“Group Selection” and the Human Conquest of Earth

27 Feb

Edward O. Wilson, professor emeritus at Harvard, is a highly respected pillar of modern evolutionary biology. Check out this link for a summary of his many contributions to our understanding of life and humankind.

I recently read Wilson’s latest book The Social Conquest of Earth and greatly enjoyed parts of it. Wilson’s writing is clear and compelling as he tackles THE BIG QUESTION: How did a single primate species (If you’re reading this, you’re a member of that species) so quickly conquer the world? But I was surprised to see that much of Wilson’s argument is built on the foundation of group selection, also called “multilevel selection.”

Group selection attempts to explain how traits (for example, altruistic behavior) that are costly to individuals, but beneficial to larger groups, can persist. Why doesn’t natural selection, which acts on individuals, eliminate such “maladaptive” traits? If it pays (evolutionarily) to be selfish, why do humans routinely perform selfless acts? As applied to humans, group selection is the idea that groups composed of cooperative altruists are able to outcompete groups of selfish people, increasing their populations, and fostering the spread of altruism.

Most scholars view group selection as highly unlikely or, at best, a very weak force in the evolution of human cooperation. It’s not a bad idea, just not as parsimonious an explanation as inclusive fitness or kin selection: “The concept that altruistic behavior can be selected for if it increases the probability of survival of close relatives” (Relethford 2013:148) – and for the vast majority of our evolutionary history, we lived in societies composed almost exclusively of close relatives.

This week, E. O. Wilson reiterated his support for multilevel selection in a New York Times piece called “The Riddle of the Human Species.” It’s a short summary of the argument detailed in his book. For a counterpoint from Jerry Coyne, professor of biology at the University of Chicago, please see this post at Coyne’s Why Evolution is True website (the linked post also includes links to previous posts on this topic of group selection).

I highly recommend these resources for anyone interested in anthropology and the evolution of human behavior. As stated, I think kin selection is a better explanation for the evolution and spread of altruism than group selection, but remain open to the possibility of new evidence. What do you think? Did multilevel selection, as argued by Wilson, play a role in the social conquest of Earth by Homo sapiens?

3 Responses to ““Group Selection” and the Human Conquest of Earth”

  1. bonesofculture 02/27/2013 at 6:37 pm #

    BioAnth is not my specialty. Reading the two articles, however, Jerry Coyne makes a more persuasive argument. E.O. Wilson’s argument seems to imply that a biological fact, change in the gene pool, is more affected by behaviors not linked directly with genetics (like kinship selection is). That seems unlikely.

    Am I missing something here?

    • jayfancher 02/28/2013 at 2:20 pm #

      You make a good point. Steven Pinker addressed this issue in an essay critical of group selection (http://edge.org/conversation/the-false-allure-of-group-selection).

      He wrote: “…most of the groupwide traits that group selectionists try to explain are cultural rather than genetic…Sure, some cultures have what it takes to become more populous or powerful or widespread, including expansionist ideologies, proselytizing offensives, effective military strategies, lethal weaponry, stable government, social capital, the rule of law, and norms of tribal loyalty. But what does ‘natural selection’ add to the historian’s commonplace that some groups have traits that cause them to grow more populous, or wealthier, or more powerful, or to conquer more territory, than others?”

      Thanks for commenting!

      • bonesofculture 02/28/2013 at 2:38 pm #

        From the same Steven Pinker article:

        “The problem is that it also obfuscates evolutionary theory by blurring genes, individuals, and groups as equivalent levels in a hierarchy of selectional units; … this is not how natural selection, analyzed as a mechanistic process, really works.”

        That’s a much more succinct expression of my read of the theory. While I am a trained cultural anthropologist (M.A.), I do have a background in biology, especially ecology.

        Culture certainly does have the potential to affect genetics, but it is unlikely to have the same kind of feedback loop–those changes in the genetics are not going to select genetically for behaviors that aren’t genetically dictated.

        The alternative interpretation of Wilson’s approach is to suggest that genetics have a much broader impact on behavior than we currently can prove. This seems to be the real implication of group selection theory. I have yet to see the evidence that this kind link can be made.

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