There was a lot of attention given to an erroneous argument against Hamilton’s theory of inclusive fitness, the role of haplodiploidy, and the evolution of eusociality a couple of years ago. In a recent blog, Masatoshi Nei has resurrected it, causing David Queller to write a particularly lucid piece on agreement and disagreement over how altruism evolves. I copy it (with permission, of course) below:
I agree with Ken Weiss about molecular versus evolutionary explanations. The royalactin results are really interesting but they provide proximate explanations of mechanism and not ultimate explanations of selective causes. Nothing in them bears on the issue of whether eusociality evolved because of benefits provided to relatives.
The field of social evolution is not in nearly as much turmoil as it may appear to outsiders. The theoretical arguments are partly a matter of ego and partly a matter of preferences for different modeling strategies. The strategies differ in generality, simplicity, precision, and in how easily we can compare them to the real world. Different modelers weigh these factors differently, often unconsciously. Yet the various models, if we take the trouble to compare them, usually show similar things, viewed from different angles. This leads to priority issues; does this new model using method A show fundamentally new result or is it expressing in a new language something we already knew from method B? The resulting arguments over priority often get confused with disagreements over substance.
So let me say a few words about what I think the theoreticians agree on. I think they all agree that Hamilton was correct that having fitness effects on genetic relatives is important and that altruism can evolve if sufficient benefits are given to sufficiently related kin. I think they would all agree that Hamilton’s rule is correct when fitness effects are additive. I think they would all agree that non-additivity of fitness effects is another important social phenomenon, for example when it takes two cooperators to generate any benefit. This is the area that game theoretic approaches were devised for.
Many of the disagreements appear when those two insights – kin selection and non-additivity – are both in play at the same time. Then you can get arguments over when Hamilton’s rule is still correct, how it can be modified to make it correct, or whether it is worth the trouble when other methods are available. But none of these arguments affect Hamilton’s basic insights about kin selection.
I should mention that at least one person, E. O. Wilson, does not agree. He now seems to believe that social insects evolved for some completely different reason and that genetic relatedness was not important. But Wilson is not a theoretician and there is no theoretical support for his view. Even the models of the evolution of eusociality in the Nowak, Tarnita, and Wilson paper assume high relatedness. That paper is a forced and unproductive marriage between Wilson’s desire to dethrone kin selection to Nowak and Tarnita’s preference for a modeling strategy other than inclusive fitness. People who don’t read the paper (and the math) carefully, believe that the two views mutually support each other, but they do not. Masatoshi gave the reference for Nowak et al. and for their response to critics, but not to the criticisms themselves, so those are appended below 1-5, but remember these contain a mix of criticisms of Wilson’s odd view that kin selection is unimportant and issues on the theoretical preferences on modeling strategies.
I started out trying to be completely dispassionate, and now I find myself getting a little edgy, so it is time to stop. The main point is that there is really a huge amount of agreement on social evolution theory, and that arguments over preferred modeling strategies should not obscure this.
1 Ferriere, R. & Michod, R. E. Inclusive fitness in evolution. Nature 471, E6-E8 (2011).
2 Abbot, P. et al. Inclusive fitness theory and eusociality. Nature 471 (2011).
3 Strassmann, J. E., Page, R. E., Robinson, G. E. & Seeley, T. D. Kin selection and eusociality. Nature 471, E5-E6 (2011).
4 Herre, E. A. & Wcislo, W. T. In defence of inclusive fitness theory. Nature 471, E8-E9 (2011).
5 Boomsma, J. J. et al. Only full-sibling families evolved eusociality. Nature 471, E4-E5 (2011).