Does Dawkins understand group selection?

This struck me as a very odd passage. It’s from a recent, critical review by Richard Dawkins of E.O. Wilson’s latest book.

“Nobody doubts that some groups survive better than others. What is controversial is the idea that differential group survival drives evolution, as differential individual survival does. The American grey squirrel is driving our native red squirrel to extinction, no doubt because it happens to have certain advantages. That’s differential group survival. But you’d never say of any part of a squirrel that it evolved to promote the welfare of the grey squirrel over the red. Wilson wouldn’t say anything so silly about squirrels. He doesn’t realise that what he does say, if you examine it carefully, is as implausible and as unsupported by evidence.”

That’s not group selection among conspecifics, that’s interspecific competition. And I can easily imagine traits evolving in response to competitive pressure. However, if grey and red squirrels have only recently come into sympatry then this wouldn’t apply and this would be an irrelevant example. It’s curious to see Dawkins make such a silly argument. Reminds me of Jerry Coyne’s misunderstanding of punctuated equilibria.


30 comments to Does Dawkins understand group selection?

  • Before anyone jumps to the “punk eek = saltationism” claim, please consult my earlier posts on this subject.

    http://www.genomicron.evolverzone.com/2009/02/gould-1980/ 

    http://www.genomicron.evolverzone.com/2009/02/gould-1982/
     

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  • I found another quote in that review to be most entertaining, given that Dawkins doesn’t seem to notice that it describes his own career of fighting his battles in the popular literature rather than submitting them to peer review.

    Does he think his authority justifies going over the heads of experts and appealing directly to a popular audience, as if the professional controversy didn’t exist—as if acceptance of his (tiny) minority view were a done deal?

     

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    • LOL. Not to mention the fact that Wilson and colleagues did publish some of the ideas in Nature.

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      • To be fair to Dawkins, this quote is in the context of that very paper and the fact that Wilson has apparently ignored all of the (many) criticisms that paper received in reply when writing his book. (i.e. He doesn’t mention them.)

        Perhaps Dawkins has done the same in the past (I don’t know) but it not actually invalidate his point, even if it knocks him off the moral high ground.  

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  • Wait, Hölldobler “will have no truck with group selection”? This is the same person who wrote a book with Wilson, The Superorganism (2008), which states on p. 35,

    It is important to keep in mind that mathematical gene-selectionist (inclusive fitness) models can be translated into multilevel selection models and vice versa. As Lee Dugatkin, Kern Reeve, and several others have demonstrated, the underlying mathematics is exactly the same; it merely takes the same cake and cuts it in different ways. Personal and kin components are distinguished in inclusive-fitness theory; within-group and between-group components are distinguished in group selection theory. One can travel back and forth between these theories with the point of entry chosen according to the problem being addressed.

    And who coauthored a PNAS paper with Wilson in 2005 the first sentence of whose abstract states, “group selection is the strong binding force in eusocial evolution”?

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    • Hölldobler has been talking in group-selectiony terms as recently as 2010, in a perspective printed in Social Behaviour: Genes, Ecology and Evolution (T. Székely et al., eds).

      In such advanced eusocial organisations the colony effectively becomes a main target of selection […] Selection therefore optimises caste demography, patterns of division of labour and communication systems at the colony level. For example, colonies that employ the most effective recruitment system to retrieve food, or that exhibit the most powerful colony defence against enemies and predators, will be able to raise the largest number of reproductive females and males each year and thus will have the greatest fitness within the population of colonies.

      I find it hard to believe that someone “who has no truck with group selection” would write any of these things.

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  • I’m not an evolutionary biologist; but this quote sounds like Dawkins is simply trying to say that just because one group is beating another group doesn’t mean the selection is happening at the level of the group. Isn’t that just the standard objection to group selection?
    The specific example may be weak, but it didn’t seem like the error you are suggesting. Can you clarify a little?

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    • Hi Andrew,

      I’m not sure I understand the source of confusion. Dawkins gives an example that has nothing to do with group selection as an attempt to criticise group selection. Not sure how else to explain the issue.

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      • I don’t think this is what Dawkins is doing. He is simple explaining why differential group survival is not group selection. He is right to do so because it isn’t. No one (I think) doubts that differential group survival exists. I think that most people would even agree that it can have long-term consequences for evolution. What is at stake is whether an adaptation can arise and spread for the good of the group at the expense of the individual. The answer is no, with the exception of kin selection.
         

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        • No, he’s explicitly equating this example of squirrels with what he thinks Wilson is doing with ants. But if Wilson is talking about groups vs. groups (colonies vs. colonies) within species, with long-term selection among them, it is an irrelevant analogy. Unless, of course, you don’t know the difference between group selection and interspecific competition.

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          • OK, now I see your problem. I disagree that it’s explicit – it is only after your reply that I realised that is what he might be doing. (Having not read the Wilson book, I don’t know what’s in it and the content you refer to is not mentioned in the review.) In the context of the piece, it follows a brief mention of human and social insect evolution and an explicit reference to rejecting kin selection and accepting group selection. He doesn’t mention ants at all until much later.

            To me, it appears to be a simple example (may be over-simple but clearly deliberately so) to show that differential group survival is not Group selection – as you say, it is interspecific competition in this case – and lay the ground work to introduce kin selection. (The way I read the article, I think Wilson’s rejection of kin selection might be the real issue for Dawkins but I could be wrong.) Perhaps, he should have made an explicit reference to colonies vs. colonies if Wilson is doing this. Instead, he seems satisfied to make the case that kin selection and inclusive fitness is sufficient.

            I guess the balance between accessibility, conciseness and accuracy is hard to get right. I think he did a pretty good job but, clearly, it isn’t a scientifically deep piece. (It is a book review and opinion piece, after all!) It does make me want to go and read the 2010 paper and resulting criticisms, though. (They’ve been on my wishlist for a while but life keeps getting in the way!)

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          • I’ll try to parse it clearly.

            “The American grey squirrel is driving our native red squirrel to extinction, no doubt because it happens to have certain advantages. That’s differential group survival.”

            No, it isn’t. It’s competition among individuals from two different species. This has nothing to do with selection among groups within a species.

            “But you’d never say of any part of a squirrel that it evolved to promote the welfare of the grey squirrel over the red.”

            I might, if they competed regularly in their history. However, since they have recently come into competition, I suspect this is an irrelevant example.

            “Wilson wouldn’t say anything so silly about squirrels. He doesn’t realise that what he does say, if you examine it carefully, is as implausible and as unsupported by evidence.”

            Dawkins is saying that Wilson is using the same basic argument about other groups (e.g., ants) as in the squirrel example. He isn’t, because the squirrel example is not what anyone would consider group selection.

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          • ” He isn’t, because the squirrel example is not what anyone would consider group selection.”

            It’s probably more semantic than not but species-selection models (which often invoke interspecific competition) have figured prominently in the group-selection debate.  I’m not sure why you seem to think they haven’t (unless I am not understanding you).  As you know, most of the discussion is now cast under the rubric of “multilevel selection.”  Whether is it’s kin groups, unrelated cohorts, or species, all of these units have been put forth as supporting or not supporting group-selection.  The fundamental issue that unites all of these different types of groups is whether they have group-level properties that are heritable and strong enough to swamp out selection at the individual level. 

             

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          • Species selection has to do with differential speciation and/or resistance to extinction on the basis of emergent species-level traits (or, according to some authors, emergent fitness). Direct competition among species is not part of species selection models in that regard, because it easily reduces to the individual level.

            Group selection has its own set of models (such as the trait group model), which also are not about competition among individuals of two different species.

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          • PS. By “your problem”, I mean the problem you perceive in Dawkins’ article, not the problem that you have. Just in case that’s not clear. (Oh, the ambiguities of written word!)

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          • From reading some of the comments and responses, I am a bit worried that there are different definitions knocking around for “Group Selection”. I grew up with the “for the good of the species” definition, which is clearly wrong – the squirrels example. The essence of this was that the individual’s fitness was of no consequence as long as the group would benefit. This is clearly wrong (to me) as if the group benefits only at the (average) expense individual bearing the relevant alleles, it will disappear. (i.e. failing the rB > C condition)Is there a new, contemporary definition of Group Selection that recognises that the individual fitness of allele-carriers is still important? Is this all just semantics and definitions? (Is the new Group Selection just rB > C redefined using different words?) 

            I’m not afraid to acknowledge that my confusion may stem from ignorance. A little knowledge can be a dangerous thing, especially when people move the goal posts without you knowing. (And yes, I am being lazy because I don’t have time to read all the papers right now, but a link to  a paper with the definitive definition of Group Selection would also be welcome.)

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  • gerdien

    Dawkins seems not to have bothered reading up on group selection since 1980 or so. Actually, Dawkins might not have read a lot of the recent literature at all. The book ‘The Greatest Show on Earth’ was painfully illiterate on evolutionary biology.

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    • Recent papers which I doubt Dawkins has read:

      P. Bijma and M. Wade (2008), “The joint effects of kin, multilevel selection and indirect genetic effects on response to genetic selectionJournal of Evolutionary Biology 21: 1175–88.

      In levels-of-selection models, relatedness is hidden in the between- and within-group heritabilities, whereas, in kin selection models, the multilevel selection process is hidden in the costs and benefits.

      J. D. Van Dyken, T. A. Linksvayer and M. Wade (2011), “Kin Selection–Mutation Balance: A model for the origin, maintenance, and consequences of social cheatingAmerican Naturalist 177, 3: 288–300.

      [In a model including mutation] Hamilton’s rule, then, does not preclude the existence of cheaters in an otherwise cooperative population, nor does it predict the frequency of cooperators or cheaters in a population.

      J. A. Damore and J. Gore (2012), “Understanding microbial cooperationJournal of Theoretical Biology 299: 31–41, PMID:21419783.

      [E]very definition of relatedness must take into account the population. Therefore, relatedness is not the percent of genome shared, genetic distance, or any extent of similarity between two isolated individuals in a larger population. Also, because horizontal gene transfer is commonplace between microbes and selection is strong, phylogenetic distance or any other indirect genetic measure is likely to be inaccurate. Many of these false definitions live on partly because ambiguous heuristics like “1/2 for brothers, 1/8 for cousins,” which require very specific assumptions, are repeated in the primary literature. Also, most non-theoretical papers simply define relatedness as “a measure of genetic similarity” and do not elaborate or instead leave the precise definition to the supplemental information […] Unfortunately, scientists can easily misinterpret this “measure of genetic similarity” to be anything that is empirically convenient such as genetic distance or percent of genome shared. Largely because of this confusion, we support the more widespread use of the term “assortment,” which is harder to misinterpret […] For similar reasons of reader understanding, we also encourage authors to make calculations more explicit, either in the main or supplemental text, and to avoid repeating previous results without giving the assumptions that went into deriving them.

      B. Simon, J. A. Fletcher and M. Doebeli (2012), “Hamilton’s rule in multi-level selection models” Journal of Theoretical Biology 299: 55–63, PMID:21820447.

      In particular, r is often taken to be the average relatedness of interacting individuals, as compared to the average relatedness in the population, in which case inequality (1) [rB > C] is referred to as Hamilton’s rule. It is important to note that inequality (1) is only a description of whether the current level of assortment as subsumed in the parameter r is sufficient to favour cooperation, but not a description of the mechanisms that would lead to such assortment. It has been suggested repeatedly that the problem of cooperation can be understood entirely based on Hamilton’s rules of the form (1). Even though often taken as gospel, this claim is wrong in general, for two reasons.

      First, and foremost, even if a rule of the form (1) predicts the direction of selection for cooperation at a given point in time, the long-term evolution of cooperation cannot be understood without having a dynamic equation for the quantity r, i.e., without understanding the temporal dynamics of assortment. The dynamics of r in turn cannot be understood based solely on the current level of cooperation, and hence expressions of type (1) are in general insufficient to describe the evolutionary dynamics of cooperation. Second, the quantity r, which measures the average relatedness among interacting individuals, is insufficient to construct Hamilton’s rule in models that account for variable individual-level death rates and/or group-level events.

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      • Some interesting-looking papers, thanks. Will add to the reading list! Correct me if I am wrong, though, but are these not all concentrating on r? As Dawkins points out, “It is extremely important not to forget B and C and conclude that only r matters in evaluating the success of the theory in particular cases.” Do models tend to fix B and C? In reality, B and C are likely to change through time, I would imagine, and certainly vary according to genetic and environmental background factors.
        The fact that simplified explanations of kin selection are, whilst useful for popular science explanations, not fully encompassing the true complexity of nature, does not mean that the author is unaware of such complexities.
        Apart from sniping at Dawkins, it is not clear to me what your main point is. Are you saying that you agree with Wilson? That kin selection does not work and Group Selection does? Just that it is more complicated than pop Sci implies? None of the above? For the benefit of those of us not in the field, who get the impression that kin selection still works and the problem is predominantly assigning appropriate r, B and C values (really hard to do in reality), it would be useful to know how wrong you think Dawkins is in his piece. Is it just the squirrel example, or is there more to it?

        PS. Please forgive typos and format issues – this is a really iPad-unfriendly site! (It seems to identify half a word as something else and autocorrect it!)

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        • I don’t think “it’s only a popularization” excuses oversimplifications which misrepresent years of scientific research.  Being aware of complexities and subtleties oneself does no good if one’s writing elides them completely, to the point of elevating heuristic rules-of-thumb to fundamental principles of evolutionary biology.
           
          <blockquote>Are you saying that you agree with Wilson? That kin selection does not work and Group Selection does?</blockquote>
           
          The terms are, in my view, so muddled as to be worse than useless.  (Just getting people to decide on whether “kin selection” requires an explicit mechanism of kin <i>recognition</i> has been in my experience head-bangingly awful.)  Few people recognise the assumptions they make before they write their first equation.  Both approaches have remarkably limited intellectual horizons.  Changing from one to the other is about as dramatic as changing one’s reference frame while studying the collision of two billiard balls.
           
          I do not think Wilson has been agitating for intellectual change very effectively, but the whole issue is so politicised that it clear communication is not easy.

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          • Hmmm. Part of me really wants to go and read up on all of this once the exam period is over but another part of me is worried that it’s all going to come down to semantics and different opinions on what “kin selection” and “group selection” actually mean and that people are really just arguing past each other.

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    • Oops, managed to break the first link. It should point to http://dx.doi.org/10.1111/j.1420-9101.2008.01550.x .

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  • Bobo

    Does Gregory understand not being a narcissistic ass?
     

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  • “He’s confused.  Richard Dawkins is a good man, but he does not publish in peer reviewed journals and has not really examined the basic theory.” –EO Wilson
    http://www.youtube.com/watch?v=dEaMtSLwkDs#t=3043s

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  • eratosignis

    This is a fascinating discussion.
    One of the interesting things about “interspecific competition” is that it is a form of selection (also true of “intraspecific competition”), and my impression that it only became completely separated from natural selection after the mid 20th Century. Gause’s book “The Struggle for Existence” was specifically intended as an experimental investigation into natural selection. Darwin’s term used by Gause for his book title includes both competition and natural selection.
    One confusion is that “selection” the way we use it now seems to have an implication of evolution wrapped up in it (e.g. in Dawkins’ selfish gene ideas). But it seems to me that it shouldn’t: if natural selection is a cause of evolution, it needs to be kept separate, and sometimes it needs to be allowed that it fails to cause intraspecific evolution (e.g. without suitable mutations or other variation arising). This is how we portray interspecific competition in ecology texts, and one of the reasons why I think we tend to keep it separate from selection. In theories of adaptive radiation, we say (e.g. Schluter) that interspecific competition causes natural selection, and that natural selection causes evolution. But selection/competition is really a single process driving the evolution.
    The American Eastern Gray Squirrel is the “grey squirrel” referred to by Dawkins. It is an invasive species in UK and has all but driven the native Eurasian red squirrel extinct. There’s no evidence it did this because it evolved (though it might have). I am confused by Dawkins’s use of “differential group survival” – because that’s a normal outcome of evolution by natural selection is, to me.
    In the squirrels, there’s no hybridization, so all of the red squirrel’s genes decline in frequency at the same time that all the grey’s genes increase. So it’s a sort of natural selection where all of the genes are in perfect disequilibrium, and the whole grey genome hitchhikes to high frequency due to some grey genes which allow it to beat up the reds, while driving all the red’s genes to low frequency. Nonetheless, the processes are taking place at the individual level: so it’s a case of individual selection.

    But, finally, I agree that Dawkins is throwing out a red herring and not really addressing what Wilson claims.

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  • Dawkins gets a lot of mileage out of cynicism and anger: he’s still reliving the backlash to Wynne-Edwards’ 1966 book.  This wouldn’t be such a big deal if (a) he wasn’t a <em>de facto</em> spokesperson for evolutionary biologists and (b) a lot of other scientists weren’t thereby encouraged to do the same thing.  I once mentioned what somebody thought was group selection in a class and the professor turned bright red and almost lifted off the floor.
     
    People equate group selection with altruism, when I think we can take a colder, mathematical look at it and just see it as a plausible natural process.  That might lead to fewer red faces.

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  • DMark

    Hello, non-biologist here. I would like to ask, could any of you provide me with a link on a paper that deals with what exactly is (could be) ment by “group selection” (e.g. a good review of definition(s) of group selection)? Many thanks!

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  • KParson

    Are groups replicating themselves?  No.  What replicates?  Individuals.  

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  • KParson

    To show that selection is operating at the level of groups one needs to demonstrate that there exists a distribution of groups that exhibit quantifiable phenotypic variation relative to each other, that their differences are transmitted to future generations through some mechanism of herita- bility, and that there is differential reproduction of groups over time. 

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