A few days ago E. O. Wilson published a bit in The New York Times entitled The Riddle of the Human Species. Wilson, of course, is a fine writer and a great thinker who’s books include, among others, the seminal Sociobiology. He has been referred to as the “Father of Evolutionary Psychology,” or was, at least, until he challenged some academic orthodoxies in his latest, The Social Conquest of Earth. Among the most egregious of these was his defense of group selection, a subject with a fascinating history which I have often discussed in this blog. Basically, the group selection hypothesis is that natural selection of certain traits occurred because it favored the survival of groups, even though those traits were either neutral or detrimental to the survival of individuals. This drew a chorus of boos from the likes of Richard Dawkins and Steven Pinker, who have more or less staked their reputations on the assertion that group selection never happened or, if it did, it wasn’t important. There’s really nothing new in Wilson’s latest bit. He basically reiterates the themes of his latest book, including group selection. This again drew the predictable catcalls from the Dawkins/Pinker camp. One of them was penned by Jerry Coyne, proprieter of the blog, Why Evolution is True. I certainly agree with his take on evolution, but I found some of the arguments in his response to Wilson’s latest risable.
So it’s sad to see him, at the end of his career, repeatedly flogging a discredited theory (“group selection”: evolution via the differential propagation and extinction of groups rather than genes or individuals) as the most important process of evolutionary change in humans and other social species. Let me back up: group selection is not “discredited,” exactly; rather, it’s not thought to be an important force in evolution. There’s very little evidence that any trait (in fact, I can’t think of one, including cooperation) has evolved via the differential proliferation of groups.
Here Coyne does a complete 180 in a single paragraph, making the bombastic claim that group selection is discredited and then doing a quick rowback to the more prosaic, “Well, maybe not quite.” There may be very little evidence that any trait evolved via group selection, as Coyne suggests, but there’s very little evidence that those that might have evolved via group selection didn’t, either. Coyne continues,
I’ve covered this issue many times (e.g., here, here, here, here, and here), so I won’t go over the arguments again. Wilson’s “theory” that group selection is more important than kin selection in the evolution of social behavior (published in Nature with Martin Nowak and Corina Tarnita) was criticized strongly by 156 scientists—including virtually every luminary in social evolution—in five letters to the editor, and sentiment about the importance of group selection has, if anything, decreased since Wilson’s been pushing it.
This is the classic “50 billion flies can’t be wrong” argument, or, in more polite parlance, the argument from authority. Coyne knows that it is just as flimsy as the claim that group selection is a “discredited theory,” but this time he takes a bit longer to do a 180, writing near the very end of his bit,
His theories have not gained traction in the scientific community. That doesn’t mean that they’re wrong, for, in the end, scientific truth is decided by experiment and observation, not by the numbers of people initially on each side of an issue.
If that’s the case, why bring up the “156 scientists” argument to begin with? If memory serves, there were very few “experts” in the behavioral sciences who didn’t at least pay lip service to the Blank Slate orthodoxy until a very few decades ago. Did that make it right? Coyne next takes Wilson to task for his “inaccurate” use of the term “eusociality”:
“Eusociality” as defined by Wilson and every other evolutionist is the condition in which a species has a reproductive and social division of labor: eusocial species have “castes” that do different tasks, with a special reproductive caste (“queens”) that do all the progeny producing, and “worker castes” that are genetically sterile and do the tending of the colony. Such species include Hymenoptera (ants, wasps and bees, though not all species are eusocial), termites, naked mole rats, and some other insects.
But humans don’t have reproductive castes, nor genetically determined worker castes. Wilson is going against biological terminology, lumping humans with ants as “eusocial,” so he can apply his own theories of “altruism” in social insects (i.e., workers “unselfishly” help their mothers produce offspring while refraining themselves from reproducing), to humans.
Here, one can but smile and wonder if Coyne is actually serious. Is he really unaware that, while he may not have actually coined the term “eusociality,” Wilson supplied the first scientific definition for it? Is he no longer allowed to use a term that he essentially invented as he sees fit? The presence of “castes” is by no means universally accepted as a requirement for eusociality in any case.
As it happens, Wilson is co-author with Martin Nowak and Corina Tarnita of a paper presenting a mathematical theory of group selection entitled, The Evolution of Eusociality. Alluding to this, Coyne writes,
The mathematical “proof” given by Nowak et al. does not show that group selection is a better explanation than kin selection for social behavior in insects, for their “proof” does not vary the level of kinship, as it must if it could allow that conclusion.
This begs the question of whether alternative mathematical “proofs” of kin selection are any better. To this, as one who has spent a good part of his career as a computational physicist, I can only laugh. Consider the case of the National Ignition Facility (NIF), built to demonstrate inertial confinement fusion. The finest three-dimensional full physics codes, amply benchmarked with the results of previous experiments on earlier giant laser facilities such as Nova at Lawrence Livermore National Laboratory and OMEGA at the Laboratory for Laser Energetics at the University of Rochester, confidently predicted that the NIF would succeed in achieving its ignition goal. It did not. It is currently short of that goal by more than an order of magnitude. Trust me, the mathematical models that are supposed to “prove” group selection or kin selection are hopelessly crude by comparison. They can all be taken with a grain of salt. Coyne continues,
The second egregious and false claim in this paragraph (a paragraph that’s the highlight of the piece) is that “multilevel selection is gaining in favor among evolutionary biologists” because of the Nowak et al. paper. That’s simply not true. The form of multilevel selection adumbrated in that paper is, to my knowledge, embraced by exactly four people: the three authors of the paper and David Sloan Wilson.
Here, I can but suggest that Coyne try Google, using the search term “group selection.” It would seem based on a cursory search that there are rather more embracers of group selection than he imagined. Coyne concludes,
Why does Wilson keep writing article and article, and book after book, promoting group selection? I’m not a psychologist, so I don’t know the answer. What I do know, though, is that his seeming monomaniacal concentration on a weakly-supported form of evolution can serve only to erode his reputation… Wilson’s reputation is secure. It’s sad to see it tarnished by ill-founded arguments for an unsubstantiated evolutionary process.
What, exactly, is this supposed to be? A thinly veiled threat? If not, how else is one to construe it? Is Coyne suggesting that Wilson either repeat orthodoxies about group selection that he clearly believes to be false, or, alternatively, shut up and surrender his freedom of speech because he’s worried about his precious reputation? It brings to mind my own furious denunciation of Aristotle in my 9th grade biology class for promoting wrong theories of cosmology. My teacher, Mr. Haag, who was much wiser than I deserved, observed, “Well, at least he thought.” I’ve thought a great deal about that reply since the 9th grade. To this day I have no idea whether group selection was really important or not, and don’t believe that anyone else has adequate evidence to decide the question one way or the other, either. However, regardless, I will always honor and admire E. O. Wilson. At least he thought.