Darwinism
Mr. Darwin’s statements elude, by their vagueness and incompleteness, the test of natural history facts. ~ Richard Owen
The term Darwinism is loaded with historical and political baggage. Nominally it means the hypothesis labeled natural selection that was roughed out by Darwin.
Though Darwin was not aware of Mendel’s work, the conceptualizations generally coincide. Lamarckism is a different beast altogether; generally considered by Darwinists fanciful in embracing adaptation as teleological (goal oriented). Darwin’s own pangenesis prognostications are politely ignored in construing Darwinism.
In its modern context, Darwinism includes constructs that do not contradict Darwin’s thrust of competitive natural selection via random mutation. This is how Darwinism is understood by the British.
In the United States, creationists use the term Darwinism as a pejorative for atheistic naturalism: Nature inexplicably crafted without divine input. God-fearing folk cotton to creationism, which is that the Almighty made life as it is and always has been. This creed rejects evolution in favor of divine design.
The authoritative scientific reference to which creationists subscribe is the Christian Bible. Fundamentalists endorse a literal reading of the first chapter, Genesis: that the Lord managed the wondrous display of the entire cosmos in a mere 6 days, then took a day off before moving on to other godly business.
Atheistic naturalism is the metaphysical embrace of godless heathens who espouse the worldview that the universe is nothing but natural elements and forces. Some modern scientists sway toward this secular conviction, though pantheism retains its popularity. Pantheists philosophically try to have their cake and eat it too, in believing that Nature includes an immanent God.
In contrast to pantheism, transcendence posits that God is wholly independent of the material universe, and beyond all physical laws. While pantheism puts God as both an active being and a force, the remove of transcendence posits God as an outsider: divinity at a distance, having conceived the wondrous platform called Nature and now resting on his laurels.
Transcendence and immanence may be combined: God both within and beyond the universe. This fantastic supremist conceptualization – of God simultaneously and constantly everywhere and nowhere – accords with numerous religions, including Judaism, Christianity, Islam, and Hinduism.
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Many techniques used by evolutionary biologists to detect selection may be flawed. ~ evolutionary biologist Matthew Webster
Under Darwinism, the common term for the mechanism of evolution is natural selection, or simply selection, which broadly refers to selective survival of a species by natural means; an attribution so open-ended as to be vacuous.
While the term selection appears conceptually agnostic – that a natural selection of one or more traits transpired – the shibboleth is swathed in misunderstandings. Most of these misconceptualizations stem from Darwin’s own speculations, though they are blindly carried on by scientists worldwide.
One day the Darwinian myth will be ranked the greatest deceit in the history of science. ~ Danish embryologist Søren Løvtrup
Competition
Darwin’s presumption that the world may be dominated by competition is wrong. ~ American ecologist Bradley Cardinale
A fundamental misunderstanding behind the notion of natural selection is that evolution is necessarily competitive: Darwin’s imagined struggle to “survival of the fittest.”
Evolution via competition would eventuate in a dearth of the diversity which is characteristic of populations of every organism. This fact alone dispels this crucial claim of Darwinism.
Divergence can proceed within a single population. ~ American evolutionary biologist Kathryn Langin et al
Instead of this Darwinist sophism, populations get fit by adapting to their environment. Diversity plays an important part.
Scrub jays live in California’s forests. Birds living in pine forests have longer, shallower bills – presumably for prying open pinecones – than jays in oak forests, even though the 2 habitats neighbor each other. When opportunity knocks adaptation answers.
While resource competition plays a role in many ecological interactions, so too mutualism. Species often coevolve, able to flourish only because of reinforcing relations with others. The evolution of eukaryotes provides a prime example.
Seabird Colonies
Breeding seabird colonies require abundant food resources within foraging range of its members. In a large seabird colony, hundreds of thousands of birds mate and rear their hatchlings.
A neighboring colony of the same species may be of similar magnitude, yet there is no territorial competition between the closely situated colonies. Individuals in different colonies avoid overlap by voluntarily restricting themselves to areas where others in the same colony forage, and not encroach upon the neighboring colony’s feeding grounds. Some as yet unidentified information transfer takes place that establishes boundaries.
Mutualism
If it could be proved that any part of the structure of any one species had been formed for the exclusive good of another species, it would annihilate my theory, for such could not have been produced through natural selection. ~ Charles Darwin
Coinciding interests have repeatedly led to interspecies mutualism, where both parties contribute, and both gain from cooperation. The most intimate mutualism is between a macrobe and its microbiome.
The structural composition of multicellular eukaryotes comprises organs with cells specialized for certain functionality. Plants and animals regularly contribute to their microbiomes: helping themselves by helping their closest companions.
Secretions are a common symbiotic expression, produced by specific organs for intended effect. Human breast milk contains copious amounts of complex sugars that a suckling infant cannot metabolize, but that a baby’s microbiota can. Likewise, plants produce nutrients exclusively for its cooperative cohorts at its roots.
Bobtail squid have light organs which they house with specific luminescent bacteria. Without the bacteria, the light organ is nonfunctional. Legumes manufacture nodules in their roots to provide a private residence for nitrogen-fixing bacteria. Flowers are expressly designed for pollinators. Bullhorn acacia creates its namesake horns to house ants, some species of which may be provide protection in return for room and board, whereas other ants may do nothing to repay a plant’s generosity.
In these and other examples, proactive accommodation initiates an ongoing mutualism. Darwin’s simplistic hypothesis of competitive natural selection cannot account for cooperative coevolution, let alone freeloading commensalism.
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Fitness is a conceptual assertion of procreation probability: a likelihood of an organism passing on its genetic package. Many animal species have dominance hierarchies, where breeding appears a competitive exercise. But breeding habits are much more complex. Extra-pair mating is common in many species. The nominally dominant gene package does not always carry fate within it.
Evolution is not inexorably the product of competitive selection. Instead, speciation is adaptive, not some haphazard selection process. Populations do not diverge from variation to speciation as a potential suicide pact.
Though populations face survival pressures, adaptation is not a species competition, with a winner among losers that go extinct. If that were the case, chimps and other great apes would be extinct, leaving only humans. And there would not have been several hominid species during the descent of the human races (nor multiple human races, for that matter). Contemporaneous existence of closely related species and variant populations belies the notion of competition as a primary evolutionary driver.
If evolution was competitive, adaptive niche speciation would not be ubiquitous. Instead, a few species would dominate wide swaths of ecosystems. Generalists with wide tolerances would outcompete niche specialists.
Observation of the best-known species – humans – indicates that mating selection is not entirely competitive. Breeding selection is too complex a behavior to consider fitness as anything more than an idealized concept of probability.
Genomic Symphony
A hen is only an egg’s way of making another egg. ~ English novelist Samuel Butler
The gene-centric view of the purpose of life is an extension of the quip by Samuel Butler, answering which came first: the chicken or the egg.
If a chicken is an egg’s vehicle for reincarnation, then the purpose of life is gene transfer. The absurdity of that should be self-apparent; but not to all.
The competitive fitness concept was taken to an absurd conclusion by English evolutionary biologist Richard Dawkins in the 1976 book The Selfish Gene, where Dawkins fantasized gene-centric evolution: every gene for itself in a “gene-eat-gene” world.
We are survival machines – robot vehicles blindly programmed to preserve the selfish molecules known as genes. ~ Richard Dawkins
In Dawkins’ imagination, organisms exist to perpetuate genes. The notion flies in the face of well-known facts that genes interrelate to create an organitype that serves an individual organism, which ultimately contributes to species population survival (if one simplistically views the purpose of life as propagation).
If genes were generally selfish, a parent gene would squelch alleles as cheap imitations aiming at usurpation. Adaptive evolution would grind to a halt under such a scenario.
An allele is one of multiple forms of a gene or genetic locus (group of genes). Allele is the short form of allelomorph (other form), historically used to describe variant gene forms detected as invoking different phenotypes.
When making his fervent proclamation of selfish genes, Dawkins had no notion of epigenetics. As with alleles, if Dawkins’ premise had any merit, no self-respecting gene would allow itself to be so suppressed as to not be expressed.
Perhaps Dawkins’ retort would be that epigenetics is simply the battleground of an ongoing gene-versus-gene war, with certain genes becoming casualties. That is readily disabused in knowing the gene regulation is an intricate concerted process which varies greatly and is almost always reversible. As memory has an epigenetic correlate, unselfish gene regulation is essential to intelligent life.
Competition plays no part in the functioning of genomics. Instead, genetics demonstrates the symphonic nature of life at the molecular level.
Selfishness isn’t evolutionarily sustainable. ~ Flemish geneticist Christoph Adami
Exceptions prove the rule. There are selfish genes.
Selfish Genes
Selfish DNA poses a significant challenge to genome stability and organismal fitness in diverse eukaryotic lineages. It remains unclear why the observed evolutionary patterns conflict with theoretical expectations. ~ American geneticist Katie Clark
Despite the musical symphonic score of genic harmony, sour notes sometimes appear. Selfish genes do exist.
Selfish genetic elements are parasitic replicators that are specialists in ensuring their own transmission despite conferring no benefit, or even exacting a cost, on their bearers. They come in many flavors, such as transposable elements, segregation distorters, female meiotic drivers, and B chromosomes (or accessory chromosomes). ~ Indian microbiologist Nitin Phadnis
Self-centered mitochondrial DNA has been found in yeast, fungi, plants, and animals. Such parasitic sequences are deleterious to a cell or organism; yet they persist.
Selfish genes can preferentially insert themselves into the chromosomes of gametes, thus ensuring their propagation into the next generation. This genetic uppitiness violates the understood laws of inheritance first spelled out by Gregor Mendel.
Some alleles defy Mendel’s law and can increase their chances of being transmitted to the next generation by killing gametes that do not share the same alleles. ~ American biologists Antonis Roka & Dylan Shropshire
The few selfish genes that do exist demonstrate that genomes simply could not function if self-serving genes were the norm.
Random Mutation
Darwin’s theory – of random variations acted on by natural selection – is not a sufficient mechanism by which evolution might produce the life forms existing today. ~ American biologist Jerry Bergman
A ridiculous fiction bruited by Darwinists about evolution lies in its mechanism: that selection transpires by random mutation. According to this account, an initial error in replication causes a variation which may turn out favorable or unfavorable to survival.
Under the random mutation hypothesis, selection is initially arbitrary: a genetic crap shoot.
For many years in evolution there has been an assumption that mutations occur randomly, and that selection ‘cleans them up’. But genomes have developed mechanisms to avoid mutations in regions that are more valuable than others. ~ Spanish evolutionary biologist Iñigo Martincorena
That evolution is a predictable process, and can occur rapidly, demolishes the notion that randomness has anything to do with evolution. Evolvability – the capacity for adaptive evolution – and convergent evolution confound random mutation as an evolutionary mechanism.
Nonetheless, because randomness is the foundation upon which Darwin’s competitive natural selection was based, there is astonishing volume of literature espousing evolution via random genetic mutation.
Randomness, after all, is always and necessarily related to ignorance. ~ German physicist Jens Eisert et al
Nothing is random. As everything is entangled from the quantum level up, there are always agencies effecting changes, however obscure the initial provocation.
At the heart of the scientific method is the assumption that when something happens there is a cause. ~ American entomologist Richard Gawne
Only religious faith in empiricism blinds researchers to a wealth of evidence. Yet such is the gospel according to Darwinist priests.
Beside pseudo-scientific religiosity, belief in random mutation stems from ignorance about the nuances of genetics and of the influence that microbiomes have on macrobes.
Although random mutations influenced the course of evolution, their influence was mainly by loss, alteration, and refinement. Never did mutation make a wing, a fruit, a woody stem, or a claw appear. Mutations, in summary, tend to induce sickness, death, or deficiencies. No evidence in the vast literature of heredity changes shows unambiguous evidence that random mutation itself, even with geographical isolation of populations, leads to speciation. ~ American evolutionary theorist Lynn Margulis
Bacteria can be frozen for a million years or more and still come back to life. In order to survive that long, there must be some dormancy mechanism, as well as a vitality to life that extra-dimensionally extends beyond physical being.
Further, without an active DNA repair capability, accumulated genetic defects would cause cell death. Even after exposure to ionizing radiation, frozen bacteria can self-repair.
This isn’t a random process. The cells are repairing their DNA. ~ American biologist Brent Christner
Cellular self-repair is a most ancient mechanism. All cells have it to some degree, though descent created trade-offs, such that eukaryotic cells lost some of the vitality that prokaryotes possess for gains in other areas.
Epigenetics regulate genetic expression in myriad ways which are still being discovered. The genome of an organism is replete with coding sequences that offer a tremendous variety of active selection.
Cells constantly make decisions about how best to deploy their genetic databases. If any of this was random, survival itself would be a crapshoot. Clearly it is not.
If instead evolution is vectored by adaptation, however obscure the impetus of the variation, there is no need for Darwinist “natural selection” process. Adaptation is, by definition, a decision from available information.
If genetic evolution is non-random, then a winnowing of the gene pool need not transpire. There is no evidence that such reduction takes place as a evolutionary mechanism.
In contrast, there is abundant evidence that evolution does not result in the die off of antecedent variations, as Darwin conjectured, and as random mutation as an evolutionary force implies. Quite the contrary. Variation to speciation, where several similar species coexist nearby, is abundantly evidenced. Birds, bees, and butterflies are exemplary.
Further, coevolution belies that adaptation is random. Intertwining interspecifics via coevolution simply could not have transpired as it has, innumerable times, if randomness were at the root of evolution.
Is evolution predictable? To a surprising extent the answer is yes. ~ Canadian evolutionary biologist Peter Andolfatto
Nematode Timing
The nematode Caenorhabditis elegans either goes through its 2-week life cycle or puts itself into suspended animation as a dauer larva, awaiting better conditions, notably sufficient food supply. The roundworm is genetically programmed to take the dauer larva route during overcrowding, which can be sensed by the level of local nematode pheromones.
Facing overcrowding, but with an adequate food supply, nematodes predictably mutate to drop the pheromone sensing that sets them into suspension. Instead, the worms put themselves in the thick of things.
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Genetic variation is a cumulative experience. Antecedent genes are conserved. Regressions are common, as the 3-spine stickleback has testified thousands of times, in repeatedly adapting between salt and freshwater living.
Consider the human body: trillions of cells woven into unimaginably intricate complexity. It must maintain itself within strict thermal and physiological limits while enduring an often-unpredictable environment.
To achieve and sustain life, a body must have some robustness and be able to evolve in succeeding generations. The ability to adapt requires sensory capability and the intelligence to make sense of the environment. There is nothing random about that.
The key ingredient to complex life is entanglement. Genes do not act on their own. Instead, they are recipes in a baroque ensemble of interactive operations.
So it is with every bodily function. The only possibility for multicellular life to have evolved is through a networked orchestration. A body is robust only because randomness plays no productive part in its construction or maintenance, nor in its evolution.
Progress
In train with the concept of selection as competition is the notion that the outcome of natural selection represents evolutionary progress. After all, if selection is competitive, the winner must be better.
Nothing can be more hopeless than to attempt to explain this similarity of pattern in members of the same class, by utility or by the doctrine of final causes. ~ Charles Darwin in 1859
Inconsistently, despite his espoused belief in the randomness of evolution, Darwin and other naturalists in his wake believed that life advanced in evolutionary time, evolving from more “primitive” species to “higher” ones. They were likely influenced by the philosophers Georg Hegel and Herbert Spencer, who envisaged history as advancing toward perfection. Ascendance through descent is still widely accepted.
The evolution of life has ascended increased grades of complexity. ~ American molecular biologist Sean Carroll
The supposed overarching trend has been complexity, sold as a story. Life started simple and single-celled. From this arose more complex multicellular organisms, with evolution eventuating to backbones, bigger brains, and so on, culminating in the grandest creature of all: humans.
This fable forgets that prokaryotes possess effective communication skills, are gregarious, have adaptation abilities beyond all others, and remain essential to all eukaryotic life. Proposing the history of life as progressive was due solely to ignorance about microbial life.
Organic life, we are told, has developed gradually from the protozoon to the philosopher, and this development, we are assured, is indubitably an advance. Unfortunately, it is the philosopher, not the protozoon, who gives us this assurance. ~ Bertrand Russell
Statistically, by numbers of species or populations, microbes are the monarchs of life. By this reckoning, the vector victor may be found on the doorstep of evolution, not in the grander mansions constructed much later.
The lifestyles of viruses are practically miraculous when it comes to wiles with next to nothing for physicality. If anything, the ostensible simplification of dropping bodily baggage and living zealously Zen is as remarkable as the specialization that characterizes multicellular organisms.
In evolution, complexity is easy. (And simplicity is hard.) ~ American evolutionary biologist Daniel McShea
Devolution
There is no such thing as devolution. ~ American biologist Michael Dougherty
English zoologist Ray Lankester criticized the Darwinian notion of evolution necessarily being progressive. After seeing apparent regressions during the life cycle of sea squirts, Lankester suggested in 1880 that life may revert to a more primitive state. Evolutionary developments were not always one-way.
Organisms which abandoned their independence for a life of parasitism were once considered devolved. Under this notion, viruses would be the ultimate degenerates, though their existence was not known when devolution was in vogue.
Countering Lankester, Belgian paleontologist Louis Dollo declared evolution irreversible in 1893.
An organism is unable to return, even partially, to a previous stage already realized in the ranks of its ancestors. ~ Louis Dollo
This denouement became known as Dollo’s law. Preaching to the Darwinist choir, Dollo became much better known than Lankester. Dollo’s law is still accepted by many evolutionary biologists.
Dollo’s law of irreversibility states that once a complex trait has been lost in evolution, it cannot be regained. It is thought that complex epistatic interactions and developmental constraints impede the re-emergence of such a trait. ~ Scottish evolutionary biologist Kathryn Elmer et al
In reptiles, viviparity (live birth) repeatedly evolved from oviparity (egg laying). This progressive evolution occurred among common lizards, found across Eurasia, ~2 million years ago. But, in some populations, evolution went backward, and egg laying re-evolved. This happened relatively recently in evolutionary time.
Oviparous reproduction requires the formation of an eggshell and represents a complex trait. ~ Kathryn Elmer et al
There are several other known examples of reversion evolution, including metamorphosis re-evolving in salamanders that had lived their entire lives as juveniles, and wings returning to stick insects which had lost them. Reversion evolution is further explored later in the book.
Decreasing complexity is common in the record of evolution. The lower jaw in vertebrates shows decreasing complexity, as measured by the numbers of bones, from fish to reptiles to mammals. (Evolution adapted the extra jaw bones into ear bones.) Likewise, ancestral horses had several toes on each foot; modern horses have a single toe with a hoof. ~ Michael Dougherty
In 1893, German zoologist Wilhelm Haacke hypothesized orthogenesis: that organisms have an innate direction in their evolution. Orthogenesists did not deny the influence of external factors, but rather stressed an internal goal-directed drive. The famous, fictional descent-of-man image is exemplary of the straight-line evolution proposed by orthogenesists.
Supporters of orthogenesis pointed to extinct animals, such as the enormous dinosaurs who needed so much food, and the Irish elk, with antlers so large that they contributed to the animal’s demise. Orthogenesists argued these excesses would not have arisen if the traits were not predestined.
Wings for flight independently evolved at least 4 times (insects, pterodactyls, birds, and bats). American geologist and paleontologist Henry Osborn argued that such convergent evolution was convincing evidence of orthogenesis. Convergent evolution is now conventionally considered adaptive, but paradoxically without purpose. Therein lies the root issue: that orthogenesists could not identify the force behind directed evolution foretold its moribundity.
However much in the dark we may be, an assumption of a mystic, essentially teleologic force wholly independent of and dominating all the physico-chemical forces and influences that we do know – such a surrender of all our actual scientific knowledge in favour of an unknown, unproved, mystic vital force we are not prepared to make. ~ American entomologist and evolutionary biologist Vernon Kellogg in 1907
Purely empirical evolutionary biologists have the opposite problem of orthogenesists, in that they cannot explain how adaptation might work aimlessly. Vitalism, or lack thereof, remains the critical quandary of evolutionary theory.
Ronald Fisher rejected orthogenetic evolution in favor of particulate inheritance in his 1930 book The Genetical Theory of Natural Selection. Fisher touted genes as the hypothesized particles that cast Mendelian inheritance into a Darwinist mold.
Mendelism validates Darwinism. ~ Ronald Fisher
Fisher’s work was a synthesis of surmises. Mendel’s results had been quite specific, confined to pea plants. Conversely, though highly influential, Darwin’s speculations were hand-waving. DNA was not discovered until 1953. Ironically, it was Haacke who first conceived of the concept of genes.
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Many people evaluate nonhuman organisms according to human anatomy and physiology, and mistakenly conclude that humans are the ultimate product, even goal, of evolution. ~ Michael Dougherty
There is no rational reason to consider humans superior to other species. The metric of intelligence is adapting to the environment in a sustainable fashion. On this count, humanity fails miserably. By this criterion, bacteria make humans seem like germs.
(Counter-factual thinking is essential to problem-solving. This aspect of abstraction is common to all life. Conversely, the ability to create paracosms – a facility highly developed in the human mind – is maladaptive, as an indulged imagination facilely divorces perception from actuality. Creativity – conventionally prized as a hallmark of intelligence – is a bane to acumen if not held in check. Self-control is as much an aspect of intelligence as problem-solving.)
Symbiogenesis
The view of Linnaeus and most biologists – Nature does not make leaps – is not correct, since formation from two (or more) organisms of a third is a leap. ~ Boris Kozo-Polyansky in 1921
Symbiogenesis – that eukaryotes arose via symbiosis – was first suggested by German botanist Andreas Schimper in 1883. In 1905, Russian biologist and botanist Konstantin Mereschkowski outlined a theory that the organelles of complex cells evolved from symbiotic relationships with simpler ones. He came to this concept after studying lichen, which are a composite life form. French biologist Paul Portier claimed in 1918 that mitochondria resulted from symbiosis. In 1924, Russian botanist Boris Kozo-Polyansky cast symbiogenesis in a conventional Darwinian context, albeit trying to flip “survival of the fittest” on its head.
The theory of symbiogenesis is a theory of selection relying on the phenomenon of symbiosis. ~ Boris Kozo-Polyansky
The theory didn’t take. Though others made similar proposals, symbiogenesis was ridiculed and ignored for over a half century.
The eukaryotic cell is the result of the evolution of ancient symbioses. ~ Lynn Margulis
Lynn Margulis revisited symbiogenesis in 1967, proposing that eukaryotes evolved via the symbiosis of prokaryotes. Her theory was ignored for a decade, until substantiated via genetic analysis. The symbiogenesis of eukaryotes is now universally accepted.
Margulis went on to generalize the importance of mutualism in evolution.
The view of evolution as a chronic bloody competition among individuals and species, a popular distortion of Darwin’s notion of “survival of the fittest,” dissolves before a new view of continual cooperation, strong interaction, and mutual dependence among life forms. Life did not take over the globe by combat, but by networking. ~ Lynn Margulis
Punctuated Evolution
Biological evolution is not gradual, but episodic, with long periods of stasis interrupted by bursts of rapid activity. ~ Stephan Jay Gould
In 1972, American paleontologists Niles Eldredge and Stephen Jay Gould proposed punctuated equilibria: that evolution occurs in spurts, with long stretches of stagnation. Substituting a stutter-step for a vector, punctuated equilibria is nonetheless of similar ilk of sophistically simplifying evolution with storytelling.
The idea of punctuated equilibria was an extension of mid-1950s speculations by German-born American evolutionary biologist Ernst Mayr. Mayr is generally credited with the modern definition of species. Rejecting reductionism in evolutionary biology, Mayr argued that evolutionary pressures acted on the whole organism, not genes.
American paleontologist Elisabeth Vrba’s turnover pulse hypothesis built upon the punctuated proposal. It suggested that evolution is nominally conservative, and that speciation occurs only when forced by environmental change.
An extinction event would be at the extreme end of an environmental pulse creating species’ turnover. Most environmental changes are much more modest.
The turnover pulse hypothesis ignores adaptations that are environmentally unforced: opportunistic evolution. Plants pioneered the land from coastal regions to take advantage of the sun and the air: rich inorganic sources of energy. Insects evolved on land to feast on available plant matter. Microbes evolve all the time for a variety of reasons, only some of which we comprehend, but all aimed at staying alive, which is the epitome of opportunity.
Primordial metazoa quickly radiated into 30–40 phyla. Archaic designs went extinct while new ones emerged. Animal evolution proceeded in waves and continues similarly.
Fundamental evolutionary change was not limited to an early burst of evolutionary experimentation. Animal designs have continued to evolve to the present day – not gradually as Darwin predicted – but in fits and starts, episodically through their evolutionary history. ~ English paleontologist Philip Donoghue
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The evolution of any specific organism is the product of historical coincidences, most dramatically in the aftermath of geophysical events which have provoked mass extinctions. This is a strong counterargument against the idea of evolution having an overarching trend. Another argument against evolutionary trending has been the continuing diversity of life in every phylum.
In hindsight, with details stripped out, history may be interpreted as directional movements. The mind’s propensity for patterns engenders this. But the breadth of life and vast diversity of circumstances which invoke adaptation defies characterizing evolution in the large.
We do not understand why the actual complexity realized in evolution is far less than what seems to be possible genetically. ~ Sean Carroll
Evolutionary theories typically suffer survivorship bias: the clades that last are those that theory relies upon. Short-lived clades are ignored or treated as oddities. History is written by the victors. Hence, patterns are perceived which do not aptly characterize evolution.
Though evolution does not have an overarching trend, it does exhibit patterns regarding inclinations, means, and constraints. Evolution exercises a little localized vector, but not a big one.
Wrasses
The biomechanics of animal limbs has evolved to meet the functional demands for movement associated with different behaviors and environments. Effective movement relies not only on limb mechanics but also on appropriate mechanosensory feedback. ~ American biomechanist Melina Hale et al
Wrasses are a large and diverse family of marine fish. Many are brightly colored. Researchers studied the fins of different wrasse species to discern the dynamics of their evolution. What they found, unsurprisingly, was that the means to use fins coevolved with the fins themselves.
As fins evolve different shapes, behaviors, and mechanical properties, the sensory system is also evolving with them. This allows the sensory system to be tuned to the different stimuli relevant to the locomotor behaviors and fin mechanics of different species. ~ American biologist and anatomist Brett Aiello
This is just one of countless examples illustrating that trait emergence is a coordinated endeavor. Evolution simply would not be possible if this were not so.
There are high levels of parallelism between swimming behavior, fin shape, mechanics, and mechanosensation in fishes. ~ American evolutionary biologist Mark Westneat et al
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In the history of life, the facile appearance of increased complexity was achieved mostly through modularity. Once a structure is established, the potential exists for fractal repetition for distinct functionality.
In modern complex organisms, novel adaptations result mostly from reorganization of existing structures. ~ Russian evolutionary biologist Alexander Badyaev
Organs are macroscopic extensions of the organelles within cells. The main innovation in plants was modular: the evolution of semi-autonomous regions embodied in the embryonic meristems of roots and shoots. Grasses amply illustrate this principle at work.
Energy efficiency mediates the interactions of physics and chemistry. Such frugality is also an apparent inclination in evolutionary developments. Photosynthesis and vision are obvious examples of astonishing efficiency in taking advantage of light.
Economy as an inclination might seem to work against complexity. Yet, given the vast diversity of elaborated traits in Nature, there is abundant evidence that it does not. Instead, Nature often hones the functionality of multifaceted traits toward efficiency, as with photosynthesis and vision.
That is not to say that parsimony does not affect complexity. Efficiency acts as a constraint on the directions that evolutionary developments take. Bottom-up physio-chemical constraints pave the avenues of evolution. Then there are strategic trade-offs – life-history variables – that affect tactical approaches. Evolution may not have an overarching vector, but it does play by a rulebook (which is fantastic in its intricacy).
20th-century biology was structured according to a linear Newtonian worldview – not the kind of thinking that’s needed to study evolution. It doesn’t help you understand the nature of systems. Molecular biologists were so set about linearity that when the gene came along, they took the gene to be the be-all and end-all of basic biology. That comes out of thinking in terms of particles and linear interactions. Evolution is the quintessential nonlinear dynamics problem. ~ American microbiologist and physicist Carl Woese
