Wednesday, July 4, 2007

Faith, Science and Reason, Part VI: More on Group Evolution and the Moral Law


I have posted before my view that the C.S. Lewis/Francis Collins argument that the innateness of morality supports the existence of God was in danger of the "God of the Gaps" fallacy because evolutionary scientists may well find a evolutionary explanation for altruism and morality. In my post, I noted that one difficulty with an evolutionary explanation is that it relies on group selection.

I was therefore interested to read an essay by David Sloan Wilson, a Distinguished Professor in the Departments of Biology and Anthropology, Binghamton University, who is studying the evolutionary explanation of religion. While the essay is interesting because Wilson, an atheist, is attacking the views on religion of Richard Dawkins, another atheist. What I found interesting, however, is Wilson's explanation for why group selection is indeed credible in such a social animal like human beings:

Much has happened in the four decades following the rejection of group selection in the 1960s. Naïve groupism is still a mistake that needs to be avoided, but between-group selection can no longer be categorically rejected. Claims for group selection must be evaluated on a case-by-case basis, along with the other major evolutionary hypotheses. Demonstrations of group selection appear regularly in the top scientific journals.

As one example reported in the July 6, 2006 issue of Nature, a group of microbiologists headed by Benjamin Kerr cultured bacteria (E. coli) and their viral predator (phage) in 96-well plates, which are commonly used for automated chemical analysis. Each well was an isolated group of predators and their prey. Within each well, natural selection favored the most rapacious viral strains, but these strains tended to drive their prey, and therefore themselves extinct. More prudent viral strains were vulnerable to replacement by the rapacious strains within each well, but as groups they persisted longer and were more likely to colonize other wells. Migration between wells was accomplished by robotically controlled pipettes. Biologically plausible migration rates enabled the prudent viral strains to persist in the total population, despite their selective disadvantage within groups.

As a second example reported in the December 8, 2006 issue of Science, economist Samuel Bowles estimated that between-group selection was strong enough to promote the genetic evolution of altruism in our own species, exactly as envisioned by Darwin. These and many other examples, summarized by Edward O. Wilson and myself in a forthcoming review article, are ignored entirely by Dawkins, who continues to recite his mantra that the selective disadvantage of altruism within groups poses an insuperable problem for between-group selection.

. . .

Not only can group selection be a significant evolutionary force, it can sometimes even be the dominating evolutionary force. One of the most important advances in evolutionary biology is a concept called major transitions. It turns out that evolution takes place not only by small mutational change, but also by social groups and multi-species communities becoming so integrated that they become higher-level organisms in their own right. The cell biologist Lynn Margulis proposed this concept in the 1970s to explain the evolution of nucleated cells as symbiotic communities of bacterial cells. The concept was then generalized to explain other major transitions, from the origin of life as communities of cooperating molecular reactions, to multi-cellular organisms and social insect colonies.

In each case, the balance between levels of selection is not fixed but can itself evolve. A major transition occurs when selection within groups is suppressed, making it difficult for selfish elements to evolve at the expense of other members of their own groups. Selection among groups becomes a dominating evolutionary force, turning the groups into super-organisms. Ironically, during the Age of Individualism it became taboo to think about groups as organisms, but now it turns out that organisms are literally the groups of past ages.

. . .

Consider genetic evolution by itself. When a new mutation arises, the total population consists of one group with a single mutant and many groups with no mutants. There is not much variation among groups in this scenario for group selection to act upon. Now imagine a species that has the ability to socially transmit information. A new cultural mutation can rapidly spread to everyone in the same group, resulting in one group that is very different from the other groups in the total population. This is one way that culture can radically shift the balance between levels of selection in favor of group selection. Add to this the ability to monitor the behavior of others, communicate social transgressions through gossip, and easily punish or exclude transgressors at low cost to the punishers, and it becomes clear that human evolution represents a whole new ball game as far as group selection is concerned.

In this context, the human major transition probably began early in the evolution of our lineage, resulting in a genetically evolved psychological architecture that enables us to spontaneously cooperate in small face-to-face groups. As the great social theorist Alexis de Tocqueville commented long ago in Democracy in America, “the village or township is the only association which is so perfectly natural that, wherever a number of men are collected, it seems to constitute itself.” As the primate equivalent of a beehive or an ant colony, our lineage was able to eliminate less groupish competitors. The ability to acquire and socially transmit new behaviors enabled our ancestors to spread over the globe, occupying hundreds of ecological niches. Then the invention of agriculture enabled group sizes to increase by many orders of magnitude, but only through the cultural evolution of mechanisms that enable groups to hang together at such a large scale. Defining, motivating, coordinating, and policing groups is not easy at any scale. It requires an elaborate system of proximate mechanisms, something akin to the physiological mechanisms of an individual organism. Might the elements of religion be part of the “social physiology” of the human group organism?

Read it all here.

If Wilson is correct--and he is persuasive--group selection of traits like altruism might well explain why moral views appear fairly uniform across human cultures. And accordingly, a faith in God based on this "Moral Law" is on shaky ground indeed.

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