In 2009, the distinguished evolutionary biologist Jerry Coyne published a book for a general audience titled Why Evolution is True. The in-your-face title drew criticism for hubris unbecoming to a scientist. Shouldn’t scientists cultivate a more humble attitude toward their theories du jour? Doesn’t history provide many examples of the pride of scientists, broken in the dust again?
All true (Oops! Perhaps I shouldn’t even use the t-word this way!) but Coyne was making a valid point with his assertive title. Science can’t move anywhere, forward or back, without accepting some hypotheses and rejecting others. If some people obstinately refuse to accept a hypothesis, no matter how much evidence piles up in its favor, then they have brought the scientific process to a halt. It is important to move on when enough evidence has accumulated, even knowing that the future might reveal new weaknesses and unforeseen alternatives. This is why creationism is not and should not be taught in schools as a legitimate scientific alternative to evolution, even though its exclusion seems to offend sensibilities about letting everyone have their opinion and say.
Now I am drawing fire for hubris in my new book, Does Altruism Exist? In it, I claim to offer a “post-resolution” account of group selection, which explains the evolution of altruistic traits at face value. By this I mean that there is no need to re-define the traits as selfish after showing how they evolve. The chapter of my book titled “How Altruism Evolves” could have been titled “Why Group Selection is True.” I think that I can justify my immodesty in the same way that Coyne justifies his. How ironic that Coyne is among those accusing me of hubris.My strong claim about group selection cannot be understood or evaluated without also understanding a concept called equivalence. Imagine that Joan is talking to Bob and makes a statement based on certain definitions. Bob gets upset and blurts “Well that’s not true according to my definitions!” That is a stupid move on Bob’s part, which puts an end to productive communication. Of course any given statement depends on the definitions underlying the statement. Productive communication requires Bob to evaluate Joan’s statement according to her definitions and then translate her statement into an equivalent statement according to his definitions, like translating a statement from one language to another.
I wish I could say otherwise, but Coyne is acting like Bob in his recent blog post on my book. Steve Pinker also acts like Bob in his essay titled “The False Allure of Group Selection” published on Edge.org with commentaries (be sure to read the commentaries), which is the only source that Coyne provides to his readers to learn more. Both are saying in effect: “Wilson is wrong! Altruism doesn’t evolve by group selection according to my definitions!” Why don’t they try evaluating my claims according to my own definitional framework (multilevel selection theory)?
What is the optimal number of definitional frameworks for the study of a given subject? Part of the answer to this question is “more than one” because different frameworks can offer different perspectives on a given topic, like viewing a mountain from different angles. Another part of the answer is “not too many” because of the burden of translating among frameworks. Also, a definitional framework is like a mutation; for every one that works well, hundreds work poorly. In productive scientific and scholarly inquiry, there is a manageable number of definitional frameworks that pull their weight in some sense, and the community of scientists/scholars is capable of recognizing and operating within each framework.
The task of the scientist/scholar is made even more complex when we take history into account. Definitional frameworks aren’t static. They change as inquiry proceeds. The definition of the coefficient of relatedness (r) in inclusive fitness theory (also called kin selection theory) provides a good example. Originally interpreted as a measure of genealogical relatedness, it was later generalized to become a measure of genetic correlation for any reason. In one of the most recent reviews of inclusive fitness theory, Birch and Okasha1 provide three definitions of r that are useful for different purposes, illustrating the principle of “more than one but not too many.” Multiple definitions and changes in definitions over time are not arbitrary. They are driven by scientific/scholarly inquiry, as reported in peer-reviewed books and journals. Scientists/scholars have a responsibility to keep all of these distinctions and their rationales alive in collective memory.
When someone like Coyne or Pinker declares a theoretical framework such as multilevel selection confusing, good for nothing, and changing arbitrarily over time, there is a good chance that they are acting like Bob. While I’m calling out luminaries, let me add Martin Nowak and E.O. Wilson on the subject of inclusive fitness theory. When Nowak2 wrote, “Casting a problem in terms of inclusive fitness is like having to undergo elaborate and time-consuming initiations to join a club, only to end up with nothing in the way of privileges,” he sounded like Bob. It was appropriate for Nowak and Wilson to be held to a higher standard and criticized for their dismissal of inclusive fitness theory as a useful theoretical framework in the infamous letter published in Nature magazine,3 signed by nearly 150 scientists. Now let’s apply the same standard to Coyne and Pinker for their dismissal of multilevel selection theory.
Water striders, a species that includes males with either selfish or altruistic mating strategies. Experimental groups that include only altruistic males produce nearly double the offspring of groups with only selfish males4.
When you consult the work of scientists who think hard enough about multilevel selection to publish on the subject in peer-reviewed journals, you find widespread acceptance of the fact that traits evolve by virtue of benefiting groups, despite being selectively disadvantageous within the groups; this is the central claim of multilevel selection theory (for some empirical examples, see references 4-6). Even scientists who prefer to use other frameworks, such as David Queller7 and Stuart West,8 acknowledge this much. To summarize: The earth revolves around the sun. Continents drift. Evolution is true. And altruism evolves by group selection as “altruism” and “group selection” are defined within multilevel selection theory.
Does Altruism Exist? covers this ground in more detail for the general reader. It has been praised by reviewers for its clear account of multilevel selection and equivalence (go here and here). Even H. Allen Orr, who also accuses me of hubris in his New York Review of Books review, commends the chapters on multilevel selection and equivalence.
To learn more online, please consult my essay titled “Richard Dawkins, E.O. Wilson, and the Consensus of the Many,” where I call out both Dawkins and Wilson for their Bob-like behavior. Please read the comments in addition to the article to see how others are working with the ideas. My more recent essay titled “Challenge to Kin Selectionists—Explain This!” explores the interesting possibility that two theoretical frameworks can be equivalent in some but not all respects. My challenge to kin selectionists is friendly and I will be happy if they can meet it. Bob-like rants against kin selection or group selection are not productive. It is time to move on.
References:
1. Birch, J., & Okasha, S. (2014). Kin Selection and Its Critics. BioScience, 65(1), 22–32. http://doi.org/10.1093/biosci/biu196
2. Nowak, M., & Highfield, R. (2011). SuperCooperators: Altruism, Evolution, and Why We Need Each Other to Succeed. New York: Free Press.
3. Abbott, P., Abe, J., Alcock, J., & al., et. (2010). Inclusive fitness theory and eusociality. Nature, 471, E1–E4. http://doi.org/doi:10.1038/nature09831
4. Eldakar, O. T., Wilson, D. S., Dlugos, M. J., & Pepper, J. W. (2010). The role of multilevel selection in the evolution of sexual conflict in the water strider aquarius remigis. Evolution; International Journal of Organic Evolution, 64(11), 3183–9.
5. Kerr, B., Neuhauser, C., Bohannan, B. J. M., & Dean, A. M. (2006). Local migration promotes competitive restraint in a host-pathogen “tragedy of the commons.” Nature, 442, 75–78.
6. Pruitt, J. N., & Goodnight, C. J. (2014). Site-specific group selection drives locally adapted group compositions. Nature, 514(7522), 359–362. http://doi.org/10.1038/nature13811
7. Queller, D. C. (1991). Group selection and kin selection. Trends Ecol. Ecol., 6(2), 64.
8. West, S. A., Griffin, A. S., & Gardner, A. (2007). Social semantics : altruism, cooperation , mutualism , strong reciprocity and group selection, 20, 415–432. http://doi.org/10.1111/j.1420-9101.2006.01258.x
