Does Darwinian evolution reward cooperative behaviors?
Behaviors have an effect on the evolution of species and vice versa. But let's not forget that evolution is the result of random events that generate consequences that are subject to natural selection. Some random changes improve an organism’s chance of surviving and reproducing in a specific environment, and some decrease it. Scientists strive to quantify these changes statistically so that we can make predictions and figure out what happened in the past.
To be clear: There is no conscious goal or direction or systemic intentionality built into the evolutionary trajectory of a given entity, be it unicellular or multicellular. Nonetheless, in scientific conversation, it is often convenient to talk about behaviors as if they are the result of choices. But cells are not conscious beings competing in a game like Prisoner's Dilemma, say, which treats outcomes as decisions.
Why, then, is game theory used so much in evolutionary biology?
It was originally developed as a tool for finding solutions to zero-sum games played by conscious agents, and it was used extensively for economic analysis in a Western capitalist environment. It is riddled with anthropomorphic, value-laden language and, partly as a result, its adoption by many scholars of evolutionary biology means that we now casually talk about “altruistic” cells that commit genetic “suicide” by “cooperating” with “defectors” who “won” a “competition” for “control” of “public goods” in a test tube.
These human-centric metaphors become problematic when we forget that the linguistic shorthand does not refer to human societies and our own choices. That is why in the evo-devo-eco scheme of things, I am drawn toward developmental biology and its emphasis on understanding physical and chemical structures quantitatively.
Is it possible to unlock the secret of how we—as multicellular creatures—came to be?
My goal is to understand the genetic programs that allowed cells in multicellular entities to evolve a germ-soma division of reproductive labor in specific environments, not to analyze how our multicellular origin has affected the evolution of our societies. Frankly, I am distressed by the amount of subjectivity in human society, and I seek to avoid that in science. I grant, though, that biologists must be fascinated by the evolution of multicellularity, because we are multicellular creatures. A single cell cannot sing with the symphony!
Reprinted with permission from Quanta Magazine, an editorially independent division of SimonsFoundation.org whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences.