The Web of Life (36-7) Bacteria Sociality


Bacteria have developed intricate communication capabilities (e.g. quorum-sensing, chemotactic signaling and plasmid exchange) to cooperatively self-organize into highly structured colonies with elevated environmental adaptability. Communication permits colonial identity, intentional behavior, purposeful alteration of colony structure, decision-making and the recognition and identification of other colonies. ~ Israeli physicist Eshel Ben-Jacob et al

Many bacteria live as single cells. Others are more communal. Regardless of lifestyle, bacteria are sociable: communicating among themselves and operating as a community.

Bacteria interact by releasing biocompounds to help them adapt to their environment. Colonial populations coordinate actions, such as mass secretions, by first releasing signaling molecules.

When conditions become too stressful, bacteria can transform themselves into enduring inert spores. (Bacterial sporulation is an exemplary existence proof of energyism: that physical bodies are artifacts of vital life energy. If life was merely made of matter, revival from sporulation would not be possible, as spores are utterly inert: dehydrated, and materially dead. But then, material science cannot explain life at all.) Sporulation is a collective process which begins only after consultation and assessment by colony members. Starving bacteria emit chemical messages conveying their distress. With such communiqués about, each bacterium makes its own interpretation of the state of the colony relative to itself. Sporulation is put off until a majority rule in its favor. Colonial bacteria are democratic in their decisions.

Bacterial colonies are invariably diversified. Individuals within possess a spectrum of distinct characteristics and talents. This diversity increases the probability of population survival in unpredictable environments.

Bacteria face a social problem which humans are well acquainted with: cheaters. To single out microbial miscreants, cooperators first generate a new communication dialect which defectors have trouble imitating. They can then collectively alter their own identity into a new genetic state, leaving the cheaters out of further cooperative endeavors. These periodic intelligence operations benefit the group by improving cooperative social skills.

Neisseria, a commensal bacterium that colonizes the mucous membranes of many animals, pair up to be more effective. Streptococcus, another commensal genus, though with some pathogenic species, grow in chains. Staphylococcus, a cocci genus, form clusters that resemble grapes. Most are harmless residents of the skin and mucosal surfaces, as well as a worldwide presence in soil.

Some bacteria elongate, forming filaments that contain numerous cells, like mycelium (a threaded fungal mass). This is what actinobacteria do. They are one of the dominant bacterial phyla, common in soil, freshwater and seawater, and a major player in the carbon cycle, thanks to their saprotrophic lifestyle of breaking down organic matter.