you all are probably familiar with the debate occurring in new scientist between e.o. and d.s. wilson and dawkins -- i mentioned it over in the evolution tribe. since my posts, dawkins has written a much longer commentary on the wilsons' attempt to resurrect group selection. i have to say, richard sounds right on, as usual:


"Comment: The group delusion
12 January 2008
From New Scientist Print Edition. Subscribe and get 4 free issues.
Richard Dawkins

EDWARD WILSON has given us a characteristically fascinating account of the evolution of social insects (see "Kinship doesn't matter - how insects are altruistic" and BioScience, vol 58, p 17). But his "group selection" terminology is misleading, and his distinction between "kin selection" and "individual direct selection" is empty.

What matters is gene selection. All we need ask of a purportedly adaptive trait is, "What makes a gene for that trait increase in frequency?" Wilson wrongly implies that explanations should resort to kin selection only when "direct" selection fails. Here he falls for the first of my "12 misunderstandings of kin selection"; that is, he thinks it is a special, complex kind of natural selection, which it is not.

“Edward Wilson thinks kin selection is a special, complex kind of natural selection, which it is not”
In the true sense of kin selection, offspring are "kin" just as siblings are. Parental care and sibling care both evolve because copies of genes for caring are present in beneficiaries. Genes promoting feeding of larvae by sterile workers are passed on by those larvae - sisters, nephews, and so on - destined to become reproductives. That's kin selection, and it maintains sterile worker castes in insect colonies. Wilson could not dispute that.

What he does dispute - perhaps correctly - is that eusociality originated through related females clubbing together because of kinship. It could also originate through unrelated females nesting together. But to call this "group selection" is massively confusing. A better approach is John Maynard Smith's concept of evolutionarily stable strategies (ESS). "Stable" means that when most individuals follow the strategy, no alternative does better. If "breed cooperatively" were a stable strategy for unrelated females, this would furnish a good preadaptation for the evolution of eusociality.

Jane Brockmann, now at the University of Florida, Gainesville, and I explored this with an ESS model developed with Alan Grafen of the University of Oxford, using Brockmann's fieldwork on solitary digger wasps, Sphex ichneumoneus. When following the "dig" strategy, a female digs a burrow, provisions it with prey on which she lays a single egg, seals the burrow and departs. But burrows may be abandoned and this opens the way for an alternative strategy: "enter" an existing burrow and take it over, saving the time and effort of digging. The disadvantage is that the original owner may not have abandoned the burrow, and you run the risk of a dangerous fight. So the decision whether to enter or dig is a gamble.

With too much entering in the population, not enough new burrows get dug and chances rise that a given burrow will be occupied. Selection would therefore favour digging. With too much digging, many abandoned burrows go begging, and individuals should enter instead. Grafen's ESS model predicted an equilibrium frequency of digging versus entering with equal benefits to each. Brockmann's field measurements were rich enough to test this prediction, and it was, with reservations, fulfilled.

Brockmann and I then postulated an ecological "landscape" over which the parameters governing Grafen's model might vary. A change in ecological conditions might move digger wasps from an "aggressive space" strategy, as used by S. ichneumoneus, to "tolerant space" - where diggers benefit from being joined by an enterer. From here there is a smooth gradient to "cooperative space", where both parties benefit from sharing. Our review of the literature uncovered wasp species that apparently take such intermediate positions. From here, the evolutionary journey to full eusociality is easy.

Revealingly, Wilson's great book Sociobiology allots only four sentences - in the chapter on group selection - to ESS theory. Kin selection is also here, as a form of group selection! Evidently Wilson's weird infatuation with "group selection" goes way back: unfortunate in a biologist who is so justly influential.

From issue 2638 of New Scientist magazine, 12 January 2008, page 17"

"well, it sure sounds a lot like a looser kind of kin selection to me. maybe it's "kin" that needs to be redefined along a wider coefficient of relatedness, and the controversy disappears?"

What controversy? It's 'Group Selection' because it is driven by the relative success (relative extinction rates) of groups of individuals as coherent units. Dawkins thinks that's misleading. It's clearly not misleading to evolutionary biologists and I see no point in tweaking what is clearly *appropriate and accepted* terminology just so non-biologists won't get confused between the Wynne-Edwards nonsense and the kind of Group Selection that is both theoretically possible (can be modeled) and has been demonstrated experimentally. Levin and Kilmer (1974. Interdemic selection and the evolution of altruism: a computer simulation study. Evolution 28:527-545) demonstrated that an altruistic allele *can* be maintained in a fixed or polymorphic state by Group Selection, but only under restrictive conditions (the allele must not be too detrimental to its bearers, on average, must appreciably enhance the survival of the population, there must be little gene flow among demes, and the demes must be fairly small (10-25 individuals). Wade (1977. An experimental study of group selection. Evolution 31:134-153) demonstrated experimentally that group selection can counteract individual selection.
Dawkins either doesn't understand the subtleties of selection at multiple levels, or he doesn't think *you* are capable of understanding them. Or he is blinded by his own dogma and is constitutionally unable to accept what is clear to the rest of us. In any case, he is wrong.