create light interference patterns).

iridoid: a defensive secondary metabolite produced by plants, typically as a glycoside.

iron (Fe): the element with atomic number 26; a metal. Iron is the most common element (by mass) in Earth, forming much of its core.

isopod: a crustacean with a rigid, segmented exoskeleton, including woodlice and sea slaters. Isopods lack a carapace (dorsal (upper) section shell) and have a special pouch for brooding eggs (which characterizes peracarid crustaceans).

isotocin (C41H63N11O12S2): a peptide hormone which regulates sociability in fish; functionally like oxytocin in humans.


jackdaw (Corvus monedula): a corvid with a range from the British Isles to central Asia.

jackal: a small to medium-sized opportunistic omnivorous relative of the wolf, native to Africa and south-central Eurasia. There are 3 jackal species (genus: Canis).

Japan: an island nation off the eastern coast of China, comprising 6,852 islands.

Japanese archipelago: the 6,852 islands that comprise the country of Japan.

Japanese macaque (Macaca fuscata): a terrestrial monkey native to Japan.

Japanese Oakblue (Arhopala japonica): a butterfly in the Lycaenidae family, indigenous to east Asia.

Japanese rice fish (aka medaka, Oryzias latipes): a small, hardy, amphidromous fish native to Southeast Asia; a common denizen of rice paddies in coastal Asia.

Japetella: a genus of small (4 cm), pelagic octopi with 1 or 2 species (a classification controversy).

jasmonate: a plant hormone employed for defense, growth, and reproductive development.

jasmonic acid (C12H18O3): a plant hormone, employed in regulating growth and stress response.

jay: a bold, raucous, medium-sized corvid of ~40 species.

jellyfish (aka sea jelly): a free-swimming marine animal with a gelatinous bell shaped like an umbrella, trailing tentacles. Jellyfish are the oldest multiple-organ animal, having been around for at least 700 million years. ~2,000 jellyfish species are extant.

jerboa: a hopping desert rodent found from northern Africa to east Asia.

jet stream: an atmospheric river. Earth’s polar jet is at roughly 50º–60º latitude, and the subtropical jet is at around 30º.

jeweled beetle: a beetle with a glossy, iridescent elytra, in the Buprestidae family, with ~15,500 species in 775 known genera.

jewelweed (aka impatiens, touch-me-not, snapweed): a flowering plant in the Impatiens genus, with ~1,000 species, including both annual and perennial species.

joule: the energy equivalent of passing a 1-amp current through 1-ohm resistance for 1 second. Named after James Prescott Joule, who studied energetic relationships.

juglone (C10H6O3): an allelopathic secondary metabolite that is toxic or growth-stunting to many types of plants. The black walnut tree produces juglone.

jujube (aka red date, Ziziphus jujuba): a fruit-bearing Asian tree or shrub. The fruits and seeds are a Chinese and Korean traditional medicine.

jumping plant louse (aka psyllid): a small plant-feeding louse in the family Psyllidae. Each louse species feeds on only 1 plant species (monophagous).

jumping spider: an agile spider in the Portia genus, with the best vision of all invertebrates. Jumping spiders have 4 pairs of eyes, with particularly large anterior median (central) eyes. Jumping spiders normally move slowly and quietly, but are capable of incredibly athletic jumps, either to snag prey or to avoid a threat. There are 5,000 distinct jumping spiders, making up 13% of all spider species – the most specious spider.

junco: a sparrow found in North American forests.

jungle-runner (Ameiva corax): a whiptail lizard. The lizard is endemic to the tiny islet of Little Scrub off the east coast of Anguilla.

juxtacrine signaling: intercellular communication by direct contact. Compare paracrine signaling and endocrine signaling.


kalaw (Hydnocarpus wightiana): a semi-deciduous tree in the Achariaceae family that grows to 10 meters. Kalaw is native to the Indian subcontinent and southeast Asia. The oil from its seeds is chaulmoogra.

kakapo (aka night parrot, owl parrot, Strigops habroptilus): a large, ground-dwelling, flightless, nocturnal parrot endemic to New Zealand.

kangaroo: a bipedal Australian marsupial in the macropod family, noted for hopping on their powerful hind legs.

kangaroo mouse: a bipedal jumping mouse native to southwestern United States deserts.

karyotype: the number and arrangement of chromosomes in the nucleus of a eukaryotic cell.

katydid (aka bush-cricket): a nocturnal insect in the Tettigoniidae family, related to crickets and grasshoppers, noted for its loud mating calls.

kelp: a large seaweed (brown algae), of which there are ~30 genera.

Kelvin-Helmholtz instability: a turbulent velocity shear in a continuous fluid.

keratin: a family of fibrous structural proteins, found in animal nails, claws, hooves, and other sturdy parts, including scales, skin, feathers, and hair. The only other biochemical substance with such toughness is chitin. See lignin.

Kerguelen Plateau: a submerged continent in the southern Indian Ocean.

Keystone Cops: incompetent fictional policemen featured in an American comedic silent-film series between 1912 and 1917.

keystone species: species in a biome that act as a provider or facilitator for other species, even indirectly.

kin selection: the theory that organisms altruistically help their relatives.

kinesin: a motor protein found in eukaryotic cells.

kinetic energy: energy associated with motion.

king cobra (Ophiophagus hannah): the longest venomous snake (up to 5.7 m, averaging 3.5 m), which chiefly preys on other snakes. Endemic to forests from India through Southeast Asia. Not a true cobra.

kingdom (biological classification): the taxon above phylum and below domain. There are 4 eukaryotic kingdoms: protists, plants, fungi, and animals.

kingsnake: a nonvenomous snake in the genus Lampropeltis, native to the Americas.

kinkajou (aka honey bear, Potos flavus): a reclusive, frugivorous, arboreal mammal native to Central and South America.

kleptoparasitism (aka cleptoparasitism): habitual food theft. The term is also used for robbery, such as nesting materials.

Klosneuvirus: a giant virus able to stitch together proteins, as it can synthesize all 20 of the requisite amino acids; so-called from being found in a waste-water treatment tank in Klosterneuburg, Austria. Klosneuvirus preys on protists.

knapweed: an herbaceous thistle-like angiosperm in the Centaurea genus, with 350–600 species in the Asteraceae family.

kneeling angelica (Angelica genuflexa): a taprooted perennial herb that grows in moist areas of coniferous forests, such as stream banks; native to northwestern North America, from northern California to Alaska.

knowledge: cognition of facts or principles about Nature.

kudzu (aka Japanese arrowroot): a rapid-growing, edible, perennial vine in the pea family.

kudzu bug (aka kudzu beetle, stink bug, lablab bug, shield bug, Megacopta cribraria): a roundish beetle native to India and China. For defense, the kudzu bug sprays a foul liquid.

kukri snake: an egg-eating colubrid snake in the Oligodon genus, endemic to central and tropical Asia.

Kwongan: an arid biome in southwestern Australia.


La Niña: the opposite Pacific Ocean dynamic to El Niño.

labellum: a special petal at the bottom of an orchid flower which attracts pollinating insects and acts as a landing platform.

Laccaria bicolor: an ectomycorrhizal fungus that appears a small tan mushroom with lilac gills.

Lactobacillus: a genus of rod-shaped, non-spore-forming bacteria which is either anaerobic or microaerophilic. Lactobacillus can convert lactose and other sugars to lactic acid.

laetrile: a modified form of amygdalin, promoted since the early 1950s as a cancer cure.

lamella (surface anatomy) (plural: lamellae): a thin, plate-like structure. Fish gills and gecko feet use lamellae to achieve their respective functionality.

language: a system of symbols with interrelated meanings.

langur: a general name given to several Asian monkey species.

lanternfish (aka myctophid): a small, mesopelagic (twilight zone) fish in the Myctophidae family, with 33 genera and 246 species. All but 1 species of lanternfish are bioluminescent.

lark: a passerine in the Alaudidae family, with 21 genera; extant in the Old World, and in eastern and northern Australia. The horned lark is found in North America. Many larks live in dry biomes.

lark bunting (Calamospiza melanocorys): a medium-sized sparrow native to central and western North America.

larva (biology) (plural: larvae, larvas): the immature, wingless, and often wormlike (vermiform) feeding stage of a holometabolous insect hatched from an egg. The next development stage is as a pupa. Compare nymph.

Last Glacial Maximum (26.5–19.5 TYA): the last period of peak glaciation on Earth.

late blight: a potato blight caused by Phytophthora infestans. In small contrast, early blight is caused by Alternaria solani, another fungus. The term early is a misnomer, as it usually occurs on older potato plant leaves.

lateral line: a sense organ system in aquatic vertebrate, chiefly fish, used to detect movement via vibration.

lateral meristem: a meristem which grows a plant larger in diameter.

leaching layer: the uppermost soil horizon, where organic debris breaks down and is washed downward into the middle soil layer by rainwater.

leaf: a vascular plant organelle, typically employed in photosynthesis. Leaves evolved to suit plants specific needs, optimized to constraints imposed by physics at the quantum level. See foliage.

leaf beetle: a beetle in the Chrysomelidae family, with over 50,000 species; one of the most commonly encountered beetles.

leaf monkey: an arboreal Asian monkey with a slender body and long tail.

leafcutter ant: a tropical leaf-chewing, fungus-farming ant. There are 47 non-generic species that go by the leafcutter name.

leafhopper (aka hopper): a small (up to 1.5 cm), slender, winged insect of 20,000+ species in the Cicadellidae family, named for their hopping ability. Leafhoppers suck plant sap for food.

learning: the process of constructing a conceptual framework.

least weasel (Mustela nivalis): the smallest weasel, but a fierce hunter, able to bring down a rabbit 5–10 times its weight. Least weasels are native to Eurasia, North Africa, and North America.

Legionnaires’ disease: an atypical pneumonia caused by the freshwater Legionella bacterium.

legume: an herbaceous perennial plant or its fruit or seed. Well-known edible legumes include alfalfa, beans, carob, lentils, peanuts, peas, and soybeans.

lek: a gathering of animal males for competitive courtship display.

lemur: a clade of prosimian, named after the lemures (ghostly spirits) of Roman mythology, owing to lemurs’ ghostly vocals, reflective eyes, and often nocturnal lifestyle. Lemurs are endemic to Madagascar, having arrived by rafting 62–65 MYA. Some lemurs were as large as male gorillas until after humans arrived on the island 2,000 years ago. The invasive humans wiped the large lemurs out.

lengyre (aka vital energy, chi (Chinese), prana (Hindu)): an organism’s life-force energy system.

lenticel: porous tissue that allows gas exchange between internal plant tissues and the atmosphere.

Lepiotaceae (fungus): a family of fungi that have a mutualism with leafcutter ants.

leprosy: a bacterial infection with progressive symptoms that can permanently damage the skin, limbs, eyes, and nerves.

Leptopilina heterotoma: a parasitic wasp that infects fruit flies.

Levant: the geographical region encompassing modern-day Jordan, Israel, Lebanon, and Syria. The term Levant first appeared in English in 1497; originally meaning “the East.” The Levant has been characterized as the “crossroads of western Asia, the eastern Mediterranean and northeast Africa.”

liana: a woody vine, rooted in the soil, that climbs trees to the canopy.

Liberibacter: a bacterium that infects citrus trees.

lichen: a composite organism comprising a fungus (mycobiont) and a photosynthetic (photobiont) cyanobacterium or algae.

life: anything capable of perceiving its environment.

life-history variable: a trait or aspect of an organism’s existence related to others; often viewed comparatively, as a trade-off with other, mutually exclusive possibilities.

life zone: according to a biome classification scheme by Leslie Holdridge, a region with similar soil type and climax vegetation (dominant plants).

ligand (biochemistry): a molecule that emits a signal by binding to a site on a target protein.

lignin: an amorphous polymer related to cellulose, employed as a cellular scaffold. Lignin is an integral part of the cell walls of plants and some algae. See chitin, keratin.

light: electromagnetic radiation visible to the human eye, at a wavelength between 380–740 nanometers.

lilac: a flowering woody plant in the Syringa genus of the olive family, with 20–25 species, endemic to temperate Eurasia.

lily: an herbaceous angiosperm which grows from bulbs. There are at least 111 species in the Lilium genus. All have large prominent flowers. Numerous plants with the lily name are not true lilies.

lima bean (aka butter bean): a legume.

limestone: a sedimentary rock, largely comprising calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO3). Many limestones are the compressed remnants of marine organisms, such as coral and foraminifera.

lion: a large cat in the Panthera genus. Lions were endemic to Africa and Eurasia until hunted by humans to extinction in all but Africa, where they are increasingly endangered by the same dynamic.

lionfish: a venomous marine fish in the Pterois genus.

lipid: a broad group of relatively complex nonpolar carbon-based compounds, used for energy storage and a wide variety of biological functions.

lipogenesis: conversion of carbohydrates into triglycerides.

lipopolysaccharide (aka lipoglycan): a lipid and a polysaccharide joined by a covalent bond.

liquid: a fluid that flows freely. Water is a liquid.

lithotroph: an organism that consumes inorganic minerals.

lithosphere: the outermost shell of a rocky planet. Earth’s lithosphere comprises its crust and upper mantle: the portions that behave elastically over geological expanses of time.

liverwort (aka Marchantiophyta): a non-vascular embryophyte.

lizard: a scaled reptile of over 5,600 extant species in all continents except Antarctica, including most oceanic islands.

lobe-finned fish (Sarcopterygii): a clade of bony fish with fleshy, lobed, fin pairs, joined to the body by a single bone. Each fin is on a scaly stalk extending from the body. Contrast ray-finned fish.

lobster: a large marine crustacean with 5 pairs of legs, a long body and muscular tail. Lobsters are found in all oceans, residing in burrows or crevices on the sea floor. Lobsters may live 40–60 years, possibly more.

locality (physics): the idea that an object can only be influenced by its immediate surroundings. See entanglement. Contrast nonlocality.

long call: a loud, long call of orangutans that may carry for a kilometer, used for mating and other purposes.

long con: a grift that takes time to come to fruition.

loon (aka diver (in the UK & Ireland)): a group of aquatic carnivorous bird endemic to North America and northern Eurasia.

loris: a slow-moving, nocturnal, tailless, arboreal strepsirrhine, endemic to India, Sri Lanka, and parts of Southeast Asia.

lotus (sacred) (aka Indian lotus, Nelumbo nucifera): a flowering perennial aquatic plant, of which there are 2 species. The lotus is often wrongly considered a water lily. The lotus has been a symbol of divinity in Asian culture since antiquity, representing purity and enlightenment.

lotus effect: water-based self-cleaning of a waxed leaf owing to hydrophobic nanoscale structures in the wax on the leaf.

lovebird: a small parrot with a big heart; 9 species, endemic to Africa and Madagascar.

LSD (lysergic acid diethylamide): a semisynthetic mammalian hallucinogen.

luciferin: a bioluminescent compound.

lupin (aka lupine): a legume in the Lupinus genus, found in the Americas, North Africa, and the Mediterranean.

Lusitanian toadfish (Halobatrachus didactylus): a toadfish resident along the Atlantic and Mediterranean coasts of western Europe and western Africa. The Lusitanian toadfish has venomous spines.

lutung (aka langur, leaf monkey, Trachypithecus): an Asian monkey with a slim build and long tail.

lymphocyte: a type of white blood.

lysigeny (botany): the process of selectively eliminating cells to produce spaces for gas pathways; employed by plants to cope with waterlogging.

lysis: viral reproductive release by cell wall rupture: killing the host cell in a violent outburst that releases a multitude of offspring. Contrast lysogeny.

lysogeny: viral reproduction by exuding offspring through a host cell membrane. Contrast lysis.

lysosome: the organelle in animal cells responsible for autophagy.


macaque: an Old World monkey of 22 species.

macaw: a long-tailed New World parrot of 18 species, often colorful.

macerate: to soften by wetting or chewing.

macrobe: non-microbial life; any life form not requiring a microscope to be seen. Contrast microbe.

macrofungi: macroscopic fungi.

Macronema transversum: a caddis fly with aquatic larvae that create elaborate protective cases.

macrophage (derived from the Greek for “large eater”): a type of phagocyte employed in vertebrate immune system defense.

macropod: a marsupial in the Macropodidae family, native to Australia, New Guinea, and nearby islands. Macropods include kangaroos, wallabies, and several others. Macropods have large, strong hind legs and powerfully muscled tails.

macroscopic: visible to the human eye. Contrast microscopic.

Madagascar: a large island in the Indian Ocean off the coast of east Africa.

mafic: silicate mineral rich in in magnesium and iron. Basalt is a mafic rock. Mafic is a portmanteau of “magnesium” and “ferric” (referring to iron). Mafic rocks are 45–55% silica. Contrast felsic.

magma: molten rock made underground. Igneous rocks come from cooled magma.

magnesium (Mg): the element with atomic number 12; an alkaline earth metal; the 8th most abundant element in Earth’s crust.

magnetoreception: sensory reception of the Earth’s magnetic fields by biochemical means.

magnetosphere: the area of astrological space where charged particles are controlled by a heavenly body’s magnetic field. The Earth’s magnetosphere is an outer layer of the ionosphere. Distinguished by its ionization, Earth’s ionosphere is 85–600 km altitude.

Magnetospirillum: a genus of bacteria sensitive to magnetic fields. Magnetospirilla live in sediments and shallow fresh water.

magpie: a long-tailed corvid in the genus Pica.

major histocompatibility complex (MHC) (genetics): a group of vertebrate genes that code for cell-surface glycoproteins (MHC molecules) which are part of the immune system.

major histocompatibility complex molecule (molecular biology) (MHC molecule): a cell surface glycoprotein that consciously identifies a cell as native or not (biologically compatible or foreign).

malaria: a mosquito-borne infectious animal disease caused by Plasmodium falciparum, a parasitic protozoan.

mallow: an herbaceous plant in the Malva genus, with 25–30 species, widespread through Africa, Europe, and Asia, in tropical to temperate biomes.

mamavirus: a variant strain of the mimivirus.

mamba (Dendroaspis): a legendary, venomous, diurnal, African snake. Most mamba are arboreal, but the black mamba is terrestrial.

mammal: a class of air-breathing vertebrate animals, characterized by endothermy, hair, and females with functional mammary glands.

manakin: a 60-species clade of small passerines in the American tropics.

manatee: a large marine mammal in the same order (Sirenia) as dugongs.

mandible: jawbone (the lower jaw in mammals).

mandrake: a plant in the genus Mandragora that produces powerful alkaloids which affect the nervous system, such as atropine and scopolamine.

mandrill (Mandrillus sphinx): an Old World monkey endemic to the western coastal region of equatorial Africa; closely related to the baboon.

mangabey: an Old World monkey of 3 genera. The name arose when mangabeys were mistakenly thought to be in a single genus. Whereas white-eyed mangabeys (Cercocebus) are closely related to mandrills, crested mangabeys (Lophocebus) are close kin to baboons. The highland mangabey (aka kipunji) is recently discovered – a single species in the genus Rungwecebus.

mangrove: a salt-tolerant (halophyte) tree that grows in coastal biomes in the tropics and subtropics.

mangrove snapper (Lutjanus griseus; aka gray snapper): a snapper species native to the western Atlantic Ocean.

mantis shrimp (aka stomatopod): a worldwide marine crustacean of around 400 species, typically solitary and aggressive. Mantis shrimp sport powerful claws which can spear, stun, or dismember prey. The ancient Assyrians called mantis shrimp “sea locusts.”

mantle: the layer of Earth above the core and below the crust.

mantle plume: the rising of hot rock from the core-mantle boundary through the mantle to become a diapir (intrusion) in the Earth’s crust.

margay (Leopardus wiedii): a spotted, nocturnal, arboreal cat, native to the Americas. Margays look much like ocelots.

marine iguana (aka sea iguana, saltwater iguana, Amblyrhynchus cristatus): an iguana endemic to the Galápagos Islands with the unique ability to forage in the sea, feeding almost exclusively on algae residing on rocks.

marine snow: see dissolved organic matter.

mariposa lily (Calochortus apiculatus): a lily with open wedge-shaped petals; endemic to California.

marmoset (aka zari): a small New World monkey of 22 species in 4 genera.

marmot: a large, herbivorous squirrel found in mountainous regions in the northern hemisphere, of 15 species in the Marmota genus. Marmots typically live in burrows and hibernate there through the winter.

marsh: a wetland that is dominated by herbaceous rather than woody plants.

marsupial: a clade of mammals characterized by giving birth to relatively undeveloped live young. An infant marsupial (joey) develops within its mother’s pouch.

masked hunter (Reduvius personatus): an assassin bug that lures its victims by attaching debris to itself and making itself a curiosity. Bed bugs are a favorite, though humans are tasty too. Its bite is painful.

mason bee: a bee so named for its practice of using mud or other masonry materials to build its nest.

mass extinction: the indiscriminate extinction of many species during extinction events. Contrast background extinction.

mast seeding: a stratagem of some trees to greatly vary seed production from year to year, to stress animal seed eaters and improve plant survival prospects.

mastodon (26.8 MYA–11 TYA): an elephant-like animal hunted to extinction by humans.

mason bee: a bee so named for its practice of using mud or other masonry materials to build its nest.

materialism (psychology, economics): a worldview valuing material consumption and possessions.

matric potential: the adhesive intermolecular forces that water has for solid particles; in other words, water’s cling to things.

matriline: a female-dominated social group. Matrilines are formed by females staying with their natal group. Males typically emigrate to another group upon reaching sexual maturity. Most Old World monkeys are matriline.

matter (physics): something with mass, constructed of fermions. See energy.

matterism (aka (philosophical) materialism): the monistic belief that reality is made of matter. Matterism ignores that matter of made of energy and supposes that the mind is a figment of something substantial. Contrast energyism.

mavirus: a virophage that relies upon and fouls the works of CroV, a giant marine virus. The name mavirus is a contraction of “maverick virus.”

measles: a highly contagious viral disease, as it may infect through the air, with symptoms developing 7–10 days after infection.

meat ant (aka gravel ant, Iridomyrmex purpureus): an ant native to Australia.

Mediterranean Sea: the sea connected to the Atlantic Ocean and enclosed by the Mediterranean region of southern Europe and western Anatolia, north Africa, and the Levant.

meerkat (aka suricate, Suricata suricatta): a gregarious mongoose with a decided social hierarchy, endemic to south Africa.

megabat (aka fruit bat, Old World fruit bat): a herbivorous bat in the suborder Megachiroptera, native to tropical and subtropical Eurasia, Africa, and Oceania. Fruit bats are relatively large and do not navigate via echolocation, with some exceptions.

megapode (aka incubator bird): a stocky, chickenish bird with a small head and large feet, living in wooded habitats; endemic to Australasia. Megapodes are mainly solitary birds.

meiosis: the special cell division for sexual reproduction, producing germline gametes (sperm or eggs). Meiosis also refers to the cell division process for making spores.

melanin: a group of pigments found in most organisms.

melinjo (tree) (Gnetum gnemon): a tree native to Southeast Asia and western Pacific Ocean islands. Melinjo seeds, fruit, flowers, and leaves are used in Indonesian cuisine.

meliponine (aka stingless bee): a eusocial bee of ~500 species in the tribe Meliponini, closely related to honeybees, bumblebees, carpenter bees, and orchid bees.

melody: the tonal pattern of music. Compare rhythm.

melon (botany): the fleshy round fruit of plants (e.g., watermelon, muskmelon (including cantaloupes, and the smooth-skinned honeydew)).

melon (zoology): the round organ at the top front of a dolphin’s head, used for echolocation.

membrane (cytology): a lipid bilayer surrounding a cell, providing a barrier between the cell and the outside world.

meninges: the protective membranes that envelop the central nervous.

meningitis: acute inflammation of the meninges.

meningococcus (Neisseria meningitidis): the bacterium that causes meningitis.

menopause: the transitional period in vertebrates of reproductive senescence some time before natural death; typically occurring in women between 45–55 years of age.

mental time travel: remembering previous activity patterns and anticipating and planning for future events.

meristem: plant tissue where growth occurs. Meristematic plant cells are analogous to animal stem cells.

meroplankton: organisms that are planktonic for only part of their lives.

mesh: a crystal lattice.

mesoglea: a non-living jelly, sandwiched between 2 thin (single cell) layers of epithelium, which functions as a hydrostatic skeleton.

mesophile: an organism suited to moderate temperature: 20–45 ºC.

Mesopotamia: an area of the Tigris–Euphrates river system, widely considered the Western cradle of civilization during the Bronze Age. Indigenous Sumerians, Assyrians, and Babylonians were there at the onset of written history 3100 BCE.

mesosphere: the layer of Earth’s atmosphere below the thermosphere and above the stratosphere. The mesosphere is 53–85 km above Earth’s surface.

mesotherm: an animal with internal means to raise body temperature, but not with the precision of maintaining thermal homeostasis like endotherms. See ectotherm, endotherm.

mesotocin (C43H66N12O12S2): a peptide hormone which regulates sociability in birds; functionally like oxytocin in humans.

messenger RNA (mRNA): an RNA molecule with the physical blueprint for a protein product.

metabolic pathway: a series of chemical reactions within a cell, typically with an intended biological end-product.

metabolism: cellular chemical reactions which provide energy for vital processes. See anabolism, catabolism.

metabolite: a chemical product of metabolism.

metacognition: knowing what one knows. See introspection.

metacommunication: a communication qualifier; indirect cues as to how information is meant to be interpreted. Animals employ metacommunication to convey the intent of communications that follow a metacommunication. An adult male lion bows before a cub as an invitation to play; a gesture that has no other context.

metamerism: a plant or animal with a body comprising a linear series of segments, similarly in structure. Earthworms and centipedes are metameric.

metamorphic (rock): a rock arising from transformation via heat and pressure. The original rock (protolith) may be igneous, sedimentary, or a previous incarnate metamorphic. Compare igneous and sedimentary. See basement.

metamorphism (geology): the recrystallization of a rock owing to heat, pressure, or chemically active fluids.

metamorphosis: conspicuous and relatively abrupt changes in phenotype during the life cycle of an animal, usually accompanied by a change in habitat and/or behavior. Some insects, mollusks, amphibians, crustaceans, cnidarians, echinoderms, and tunicates undergo metamorphosis. The 3 types of metamorphosis are ametabolous, hemimetabolous, and holometabolous.

metapleural gland: an antibiotic secretory gland unique to ants, and basal in the evolution of ants. Ants groom the secretion onto their exoskeleton to prevent bacterial and fungal growth. Some ant species lack metapleural glands, especially arboreal ants, who suffer less exposure to parasites than terrestrial ants. Most male ants do not have metapleural glands, instead benefiting from shared secretions from female ant workers.

metastasis: movement of a disease-producing agent, such as cancer, to another bodily site.

metazoan (plural: metazoa, metazoans): a multicellular animal.

meteorite: a sizeable rock from space that managed to smack Earth’s surface without being vaporized on atmosphere entry. A meteorite might be a comet or asteroid.

methane (CH4): a flammable, explosive gas. Methane forms in mashes and swamps from decaying organic matter, and so is sometimes called marsh gas or swamp gas.

methanogen: anoxic archaea that produce methane as a metabolic byproduct.

methanotroph (aka methanophile): a prokaryote that consumes methane.

methodicalness: the tendency to habitually proceed systematically.

methyl jasmonate (C13H20O3): a volatile compound that plants employ for defense.

methyl salicylate (C8H8O3): an ester produced by plants for bacterial defense.

Mexican yam: a yam native to Mexico that grows an aboveground caudex dome.

MHC: see major histocompatibility complex.

Micaria: a genus of ground spider found throughout much of the world except Central and South America.

microaerophile: a microbe that requires only modest amounts of oxygen to survive.

microbe: a microorganism, too tiny to be seen without a microscope; typically, a single-celled prokaryote. Microbes include archaea, bacteria, and fungi. Contrast macrobe.

microbial loop: recovery of otherwise lost organic energy by bacteria.

microbiome: the endosymbiotic, microbial, ecological community that comprises every eukaryotic organism, especially multicellular eukaryotes. Commensal prokaryotic inhabitants are essential to eukaryotic life.

microbiota: the microbes in a microbiome.

micrometer (µm): 1-millionth of a meter.

microparasitism: parasitic behavior by a microbe.

microRNA (miRNA): a class of post-transcriptional regulators which bind to microRNA response elements, thereby decreasing the stability of protein-coding messenger RNAs (mRNA) or limiting their protein translation. The result is typically stifling or silencing gene expression.

microscopic: visible to humans only by using a microscope. Contrast macroscopic.

microsporidium (plural: microsporidia): a unicellular spore-forming intracellular fungal parasite in the phylum Microspora.

microtubule: a protein fiber found throughout the cytoplasm as a part of the cytoskeleton.

mid-ocean ridge: a marine mountain range formed by plate tectonics.

midge: a common term for a species-diverse group of tiny flies.

migration: purposeful travel over long distance by an animal.

Milankovitch cycle: a 1920 hypothesis by Milutin Milanković relating changes in sunlight, and thereby climate, to variations in Earth’s orbit about the Sun. Earth has an elliptical orbit, with eccentricities in that orbit, as well in its axial tilt and precession (rotational orientation). Milankovitch cycles are now used extensively to explain the timing of glacial-interglacial cycles in Earth’s evolution.

milk snake (Lampropeltis triangulum): a nonvenomous kingsnake found from southeastern Canada through much of the United States, down to northern South America.

milkweed: an herbaceous perennial dicot of over 140 known species in the Asclepias genus, native to North America. Milkweeds are among the most complex flowers, comparable to orchids.

millipede: a segmented wormy arthropod comprising over 20 segments with 2 pairs of jointed legs on most body segments, of 15,000–80,000 species, of which 12,000 have been described.

milt: the seminal fluid of fish, mollusks, and other water dwellers, who reproduce by spraying milt, which is loaded with sperm, onto roe (fish eggs).

mimesis: imitative behavior; typically, an animal defense.

mimicry (biology): trait imitation by a species.

mimivirus: a giant virus in the Mimivirus genus that infects amoebae.

mind: an intangible organ for symbolic processing.

minnow: a small freshwater fish in the carp family.

mint (aka deadnettle, Lamiaceae, Labiatae): a family of predominantly perennial flowering plants with 13–18 species, many of which have aromatic parts. Mint family plants include many widely used culinary herbs, such as basil, lavender, marjoram, mint, oregano, rosemary, sage, savory, and thyme.

Miocene (23–5.3 MYA): the 1st of 2 epochs in the Neogene period, divided into 6 ages with corresponding rock stages.

mirror test: the dumb idea by Gordon Gallup Jr. that some sense of animal self-awareness can be ascertained by gauging the reaction of an animal to a mirror (ostensibly seeing its own reflection).

mistletoe: an obligate parasitic plant, though with evergreen leaves that perform photosynthesis. The host provides water and mineral nutrients. There are 1,300 mistletoe species.

mistletoebird (Dicaeum hirundinaceum): a bird native to Australia that eats assorted berries and insects, though favors mistletoe berries.

mite: a tiny arthropod in the subclass Acari, along with ticks. With 48,200 described species, mites are among the most diverse and successful invertebrates, having adapted to a vast array of habitats: living free in water or soil, and as parasites on plants, animals, and even mold. Studying ticks and mites is acarology.

mitochondrion (plural: mitochondria): an organelle that acts as a cell’s power plant, generating a supply of ATP. Mitochondria play other important roles in the cell life cycle, including growth and aging. Mitochondria maintain their own genome, independent of the cell nucleus. Some eukaryotic cells have multiple mitochondria, others none. Whereas human red blood cells have no mitochondria, liver cells may have over 2,000.

mitosis: the eukaryotic cell division process.

mitotic recombination: a relatively rare genetic recombination that occurs in somatic cells during mitosis.

mixotroph: an organism, typically a microbe, that can use a mix of different sources of energy and carbon. This affords taking advantage of different environmental conditions.

moa: a large flightless bird endemic to New Zealand; the dominant herbivore there until hunted to extinction by men in the late 13th century. The 2 largest species reached 3.6 meters in height and weighed up to 230 kilograms.

moccasin (Agkistrodon piscivorus): a pit viper native to the southeastern United States.

mockingbird: a New World passerine known for their imitative songs, of 17 species in 3 genera.

Moho discontinuity: the boundary between the crust and mantle of the lithosphere; named after Andrija Mohorovičić.

moiety: a functional group that is part of a molecule.

mold (aka mould): a fungus that grows as multicellular filaments (hyphae). In contrast, fungi that grow as single cells are called yeast.

mole (zoology): a small subterranean mammal found in the northern hemisphere, with powerful forelimbs for digging.

molecular motor: biological molecular motion agents. A molecular motor converts energy into movement or mechanical work. Protein motors are common.

molecule: a combination of 2 or more atoms.

mollusk (aka mollusc): a phylum of invertebrates. Mollusks are highly diversified in marine environments, comprising 23% of identified macroscopic marine species. There are also freshwater and terrestrial mollusks, such as snails.

molting (aka sloughing, shedding, ecdysis): shedding a body part, such as the epidermis (skin), during development or at a certain time of year, as with antlers. Arachnids, amphibians, and squamates are among animals which molt to grow.

monarch butterfly (Danaus plexippus): a large migratory butterfly. Its larvae dine on milkweed.

Moneke: the son of Martin the Ape in the 16th century German fable Reynard the Fox. The term monkey derived from this, albeit as a misclassification of monkeys as apes. See monkey.

mongoose (plural: mongooses or mongeese): a small carnivore of 33 extant species, endemic to southern Eurasia and Africa.

monitor lizard: a large, venomous, carnivorous lizard in the Varanus genus, with ~79 species, native to Africa, Asia, and Oceania.

monkey: a primate, excluding apes.

monkey-flower (aka musk-flower): a flowering plant of 150 species in the genus Mimulus. Monkey-flower species diversity is greatest in western North America, with Australia another area of considerable diversity.

monitor lizard: a large, venomous, carnivorous lizard in the Varanus genus, with ~79 species, native to Africa, Asia, and Oceania.

monobasic acid: an acid with only 1 hydrogen ion to donate to a base in an acid-base reaction.

monochromacy: having a single type of vision receptor. Marine mammals, with only 1 color cone type, are monochromats, as are night monkeys.

monocot (monocotyledon): a plant with 1 embryonic leaf (cotyledon) in its seed. Compare dicot, eudicot.

monoculture: agricultural use of land for growing only 1 crop.

monogamy: a mating system comprising a male and female pair. Contrast polygamy.

monologue: prolonged 1-way communication by an organism. Contrast dialogue.

monomer: a molecule that may bind with other molecules to form a polymer.

monophagy: an animal with a diet limited to a single specific type of food. Contrast polyphagy.

monosaccharide (aka simple sugar): a simple carbohydrate with the formula (CH2O)n, where n = 3 (triose), 5 (pentose), or 6 (hexose). Glucose, fructose, and ribose are exemplary monosaccharides. See disaccharide.

monotreme: a mammal that lays eggs. Although they were once more widespread, the only extant species are platypuses and echidnas (spiny anteaters).

montane: the biome of mountain regions.

Moon: Earth’s solitary satellite; the 5th largest satellite in the solar system.

moral: conforming to a principle of appropriate behavior based upon respect of other life.

moray eel: an eel in the Muraenidae family, with 200 species across 15 genera. Moray eels are shy and secretive.

mordant: a chemical compound that sets dyes onto fabrics or tissue by forming a coordination complex with the dye, the combination of which attaches to the substrate. There are many mordants, including tannic acid and sodium chloride. A mordant is typically a polyvalent metal ion.

more (sociology): a folkway of central importance; a strongly held norm. See taboo.

morphine (C17H19NO3): an opium extract, used medicinally for pain.

morpho dragonfly: a South American tropical rainforest dragonfly with 5–6 species.

morphology: the form and structure of an organism or other system. Compare physiology.

mosaic evolution: an evolutionary change in only part of an organism.

mosquito: a family of small, midge-like flies. The females of most species are blood suckers.

moss: a phylum of 12,000 species of small, soft, non-vascular plants that usually grow in clumps, typically 1–10 cm tall, though a few are larger. Moss are commonly confused with lichen. In their afterlife moss form peat.

moss rose (Portulaca): a flowering plant of 40–100 species found in the tropics and warm temperate regions.

moth: a flying insect related to the butterfly. Most moths are nocturnal. ~160,000 species are extant. Compare butterfly.

mother cell (aka parent cell): a cell that produces other cells.

motile: capable of movement. Contrast sessile.

motor protein: a class of proteins in cells which convert the chemical energy in ATP into movement.

mountain goat (Oreamnos americanus): a large, even-toed ungulate native to North America.

mouse (plural: mice): a small rodent of ~40 extant species.

mouse lemur: a nocturnal lemur in the Microcebus genus; the smallest primate.

multiplicity reactivation (cells): restoration from damage.

mung: a gathering of female animals for males to pick a mate. Contrast lek.

murein (aka peptidoglycan): a polymer of amino acids and sugars that is used in the cell wall of a bacterium.

murre (aka guillemot (UK), turr (Canada)): a large black-and-white diving auk that spends most of its life over northern coastal seas, only venturing onto land for colonial breeding. There are 2 species in the murre genus (Uria): the common murre (U. aalge) and the thick-billed murre (U. lomvia).

muscovite: a mineral high in aluminium and potassium.

muscular hydrostat: a set of muscles that can move without skeletal support. Since muscles can only produce force via contraction, different muscle groups must work against each other: one group lengthens by relaxation while another produces force through contraction.

mushroom: a fleshy, spore-bearing fungal fruiting body, typically produced aboveground. See toadstool.

mustard (botany): any of several plants in the Brassicaceae (mustard/crucifer/cabbage) family.

mustelid: a carnivorous mammal in the Mustelidae family, which includes badgers, minks, martens, otters, polecats, weasels, and wolverines. Owing to its diversity and lack of unified lineage, mustelid classification remains unsettled.

mutation: a change in a DNA sequence.

mutualism: regular interaction between 2 organisms that provides mutual benefits.

MYA: millions of years ago.

mycelium (plural: mycelia): a threadlike filament of a mesh-like mass of fungal filaments (hyphae).

mycoheterotrophy: a plant that is a mycorrhiza parasite.

mycoheterotrophyte: a plant that practices mycoheterotrophy.

mycology: the study of fungi.

mycophagy: fungus eating (by a fungivore or mycophagist).

Mycoplasma: a genus of tiny bacteria that have no cell wall.

mycorrhiza (plural: mycorrhizae or mycorrhizas): a mycelial fungus that has a symbiotic relationship with a vascular plant.

myoglobin: an iron- and oxygen-binding protein in vertebrate muscle tissue, employed for oxygen transport.

myosin: an ATP-dependent motor protein, best known for its role in muscle contraction, but involved in a wide range of eukaryotic motility actions.

myrmecochory: a plant-ant mutualism. Some plants bribe ants to disperse their seeds by coating them with an elaiosome.

Myrmecolacidae: a family of insects in the Strepsiptera order, with 4 genera and ~98 species.

myrmecology: the study of ants.

Myrmica: a genus of 200+ species of ant, endemic to temperate and mountainous regions of Southeast Asia.

myxamoeba (plural: myxamoebae or myxamoebas): a single amoeboid that forms a plasmodium (slime mold colony) when it finds friends.

myxobacteria (aka slime bacteria): a group of soil bacteria.

Myxozoa: a group of microscopic aquatic parasites. Once considered protozoan, myxozoans are instead cnidarians that shrank and dumped much their genome to make their livelihoods from infestation.


naked mole rat: see sand puppy.

Namibia: a country on the western coast of southern Africa, the driest in sub-Saharan Africa.

nanometer (nm): 1-billionth of a meter.

Napoléon complex (aka short man syndrome): a pejorative referring to short men overcompensating for their lack of physical stature by overbearing behavior. Named after the chronic aggressiveness displayed by Napoléon Bonaparte, a man of oversized ambition, but not actually short stature. Napoléon was average height for his time (1.57 m).

Nasa poissoniana: an angiosperm endemic to the Peruvian Andes with a star-shaped flower, in the Loasoideae subfamily, known for their polychrome blooms and painfully stinging hairs on their stems.

nastic movement: plant movement that does not depend on the direction of the stimulus. Contrast tropism.

Nasutitermitinae (termite): a subfamily of termites found through much of the world. Nasutitermitinae soldiers have a pointed snout – nasus – on their forehead, from which they squirt an aerosol to deter or repel an attack (chemical warfare). They have accurate aim despite being blind.

native (biology): naturally occurring and associated with a certain environment or biome. Compare indigenous, endemic.

natural gas: a methane-rich gas formed either by methanogens or thermogenically from buried organic matter compressed and heated over millions of years. Compare coal, petroleum.

natural selection: a meaningless term acclaiming Darwinism, popular among religious evolutionary biologists who should know better. See Darwinism.

natural transformation (genetics, molecular biology) (aka transformation): a cell altering its genetic makeup through uptake and incorporation of exogenous DNA.

Nature: the exhibition of existence.

nautiloid: a diverse group of marine cephalopods with hard outer shells for protection, such as the nautilus. Nautiloids arose during the Late Cambrian. Compare coleoid.

nautilus: a pelagic marine nautiloid that emerged during the Late Cambrian, with 6 extant species in 2 genera.

Nazca Plate: an oceanic tectonic plate in the eastern Pacific Ocean basin off the west coast of South America.

Neanderthal (aka Neandertal) (450 – 45 TYA): an extinct species in the Homo genus, closely related to modern humans.

Near East: a geographical area of southwest Asia and northeast Africa. The term has generally been applied as being the area of the Ottoman Empire at its apogee in the mid-1500s. Since the mid-1900s, the terms Near East and Middle East have been approximated as synonymous.

near passerine: an arboreal bird, related to (true) passerines. Near passerines include cuckoos, swifts, hummingbirds, woodpeckers, toucans, hornbills, kingfishers, nightjars, mousebirds, trogons, and quetzals. A comprehensive listing is somewhat controversial, as some birds, such as pigeons and parrots, were traditionally considered near passerines, but their inclusion is no longer generally accepted.

Nearctic: related to organisms indigenous to North America before the Great American Interchange. Contrast Neotropic.

necrosis: premature cell death in living tissue via autolysis. Compare apoptosis.

necroptosis: programmed inflammatory cell death (a form of necrosis).

necrotroph: an infectious organism that kills living host cells, and then feeds on the remains. Contrast biotroph.

nectar: a sugar-rich solution produced by plants as a bribe for pollinators.

nectarivore: an animal that eats primarily or exclusively nectar. Most nectarivores are insects or birds but there are also nectarivorous geckos, bats, and the tiny honey possum.

Neesia: a fruit-bearing tree genus, endemic to Southeast Asia.

Neisseria: a large genus of spherical commensal bacteria that colonize the mucous membranes of many animals.

nematocyst: a barbed chemical stinger within a nematocyte.

nematocyte: a cell housing a nematocyst. Cnidarians have nematocytes.

nematode (aka roundworm): a worm in one of the most diverse phyla, with an estimated 100,000 species. Over 28,000 species are known, of which over 16,000 are parasitic. Unlike earlier-evolved cnidarians and flatworms, nematodes have tubular digestive systems, with openings at both ends.

neocortex: the mammalian portion of the brain associated with higher cognitive functions.

Neogene (23 – 0.05 MYA): the 2nd geological period of the Cenozoic era, during which mammals and birds evolved into their modern forms. Late in the period hominoids arose.

neonate: a human infant within 28 days of birth.

Neoproterozoic (1 BYA–542 MYA); the 3rd and last era of the Proterozoic eon.

neoteny: retention by adults of traits previously seen only in the young (in the perspective of evolutionary descent).

Neotropic: related to organisms indigenous to South America before the Great American Interchange. Contrast Nearctic.

Neotropics: tropical Central and South America.

Nepenthes hemsleyana: a giant tropical pitcher plant endemic to the peat swamp and heath forests of Borneo.

nepotism: favoritism granted to relatives. Nepotism is ubiquitous in all social life forms. See kin selection.

nerve (cell): see neuron.

nervous system: the communication and motor control system in an animal, comprising a network of neurons.

neurohypophysial hormone: a family of peptide hormones synthesized in the hypothalamus. Oxytocin and vasopressin are neurohypophysial hormones.

neuron (aka nerve cell): an electrically excitable intercellular signaling cell as part of the nervous system, employed for sensory or motor communication. Functionally, neurons are managed by glia.

neuropeptide: small protein-like molecules (peptides) employed by neurons to communicate with each other.

neuroticism: chronic emotional disturbance.

neutrophil: the most abundant (40–75%) type of white blood cell in mammals. A phagocyte, neutrophils are an essential part of the innate immune system.

New Caledonian crow (Corvus moneduloides): an all-black, medium-sized corvid native to New Caledonia.

New World: the Western Hemisphere, specifically the Americas and nearby islands; sometimes Oceania is included. The term originated in the early 16th century by European explorers expanding their worldly horizons. Contrast Old World.

New Zealand cockle (Austrovenus stutchburyi): a marine clam resident in the harbors and estuaries of New Zealand.

newt: an aquatic salamander.

nicotine (C10H14N2): a potent alkaloid made in the roots of nightshade plants, notably tobacco, and accumulated in the leaves to prevent herbivore consumption. Nicotine is unusual in its nervous system effects, in changing from stimulant to sedative via increasing dosage and tolerance.

night monkey (aka owl monkey, owing to its unusually large eyes): a monogamous New World monkey; the only nocturnal monkey.

nightingale (Luscinia megarhynchos): a small migratory insectivorous passerine bird which breeds in the forests and scrub of Europe and southwest Asia, and winters in west Africa.

nightshade (aka bittersweet (UK)): a flowering plant in the Solanum genus of ~2,300 species in the nightshade (Solanaceae) family. The grouping originated with these plants producing toxic alkaloids, but several nightshades, including potatoes, tomatoes, eggplant, bell and chili peppers, and tobacco, are consumed by humans.

nitrate (NO3): a salt or ester of nitric acid. Nitrate is a polyatomic ion.

nitric oxide (NO) (aka nitrogen oxide): a free-radical molecule. In mammals, NO is an important cellular signaling molecule.

nitrification: the process of nitrogen compound oxidation. Contrast denitrification.

nitrite (NO2): a symmetric anion. Nitrite may be oxidized or reduced.

nitrogen (N): the element with atomic number 7; a colorless, tasteless, odorless element that, as a diatomic gas (N2), is relatively inert.

nitrogen fixation: fixing atmospheric nitrogen gas into a biologically employable form; the process by which diatomic nitrogen gas is converted to ammonium ions which can be employed by plants. Only certain microbes have mastered the trick of fixing nitrogen.

nitrogenase: an enzyme that reduces nitrogen (N2) to ammonia (NH3). Nitrogenases are produced by certain bacteria, including cyanobacteria.

nitrous acid (HNO2): a weak monobasic acid.

nocturnal: during the night. Contrast diurnal.

nodulation: the process of a legume creating a nodule for symbiotic bacteria to live in.

nonanal (C9H18O; aka nonanaldehyde, pelargonaldehyde): a colorless, natural oil; an alkyl aldehyde.

norepinephrine (C8H11NO3): a versatile organic compound with various roles depending upon species.

NP-hardness (non-deterministic polynomial-time hardness): the computational difficulty of a mathematical problem.

nucleation: the process of airborne water molecules coalescing around a seed particle to form a drop of precipitation.

nucleic acid: an acidic biomolecule comprising a nucleotide, discovered by Friedrich Miescher in 1869. DNA and RNA are nucleic acids.

nucleotide: an individual structural unit of nucleic acid.

nulliparous: a female that has not borne offspring.

Nuna (aka Columbia): a supercontinent created 1.9 BYA. Nuna began breaking up 1.5 BYA.

nursery-web spider (Pisaura mirabilis): a spider with the practice of male nuptial gift giving.

nutcracker: a Eurasian corvid fond of seeds and nuts, in the genus Nucifraga, of 3 species.

nyctinastic: a plant with leaves or leaflets that assume a vertical orientation in the dark. Nyctinastic movement is responsive to the diurnal (daily night and day) cycle.

nymph: an immature hemimetabolous insect. Nymphs roughly resemble adults, albeit with distinctive body proportions, size, and color patterns. Compare larva.


oak: a flowering tree or shrub native to the northern hemisphere in the Quercus genus, with ~600 species. The term oak is also used in related genera.

obligate: obligatory.

obligate parasitism: an organism that depends upon its host to complete its life cycle and reproduce. Contrast facultative parasitism, hemiparasitism.

Occam’s razor: a principle of parsimony in logic, courtesy of William of Ockham. Occam’s razor is the axiom that the simplest explanation is preferable. Regarding biology, however complex genetic expressions may be, the evolutionary driver behind them is typically a coherent rule that is life-affirming.

ocean: a large, deep body of saltwater.

ocean conveyor belt: the continuous global system of interconnected ocean currents. This marine conveyor belt system affects climate worldwide.

Oceania: a region centered on the islands in the tropical Pacific Ocean, including Australasia.

octopamine (C8H11NO2): a biogenic compound with various effects in different species.

octopus (plural: octopuses, octopi, or octopodes): a cephalopod with a soft body and 8 limbs, of over 300 species.

oegopsid: a squid in the order Oegopsida, characterized by heads without tentacle pockets, eyes without a corneal cover, arms and tentacle clubs with hooks, buccal supports without suckers, and paired oviducts in females.

Old World: Africa, Europe, and Asia; the part of the world known to Europeans prior to their sojourns to the Americas. Contrast New World.

olfaction (aka oflactics): the act or sense of smell.

Oligocene (34–23 MYA): the 3rd and last geologic epoch in the Paleogene period.

oligophagy: eating only a few specific foods. Compare monophagy, polyphagy.

oligosaccharide: a saccharide (sugar) polymer, typically with 2 to 10 component simple sugars (monosaccharides).

olive baboon (aka Anubis baboon, Papio anubis): the baboon with the most extensive range: throughout north-central Africa. The olive baboon inhabits savannas, steppes, and forests. Its name derives from the color of its fur.

olivine ((Mg+2, Fe+2)2SiO4; aka peridot, chrysolite): a magnesium iron silicate mineral, common in Earth’s asthenosphere, but which weathers quickly on the surface.

ommatidium (plural: ommatidia): an individual photoreceptor unit in a compound eye.

omnivore: an organism that consumes a variety of plant and animal matter as food. Compare herbivore, carnivore, and saprovore.

oncogenesis: the creation of a tumor (cancer).

oncovirus: a virus that causes cancer in its host; often restricted to mammals.

ontogeny: the course of development in an organism.

oomycete: an algae-like fungus in the Oomycota phylum. Many are plant pathogens.

Ophiocordyceps unilateralis: a fungus that infects ants.

ophiophagy: snake eating.

opisthokont: a broad grouping of eukaryotes that includes fungi and animals.

opium: the dried latex from the opium poppy. Opium is 12% morphine, which has been processed since antiquity to produce various medicines and chemical recreations.

opium poppy (aka breadseed poppy, Papaver somniferum): a flowering plant in the Papaeraceae family, with an original native range in the eastern Mediterranean. This poppy is grown agriculturally for its edible seeds and pharmaceutical alkaloid metabolites, most notably opium.

opossum (colloquially possum): a marsupial indigenous in the western hemisphere. Opossums are biological generalists, and so successful colonizers. There are 103+ opossum species in 19 genera.

opsin: a light-sensitive protein; an organic photoreceptor that mediates the conversion of a photon into an electrochemical signal as a 1st step in a transduction cascade that results in a visual image. A distinct opsin is employed by mammals for the pupil reflex and non-image light detection as a basis for biorhythm.

orangutan: a red-haired ape of 3 extant species, native to the rainforests of Indonesia and Malaysia. The orangutan is the largest arboreal ape.

orb-weaving spider (Cyclosa ginnagamay): an orb web weaving spider that employs camouflage in its web that mimics bird droppings.

orca (Orcinus orca): the largest oceanic dolphin; wrongly, commonly called a “killer whale.”

orchid: a flowering plant in a diverse family with 21,950–26,049 species in 880 genera.

order (biological classification): the taxon above family and below class. Augustus Rivinus first used order in the 1690s in his classification of plants. Carl Linnaeus incorporated order into his taxonomic schema in 1735. There is no consensus on the taxonomical meaning of order.

ordinal (number): a number indicating rank order (1st, 2nd, et cetera). Compare cardinal number.

Ordovician (485–443 MYA): the 2nd of 6 periods in the Palaeozoic era, following the Cambrian period and preceding the Silurian. The name derives from the Celtic tribe of the Ordovices in Wales, from where rocks of the period were first taken for study.

organelle: a subunit within a eukaryotic cell that has a specialized function. Organelles are membrane-bound. Cell organelles evolved through endosymbiotic union with an archaeon host cell and a bacterial endosymbiont.

organic: related to living organisms. From a chemistry viewpoint, a complex molecular structure based upon a carbon backbone.

Organic Lake: a shallow, salty, sulfuric body of water in East Antarctica.

organism: a life form; an animated organic structure.

Oriental fruit moth: a large moth of the Tortricidae family, native to China.

ornithology: the study of birds.

orogen: a mountain belt formed from compressive deformation of a tectonic plate. Orogeny refers to the process of forming orogens: mountain making.

orthomyxovirus: a family of RNA viruses comprising 7 genera. 4 genera cause influenza in vertebrates. 1 is an arbovirus, infecting both vertebrates and invertebrates.

oryx: a large antelope of 4 species, endemic to arid Africa and the Arabian Peninsula.

oryx osmobiosis: a cryptobiotic response to extreme solute (typically high-salinity water).

osmobiosis: a cryptobiotic response to extreme solute (typically high-salinity water).

osmophile: an organism capable of growing in a sugary habitat.

osmosis: the net movement of solvent molecules through a partially permeable membrane into a region with higher solute concentration, to effect an equalized solute concentration on both sides of the membrane. Osmosis relies upon kinetic energy.

osmotic pressure: the pressure needed to prevent inward water flow across a semipermeable membrane.

osprey (aka sea hawk, fish eagle, fish hawk, Pandion haliaetus): a piscivorous bird of prey with keen vision.

ostracod (aka seed shrimp): a small crustacean of 70,000 species throughout natural history (30,000 extant).

ostrich: a large, long-necked, flightless bird native to Africa, in the family Struthionidae, with 2 extant species.

otariid (aka eared seal, otary): a semiaquatic seal. Sea lions and fur seals are otariids. True seals (phocids) are earless, and more streamlined than otariids.

outcrossing: introduction of unrelated genes into a breeding line. Outcrossing increases genetic diversity.

ovary (botany): the enlarged lower part of the pistil on flowers, enclosing ovules, which develop into seeds once fertilized. Such floral ovaries mature into fruit.

overstory: the layer of foliage in a forest canopy. Compare understory.

ovicide: an egg killer.

oviduct (aka Fallopian tube): the passageway from the ovaries to the outside of the body in a vertebrate.

oviparity: egg-laying. Contrast viviparity. See ovoviviparity.

ovipore: a pore-like sex organ of a female animal, typically an insect, in which spermatophores are inseminated.

ovoviviparity: a reproduction mode in animals in which embryos develop inside eggs that are retained within the mother’s body until they are ready to hatch.

ovule: the plant part that contains the female germ cell which develops into a seed.

owl: a bird among 200 species of mostly solitary and nocturnal birds of prey; typified by an upright stance, a large, broad head, sharp vision and hearing, and feathers that provide silent flight. Owls are found in all biomes except the coldest (Antarctica, most of Greenland).

oxidation: an increase in oxidation state by loss of electrons. Contrast reduction.

oxidation state (aka oxidation number): a characterization of the charge potential of an atom within a chemical species. An electrically neutral compound necessarily has net oxidation state of zero. The more electronegative or electropositive atoms in a compound are considered 1st in calculating the oxidation state of molecular atoms.

oxygen (O): the element with atomic number 8; a highly reactive nonmetallic element that readily forms compounds (notably oxides) with almost all other elements.

oxygen minimum zone (OMZ): the layer of water in the ocean with the least oxygen. OMZ is at a depth of 200 to 1,000 meters, depending upon location and local circumstances. Oxygen minimum zones are significant in regulating the productivity and ecology of the ocean. For example, some bacteria species in the OMZ consume nitrate rather than oxygen, concentrating this nutrient. Huge bacterial mats in the OMZ off the west coast of South America engender fish populations.

oystercatcher: a coastal wader bird of ~11 species.

ozone (O3; aka trioxygen): a triatomic molecule comprising 3 oxygen atoms. O3 is less stable than O2 (dioxygen). Ozone is formed by ultraviolet radiation of dioxygen.


Pacific pygmy octopus (Octopus digueti): a small octopus native to the coasts of California and Baja California.

Pacific Ring of Fire: a seismic belt of geological hot spots that runs from north of New Zealand up through Indonesia, Japan, and the Aleutian Islands, then down the west coast of the Americas, ending in Southern Chile.

Pacific yew (tree) (Taxus brevifolia): a conifer native to the Pacific Northwest of North America.

Paenibacillus vortex: a pattern-forming, social, soil bacteria species.

pain: a sensation of severe discomfort; a discomfort that provokes reaction.

Palearctic: the largest terrestrial ecozone in the world, including northern Africa and the northern portion of the Arabian Peninsula, all of Europe, and Asia north of the Himalaya foothills.

paleoanthropology: the study of hominins from physical evidence. Paleoanthropology combines paleontology and anthropology.

paleoatmosphere: the atmosphere before life arose.

paleodicot: the most basal angiosperms, now comprising only a few hundred species.

Paleogene (66–23 MYA): the 1st of 3 periods in the Cenozoic era.

paleontology: the study of prehistoric life.

palindrome: a word, phrase, or sentence that reads the same forward or backward. Exemplary palindrome words include civic, deified, kayak, level, madam, racecar, radar, redder, refer, reviver, and rotor.

palolo: a marine worm that lives in tropical coral reefs.

palynivore: a specialized pollen eater.

Panderichthys: a genus of extinct lobe-finned fish that arose in the late Devonian, from which tetrapods arose.

pandoravirus: a virus with relatively large size and genome: typically, over 2,000 genes (over 2 million base pairs). Oddly, considering their size, pandoraviruses lack the gene for the capsid protein.

Pangea (aka Pangaea): the supercontinent that contained most of Earth’s land mass 300–200 MYA. The global ocean of the time was Panthalassa. Pangea broke up into Laurasia to the north and the southern Gondwana.

pangolin: a nocturnal mammal with large scales covering its skin. Pangolins spend most of the day sleeping, curled up in a ball. Pangolins live in tropical regions throughout Africa and Asia. Different pangolin species in trees or on the ground. Pangolins are good swimmers. Pangolins lack teeth, and the ability to chew. They use their exceptionally long tongue to snag termites and ants from mounds or anthills torn open with their powerful font claws. Pangolins have glands that lubricate their tongues with sticky saliva; the better for their snatch-and-snack lifestyle.

Pannotia (610–550 MYA): the largely southern supercontinent that broke into 4 major landmasses.

Panthalassa: the global ocean that surrounded Pangea.

pantheism: the belief that all reality is identical with divinity.

paper wasp: a wasp in the genus Polistes that makes its nest out of thin, paper-like sheets. The North American paper wasp (P. metricus) does so alone. In contrast, the golden paper wasp (P. fuscatus) creates a communal nest with other females.

paracrine signaling: intercellular communication over a short distance. Compare juxtacrine signaling and endocrine signaling.

paraheliotropism: plant leaf movement to minimize exposure to sunlight.

parapatric speciation: speciation by preference, of populations in nearby habitats which are not physically separated. Compare sympatric speciation and allopatric speciation.

paraphyletic: a taxonomic group that does not include all descendants of a common ancestor.

parasite: an organism living in, on, or with another organism, obtaining benefits that usually reduces the fitness or health of its host.

parasitoid: an organism that spends a large part of its life in a parasitic relationship with a host. Unlike a true parasite, a parasitoid ultimately sterilizes or kills its host, and sometimes consumes it.

parasociality: animals of the same generation living together cooperatively in a single dwelling.

Paratarsotomus macropalpis: a 0.5-mm mite endemic to southern California.

parenchyma (botany): the most common and versatile ground tissue in plants, composed of thin-walled cells able to divide.

Paridae: a family of small passerines that includes chickadees, tits, and titmice; endemic to Africa and the northern hemisphere.

parrot: an uncommonly intelligent bird of 372 species in 86 genera, found in many tropical and subtropical biomes. The greatest parrot diversity is in Australasia and South America.

parthenogenesis: asexual reproduction where an unfertilized egg cell nonetheless develops into an embryo. Sperm or pollen may trigger embryonic development without making a genetic contribution. In animals, parthenogenesis means an embryo developing from an unfertilized egg. From the Greek for “virgin birth.” Contrast heterogamy. See gynogenesis.

parturition: expulsion of a newborn from the birth canal. Also called birth.

parvovirus: a rugged, genomically-compact, single-strand DNA virus in the family Parvoviridae, of 13 genera with over 75 species. Parvoviruses are categorized into 2 subfamilies: one which infects vertebrates (Parvovirinae), the other invertebrates (Densovirinae).

passerine (bird): a bird in the Passeriformes order, comprising over half of all bird species (over 5,000 identified species in over 110 families). One of the most diverse terrestrial vertebrate orders, around twice that of the large mammal order: rodents. Passerines include most perching birds, such as sparrows, wrens, finches, tits, and corvids.

passive margin: a transition area between oceanic and continental crust, absent an active plate margin. Contrast active margin.

patas monkey (aka Wadi monkey, Hussar monkey): a ground-dwelling monkey native to semiarid areas of equatorial Africa.

pathogen: an infectious agent, commonly called a germ; a microorganism that causes diseases in its host, including certain viruses, bacteria, fungi, and prions.

pathology: the study of disease and its diagnosis.

pathotype: one of numerous variations of pathogenic properties in a species of bacteria. See phage type, serotype.

patrilocality: a social system where mates live in the male’s natal community.

pavement ant (Tetramorium caespitum): an aggressive, caste-based, eusocial ant 2.5–4 mm long, native to Europe but brought to America in the 18th century. Named for their ingenuity in being able to make a home in inhospitable urban environments. Considered a household pest.

peach-potato aphid (aka green peach aphid, Myzus persicae): a small green aphid that is a pest of peach trees, and acts as a transport vector for plant viruses that infect potatoes.

peacock: a male peafowl, known for its iridescent blue and green plumage.

peafowl: a female bird in 1 of 3 species in the Pavo or Afropavo genera. Male peafowls are commonly called peacocks. The Indian peafowl is native to the Indian subcontinent, the green peafowl of Southeast Asia, and the Congo peafowl endemic to the Congo Basin of central Africa.

peat: an accumulation of partly decayed vegetation and other organic matter that becomes part of the soil. Areas rich in peat are called peatlands, bogs, mires, moors, or muskegs.

pecten oculi: a comb-like structure of blood vessels in a bird’s eye that provides nourishment, including oxygen, to the eye. Pecten pigmentation helps protect the eye against damage from ultraviolet light.

pectin: a polysaccharide in plant cell walls that allows growth.

pedology: the study of soil.

pedosphere: the outermost terrestrial layer of Earth, comprising soil. Compare geosphere.

pelagic (zone): a zone in a body of water that is neither near the shore nor close to the bottom (benthic).

pelican: a large water bird in the Pelecanus genus, characterized by a long beak and large throat pouch for catching prey and draining water before swallowing. Pelicans frequent coastal and inland waters, feeding principally on fish. Pelicans are gregarious: traveling in flocks, hunting cooperatively, and breeding colonially.

penguin: a flightless seabird of 17–20 species, living in the southern hemisphere, commonly Antarctica.

penicillin: an antibiotic derived from Penicillium fungi.

peptide: a short chain of amino acids: 2 to 50 or so. A longer chain is properly termed a protein.

perceive, perception: mentally integrating sensory input (sensation) using memory. Perception is a 3-stage process: 1) turn a sensation into a symbolic representation, 2) identify sensed symbols using memory and categorization, then 3) derive the meaning of the identified symbols, especially regarding affinity or avoidance. See conceptualization.

perching bird: an arboreal passerine.

perennate: persist; be perennial.

perennial (botany): a plant that is present aboveground throughout the year, and which lives for more than 2 years. Woody plants, such as shrubs and trees, are perennials. Compare annual, biennial. See herbaceous.

periderm: the secondary covering on small woody stems and non-woody plants.

period (geology): a duration in the geological time scale, roughly 100 million years; shorter than an era, longer than an epoch.

peripheral vision: vision in animals with 2 eyes that occurs outside focal gaze. See binocular vision.

perissodactyl: an odd-toed, nonruminant, ungulate mammal in the Perissodactyla order.

Permian (299–252 MYA): the 6th and last period of the Paleozoic era, following the Carboniferous period and preceding the Triassic. The name derives from the ancient Russian kingdom of Permia. Earth at the time had a single supercontinent: Pangea, surrounded by the global ocean Panthalassa. The extensive rainforests of the Carboniferous were gone, leaving vast regions of arid desert in the continental interior. Reptiles, better adapted to dryer conditions, rose to dominance over their amphibian ancestors.

personality: individual patterns of behavior in an organism that suggest a certain emotional orientation or worldview.

perspective-taking: the process of perceiving an event from another’s point of view.

pest: an organism deemed a nuisance.

petal: a modified leaf that surrounds the reproductive parts of a flower.

petiole (botany) (aka leafstalk): the stalk that attaches a leaf to a stem.

petrel: a tube-nosed seabird.

petroleum: a natural yellow-to-black liquid comprising algae, zooplankton, and other organisms crushed, heated, and liquefied. Compare coal.

pH: a measure of acidity which ultimately relates to the number of protons in a solution. 7 = neutral; < = acidic; ▫ = base (alkaline).

phage type: one of numerous variations of susceptibility to viruses in a species of bacteria. See pathotype, serotype.

phagocyte: an animal cell which protects it host body by ingesting harmful foreign particles, select microbes, and dying or dead cells.

phagocytosis: the process of eating by engulfing something solid and devouring it into an internal cavity (vacuole).

phagotroph: a heterotrophic protist that eats via phagocytosis.

Phanerozoic (542 MYA–now): the 4th geological eon, characterized by complex life inhabiting Earth (based upon an outdated assessment), beginning with the Cambrian period.

Pheidole: an ant genus with over 1,000 species. Pheidole tend to be an ecologically dominant species.

Pheidole pallidula: a Mediterranean and north African ant.

phenol (C6H5OH; aka carbolic acid): a mildly acidic, volatile, aromatic, organic compound, which is a white crystalline solid. A phenol comprises a phenyl group (C6H5) bonded to a hydroxyl group (OH).

phenomenal: known through perception. Contrast intuition.

phenomenon (plural: phenomena): a perceptible event.

phenotype: the composite visible traits of an organism: physical, physiological, and behavioral.

phenotypic plasticity: the ability of an organism to alter its body to suit current conditions.

pheromone: a secreted or excreted hormone employed as a communication signal.

phloem: tissue that distributes sugar-laden sap among a plant. Compare xylem.

phoresy (aka phoresis): a commensalism where the symbiont is transported by the host.

phorid fly (aka scuttle fly): a family of tiny humpbacked flies that resemble fruit flies. Many are specialist parasitoids of ants and stingless bees.

Phormidium frigidum: a psychrophilic cyanobacterium native to Antarctica.

phosphate (PO43-): a soil-bound mineral nutritionally needed by plants.

phospholipid: a class of lipids that are a major component of all cell membranes, as they can form bilayers which afford regulated communication flow.

phosphorus (P): the element with atomic number 15; as a mineral, always maximally oxidized. A component of RNA, DNA, ATP and other biocompounds, phosphorus is essential to life.

photobiont: an autotrophic photosynthetic symbiont.

photoperiodism: plant responses to changes in the length of days and nights.

photophore: a light-producing organ.

Photorhabdus luminescens: a bioluminescent bacterial symbiont to entomopathogenic nematodes that helps its host by killing insects.

photosynthesis: (an organism) converting sunlight into energy.

phototroph: an organism that can turn light energy into metabolic chemical energy.

phototropism: a natural tendency for light to be an orienting stimulus.

phycodnavirus: a large double-stranded DNA virus that infects marine or freshwater eukaryotic algae.

phycotoxin: an allelopathic compound produced by prokaryotic and eukaryotic algae.

phyllotaxy (aka phyllotaxis): the arrangement of leaves on a plant stem.

phylogenetics: the study of biological evolutionary history via genetic analysis.

phylum (biological classification) (plural: phyla): the taxon above class and below kingdom. Phylum typically refers to a uniquely identifiable body plan. Ernst Haeckel coined phylum in 1866. See family.

physiology: the physical structures and biomechanics of an organism.

phytochemical: a plant-produced chemical compound.

phytochrome: a photoreceptive protein sensitive to red light and temperature which plants employ.

phytoestrogen: a plant compound similar to estrogen.

phytohormone: a plant hormone. Phytohormones regulate plant growth.

phytopathogen: a plant pathogen.

Phytophthora infestans: the pathogenic fungus that causes potato blight.

phytoplankton (aka microalgae): photosynthesizing aquatic organisms, both marine and freshwater; from the Greek words for plant and drifter. Oceanic phytoplankton is the primary food source, directly or indirectly, of nearly all other marine life.

phytoplasma: specialized parasitic plant bacteria.

phytosteroid (aka plant steroid): a steroid naturally occurring in plants.

phyotosynthate: a product of photosynthesis.

Picrophilus oshimae: an acidophilic species of archaea.

pied flycatcher (Ficedula hypoleuca): a small, migratory European passerine which practices polygyny.

pied wagtail (aka water wagtail, Motacilla alba yarrellii): a small, slender passerine with a long, constantly wagging tail; native to the British Isles.

pigeon: a stout-bodied bird with a short, slender bill; in the clade Columbidae with doves.

pike: a freshwater fish in the Esox genus, with 6 extant species.

pillbug (aka roly polies, doodle bugs): an insect which can roll up into a ball; in the same family (Armadillidiidae) with woodlice.

pilot whale: a dolphin in the genus Globicephala, with 2 species: short-finned (G. macrorhynchus) and long-finned (G. melas).

pilus (aka fimbria; plural: pili, fimbriae): a hair-like appendage found on bacteria. Pili serve various purposes, from motility to conjugation (DNA transfer).

pine: a softwood conifer native to the northern hemisphere, with ~115 species in the Pinaceae genus.

pineapple (Ananas comosus): a fruiting tropical bromeliad.

pink (salmon): the smallest and most abundant species of Pacific salmon. These cold-water fish (5.6–14.6 °C, optimally 10.1 °C; upper incipient lethal temperature = 26 °C) live 2 years. Pink salmon traditionally range from Arctic coastal waters to the Sacramento river in northern California. Pink salmon have been a mainstay of commercial harvesting. As such, they are critically imperiled from California through Washington, but, as of 2012, faring well enough in British Columbia and Alaska.

pinna: a leaflet, or projecting animal body part.

pinnate: a biological arrangement of having similar parts on opposite sides of an axis, as with barbs on the rachis of a feather, and with compound leaves.

pinniped: a diverse group of fin-footed marine mammals, including seals, sea lions, and walruses. Pinnipeds are typically sleek-bodied and barrel-shaped: bodies admirably adapted for an aquatic lifestyle.

pinnule: a bodily part or organ that resembles a fin.

pioneer plants: the 1st wave of plants that occupy a new soil.

pinyon jay (Gymnorhinus cyanocephalus): a western United States jay. The pinyon jay and Eurasian cousin nutcracker are an example of convergent evolution in filling a similar habitat niche.

pipefish: a subfamily of small fish that resembles a seahorse, which is in the same family.

Piraha: an indigenous people of the Brazilian Amazon rainforest. The Piraha call themselves Hi’aiti’ihi, which loosely translates as “the straight ones.” The Piraha have no social hierarchy; there are no formal tribal leaders. Like many early societies, the Piraha are egalitarian and practice common ownership (sociality which Karl Marx called “primitive communism”).

piscivore: an animal which primarily eats fish.

pistil (aka carpel): the female part of a flower, acting as a pollen receptor.

pit viper (Crotalinae): a subfamily of vipers, endemic to Asia and the Americas, with a visible heat-sensing organ (pit).

pitcher plant: a carnivorous or saprophytic plant in the genus Nepenthes, endemic to the tropical or tropical-montane biomes of the Malay Archipelago, Southeast Asia, and the eastern part of Madagascar.

pith (botany): soft, spongy growth tissue in the center of a plant. Pith is replaced by xylem in grown stems and branches.

pituitary gland (aka hypophysis): an endocrine gland at the base of the brain, off the bottom of the hypothalamus. The pituitary gland is not a part of the brain. The human pituitary gland is the size of a pea, weighing 0.5 grams.

placenta: an organ that connects a developing fetus to the uterine wall of its mother, allowing nutrient uptake, waste elimination, and gas exchange.

plankton: a minute organism living in a water column (freshwater or salt) that is incapable of swimming against a current. The term plankton is both singular and plural (they’re just too damn tiny to count).

plant: a kingdom of eukaryotic autotrophs, including mosses, ferns, conifers, and flowering plants (angiosperms).

plantain (Plantaginaceae): a diverse, cosmopolitan family of flowering plants, occurring mostly in temperate climates.

plasmid: a tiny globule of genetic information (DNA), useful to microbes for horizontal gene transfer.

plasmodesma (plural: plasmodesmata): a microscopic channel traversing the cell walls of plant cells, and some algae cells, enabling communication and transport between cells.

Plasmodium: a genus of parasitic protozoa. Infection of Plasmodium falcipanum is known as malaria. Compare plasmodium.

plasmodium: an ameboid which congregates to form a slime mold. Compare Plasmodium.

plastid: a double-membrane organelle in algae and plant cells.

platypus (aka duck-billed platypus, Ornithorhynchus anatinus): a semiaquatic mammal endemic to eastern Australia. Platypus are monotremes. The platypus is one of the few venomous mammals. Males have a spur on their hind foot that delivers a painful incentive to bugger off.

Platyrrhine (aka New World monkeys): a group of New World monkeys. Compare cercopithecid.

play: entertaining recreational activity.

Pleistocene (2.588 MYA–11,700 ya): the epoch that follows the Pliocene and precedes the Holocene; defined by Charles Lyell for the emergence of modern marine mollusks. The Pleistocene ends with passing of the Younger Dryas cold spell.

pleomorphism: (an organism) able to change shape or size in response to environmental conditions.

plover: a wading bird in widely distributed group of 40 species.

plume (mantle): the rising of hot rock from the core-mantle boundary through the mantle to become a diapir (intrusion) in the Earth’s crust.

pluricellularity: the structure of multiple cells aggregating in an organized manner. Biofilms are pluricellular, as are bacterial filaments. Contrast multicellularity.

pneumatophore: a specialized aerial root that enables a plant to breath air in habitats with waterlogged soil. The black mangrove is differentiated from other mangrove species by its pneumatophores.

pod (social): a social group; often used with marine mammals.

podophyllin: a derivative from the rhizome of the American Mayapple, once commonly used against genital warts. Podophyllin is toxic and has side effects on the skin where applied.

poikilohydry: an organism lacking a mechanism to prevent desiccation, as it is tolerant of large fluctuations in hydration. Lichen and bryophytes are poikilohydric.

point mutation (genetics): a mutation of a single nucleotide exchanged for another.

Polar cell: an atmospheric circulation belt between latitude 60° and the pole.

polar easterlies: the winds from the polar cell, twisting westward because of the Coriolis effect.

polar front: the boundary between the polar cell and the Ferrel cell in each hemisphere.

polar jet: the jet stream nearest either pole.

polarization (optics): a state of light in which the radiation exhibits distinct properties in different directions.

polistine: a eusocial wasp in the Polistinae subfamily, which has ~1,100 species in 4 tribes. Polistines are commonly known as paper wasps, though other wasps, such as the yellow jacket, make their nests from paper. These wasps are mostly tropical or subtropical, yet some of the most frequently encountered wasps in temperate biomes are polistines.

pollen (botany): a mass of male microspores (microgametophytes) in a seed plant.

pollination: the process of transferring pollen, enabling plant fertilization and reproduction.

polyacetylene ((C2H2)n): an organic polymer with the repeating compound. Polyacetylene has high electrical conductivity.

polyandry: a mating system of 1 female and 2 or more males. Contrast polygyny.

polyatomic ion (aka molecular ion): an ion with 2 or more atoms covalently bonded which act as a single unit. Historically, a polyatomic icon was referred to as a radical.

polychaetes (aka Polychaeta): a class of hardy marine worms.

polydnavirus: a double-stranded DNA virus with a symbiotic relationship with parasitoid wasps. There are 2 genera of polydnavirus, based upon infected wasp genus (ichneumonid, braconid), with at least 53 species.

polygamy: a mating system of having multiple contemporaneous mates. Contrast monogamy. See polyandry and polygyny.

polygyny: a mating system where 1 male mates with 2 or more females. Contrast polyandry.

polymath; a person learned in several fields of study.

polymer: a macromolecule (large molecule) comprising repeating monomers (molecular units).

Polynucleobacter: a genus of freshwater bacteria, some of which are free-living, others as obligate endosymbionts of Euplotes ciliates.

polyp: an organism with a fixed base, columnar body, and an open end with mouth and tentacles.

polyphagy: the ability of an animal to eat a variety of food. Contrast monophagy. Compare oligophagy.

polyphenol (C6H5OH): a polymer comprising phenol.

polyphenol oxidase (aka PPO): an enzyme with various roles depending upon species. In insects, PPO provides desiccation tolerance.

polyphyletic (polyphyly): a classified group of organisms characterized by 1 or more homoplasies: traits that appear to be the same, but not inherited from a common ancestor. Endothermic animals, which includes birds and mammals, are polyphyletic. The last common ancestor of birds and mammals was ectothermic. Endothermy evolved independently in the ancestors of birds and the ancestors of mammals.

polyploidy: cells with more than 2 paired (homologous) sets of chromosomes. Polyploidy is common in ferns and flowering plants. Some animals, such as goldfish, salmon, and salamanders, possess polyploidy. In other animals, polyploidy may result from abnormal cell division.

polysaccharide (aka glycan): a complex sugar-based macromolecule. Starch and glycogen are polysaccharides, as are cellulose and chitin, which plants employ as structural materials. Compare monosaccharide.

popoto (aka Maui’s dolphin): the smallest dolphin; rare.

poppy: a flowering plant in the Papaveroideae subfamily of the Papaveracea family. One species is notably notorious: the opium poppy (Papaver somniferum).

population (biology): conspecifics within a geographical area.

porcupine: the 3rd-largest rodent (behind the capybara and beaver), with a coat of sharp spines, indigenous to the Americas, southern Asia, and Africa. Mostly nocturnal, porcupines are herbivores.

Portuguese man o’ war (aka Man-of-war, bluebottle, floating terror, Physalia physalis): a marine siphonophore, with venomous tentacles that deliver a nasty sting. This creature is a colony of specialized individuals (zooids), so physiologically integrated that they are incapable of independent survival.

potassium (K): the element with atomic number 19; a silvery-white alkali metal that rapidly oxidizes in air and is highly reactive in water. Potassium is chemically similar to sodium.

potato: a tuber of the perennial nightshade Solanum tuberosum. The potato plant is native to the Andes mountains. It was domesticated by Peruvians 10,000 years ago and is now eaten worldwide.

potato blight (Phytophthora infestans): an oomycete that blights potatoes.

potato bug (aka Colorado potato beetle, Leptinotarsa decemlineata): a 1-cm beetle with a bright yellow/orange body, and 5 bold, brown stripes that run the length of its elytra.

potoroo: a rat-like Australian marsupial. The 3 still-extant species of potoroo will soon be extinct, thanks to habitat loss, introduced species (especially foxes), and their being considered a pest to crops.

potto: a quiet, slow-moving central African strepsirrhine that inhabits the canopy of rain forests.

pouteria: a flowering tree in the Pouteria genus, widespread throughout the tropics. Pouteria maxima is a keystone species in the rainforests of Guyana.

poxvirus: a virus in the Poxviridae family which infects arthropods and vertebrates, including humans. The best-known poxvirus is smallpox.

prairie vole (Microtus ochrogaster): a small vole native to central North America.

prayer plant (Maranta leuconeura): a perennial, native to Brazilian tropical forests, so called for its habit of laying its leaves out flat during the day and folding them erect at night.

precipitate (verb): to separate from solution or suspension.

precipitation: rain, sleet, ice, snow, and fog. More generally, also defined as the quality of being precipitate, or hasty.

precocene: a compound produced by plants that inhibits juvenile hormone biosynthesis in insects.

precocial: animals with relatively mature and mobile young from the moment of birth or hatching. Many, though not all, arthropods, fish, amphibians, and reptiles are precocial. Contrast altricial.

predator: an organism that consumes other animals as a primary food source. A top predator is a predator that is not preyed upon by another organism (pathogens aside). Compare herbivore, omnivore, and saprovore.

primal emotion: an emotion common to most animals. Compare secondary emotion.

primary cilium: a non-motile animal cell that acts as a transceiver to detect local information external to a cell and act as a cell status transmitter.

primary growth: plant cell division at the tips of roots and stems, causing elongation. Compare secondary growth.

primary metabolite: a compound produced by a plant that is essential to its survival. Compare secondary metabolite.

primate: a mammal order containing prosimians (neither monkey nor ape) and simians (monkeys and apes).

primatology: the study of primates.

primeval forest (aka virgin forest, old-growth forest): a forest having obtained great age without major ecological disturbance. Contrast secondary forest.

primitive (evolutionary biology): evolved early compared to later organisms in a clade.

prion: a misfolded protein that pathogenically propagates.

proboscis: an elongated appendage from the head of an animal. In invertebrates, the proboscis usually refers to the tubular mouth parts used for feeding. In vertebrates, the term is descriptive of a snout (e.g., shrews, tapirs, elephants).

proboscis monkey (aka long-nosed monkey): a reddish-brown arproboscis monkey (aka long-nosed monkey): a reddish-brown arboreal monkey with an outsized nose, endemic to the mangrove swamps of Borneo.

procambium: the primary meristem that develops into a plant’s vascular system. The procambium is inside the protoderm.

Prochlorococcus: a genus of tiny marine cyanobacteria.

producer (biology) (aka autotroph): an organism capable of sustaining itself by inorganic means. Plants are producers. Contrast consumer.

progressive provisioning: partially digesting food and passing it to another organism, typically offspring.

prokaryote: an organism that lacks a cell nucleus or other membrane-bound organelles. Archaea and bacteria are prokaryotes. While prokaryotes are single-celled, most can form stable, aggregate communities, such as a biofilm. Compare eukaryote.

prolactin (aka lactotrope): a hormonal protein with various functions among different species.

prophage: a bacteriophage genome inserted and integrated into a bacterium’s genome.

propolis: a resinous mixture that honeybees produce from resin collected from sap flows, tree buds and other sources. Propolis is used to seal cracks, and so weatherproof a hive. Propolis is also used medicinally, to get help cure bacterial or fungal infections.

proprioception: an organism’s sense of physical self, including the relative position of various body parts and their employment, and as well the energy required for movement or other activity.

prosimian: the suborder of primate which includes lemurs, bushbabies, and tarsiers, among others. See simian.

protandry: a male that can change into a female.

protease (aka peptidase, proteinase): an enzyme employed by all organisms to facilitate digestion, particularly breaking apart the peptide bonds that hold amino acids together.

protein: a single, long, linear polymer chain of amino acids that typically takes a folded structure; a complex organic macromolecule by which living bodies are intelligently built. See enzyme.

proteome: (the idea of) the entire set of proteins expressed by a cell’s or organism’s genome.

Proteobacteria: a phylum of bacteria. Some are pathogens. Others are nonparasitic. Many nitrogen-fixing bacteria are Proteobacteria.

Proterozoic (2.5 BYA–542 MYA): the 3rd of 4 geological eons, characterized by early life (based upon an outdated estimate, lasting up to the Cambrian period).

prothallus: the gametophyte stage in the life of a fern or other pteridophyte (a vascular plant that does not produce seeds).

protist: a catchall kingdom of eukaryotic organisms, including algae and amoeba. Most protists are unicellular, though many practice pluricellularity.

protocell: a cellularly contained set of chemical reactions with evolutionary potential.

protoderm: the primary meristem that develops into a plant’s epidermis (outer layer of tissue).

protogyny: a female that can change into a male.

proton pump: a protein, integral to a cellular membrane, that can push protons across a cell or organelle membrane. Proton pumps create a proton gradient, causing a differential in pH and electrical charge, thus creating an electrochemical potential which works as an energy storage unit (like a battery). Energy from ATP comes via a proton pump.

protozoan (plural: protozoa): a single-celled, typically microscopic heterotroph. Protozoa live in aqueous environments and soil. They occupy a range of trophic levels. Protozoa are called animal-like protists because they subsist on other organisms.

prymnesin (C93H137Cl2NO36): a phycotoxin produced by Prymnesium parvum.

Prymnesium parvum: a species of golden algae that can both photosynthesize and carnivorously hunt via cooperatively- produced venom (prymnesin).

pseudocoelomate: an animal with a body cavity with loosely organized organs, as contrasted to coelomates, with quite organized organs (such as all vertebrates), or acoelomates, like flatworms, who have no body cavity at all.

Pseudomonas: a diverse genus of plant-related bacteria with 191 species. Some are plant symbionts, others pathogenic.

Pseudomonas carboxydovorans (aka Oligotropha carboxidovorans): a soil bacterium that consumes carbon monoxide.

Pseudomonas putida: a beneficial rhizobacterium.

Pseudomonas syringae: a pathogenic bacterium that can infect a wide variety of plants, causing characteristic brown spots. P. syringae is a common cause of surface frost damage in plants. P. syringae produces coronatine, which confuses a plant’s defense system.

Pseudomyrmex: a genus of wasp-like, stinging (venomous) ants. Certain species, including P. triplarinus and the P. viduus group, have a mutually protective mutualism with Triplaris trees: the ants fiercely protect the tree from all comers in return for lodgings within the tree and a wholesome diet.

pseudopod (aka pseudopodium; plural: pseudopods or pseudopodia): a temporary cytoplasm-filled projection from a unicellular protist or eukaryotic cell used for motility; from the Greek for “false foot.”

pseudoscorpion: an arachnid resembling a scorpion in having front pincers and a flat, pear-shaped body, but lacking the scorpion’s tail stinger. Some pseudoscorpions have elaborate mating dances.

psilocybin (C12H17N2O4P): an alkaloid produced by over 200 mushroom species to deter fungivores. Psilocybin metabolizes to psilocin. Ingested by humans, psilocybin is an agent of dissociation. In high doses, psilocybin is hallucinogenic.

psychology: the study of the mind, leading to philosophy about the mind. There can be no science of the mind. An individual psychology is characterized by mental and behavioral habits.

psychrophile: an extremophilic organism adapted to cold: –15 °C to 10 °C.

ptarmigan (aka Rock Ptarmigan): a sedentary, herbivorous, medium-sized bird in the grouse family.

pteridophyte: a vascular plant that reproduces and disperses via spores, producing neither flowers nor seeds.

public good: something that is publicly shared. By contrast, a private good is possessed or consumed by an organism with limited or no sharing.

puffball: a round fungus which contains and emits brown, dust-like spores.

puffbird: a small, carnivorous, tropical, near passerine native to Mexico and South America.

pulvinus: a joint-like thickening of plant cells at the base of a leaf that facilitates growth-independent movement.

puma (aka cougar, mountain lion, Puma concolor): a large, secretive felid.

pupa (plural: pupae or pupas): a development stage in an insect: typically quiescent, often enclosed in a cocoon or case, after the larval stage of development, before emerging as an adult.

purgative: something that works as a cathartic or laxative.

purple bacteria: a phototrophic bacteria group that includes Escherichia.

purple loosestrife (Lythrum salicaria): a herbaceous perennial native to northwest Africa, Europe, Asia and southeastern Australia.

purple pitcher plant (northern pitcher plant, turtle socks, side-saddle flower, Sarracenia purpurea): a carnivorous plant endemic to the bogs and infertile sandy soils of North America.

purposive behavior: action(s) taken expecting a specific outcome.

Puschkinia: a genus of bulbous perennials with 2 species, native to the Middle East and Asia.

pygmy pipe (aka sweet pinesap, Monotropsis odorata): a flowering plant that employs camouflage to protect its flowers, disguising them as woodland leaf litter.

pyramidal saxifrage (Saxifraga cotyledon): a long-lived European alpine plant with thick, dense leaves, adapted to stressful environments.

python (family): a nonvenomous snake in the Pythonidae family, with 31 species in 8 genera, endemic to Africa, Asia, and Australia.

python (genus): a nonvenomous snake of 11 extant species in the Python genus, endemic to Africa and Asia.


quail: a mid-sized bird of several genera.

quantum (physics) (plural: quanta): an infinitesimal chunk of ripple in a localized energy field that appears as a particle.

quantum coherence: the efficiency (coherence) of seeming quantum particles behaving in a wavelike manner.

quorum-sensing: decision-making in a decentralized network.

quartz: a crystal in a framework of silicon-oxygen (SiO4) tetrahedra, where each tetrahedron shares an oxygen atom, effectively rendering SiO2. Quartz is abundant in Earth’s continental crust.

Queen Anne’s lace (aka wild carrot, Daucus carota): a variable biennial plant native to temperate regions of Europe and southwest Asia. Wild carrot root is edible while young, but quickly becomes too woody. Described by Hippocrates as a contraceptive.

quelea: a seed-eating African passerine in the weaver family.

quinone: a class of aromatic organic compounds variously comprising carbon, oxygen, hydrogen, chlorine, and/or nitrogen. Numerous critters produce quinones.


racer snake (aka Galápagos racer, Pseudalsophis biserialis or Philodryas biserialis): a colubrid snake endemic to the Galápagos Islands.

rachis: an axial structure.

racoon: a medium-sized mammal native to North America. The most distinctive traits of the racoon are its dexterous front paws and its facial mask, which featured in the mythologies of native American tribes.

radiation (evolutionary biology): profuse adaptive speciation.

radical (chemistry): a reactive atom, molecule, or ion owing to an unpaired valence electron. See polyatomic.

radiolysis: radioactive molecular decay.

radioresistant: ionizing radiation resistant.

Raffles’ pitcher plant (Nepenthes rafflesiana): a tropical pitcher plant native to Borneo, Sumatra, peninsular Malaysia, and Singapore, with at least 3 distinct varieties; named after Stamford Raffles.

raft spider (aka fishing spider, Dolomedes fimbriatus): a dark-bodied spider with a conspicuous light stripe that walks on water. Raft spiders run down their prey on water. They can submerge altogether to hide from predators.

rail: a small to medium-sized bird in the large cosmopolitan Rallidae family. Rails live on every continent except Antarctica. Rails have short, rounded wings. Rail flight is not powerful, but they can stay aloft for prolonged periods. For lack of power, rails are easily blown off course, and thereby are common vagrants. This has resulted in rails colonizing many oceanic islands.

ramshorn snail: a freshwater snail in the Planorbidae family. The common name refers to the planispiral (coiled) shells that the snails have.

raptor (aka bird of prey): a carnivorous bird.

rat: a medium-sized, long-tailed rodent with superior cunning.

ratel: see honey badger.

rattlesnake: a venomous snake with a rattle at the end of its tail. Rattlesnakes kill by bite rather than constriction. 32 species are known.

raven: a relatively large corvid endemic to the northern hemisphere. The common raven is the largest perching bird.

ray spider: a spider of ~30 species which constructs a cone-shaped web.

ray-finned fish (Actinopterygii): a class of bony fishes, comprising nearly 99% of fish species, over 30,000 species; so-called because their fins are webs of skin between bony spines (rays), as contrasted to fleshy, lobed fins (lobe-finned fish).

reactive oxygen species: chemically reactive molecules containing oxygen.

reactivity: the tendency to react from deep-seated emotion, especially fear.

reception: perception of a communication signal.

receptor (cytology): a cell signal receiver; a specific area on a cell, typically on its surface, with 1 or more proteins which are either receptive to stimulus, or which are identifying something contacting it; the term is also used as a misnomer by virologists for the cell binding site that viruses favor.

recessive (trait): a genetic trait (allele) that is masked by a dominant trait.

recombination (genetics): mixing traits during meiosis that introduces diversity in offspring.

red colobus: a primarily arboreal Old World monkey native to western, central, and eastern Africa that lives in humid forests. Red colobuses live in groups of up to 80 members, albeit averaging 20–40, with twice as many females as males in a group. Groups establish dominance hierarchies via aggressive behavior. Red colobus monkeys are frequently hunted by chimps.

red deer: the 4th largest deer species (behind the moose, wapiti, and sambar deer); resident in Europe, western and central Asia.

red junglefowl (Gallus gallus): a tropical bird in the Phasianidae family, native to India, Southeast Asia, Indonesia, and nearby islands.

red-eyed vireo (Vireo olivaceus): a small American songbird.

redback spider (Latrodectus hasseltii): a nocturnal, venomous spider indigenous to Australia.

redbelly snake (Storeria occipitomaculata): a nonvenomous snake endemic to eastern North America that may play dead when distressed.

redd: the nests of a female fish.

reduction (chemistry): a gain of electrons or a decrease in oxidation state to an atom or molecule; typically, reaction with hydrogen. Contrast oxidation.

reef: a rock or other structure underwater.

regression (biosphere): sea-level lowering. Contrast transgression.

reindeer (aka caribou in North America): a deer of the Arctic and Subarctic, resident in tundra and taiga biomes.

reishi: a medicinal mushroom in traditional Chinese medicine.

reovirus: a virus of at least 87 species among 30 genera in the Reoviridae family, with a genome of double-stranded RNA and multi-layered capsids.

reptile: a clade of ectothermic, tetrapod, amniote vertebrates that is neither bird nor mammal.

reserpine (C33H40N2O9): an alkaloid derived from the root of the Indian snakeroot; a traditional Indian medicine for insanity, fever, and snakebite.

respiration (cellular): the metabolic processes and reactions that convert nutrients into ATP, with waste products released.

retinal (aka retinaldehyde, vitamin A aldehyde): one of many forms of vitamin A. Retinal binds to the protein opsin, which is the chemical basis of animal vision.

retinoic acid: a metabolite of vitamin A that mediates the functions of vitamin A required for growth and development. Chordate animals need retinoic acid.

retrotransposon: (aka transposon via RNA intermediates): a genetic element that can amplify itself in a genome. Retrotransposons are considered a subclass of transposons.

retrovirus: a family of enveloped viruses the replicate in a host cell via reverse transcription.

return-on-investment (ROI): the concept of an investment in a resource yielding a benefit to its investor.

reverse transcriptase: a DNA enzyme that transcribes single-stranded RNA into single-stranded DNA.

reverse transcription: the process of creating a single-stranded DNA from an RNA template via reverse transcriptase.

rheid (geology): a solid deformed by viscous flow. A solid becomes a rheid by sustained observation (that is, experiencing its deformation). The term was coined by Warren Carey in 1953. Contrast fluid.

rhesus macaque (Macaca mulatta): a mid-sized Old World monkey, native to south, central, and Southeast Asia; inhabiting a great variety of habitats, from grasslands to arid and forested biomes. Rhesus macaques are avid swimmers, which is unusual for monkeys.

rhizobacterium: a plant-beneficial soil bacterium.

rhizobia: soil bacteria of several species that cooperatively provide nitrogen fixation services for legumes. Rhizobia cannot by themselves fix nitrogen.

rhizoid: a specialized root-like tissue.

rhizome: a creeping rootstalk (underground stem shoot(s)) of a cloning plant.

rhizosphere: soil managed by plant roots via secretions. By contrast, bulk soil is outside the rhizosphere.

rhododendron: a genus of over 1,000 species of woody plants in the heath family. Most rhododendrons have showy flowers.

Rhodopseudomonas palustris: a common, waterborne, purple bacterium that can switch between different modes of metabolism.

rhubarb (Rheum rhabarbarum): an herbaceous perennial growing from short, thick rhizomes. Whereas the large leaves are poisonous, the long fleshy stalks are edible. Rhubarb has been used medicinally by the Chinese for thousands of years. By contrast, eating the stalks as food was first documented in 17th century England.

rhythm: the percussive propulsion of music. Compare melody.

ribosome: the cellular factory for synthesizing proteins from peptide pieces.

ribozyme: an RNA-based enzyme.

Rickettsia: a genus of obligate intracellular bacteria parasites. Rickettsia depend the cytoplasm of a eukaryotic host cell for growth and replication. Rickettsia are known to infect protists, leeches, arthropods, and humans.

rift (geology): a chasm where crust and lithosphere are pulled apart.

Rig Veda (~1500–1200 BCE): an Indo-Aryan collection of 1,028 hymns and 10,600 verses in Sanskrit; 1 of the 4 canonical Vedas which form the basis of Hinduism. The other Vedas are: Athar, Sama, and Yajur.

Ring of Fire: a 1963 Johnny Cash song: “love is a burning thing, and it makes a fiery ring.” Perhaps you intended the Pacific Ring of Fire.

rinkhal (aka ringhal, ring-necked spitting cobra, Hemachatus haemachatus): a venomous, ovoviviparous, spitting snake of southern Africa. Not a true cobra, though it looks like one, but closely related.

riparian: the bank of a natural watercourse, such as a stream, river, or lake.

risk sensitivity: the capability of an organism to discriminate between stable and unstable environments.

river: a natural watercourse, usually freshwater, that flows to a lake, sea, or ocean.

RNA (ribonucleic acid (C5H10O5)): a macromolecule comprising a long chain of nucleotides. RNA & DNA differ by their sugar (ribose versus deoxyribose (a ribose lacking an oxygen atom)). RNA & DNA also differ by 1 nucleobase: whereas RNA uses uracil (U), DNA employs thymine (T). See DNA.

RNA interference (RNAi): an epigenetic regulator of gene expression. RNAi limits gene expression.

roadrunner (aka chaparral bird): a fast-running ground cuckoo with a long tail and crest, endemic to the deserts of the southwestern United States and Mexico, in the genus Geococcyx, with 15 species.

robin: a common name for a passerine with a red or orange breast. The European robin (Erithacus rubecula) and American robin (Turdus migratorius), which are not closely related, are exemplary robins. The European robin is an Old World flycatcher. The American robin is a thrush.

rock ant (Temnothorax albipennis): a small European ant that builds simple nests in rock crevices using tiny pebbles and grains of sand.

rock-rose: a small family of flowering plants endemic to the temperate areas of Europe and the Mediterranean basin, as well as North America, with a few species in South America.

rockcress: a small flowering plant in the Arabidopsis genus, related to mustard and cabbage. There are 9 rockcress species.

rodent: an order of mammals characterized by constantly growing incisors that must be kept short by gnawing. ~40% of mammal species are rodents; 2,227 known species.

Rodinia (1.1–0.8 BYA): the supercontinent containing all of Earth’s landmass, centered at the equator. Rodinia began breaking up around 800 MYA, ending the abysmal chill of the Cryogenian period.

roe (singular & plural): fish egg masses (clusters).

room temperature: 17–25 °C; an average of 23 °C.

rootless duckweed (aka spotless watermeal, Wolffia arrhiza): an aquatic plant; the smallest vascular plant in the world.

rorqual whale: the largest group of baleen whales, with 9 species, including the largest animal that has ever lived: the blue whale. Rorquals are slender and streamlined compared to their cousins, the right whales. Most roquals have narrow, elongated flippers. Rorquals have folds of skin that allow them to widely open their mouths for feeding, which they do by gulping in water, then pushing it out through their baleen plates with their tongue. Rorquals feed on crustaceans such as krill, but also on various small fish, including sardines and herring.

rose: a woody perennial, well known for gorgeous flowers.

rostrum: the snout or beak-like projection from the head of a dolphin or other vertebrate. The term rostrum is overloaded with similar meaning for invertebrate parts. The forward extension from the carapace (front section) of a crustacean is its rostrum. Mollusks have beak-like mouthparts which are referred to as a rostrum (or proboscis).

rotifer: a tiny pseudocoelomate animal.

rove beetle: a beetle in the largest family of beetles (Staphylinidae), which has a lineage back to the Triassic, 200+ MYA.

royal jelly: bee milk fed to gyne larvae and adult queens, containing royalactin.

rumen (aka paunch): the 1st chamber of the alimentary canal of ruminant animals. The rumen is the primary site for microbial fermentation of ingested food.

ruminant: an herbivorous mammal with a rumen.


saccharide: sugar (in any form).

safranin (C20H19ClN4): a red dye, used in Gram staining.

sage: a shrub in the Salvia genus of 1,000 species, in the mint family.

sage rat (aka Belding’s ground squirrel, pot gut, picket-pin, Urocitellus beldingi): a largely herbivorous ground squirrel endemic to the mountains of the western United States, at 2,000–3,600 m elevation.

sagebrush: a plant of several species of woody and herbaceous plants adapted to arid conditions. Many sagebrushes are in the Artemisia genus.

Sahara Desert: the largest subtropical desert covering most of north Africa; the 3rd-largest desert in the world, after Antarctica and the Artic. Some Sahara sand dunes reach 180 meters.

Saint Anthony’s fire (aka ergotism): ergot poisoning, commonly caused by ingesting rye or other cereals infested with ergot fungus.

salamander: an amphibian typically characterized by a lizard-like appearance, with a short nose, slender body, and long tail. Salamanders have been around for 164 million years.

Salem witch trials (1692–1693): a series of persecutions of impoverished women as witches, in Salem Massachusetts, by God-fearing Christians.

salicin (C13H18O7): a glycoside produced by willow trees.

salicylic acid (C7H6O3): a plant hormone.

salicylaldehyde (C7H6O2): a colorless, oily liquid with a bitter almond odor which is a characteristic aromatic component of buckwheat. Several leaf beetle larvae in the subtribe Chrysomelina secrete salicylaldehyde to ward off predation.

salmon: a common name for several species of fish; others in the family are called trout. Salmon live in the North Atlantic and Pacific Oceans. There are 5 known Pacific salmon species: chinook, chum, coho, pink, sockeye. Salmon are typically anadromous: born in fresh water, migrate to the ocean, then return to fresh water to spawn (reproduce). Some populations of several species restrict themselves to fresh water throughout their lives.

Salmonella: a genus of rod-shaped bacteria with 2 species, one of which is found in endothermic animals (and the environment), the other in ectothermic animals.

sand puppy (aka naked mole rat, desert mole rat): a eusocial burrowing rodent native to East Africa.

sap: fluid transported in xylem or phloem tissue. Xylem sap is largely water, with hormones, mineral elements, and other nutrients in solution. Phloem sap comprises primarily water, with sugars, hormones, and minerals dissolved therein.

saponin: an amphipathic glycoside that is found in some plants and marine organisms. The name derives from the soapwort plant.

saprovore (aka detrivore, decomposer, saprobe, saprotroph): an organism that consumes decaying organic matter. Compare herbivore, omnivore, and carnivore.

sardine (aka pilchard): a small, oily fish related to herring.

satellite virus: a subvirus (viral agent) that depends upon another virus for infection of a host cell.

saturated fat: a fat molecule with only single bonds between carbon atoms. Contrast unsaturated fat.

saturation vapor pressure: see vapor pressure.

saturniid moth: one of the largest and most spectacular of moths. 2,300 species are known.

savanna (aka savannah): a grassland biome with trees sufficiently spaced so that the canopy does not close, despite a tree density that may be greater than a forest.

saw-scaled viper (Echis carinatus): an ill-tempered, toxic viper that hisses and rubs its scales together to loudly rasp when agitated.

scale insect: a 1–5 mm insect in the Coccoidea family, of over 8,000 species. Scales are plant parasites. Females practice neoteny: remaining in their immature form even when adult.

scarlet gilia (aka scarlet standing-cypress, skyrocket, skunkflower, Ipomopsis aggregate): a hardy American western wildflower.

scarlet pimpernel (aka red chickweed, poorman’s barometer, Anagallis arvensis): a low-growing annual plant native to north and west Africa and Europe.

schizogeny (botany): the process of forming aerenchyma.

schizophrenia: a mental disorder often characterized by short attention span, disorientation, and abnormal social behavior.

school (of fish): fish of the same species that swim synchronously. This is most efficient, as the schooling arrangements fish use minimize the drag from wakes created by swimming. Compare shoal.

Scleroglossa: a clade of lizards that includes worm lizards, geckos, anguids, skinks, and snakes. See iguana.

scorpion: an arachnid with a pair of grasping pedipalps (pincer claws), and a narrow, segmented tail sporting a venomous stinger.

scrub jay: a jay native to central America, the western United States, and Florida.

scute: an external bony plate or large-scale.

sea: a large body of saltwater partly or wholly surrounded by land, not as deep as any ocean.

sea anemone: a water-dwelling predatory animal in the Actiniaria order. Sea anemone attach themselves to a surface with an adhesive foot.

sea lion: a large aquatic pinniped, characterized by long foreflippers, the ability to walk on all fours, short, thick fur, and external ear flaps. Adult males weight 300 kg; females 100 kg.

sea otter: a marine mammal in the weasel family, endemic to the coasts of the northeastern Pacific Ocean. Sea otters have the densest fur of any animal.

sea slug: a saltwater snail, lacking a shell, or only having an internal shell.

sea star (aka starfish, despite not being a fish) a star-shaped echinoderm. Sea stars have been around for at least 450 million years.

sea turtle (aka marine turtle): a marine turtle of 7 species. The sea turtle species are: the flatback, green, hawksbill, Kemp’s ridley, leatherback, loggerhead, and olive ridley.

sea urchin (aka sea hedgehog): a small, spiny, globular marine animal, closely related to the sand dollar.

seagrass: a marine angiosperm that resembles grass, of ~60 species. Seagrasses descended from terrestrial grasses 75–100 million years ago.

seagull: an assertive, inquisitive seabird, related to terns. Seagulls are opportunistic omnivores, able to drink saltwater as well as fresh.

seahorse: a marine fish of 54 species in the genus Hippocampus.

seal: a semiaquatic marine pinniped. Seals are typically barrel shaped, with sleek bodies.

searocket (aka Cakile): a flowering annual plant in the mustard family. Searockets commonly grow close to the coast.

seaweed: a macroscopic, multicellular, benthic marine alga, either green, red, or brown, of ~12,000 species.

second messenger: see 2nd messenger.

secondary emotion: an emotion that is the product of sustained mentation. Compare primal emotion.

secondary forest: a forest which has regrown after a major ecological disturbance, such as a fire. Contrast primeval forest.

secondary growth: plant cell division in cambia or lateral meristems, causing roots and stems to thicken. Compare primary growth.

secondary metabolite: a specialty compound produced by a plant for ecological purposes. Compare primary metabolite.

secretary bird (Sagittarius serpentarius): a large bird of prey, native to the savanna of sub-Saharan Africa.

sediment (geology): a soil mixture containing small particles of rock. Sediment is classified by grain size and/or composition.

sedimentary (rock): a rock formed by cumulative material deposit. Compare igneous and metamorphic. See basement.

seed: an embryonic plant covered in a coat, usually with some stored food (endosperm) packed within.

sego lily (Calochortus selwayensis): a bulbous perennial endemic to the Western United States.

seismonastic (response): a rapid (1–2 second) plant response to tactile stimulation.

self-organized criticality: a property of dynamic systems where a critical threshold (tipping point) exists that, when passed, sets off a substantial reaction.

sensate, sensation: receiving stimuli from sensory organs for collation and interpretation via perception.

sense (physiology): a means of sensation.

sensillum (plural: sensilla): a simple epithelial sense organ comprised of few cells. Sensilla usually take the form of a plate, scale, spine, rod, cone, or peg. Arthropods and squamates have sensilla.

sensory: pertaining to sense organ stimulation.

sepal: a modified leaf that comprises the petals of a flower. Collectively, the sepals are termed calyx, which is the outermost whorl of parts that forms a flower. Sepal forms vary considerably among flowering plants. The number of sepals – merosity – is indicative of a plant’s classification. Eudicot flowers typically have 4 or 5 sepals. Monocots and paleodicots have 3, or a multiple of 3, sepals.

serotonin: a neurotransmitter with various roles, depending upon species. In humans, serotonin is associated with feelings of well-being. Serotonin is found in fungi and plants as well as animals.

serotype: one of numerous variations of immunities (antigenic makeup) in a species of bacteria or virus. See phage type, pathotype.

Serengeti: a 30,000 km2 African ecosystem in equatorial East Africa, south and east of Lake Victoria. The Serengeti is known for a circular animal migration which follows the rainfall, and thus grazing grasslands, through the region.

sessile: not free to move about. Plants are sessile. Contrast motile.

seta (plural: setae): stiff bristles on an animal body, often used for motility. Earthworms rely upon setae to grip a surface while moving another part of their body. Setae on the legs of krill and other small crustaceans help scoop phytoplankton.

sex: female or male specialization, excepting organisms which have more than 2 sexes. Also, colloquially used for the act of sexual reproduction, which combines genetic contributions from a male for a female to produce offspring. Compare gender.

sexual dimorphism: an innate size difference between male and female animals. A wide variety of animal species, including arthropods, fish, reptiles, birds, and mammals, possess sexual dimorphism. While males larger than females is typical, every animal group with sexual dimorphism has some species with larger females.

sexuality: the state of sexual activity.

Shakers (aka The United Society of Believers in Christ’s Second Appearing): an American religious sect founded upon the teachings of Ann Lee. Founded in 1758, Shakers lived a conservative lifestyle, but were socially progressive. They practiced equality of the sexes long before it was generally recognized as equitable.

At their height in the 19th century, Shakers lived in more than 20 settlements which had attracted at least 20,000 converts. As strict believers in celibacy, Shakers acquired new members via conversion, indenturing children, and adopting orphans.

The Shaker educational system was exceedingly advanced. It included literacy, oration, arithmetic, and manners. Shaker educational quality was so esteemed that outsider parents would drop their children off at a village to be schooled, returning several years later to pick them up.

Shaker life was too disciplined for most. Once a child was 21 years old, s/he had the option to remain a Shaker. Less than 1/4th chose to do so. Turnover was high. At the end of 2009, only 3 Shakers were left, residing in Sabbathlake Maine.

shark: an extremely successful order of fish that evolved more than 420 MYA; success owing to a superb generalist design.

sheep (Ovis aries): a stocky, even-toed ungulate ruminant, domesticated since antiquity for its wool. Female sheep are called ewes, whereas male sheep are called rams.

shield volcano: a type of volcano built by effusive eruptions that produce fluid lava flows of low-viscosity mafic lava. The term shield volcano derives from such a volcano producing a broad, gently sloping base from a central dome, resembling a warrior’s shield.

shining black ant (Lasius fuliginosus): a small black ant, endemic to central Europe.

shoal: fish that stay together for social reasons. Compare school.

showtivity: the seeming objectivity of Nature via a shared experiential platform provided by Ĉonsciousness and coherence as an ordering principle for the perception of Nature.

shrew: a small mammal that resembles a mole. There are shrews on all the major tropical and temperate land masses except New Guinea, Australia, and New Zealand.

shrew-rat (Paucidentomys vermidax): an earthworm-eating Indonesian rodent.

shrimp: a crustacean with an elongated body and primarily swimming mode of locomotion.

Siamese fighting fish (Betta splendens): a freshwater fish native to the Mekong basin, favoring standing waters.

siblicide: the practice of an animal killing its sibling(s).

side-blotched lizard: a lizard of the genus Uta; one of the most common lizards in the deserts of western North America.

siderophore: a high-affinity iron-chelating compound secreted by microorganisms, such as bacteria and fungi, but also by some plants, notably grasses.

sieve element cell: a specialized elongated cell in phloem, interconnected with other such cells to form a sieve tube which transports nutrients.

sifaka: a lemur in the Propithecus genus, named as an onomatopoeia of their characteristic “shi-fak” alarm call.

signal: an output of communication.

signal transduction: a 2-step cellular communication process. 1st, an extracellular signaling molecule activates a receptor on a cell surface. 2nd, surface reception prompts creation of another molecule, termed a 2nd messenger, which carries the signal into the cell, typically either the nucleus or cytoplasm.

silica: an oxide of silicon (SiO2). Silicate minerals make up 90% of the Earth’s crust.

silk: a natural protein fiber, composed mainly of fibroin.

silky flycatcher: a small family of passerines, with 4 species in 3 genera native to Central America.

silphium (aka silphion, laserwort): an extinct plant related to fennel. It was used medicinally in antiquity for a wide variety of ailments. The silphium trade was so important to the economy of the ancient north African city of Cyrene that most of its coins bore the image of the plant. Overharvesting led to the silphium’s extinction.

Silurian (444–417 MYA): the 3rd period of 6 in the Palaeozoic era, following the Ordovician and preceding the Devonian. The Silurian saw the evolution of jawed and bony fish, and life first appearing on land. The name derives from the Celtic tribe the Silures, in south Wales from where the first studied rocks of the period came.

simian: the suborder of primate comprising the “higher primates”: monkeys, apes, and humans. Simians tend to be larger than prosimians (“lower primates”). See prosimian.

singing: vocally producing melodious sounds.

siphonophore: a marine zooid. The Portuguese man o’ war is a siphonophore.

sirato (aka red pea, wild dolly): a vine endemic to the American tropics.

skink: a lizard with small legs and lacking a pronounced neck in the Scincidae family. Several skink genera have no limbs at all. Skinks love digging and burrowing. They are typically insectivorous.

skua: a predatory seabird of 7 species in the Stercorarius genus which looks like a heavily built gull. Skua are long-distance migrants; the only bird that breeds in both the Arctic and in Antarctica, as well as in temperate regions.

sleepy lizard (aka bobtail, Tiliqua rugosa): a slow-moving, short-tailed, blue-tongued skink native to Australia. Its stumpy tail roughly resembles its head, and so may confuse predators.

slime mold: a protist that reproduces via zoospores. Single-celled slime molds forage by avoiding where they have been. As they move, slime molds leave a chemical trail that lets them identify their own secretions.

slit sensilla (plural: slit sensillae): a small mechanoreceptor organ on the exoskeleton of spiders that detects strain and vibration.

sloth: an arboreal mammal noted for its slow movements and metabolism, native to the tropical rainforests of Central and South America. There are 6 sloth species in 2 families: 2-sloths and 3-toed sloths. All sloths actually have 3 toes: 2-toed sloths have only 2 fingers on each forelimb.

smog: lingering foul air; a portmanteau of smoke and fog.

smolt: a fish in freshwater having physiologically adapted to handle saltwater.

smolting: physiological changes that adapt a fish (e.g., salmon) to survive in saltwater (from its freshwater origin).

snake: an elongate, legless, carnivorous reptile descended from lizards. 3,400 snake species are known.

snakeroot (Rauvolfia serpentine): a flowering plant native to south and east Asia, used medicinally for millennia in India.

snapper: a fish in the Lutjanidae family, typically marine, though some species inhabit estuaries. Snapper are found in tropical and subtropical regions of all oceans.

Snowball Earth (~800–630 MYA): a period in Earth’s history of episodic near-global glaciation.

snub-nosed monkey: a long-furred Asian monkey that lives in mountain forests; named because of a stumpy nose on a round face.

soapwort: a perennial herb in the Saponaria genus.

sociability: the tendency to be sociable. See gregarious.

social amoeba: a slime mold with group behaviors.

social learning: learning in a social context by observation, often involving imitation.

sociality: general affinity toward others, especially conspecifics. See gregarious.

sociobiology: zoological study that assumes social behavior patterns are an outcome of evolution.

sockeye (salmon) (aka red salmon, blueback salmon): a varied Pacific salmon species. Sockeye extend from the Columbia River in the eastern Pacific north across the Bering Sea to northern Hokkaidō, Japan. Due to excessive human harvesting, sockeye is recognized as endangered in the US.

sodium (Na): the element with the atomic number 11; a soft, silvery-white, highly reactive metal; always found in compounds. Sodium is the 6th most abundant element in the Earth’s crust, as silica. As sea salt, sodium and chloride are the most abundant (by weight) dissolved elements in the oceans.

soil: the surface layer of Earth’s crust. Soil is the product of weathering rock, decomposed organic matter, and the cumulative activities of the biotic community. Soil layers are termed horizons. A cross-section of soil horizons is a soil profile. Soils differ among ecosystems. Soils are classified as young, mature, or old. A young soil accumulates organic matter, hence continues to develop a profile. Mature soil holds its own, and so has a static profile. Old soil loses material: nutrients leach away. Old soil’s horizon diminishes.

solid: a substance with structural rigidity. Crystals and glasses are solids. Contrast fluid.

Solomon Islands: a country of 6 major islands and over 900 smaller islands in Oceania, east of Papua New Guinea.

solute: a substance dissolved in solution.

song: a sonic succession recognized as including a melody.

songbird: a passerine which sings (at least 1 sex of the species, typically males).

sophistry: subtly deceptive reasoning or argument.

sorocarp: a slime mold fruiting body.

South Africa: the country on the southern tip of Africa. The Cape Peninsula is a 52 km long, generally rocky peninsula in southwest South Africa that juts into the Atlantic Ocean. The most common mammal on the mountains of the Cape is the rock hyrax (aka dassie).

South Equatorial Current: a significant ocean current that flows east to west between 5° north of the equator and 20° south in the Pacific, Indian, and Atlantic oceans. The current is part of gyres driven by different winds in various parts of the world. On the equator in the Indian Ocean, monsoons cause the winds to reverse twice a year, whereby the surface current flows either eastward or westward depending upon wind flow.

Southern Ocean: the oceanic waters around Antarctica. The Southern Ocean includes the Antarctic Circumpolar Current.

Spanish moss (Tillandsia usneoides): a New World tropical and subtropical epiphytic angiosperm.

sparrow (aka true sparrow, Old World sparrow): a family of small passerines native to Eurasia. American sparrows are more closely related to Old World buntings than true sparrows and look and act like finches.

specialist (ecology): a species adapted to its specific habitat. Contrast generalist.

speciation: the process of species formation.

species (biology): a distinct population of organisms.

species (chemistry): chemically identical molecular entities with distinct interaction characteristics, typified by different ionization or lack thereof.

species diversity (aka species richness): the variety of species in an ecosystem. Compare biodiversity.

spectrum (plural: spectra, spectrums): an array of distinguished components of a wave or emission. Discriminative characteristics of a spectrum include wavelength, energy, or mass.

sperm: a male reproductive cell. Compare egg.

spermatophore: a sperm packet used by males of various animal species, transferred to a female’s ovipore during copulation.

spermatophyte: a seed-producing land plant.

sphagnum: a genus (Sphagnum) of moss with 120 species.

spice: some portion of a plant primarily employed for flavoring, coloring, or preserving food.

spider (order Araneae): an 8-legged arachnid that injects it prey with venom via fangs. There are an estimated 90,000 spider species, on every continent except Antarctica, adapted to almost all terrestrial biomes.

spider monkey: a large New World monkey with long limbs and a long prehensile tail, in the genus Ateles, with 7 species.

spidroin: a protein for spider silk.

spin (quantum physics): the mathematically hypothesized internal rotation of a subatomic particle; a form of intrinsic angular momentum.

spinal cord: a long, thin, tubular bundle of nervous system tissue that runs much of the length of the body in vertebrates.

spinneret: the silk-spinning organ of a spider or insect larva. Some adult insects also have spinnerets. Spinnerets are usually on the underside of the abdomen, near the rear. Most spiders have 6 spinnerets, though others have only 2 or up to 8. Spinnerets may work independently or in concert.

spirillum (plural: spirilla): a curved or spirally twisted bacterium. Compare bacillus, coccus.

sponge: a simple, porous, multicellular marine animal, lacking nervous, digestive, and circulatory systems. Sponges rely upon constant water flow for food, oxygen, and waste removal. Most species are marine, though freshwater sponges are known. An estimated 10,000 species are extant.

sporangium (plural: sporangia): an enclosure, either single-celled or multicellular, in which spores form.

spore: a desiccated microbe in hibernation, able to remain dormant and survive adverse conditions, such as cold, heat and radiation. Spores are produced via sporulation.

sporophyte: the diploid, spore-producing phase of plants and algae that undergo alternation of generations. Compare gametophyte.

Sporozoa: a group of parasitic protozoans.

spreading ridge: a mid-ocean ridge with a growing rift along its spine, formed by 2 tectonic plates; an underwater divergent plate boundary.

springtail: a small, omnivorous, 6-legged (hexapod) arthropod that is not an insect, in the order Collembola.

spruce (tree): a genus (Picea) of coniferous evergreen with 35 species.

Sputnik: a virophage discovered in a water-cooling tower in Paris in 2008.

squamate: a reptile in the Squamata order, comprising all lizards and snakes – scaled reptiles. Squamates are the 2nd-largest (specious) order of extant vertebrates, after perciform (“perch-like”) fish.

Squamellaria: a genus of myrmecophytic flowering plants endemic to Fiji.

squid: a cephalopod of ~300 extant species, with elongated tubular bodies, short, compact heads, 4 pairs of arms, and 2 tentacles. Squid are strong swimmers.

squirrel: a small or medium-sized rodent. Chipmunks, marmots, and prairie dogs are squirrels. Close living relatives include the dormouse and mountain beaver.

squirrel monkey: a small New World monkey.

squirting cucumber (Ecballium elaterium): a Mediterranean cucumber that explosively ejects its seeds.

stabilimentum (plural: stabilimenta): a conspicuous silk structure within a spider orb web.

stadial: an extended cold spell of insufficient duration or intensity to be considered a glacial period.

stamen (aka androecium): the (male) pollen-producing organ in a flower. The stamen has a stalk (filament) and an anther that contains pollen (microsporangia). See stigma.

Staphylococcus: a cocci genus of bacteria fond of clustering. Found worldwide in soil, plants, and animals. Most are harmless.

starfish: see sea star.

starling: a medium-sized passerine. The larger Asian species are called mynas. Starlings have complex vocal communications.

statistics: the mathematical science of data collection, classification, analysis, and interpretation within the precepts of probability.

statocyst: a sensory receptor for balance, employed by some aquatic invertebrates, including bivalves, cnidarians, echinoderms, cephalopods, and crustaceans.

statolith: an amyloplast.

status badge: an epigenetic trait which indicates social status.

stercomare: a shell-like structure built by a xenophyophore.

stercome: xenophyophore feces that mixes with secreted cement to build a shell-like mound, termed a stercomare.

steroid: an organic compound characterized by 4 joined cycloalkane rings with 17 carbon atoms. Eukaryotic cells manufacture steroids for various functions.

sternum: a compound ventral bone or cartilage of most vertebrates other than fishes, which connects the ribs or shoulder girdle or both.

stickleback: a carnivorous fish in the Gasterosteidae family. Most stickleback species are marine.

stigma (botany): the female portion of a flower that receives pollen during pollination. A pollen grain germinates on the stigma, which is often sticky. The tube-like style connects the stigma to the ovary. See stamen.

stipule: an outgrowth on a side of the base of a leafstalk (petiole).

Stockholm syndrome (aka capture bonding): a psychological phenomenon where hostages emotionally accept their captors. Battered-wife syndrome and military basic training are examples of capture bonding; so too fraternity bonding by hazing. Stockholm syndrome is named after a bank robbery in Stockholm, Sweden, where several bank employees were held hostage in a bank vault for 6 days in August 1973. The victims became emotionally attached to their captors, at one point rejected assistance from the government, and defended the robbers after they were freed.

stolon (aka runner): a horizontal connection between organisms. Commonly used in botany for an aboveground extension from the base of a cloning plant.

stoma (plural: stomata): a plant pore.

stone plant: a genus (Lithops) of succulents in the ice plant family Aizoaceae, native to the dry lands of southern Africa.

storksbill (aka pinweed, Erodium cicutarium): a geranium that is nominally an herbaceous annual; in warm climates, a biennial. A storksbill’s small pink flowers provide pollinators with ample pollen and nectar.

stot: a gait of quadrupeds involving jumping into the air.

strain (variety) (of bacteria): a culture from a single parent, but which differs from other bacterial cultures of the same species by structure or metabolism.

stratigraphy: a branch of geology related to rock layers (stratification).

stratosphere: the temperature-stratified layer of Earth’s atmosphere below the mesosphere and above the troposphere. The stratosphere is 10–50 km above Earth’s surface.

stratus: a relatively featureless cloud with a uniform base and gray, horizontal layering.

strawberry poison frog (Oophaga pumilio): a small frog, native to Central America, that picks up its poison for the arthropods it eats. Strawberry poison frogs have a wide variation in patterns, with up to 30 different color morphs.

Strepsiptera (aka twisted-wing parasite): an endoparasitic order of insects, with 600 species over 9 extant families.

Strepsirrhine: a suborder of primates defined by their wet nose, including lemurs, galagos, pottos and lorises.

Streptococcus: a genus of spherical bacteria.

Streptomyces: the most speciated (500+) genus of actinobacteria. Streptomyces have an earthy odor, owing to their producing geosmin.

stress (biology): an organism’s sustained response to a stimulus, either environmental or internally produced.

stress (psychology): a dysfunctional form of emotional memory stored in the mind-body.

stridulation: the act of an animal producing sound by rubbing body parts together. Various insects, spiders, fish, and snakes practice stridulation.

strigolactone: a plant hormone that solicits and stimulates symbiotic relations with mycorrhizal fungi.

strike-slip: an area of tectonic lateral displacement, either between plates or within a continent. A strike-slip at between plates at a boundary is a transform-fault.

striped lava lizard (Tropidurus semitaeniatus): a gregarious lizard, native to northeastern Brazil.

style (botany): the tube-like stalk that connects a stigma to an ovary; part of the gynoecium (female part of a flower).

subduction: the process of a tectonic plate moving under another at a convergent tectonic boundary.

subduction plate: a tectonic plate undergoing subduction.

subduction zone: an area where subduction is taking place.

suberin: a waxy, fatty substance that renders cork cells waterproof.

subsociality: animals that show parental behavior.

succulent: a plant that has a portion with thickened and fleshy tissue to retain water in arid conditions.

sulfate (aka sulphate) (SO42–): a polyatomic anion of sulfur and oxygen in a tetrahedral arrangement with a symmetry synonymous with methane.

sulfide (S2–): the simplest inorganic anion of sulfur.

Sulfolobus: a genus of microscopic thermoacidophile archaea, happiest at 75–80 °C and 2–3 pH.

sulfur (S): the element with atomic number 16; an abundant, multivalent non-metal. Sulfur can react as either a reductant or oxidant. As an organic compound (organosulfur), sulfur is widely employed in biological processes, playing a key role in many enzymes. Sulfur is a component in all proteins.

Sumatra: an island in western Indonesia; the westernmost of the Sunda Islands.

Sumer: an ancient civilization in southern Mesopotamia, beginning 5000 BCE.

Sunda Shelf: a southeast extension of the continental shelf of Southeast Asia into the Gulf of Thailand to the Sunda Islands, notably Sumatra and Borneo.

Sundaland: a submerged continent that was largely exposed during the Last Glacial Maximum.

sunflower (Helianthus annuus): an annual plant native to the Americas. Sunflowers are notable for their large flowering head.

supercontinent: a landmass comprising multiple continental cores. Supercontinents in Earth’s history include: Vaalbara (3.1–2.8 BYA), Kenorland (2.7–2.5 BYA), Nuna (1.9–1.5 BYA), Rodina (1.1 BYA–750 MYA), and Pangaea (300–200 MYA).

surface tension: a property of the surface of a substance that allows it to resist an external force. Surface tension in a crystal arises from stretching interatomic bonds, whereas liquid surface tension is more about the extra atoms introduced when spreading out in increased surface area.

surili: a group of arboreal, small, slim, Southeast Asian monkeys in the genus Presbytis.

swallowtail butterfly: a large, often colorful butterfly in the Papilionidae family, of over 550 species.

sweat bee: a bee attracted to salt, particularly human sweat.

swordfish (aka broadbill): large, migratory, predatory fish in the Xiphiidae family, characterized by a long, flat bill.

swordtail characin (Corynopoma riisei): a characin endemic to Columbia, Trinidad and Tobago, and Venezuela.

syllable: a unit of spoken language.

symbiont: an organism that lives symbiotically with a host.

symbiorg: an obligate symbiotic organism. Eukaryotes with microbiomes are symbiorgs.

symbiosis: 2 dissimilar organisms in continual interaction, typically in a mutually beneficial association (mutualism).

symbol: an abstraction that signifies something; a representation of a concept.

sympathetic concern: being able to experience another individual’s emotions as distinct from one’s own.

sympatric speciation: evolution of a new species while inhabiting the same habitat as the parent species. Compare parapatric speciation, allopatric speciation.

symplast: the inner side of a plant plasma membrane, where water and low-molecular-weight solutes can freely diffuse.

Symsagittifera roscoffensis: a small marine flatworm.

synapsid: a group of mammal-like reptiles, all amniotes (egg layers). Early synapsids are usually called pelycosaurs; more mammal-like ones, therapsids.

syncytium (plural: syncytia): a multinucleate cell resulting from multiple cell fusions of uninuclear (single nucleus) cells.

Synechococcus: a genus of marine cyanobacteria.

synergism (biochemistry, pharmacology): joint action of agents that together increase each other’s effectiveness.

syntax: the patterns of language.

syrinx: the unique vocal organ of birds.


T cell: a lymphocyte of the adaptive immune system that kills or assists killing pathogens. Compare B cell.

taboo: a behavior contrary to mores.

taiga (aka boreal forest): a biome characterized by coniferous forest. Taiga is the Earth’s largest land biome, comprising 29% of the world’s forest cover.

taily weed (Ochradenus baccatus): a perennial plant that grows to a meter, with a woody base and many fleshy smooth branches; native to north Africa and the Middle East. Taily weed produces small berries year-round.

talapoin: an arboreal monkey found in swamp forests of central Africa; the smallest Old World monkey. Talapoins live in troops of 50–100.

tamarin: a squirrel-sized arboreal South American monkey.

Tamarixia radiata: a parasitic wasp that lays its eggs on jumping plant lice.

tandem running: a teaching method in some ant species, using recruitment to lead nestmates to food, or to facilitate quorum-sensing. During a tandem run, the follower maintains contact with the leader by frequent feedback touches of the antennae between the 2.

tangle web spider (Anelosimus octavius): a South American orb-weaving spider that spins a platform web under the influence of the parasitoid wasp Polysphincta gutfreundi.

Tanimbar corella (aka Goffin’s cockatoo, Goffin’s corella, Cacatua goffini): a small white cockatoo endemic to the islands of the Tanimbar archipelago in Indonesia.

tank plant: a rainforest species of bromeliad that clings to trees.

tannin: an astringent, bitter plant polyphenolic compound.

tapeworm: an obligate endoparasite of the animal gut.

taproot: a large, long, somewhat straight root.

tarantula: a group of often large and hairy spiders. Some are arboreal, others ground dwellers.

tardigrade (aka water bear): a hardy, 0.5-mm-long, aquatic animal of over 1,150 species, found in most ecosystems.

tarsier: a 10–15 cm prosimian with enormous eyes, once widespread through Asia, Europe, North America, and possibly Africa, now found only on Southeast Asian islands. Tarsiers have a distinct brain from other primates, suggesting their early, independent evolution in the lineage of primates.

tarsus (plural: tarsi): the end of a leg, near the foot.

Tasmanian native hen: a flightless rail native to Tasmania.

taxol (C47H51NO14): an extract from the Pacific yew tree employed for human cancer chemotherapy. The drug giant Bristol-Myers Squibb managed to change the generic name to paclitaxel so that it could trademark taxol.

taxon (plural: taxa): a classification of organisms. Taxa either have a formal or scientific name. Scientifically termed taxa are governed by nomenclature codes: naming rules overseen by scientific organizations.

taxonomy: the classification of organisms according to their presumed natural relationships.

tectonics: processes related to the movement and deformation of Earth’s crust, notably the roving of tectonic plates.

tectonic plate: a sizeable chunk of the lithosphere, including some of Earth’s crust, capable of movement.

teleology (evolutionary biology): the theory that adaptation is goal oriented.

teleology (philosophy): the doctrine that final causes (ends or purposes) exist.

telonemia: a phylum of aquatic, microscopic, single-celled eukaryotic protists.

telophase: the cell life-cycle phase after anaphase, during cell replication, where 2 daughter nuclei form. The result of telophase is 2 daughter cells. See interphase.

tentacled snake (Erpeton tentaculatum): an aquatic snake endemic to Southeast Asian waters; unique in having 2 tentacles protruding from the front of its head.

termite: a group of colonial eusocial insects, directly descended from cockroaches. Termites are only distantly related to ants. 4,000 termite species are known.

Termitomyces: a genus of fungi in the family Lyophyllaceae that are a food source for their cultivators: the termite subfamily Macrotermitinae.

tern: a slender, lightly built, graceful seabird that prefers an open habitat. Tern sexes look selfsame.

terpene (C5H8): a pungent hydrocarbon compound produced by various plants, notably conifers, and some insects, including termites and swallowtail butterflies. Terpene is antibiotic.

tessellated darter (Etheostoma olmstedi): a small, freshwater darter native to North America, primarily the United States.

testicle (aka testis): the male reproductive gland in animals.

testosterone (C19H28O2): a steroid hormone found in reptiles, birds, and mammals.

Tethys Sea (aka Tethys Ocean): the ocean between the continents of Gondwana and Laurasia during much of the Mesozoic era (252–66 MYA), before the opening of the Indian and Atlantic oceans during the Cretaceous period (145–66 MYA). Continental shifts reduced the Tethys Sea, eventuating into the Mediterranean Sea.

tetrachromacy: vision with 4 channels of color information.

tetrahydrocannabinol (C21H30O2; THC): a psychoactive (to humans) terpene produced by cannabis plants.

tetrapod: a 4-limbed animal.

Tetraselmis convolutae: a species of phytoplankton that is a symbiont of the small marine flatworm Symsagittifera roscoffensis.

thale cress (aka mouse-ear cress, Arabidopsis thaliana): a small flowering plant native to Eurasia. Thale cress is commonly considered a weed, despite being in salads or eaten sautéed (that is, a food crop).

thallus (plural: thalli): an undifferentiated vegetative tissue, typical of certain algae, fungi, lichen, and liverworts.

theory: fact-based explanation about the relations between concepts.

theory of mind: the cognitive ability to attribute mental states to oneself and others.

Therapsida: a group of synapsids from which mammals descended.

theridiid (aka cobweb, comb-footed, tangle-web): a web-building spider of over 2,200 species in 100 genera.

thermal (atmospheric): a column of rising warm air in the lower altitudes of the atmosphere. Thermals are one of many sources of lift that are used by birds that fly long distances.

thermoacidophile: an organism that prefers a habitat with temperatures of 70–80 °C and a pH of 2–3; a combination of acidophile and thermophile.

thermocline (ocean): a layer of seawater that separates upper, warmer water from colder, deeper water below.

thermodynamics: the branch of physics concerned with the dynamics of heat and temperature and their relation to energy and work.

thermohaline circulation: an aspect of large-scale ocean circulation driving by global seawater density gradients created by surface heat and freshwater thermal fluxes. Thermo- refers to temperature while -haline refers to saltiness. Thermohaline circulation is synonymous with ocean conveyor belt.

thermonastic tropism: plant movement in response to temperature.

thermophile: an organism that can survive a 60 °C or even hotter habitat.

Thermoplasma acidophilum: a species of highly flagellated thermoacidophilic archaea happiest at 56 °C and pH 1.8. Astonishingly, T. acidophilum lacks a cell wall. Its cell membrane is exposed to the outside environment.

thermosphere: the layer of Earth’s atmosphere below the exosphere and above the mesosphere. The thermosphere begins 80 km above the Earth’s surface.

thigmotropism: plant movement in response to touch.

Thiobacillus: a subfamily of thermophilic bacteria that consume sulfur.

thorax: the midsection of an insect body, holding the legs, wings, and abdomen; termed the mesosoma in other arthropods. A thorax has 3 segments: prothorax, mesothorax, and metathorax.

thread-legged bug (Stenolemus bituberus): an Australian assassin bug that preys on web-building spiders.

threespine stickleback (Gasterosteus aculeatus): a fish native to inland coastal waters north of 30° N which shows great morphological variation throughout its range and is quite tolerant of salinity changes.

thrip (aka thunderfly, thunderbug, thunderblight, storm fly, storm bug, corn fly, corn louse): a tiny, slender insect with fringed wings that feed on a large variety of plants and animals by puncturing its victim and sucking tissue fluids.

thrush: a ground-dwelling passerine with a worldwide distribution.

thylakoid: a membrane-bound compartment inside cyanobacteria and chloroplasts.

thymine (T) (C5H6N2O2): a DNA nucleobase. Thymine is complementary to adenine. In RNA, thymine is replaced by uracil.

tiger beetle: a beetle of over 2,600 species, known for its aggressive predation and running speed: the equivalent of a person going 770 km/h.

tinamou (plural: tinamous): a diurnal bird native to Middle and South America, with 47 species. Although some species are common, tinamous are shy, secretive birds. Though tinamou are ground-dwelling, and favor running away from danger, they are not flightless.

TirA (toll/interleukin-1 receptor A): a protein used by social amoeba to identify bacteria. A similar protein is used by animals for the same purpose.

tissue: an aggregate of cells in a eukaryotic organism that perform a specific function.

tit: a small passerine endemic to the northern hemisphere and Africa; in the Paridae family, which includes chickadees and titmice.

titan triggerfish (Balistoides viridescens): a large triggerfish found at reefs and in lagoons through the Indo-Pacific, though not near Hawaii. Titan triggerfish are busy workers, turning over rocks and stirring sand to scrounge shellfish, urchins, and crustaceans; much to the delight of smaller fish, who feed on the leftovers. Titan triggerfish also munch coral.

titi: a monogamous, territorial South American monkey.

toad: a frog with a dry, bumpy, leathery skin. The bumps visually break up a toad’s visible outline, hence helping it to blend into its environment. A toad differs from a frog only by look and its preference for a more terrestrial habitat.

toadfish: a family of mostly marine, large-mouthed, ray-finned fish, so-called for their toad-like appearance. Toadfish are benthic ambush predators that like to lurk on sandy or muddy substrates, where their cryptic coloration camouflages them. Male toadfish can sing, using their swim bladder to produce sound. They croon to attract mates.

toadstool: an inedible mushroom; from late 14th-century Middle English. Toads were then regarded as highly poisonous.

tobacco: an herbaceous plant or shrub in the Nicotiana genus in the nightshade family, indigenous to the Americas, southwest Africa, the South Pacific, and Australia.

tobacco hornworm (aka goliath worm, Manduca sexta): the larva of the Carolina sphinx moth. This caterpillar feeds on tobacco, tomatoes, and other plants in the nightshade family.

Tonga plate: a small, southwest Pacific Ocean tectonic plate, bounded on the north and east by the large Pacific plate, and on the northwest by the Niuf’ou microplate. The Tonga plate is subducting the Pacific plate along the Tonga Trench, north of New Zealand. The Tonga Trench is a convergent plate boundary.

Tonian (1,000–720 MYA): the 1st period of the Neoproterozoic era. The supercontinent Rodinia broke up during the Tonian. The first fossils date from the Tonian.

tonne: metric ton.

toothcarp: an 0.8–34 cm, freshwater, ray-finned fish. Toothcarps are not closely related to true carps. Many popular aquarium fish, such as killifish and guppies, are toothcarps.

topi (Damaliscus korrigum): a gregarious and fast antelope that lives on the grasslands of equatorial Africa. Topis have the most diverse social arrangements among antelopes, ranging from polygyny to leks.

torpor: a state of sluggishness, with mental and motor inactivity.

touch-me-not (Mimosa pudica): a plant with compound leaves that rapidly respond to touch.

toxin-antitoxin system: a prokaryotic defense system using a set of 2 or more linked genes which together encode for both a toxin protein and a corresponding antitoxin.

Toxoplasma gondii: an obligate, intercellular, protozoan parasite of endotherms, causing them toxoplasmosis.

toxoplasmosis: a disease causing both physical and mental disabilities, including encephalitis (inflammation of the brain), heart, liver, hearing, vision, and neurological disorders. Toxoplasmosis can also invoke attention deficiency, obsessiveness, schizophrenia, and suicide.

tracheophyte: a vascular plant.

trade winds: the prevailing pattern of easterly surface winds found in the tropics. Historically, the trade winds were used by captains of sailing ships to traverse the oceans. These winds facilitating seafaring trade routes gave them their name.

trait (biology): a biological feature, either in form or function.

transfer RNA (tRNA): an adapter for bridging the 4-letter genetic code in messenger RNA (mRNA) with the 20-letter code of amino acids; used for protein synthesis.

transform boundary: a rubbing of tectonic plates at a shared boundary. A transform boundary is a specific type of strike-slip fault. Contrast convergent, divergent.

transformation (bacteria): the process of a bacterium picking up and incorporating genetic material from the environment.

transgression (biosphere): sea-level rise. Contrast regression.

translocation (botany): the sugary sap distribution process in phloem.

transpiration: normal, controlled release of water by plants.

transposable element: a transposon or retrotransposon.

transposon: a DNA sequence which can change its position within a genome (typically by placing a copy elsewhere).

traveling salesman problem: the problem of determining the shortest route for multiple nonlinear waypoints; one of the most intensively studied problems in computational mathematics, as it is NP-hard (non-deterministic polynomial-time hard).

The traveling salesman problem was mathematically defined in the mid-1800s by William Rowan Hamilton and Thomas Kirkman. To this day, a provably correct algorithmic solution to the traveling salesman problem has not been found. Practically, humans are not nearly as good as bumblebees in solving it. (Only bumblebees have been studied. Doubtlessly such problem-solving acumen applies to other foragers which rely upon checking many locations for food by memory.)

tree: a perennial plant with a woody trunk, branches, and leaves.

tree frog: a frog that spends a lot of time in trees.

treepie: an arboreal corvid of 4 genera.

trematode (aka fluke): a class of parasitic flatworms.

Triassic (252 – 201 MYA): the 1st period of the Mesozoic era, following the Permian period and preceding the Jurassic. Earth’s land mass was in a single supercontinent, Pangea, during the Triassic. Dinosaurs appeared during the Triassic but did not dominate until the Jurassic. The start and close of the Triassic are marked by major extinction events. The Triassic is named after the 3-layer rocks, found throughout northwestern Europe, that characterize the period.

Trichoderma: a genus of fungi present in all soils.

trichomonad: a single-celled, flagellated, anaerobic protozoan.

Trichomonas vaginalis (Tv): a parasitic trichomonad which causes trichomoniasis.

trichomoniasis (aka trich): the sexually transmitted infectious disease caused by Trichomonas vaginalis.

trichromacy: having 3 types of color vision receptors. Marsupials and primates are the only known mammalian trichromats. They have different receptor types for red, green, and blue wavelengths. Some insect species, such as honeybees, are trichromats, but their reception is shorter wavelengths: green, blue, and ultraviolet. Trichromats can distinguish 1 million colors. Compare monochromacy, dichromacy, tetrachromacy.

trigger plant (Stylidium): a flowering plant of a diverse ~300 species, indigenous to Australia. Trigger plants are extremely sensitive to touch.

triglyceride: a lipid. More specifically, an ester derived from glycerol and 3 fatty acids.

Triplaris (aka ant tree): a genus of plants and trees native to the Americas, best known for their mutualism with ants (e.g., T. americana).

trophic: nutritional.

trophic cascade: the dynamic of predator-prey linkages, particularly in affecting carrying capacity.

trophic efficiency: the efficiency of converting food into energy for at a trophic level.

trophic level: a stratum of the food chain.

trophic pyramid: a stratified view of a food chain, from a base of producers to herbivores to predators.

tropism: (plant) directional movement in response to environmental conditions. Contrast nastic movement.

tropopause: the transition layer between the troposphere, where temperature drops with altitude, and the stratosphere, where temperature rises with altitude.

troposphere: the atmospheric layer of life: the lowest portion of Earth’s atmosphere. The troposphere extends from the Earth’s surface 7–20 km up, depending upon location and season.

true bug: an insect in the Heteroptera group of the Hemiptera order, comprising 40,000 species. Most species have forewings with both membranous and hardened portions. Bedbugs, assassin bugs, stink bugs, plant bugs, seed bugs, and water bugs are exemplary true bugs. The formal classification of Heteroptera has become confused in recent decades through suggested revisions, and there is not even ubiquitous consensus on the extent of what a “true bug” is.

trypanosome (aka trypanosomatid): a group of single-celled protozoa with only a single flagellum.

tsetse fly (aka tik-tik fly): a large biting fly endemic to central Africa that lives on the blood of its vertebrate victims. Tsetse flies are known for transmitting parasitic protozoa called trypanosomes which weaken and kill infected animals.

tuatara: a unique gray and greenish-brown lizard-like reptile, but not a lizard, native to New Zealand.

tube worm: an aquatic worm-like sessile invertebrate that anchors its tail to an underwater surface, then secretes a mineral tube shelter around its body into which it can withdraw.

tuber: a plant structure that enlarges to store nutrients.

tundra: a biome where tree growth is hindered by low temperature and short growing seasons. Tundra occurs near the poles and toward the summits of the most majestic mountains.

Túngara frog (Engystomops pustulosus): a frog found in Mexico and northern South America.

tunicate: a marine invertebrate chordate.

turaco: a medium-sized, arboreal, largely herbivorous, gregarious bird endemic to sub-Saharan Africa, in the family Musophagidae.

turbinate (aka nasal concha): nasal airway.

turgidity: a state of distension/swelling.

turgor: the normal state of turgidity and tension in living cells, particularly the distension between the protoplasmic layer and plant cell wall by fluid contents.

turgor pressure: a pressure (turgidity) against cells caused by osmotic water flow. Healthy plant cells rely upon turgidity to maintain rigidity. Other beings with cell walls, such as fungi, protists, and bacteria, appreciate turgor pressure. In contrast, animals lack the cell walls needed to support this function.

turion: a specialized overwintering bud produced by aquatic plants. Turions are produced in response to autumnal conditions, such as decreasing day length and lowering temperature. Turions are often rich in sugars and starch, allowing them to act as storage organs.

turkey: a large bird native to the Americas; related to grouse.

turtle: a reptile with a unique, defensive, bony shell developed from its ribs, in the Testudines order. Originating 220 MYA via saltation, turtles are one of the oldest reptile groups.

tuskfish: a fish of several species in the wrasse family, endemic to the Indian and Pacific oceans.

TYA (aka kiloannum or ka): thousands of years ago.


uakari: a bald-headed, short-tailed monkey of 4 species in the Cacajao genus, endemic to the Amazonian rainforest.

Uganda ironwood (Cynometra alexandri): a legume tree endemic to tropical lowland forests in central and east Asia. These trees may reach 46 meters in height.

ultrasonic: a sound frequency above human hearing (20 kHz).

ultraviolet: the 10–400 nm band of the electromagnetic spectrum, shorter than visible light but longer than X-rays.

understory: an underlying layer of vegetation; the vegetative layer between forest ground cover and the forest canopy. Compare overstory.

ungulate: a group of mammals which use the tips of their toes, typically hoofed, to sustain body weight while moving. Ungulates include the horse, cattle, bison, camel, goat, pig, sheep, donkey, deer, tapir, antelope, gazelle, giraffe, camel, rhino, and hippo. Even-toed ungulates (Artiodactyla) bear their weight equally between the 3rd and 4th toes. Odd-toed ungulates (Perissodactyla), which have an odd number of toes on their rear feet, bear weight on their 3rd toe.

uniformitarianism: a hypothesis by James Hutton of steady-state existence: the same processes and natural laws that operate in the universe now have been constant everywhere since time immortal: “the present is the key to the past.” In a temporal asymmetry, from a saner historical perspective, understanding the past explains the present. Contrast catastrophism.

universe: a presumed self-contained repository of energy – a characterization for which there is no evidence, and which quantum theory disclaims. This universe has some 4 trillion galaxies; half are light (with visible stars), half dark.

unsaturated fat: a molecule of fat with 1 or more double bonds between carbon atoms. A fat molecule with only 1 double bond is monounsaturated. Molecules of fat with more than 1 double bond are polyunsaturated. Contrast saturated fat.

uracil (U) (C4H4N2O2): a nucleobase of RNA. Uracil is complementary to adenine. In DNA, uracil is replaced by thymine.

urogenital system (aka genitourinary system): the animal organ system including reproductive organs and the urinary system.


Vaalbara (3.1 – 2.8 BYA): the first known supercontinent.

vacuole: the organelle in cells responsible for autophagy.

vagina: the female sex organ.

vagrancy (biology): a biological tendency for individual animals to appear well outside their normal range. Such individuals are termed vagrants.

vampire bat: a hematophagic bat.

vampire squid: an archaic cephalopod that lives in the oxygen minimum zone.

van der Waals interaction: the net sum of attractive or repulsive forces between atoms other than those owing to covalent bonds, electrostatic interaction between ions, or with neutral atoms.

vapor pressure: the pressure exerted by a vapor, indicating its evaporation rate. Vapor pressure relates to the tendency of particles to escape from a liquid or solid in a given ambient condition.

vascular: a life form with vessels to carry fluids; commonly used to identify certain land plants: vascular plants (aka tracheophytes).

vascular cambium: the lateral meristem that develops into vascular tissue.

vasopressin (C46H65N15O12S2): a mammalian neurohypophysial hormone that helps retain water in the body and constricts blood vessels, among other functions. In humans, vasopressin plays a key role in homeostasis, and the regulation of water, glucose, and salts in the blood.

vegetative reproduction: any one of several ways that plants asexually propagate without spores or seeds. Herbaceous and woody perennial plants often practice vegetative propagation.

veiled chameleon (Chamaeleo calyptratus): an arboreal chameleon found in the mountainous regions of the Middle East.

ventral: the belly or lower side of an organism. Contrast dorsal.

Venus fly trap (Dionaea muscipula): a carnivorous plant native to the subtropical wetlands on the east coast of the United States.

vernalization: the need for an angiosperm to have a prolonged cold period (winter) before being able to flower.

vertebrate: an animal with a backbone and spinal column. Contrast invertebrate.

vertical gene transfer: genetic transfer from parent to offspring, typically as part of the reproductive process. Contrast horizontal gene transfer.

vervet monkey (aka vervet, Chlorocebus pygerythrus): a monkey endemic to sub-Saharan Africa.

vesicle: a membrane-encased bubble within a cell; at least analogous, if not in fact, to an organelle.

vespoid wasp: a wasp in the large, diverse, cosmopolitan Vespidae family of wasps, including nearly all known eusocial wasps.

vessel element: a plant water-conducting cell type, found in xylem.

Vibrio fischeri (aka Aliivibrio fischeri): a species of bioluminescent saprotrophic bacteria that lights up the lives of marine animals.

vicariance: speciation when a new geographic barrier arises, separating a population. Contrast dispersal.

viceroy butterfly (Limenitis archippus): a North American butterfly that mimics the monarch butterfly, ranging from the northwest to central Mexico.

viduid: a small passerine in the Viduidae family, which includes indigobirds, whydahs, and cuckoo-finches. Viduids are native to Africa.

village weaver (aka spotted-backed weaver, black-headed weaver, Ploceus cucullatus): a weaverbird endemic to sub-Saharan Africa.

vine: a plant with a growth habit of runners. The term climber applies to all climbing plants.

vine snake: any one of various slender venomous snakes.

vinegar fly: a fly that lingers about overripe or rotting fruit, in the genus Drosophila. Confusingly, Drosophila are often called fruit flies. Compare fruit fly.

viper: a family of venomous snakes, found over much of the world, excluding islands and polar regions.

vireo: a family of small to medium-sized passerines of the Americas.

virion: a viral particle that contains RNA or DNA.

viroid: a tiny package of RNA lacking a capsid; smaller than a virus. Viroids are plant pathogens.

virophage: a satellite virus that is a parasite of another virus.

virulence factor: a molecule produced by a pathogen or endosymbiont that helps it colonize or obtain nutrition from its host.

virus: an obligate parasite that infects cells of all types of organisms; a domain of life, alongside archaea and bacteria.

viscacha: a rodent closely related to chinchillas, looking somewhat rabbity.

vitalism (biology): the doctrine that there is a vital energy specific to living organisms, distinct from chemical and physical energies; generally rejected by scientists. Contrast animism.

vitamin A: a vitamin needed by the retina of chordate animals for low-light and color vision.

viverrid: a small to medium-sized mammal of 38 species in 15 genera.

vivipary: a plant seed or embryo beginning development before detaching from its parent.

volcanism: volcanic activity.

volcano: a rupture in Earth’s surface that affords the flow of hot magma, gases, and ash to escape from below into the atmosphere. Volcanoes are commonly caused by divergent tectonic plates pulling apart.

vole (aka field mouse, meadow mouse): a small stout rodent of which there are ~155 species. Many are burrowers. Voles are often mistaken for other animals with similar looks and behaviors, including moles, gophers, mice, rats, and even shrews.

Volvox: a genus of freshwater green algae.

vulture: a scavenging bird of prey, of 2 distinct groups – New World and Old World – via convergent evolution.


wagtail: a small bird with a long tail that frequently wags.

Walker circulation (aka Walker cell): a conceptual model of circulatory tropospheric air flow in the tropics, discovered by Gilbert Walker.

warbler: a small, vocal, insectivorous perching bird, with ~350 species in both the Old World and New.

wasp: a flying insect of well over 100,000 species, found on every continent except polar regions. Most wasps are parasites or parasitoids as larvae, feeding on nectar only as adults. Many wasps are predatory, feeding their larvae other insects (often paralyzed). Wasp sociality varies by species, from solitary to social.

Watases lanternfish (Diaphus watasei): a lanternfish native to the seas off east Africa to Japan and Australia, at depths of 100–2005 meters.

water (H2O): the elixir of life; an odd molecule like no other.

water bug: a true bug of ~2,000 species in the Nepomorpha infraorder, known as true water bugs for their aquatic lifestyle. Water bugs live everywhere but the polar regions, mostly in freshwater habitats.

water cycle (aka hydrological cycle): the cycling of water in the biosphere.

water column: a conceptual vertical column of water, extending from the surface to the bottom sediments.

water flea (aka Cladocera): a small crustacean of 620 known species, though many more exist. Water fleas are ubiquitous in inland aquatic habitats, but rare in oceans.

water potential: the tendency of water to move from one area to another due to osmosis, gravity, pressure, or matrix effects, such as surface tension.

water spider (aka diving bell spider, Argyroneta aquatica): a spider that spends most of its life submerged in freshwater ponds and other places with slow-moving water flow.

water strider: a true bug in the Gerris genus, able to walk on water. Over 1,700 species of gerrids have been identified, 10% of them marine.

water table (aka groundwater level): the upper limit of water-saturated ground.

watershed (aka catchment, drainage basin): a region peripherally bounded by water draining to a certain watercourse (body of water).

watt: a unit of power quantifying rate of energy transfer, derived from joules. Named after James Watt.

wavelength: the spatial period of a sine wave; commonly used as a statistical measure of the energy of a waveform, which is mathematically the product of a wave’s frequency and amplitude.

weasel: a small, active predatory mammal.

weather: characterization of daily or other short-term tropospheric conditions in a locality. Compare climate.

weaver ant (aka green ant): an arboreal eusocial ant in the Oecophylla genus, renowned for nest-building skills using leaves sewn together via larval silk.

weaverbird (aka weaver finch): a small passerine related to finches, endemic to sub-Saharan Africa and tropical Asia.

weed: a derogatory term for an unwanted plant.

weevil (aka snout beetle): a typically small (>6 mm) beetle of over 60,000 species in several families, mostly in the family of true weevils: Curculionidae. Some other beetles, not closely related, bear the weevil name. Most weevils have long, elbowed antennae that can fold into special grooves on the snout. Many weevils lack wings, whereas others are excellent fliers. Most weevils are herbivores. Whereas larvae typically feed on a species-specific plant (or close relations), adult weevils tend to be less picky eaters. As crop eaters, weevils are generally regarded as pests.

Welwitschia: a monotypic (single species) gymnosperm genus. The Welwitschia plant is native to the Namib desert in Angola and Namibia.

whale: an enormous marine mammal in the clade Cetacea.

whiptail lizard: a family (Teiidae) of lizards native to the Americas.

whistling moth: a moth endemic to southeast Australia.

white-fronted bee-eater (Merops bullockoides): a richly colored, slender, bee-eating bird widely distributed in sub-equatorial Africa, with a distinctive white forehead and black mask.

whorl (botany) (aka verticil): an arrangement of at least 3 sepals, petals, leaves, stipules, or branches that radiate from a single point and surround or wrap around a stem. A pair of opposing leaves is not a whorl.

Whooper swan (Cygnus cygnus): a semiaquatic, large, migratory northern hemisphere swan.

whydah (aka widowbird): an African songbird with a long dark tail.

widow spider: a spider in the Latrodectus genus with females that eat their mate after mating.

widowbird: a species of passerine in the weaver family, native to sub-Saharan Africa.

wild nutmeg (aka baboonwood, Virola surinamensis): a tropical and subtropical plant. Its fruit contains lauric acid, which has antimicrobial properties.

wild sunflower (Aspilia mossambicensis): a medicinal flowering shrub.

wildebeest (aka gnu): an antelope, native to Africa, in the family of even-toed ungulates. There are 2 gnu: black and blue. The blue wildebeest remained in its original range, and so is little changed from its ancestors. Black wildebeest adapted to the open grassland habitat that ranges south of where blue wildebeest live.

wintergreen oil (methyl salicylate): an organic ester made by many plants, particularly wintergreens, as an herbivory defense.

wisdom of crowds: the notion that collective decisions tend to be better than those that individuals alone could make.

witches’ broom (aka witch’s broom): a deformative disease of woody plants caused by phytoplasma.

witchweed (aka witches weed): a parasitic plant in the Striga genus, endemic to Africa, Asia, and Australia.

Wizard of Oz, The (aka The Wonderful Wizard of Oz): a 1900 fantasy novel by American novelist L. Frank Baum. The Wizard is a humbug who is shamed into helping Dorothy return to her home in Kansas. The Wizard of Oz is best known in its 1939 film adaptation, staring Judy Garland.

wolf: a carnivorous social mammal native to north Africa, Eurasia, and North America. Wolves are apex predators.

wolf spider: a robust, agile spider with excellent eyesight in the Lycoside family, ranging from 1 to 3.5 cm. Wolf spiders do not spin webs. Most wolf spiders live in solitude.

wolverine (aka skunk bear, Gulo gulo): a fierce, stocky, muscular carnivore that resembles a small bear, but is the largest weasel. Wolverines are endemic to woodlands with cold winters in the northern hemisphere.

wood sorrel (common wood sorrel: Oxalis acetosella): a small flowering plant endemic to North and South America, Europe, and Australia. The tubers of wood sorrel are edible, consumed by humans for millennia. The leaves and flowers of wood sorrel contain oxalic acid, which is slightly toxic, albeit present in numerous commonly consumed foods, including broccoli, Brussels sprouts, spinach, grapefruit, chives, and rhubarb.

wood white butterfly (Leptidea sinapis): a small white-gray butterfly found in meadows and forest edges in Eurasia.

woodpecker: a near passerine in the Picidae family, found throughout much of the world, typically in forests and woodlands, though a few species inhabit rocky hillsides and deserts.

woodpecker finch (Camarhynchus pallidus): a short-tongued, strong-billed, tool-using finch endemic throughout the Galápagos Islands; named for its practice of hammering on tree branches with its bill, like a woodpecker on tree trunks.

woodlice: an isopod crustacean with a rigid, segmented exoskeleton and 14 limbs.

woolly bear caterpillar (aka woolly worm): a fuzzy caterpillar of a moth in the Arctiidae family, with 11,000 species.

woolly monkey: a monkey in the Lagothrix genus (4 species), with a prehensile tail that lives in extensive social groups, endemic to the rainforests of South America. Woolly monkeys have thick fur, brown in the body with dark gray appendages.

work (physics): energy in transit; the result of an energetic force applied to matter.

wormlion (aka vermileonid): the larva of an insect in the Vermileonidae family that traps small crawling insects, typically ants, in cone-shaped pits like antlion larvae (an instance of convergent evolution).

wormwood: a hardy herbaceous plant in the Artemisia genus, belonging to the daisy family.

wrasse: a clever, carnivorous, marine fish of 500 species in the Labridae family. Wrasse are found throughout the world in tropical and temperate seas.


X inactivation (aka lyonization): the process in which 1 of 2 copies of the X chromosome in female mammals is inactivated.

xenoma: an abnormal growth caused by a microsporidium.

xenophyophore: a giant unicellular organism found throughout the world’s oceans at depths of up to 10.6 km.

xerophile: an organism that lives in an extremely dry habitat.

xerophyte: a plant adapted to an extremely dry habitat.

xylem: plant tissue employed to transport water and nutrients up a plant. Compare phloem.


ya: years ago.

yeast: a eukaryotic microorganism classified as a fungus, of which there are 1,500 known species. Yeast are famous for brewing beer and making bread rise. Contrast mold.

yellow baboon (Papio cynocephalus): a baboon inhabiting the savannas and light forests of south-central and eastern Africa. The species epithet means “dog-head” in Greek, owing to the shape of the baboon’s head and muzzle. Yellow baboons resemble the chacma baboon.

Yucca: a genus of ~50 species of perennial shrubs and trees, native to hot and dry biomes of the Americas and Caribbean.

yucca moth: a small- to medium-sized moth that has a mutualism with Yucca plants. Yucca are among the oldest of all moths.


Zamia: a genus of cycad, with ~50 species, endemic to north and central South America (down to Bolivia), and as far north as Georgia in the United States.

zebra: an African equid of 3 species, with distinctive black-and-white stripes.

zebra finch (Taeniopygia guttata): a common estrildid finch, native to Australia, Indonesia, and East Timor. Estrildid is an Old World finch family (Estrildidae), characterized by building large, domed nests.

Zealandia: a 93% submerged continental margin, with the islands of New Zealand and New Caledonia as representative land masses.

zooid: a single animal that is colonial, in being comprised of a plethora of connected individuals.

zoology: the study of animals.

zooplankton: a tiny aquatic protozoan or metazoan.

zoospore: a motile asexual spore that gets around by flapping its flagellum.

zoosporangium: a sporangium in which zoospores develop.

zygote: a cell formed by the union of 2 gametes (male & female).