Thursday, April 21, 2011

Chet Raymo, "A Defensible Nest"

"A Defensible Nest"
by Chet Raymo

“This past Sunday, a scientific controversy that has been simmering for months made it big time onto the front page of the "Ideas" section of the Boston Globe. And once again the Harvard biologist E. O. Wilson, now 81 years old, proves his ability to stir the pot. Last August, Wilson published a paper in "Nature," with Harvard mathematicians Martin Nowak and Cornia Tarnita, challenging the accepted theory for the origin of cooperative and altruistic behavior in animals. For the last half-century the presiding idea has been "kin selection" - cooperating with others who share your genetic material is a way of promoting one's own genes. Wilson was himself an early champion of "kin selection," aka "inclusive fitness theory."

In their new paper, Nowak, Tarnita and Wilson propose that "kin selection" is not only wrong, it is unnecessary. They argue that standard natural selection theory, in the context of precise models of population structure, is a simpler and more fruitful approach, allowing the evaluation of multiple competing hypotheses, and providing an exact framework for interpreting experimental observations. The key here is mathematical modeling; hence, Wilson's co-authors. Wilson's own vast knowledge of the social insects provides the team's empirical base. But we are not just talking about ants and bees. At the end of their paper, Nowak, Tarnita and Wilson say: "We have not addressed the evolution of human social behavior here, but parallels with the scenarios of animal eusocial evolution exist, and they are, we believe, well worth examining."

A few weeks ago, "Nature Online" published five long letters, with collectively 153 authors, basically saying that Wilson and his co-authors don't know what they are talking about. Richard Dawkins was quoted in the Globe as saying that he "never met anybody apart from Wilson and Nowak who takes [their argument] seriously." Well, we'll see. It's not the first time Wilson has been a contrarian. Back in the 70s, his ideas about sociobiology as applied to humans evoked a firestorm of controversy. They are now more or less conventional.

All of which brings to mind a work of another great Harvard biologist, Ernst Mayr's "The Growth of Biological Thought," published when Mayr was 78, a magisterial summing up of biological history and philosophy. He writes: "All interpretations made by a scientist are hypotheses, and all hypotheses are tentative. They must forever be tested and they must be revised if found to be unsatisfactory. Hence, a change of mind in a scientist, and particularly in a great scientist, is not only not a sign of weakness but rather evidence for continuing attention to the respective problem and an ability to test the hypothesis again and again."

So now we wait, as the ideas of Nowak, Tarnita and Wilson are assimilated and tested, and eventually accepted or rejected. It is this capacity for self-criticism and correction, as Mayr points out, that distinguishes science from religion and other less adaptable ways of knowing.”

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