New paper shows that Nowak et al. were wrong: kin selection remains a valuable concept in evolutionary biology

In 2010 three authors—Martin Nowak, Corina Tarnita, and E. O. Wilson—published a paper in Nature (reference and link below) purporting to explain the evolution of eusociality in insects: the phenomenon whereby a colony contains different “castes” that perform different tasks, and at least one caste is sterile.  In bees, for example, there is usually a single fertile queen, who produces all the offspring, a bunch of sterile working females (“workers”) who defend the nest and tend the brood, and fertile male “drones” who do basically nothing but compete to mate with the next generation of queens. Nonreproductive castes are general (though not ubiquitious) in the Hymenoptera (ants and wasps), as well as in some other animals like termites (Isoptera) and naked mole rats.

It’s hard to understand how it could be advantageous for some individuals to evolve sterility, which, of course, seems patently maladaptive. Darwin was the first to notice this problem. At any rate, one solution involves the notion of kin selection: the idea that a gene can promote sacrificing your own personal reproduction if it more than compensates for that loss by increasing the number of relatives you have—relatives who also carry copies of the “sacrifice” gene. It turns out that under a simple calculus that involves weighing the reprodutive benefit to relatives (discounted by the degree of relatedness) versus the cost of sacrificing your own reproduction, you can indeed evolve genes that cause you to lose reproductive ability—so long as they increase it in your relatives.

Such kin selection was an important explanation for the evolution of eusociality. Some think it’s because of the peculiar “haplodiploid” nature of inheritance in Hymenoptera, whereby the male who fertilizes the queen is haploid (has only a single set of chromosomes), and the fertile queen is diploid, with the normal two sets. In such a case, the female workers are more related to their sisters than to their own offspring, which may help them evolve the tendency to stop having their own offspring and produce more sisters; i.e., become sterile and help the queen raise her brood. Others question the importance of haplodiploidy in eusociality.

But the evidence for kin selection and relatedness is still clear. For example, eusociality in Hymenoptera has evolved several times, but always occurred in an ancestral lineage in which queens mated singly rather than multiply: a statistically significant finding (Hughes 2008; reference and free link below). That’s important because in such cases offspring are more related to each other than offspring produced by different fathers. Further, Bob Trivers showed that other patterns in bees, ants, and wasps—especially the observed ratios of males to reproductive females in colonies—also followed the dictates of what kin selection predicted. There are still other behavioral recognition experiments of kin versus non-kin supporting the importance of relatedness.

Nowak et al.’s paper, however, attacked this body of knowledge, claiming that kin selection and relatedness were not only unimportant in the evolution of eusociality, but were unimportant in general. (Ed Wilson has spent the last five years, for instance, arguing in his books and talks that kin selection is a misguided notion in evolutionary biology, and that group selection is far more important.) Nowak et al. used a rather complicated model of colony selection in which mother and all offspring were genetically identical and argued that relatedness was a consequence of the evolution of eusociality and not a driver of eusociality.

As I noted at the time, their dismissal of relatedness and kin selection from their model seemed bizarre, since they didn’t vary relatedness in their model. If you don’t do that, how can you say it’s unimportant in evolving eusociality? And people in the field found other problems with both Nowak et al.’s model and their conclusions about the uselessness of kin selection (go here for all my many posts on this issue). Over 120 experts in the field, for example, wrote a letter to Nature criticizing the conclusions of Nowak et al. But Nowak, Tarnita, and Wilson have remained obdurate.

Now, a new paper in PLOS Biology by Xiaoyun Liao, Stephen Rong, and David Queller (reference and free link below) shows not only that the model of Nowak et al. was bizarre, with little obvious relationship to the evolution of eusociality, but was also flatly wrong its three major claims about the evolution of eusociality.

What Liao et al. did was simply vary the relatedness and other assumptions of Nowak et al.’s model. After doing that, they found that the original authors’ claims about the generality of their model were incorrect. Keep in mind that Liao et al.’s conclusions were based simply on manipulating the very model that Nowak et al. used to claim the irrelevance of kin selection, or on deriving new equations using Nowak et al.’s exact modeling strategy.

Here is what Liao et al. found, contra Nowak et al.:

1. Relatedness does help the evolution of eusociality, so kin selection is not irrelevant.  Unlike Nowak et al., Liao et al. varied total relatedness by allowing a certain fraction of offspring in the nest to be unrelated to the “queen” rather than simply her clones. (This could occur by immigration of insects from other nests, or by queens laying eggs in other queens’ nests.) What they found is that relatedness indeed makes a big difference: under conditions in which worker behavior is affected by their own genes rather than just the queen’s, eusociality evolves much more easily when relatedness between queen and “worker” is higher. In other words, higher relatedness (kin selection) is causal in this circumstance, not just a consequence of the evolution of eusociality. Nowak et al. were wrong, and all the statements of this group about the uselessness of kin selection based on this model are also wrong.

2. Workers’ evolutionary interests can differ from those of the queen. Nowak et al. saw workers as “evolutionary robots” who could not have an evolutionary strategy differing from that of the queen. This was a bit weird, since we’ve known from experimental and natural history data that there is a conflict between queen and workers (predicted by kin selection theory), and the results of that conflict are seen in the sex ratios produced in nests. Further evidence for that conflict occurs when the queen produces more males than the workers “want” (i.e., more than is in the workers’ genetic interests), and in that case the workers kill those males. This wouldn’t happen if the interests of queens and workers were coincident.

Liao et al. showed that varying how the genes for worker behavior and sterility were expressed—whether in queens alone or in offspring alone—had a substantial effect on the probability of evolving eusociality. As kin-selection theory predicts, eusociality evolves much more easily when the queen has absolute control over the behavior (and fertility) of her workers. When workers get a say—that is, when their own genes rather than just the queen’s genes control their own behavior—it’s not so easy to evolve eusociality, for workers sometimes have an evolutionary impetus to produce their own offspring rather than just raise the queen’s. This shows, as kin selection predicts and observation shows, that there is indeed a conflict between the interests of the queen and the workers.

3. Eusociality isn’t as hard to evolve as Nowak et al. assert.  In their paper Nowak et al. claimed that eusociality is “hard to evolve.” It’s difficult to evaluate this claim because you have to ask, “Hard relative to what?” But Liao et al. showed that some of the difficulty in the Nowak et al. model is because of two wonky assumptions: 1). Below a certainly colony size no worker can add anything to the offspring production of the colony, while 2). above that threshold there is a fixed output of offspring that does not change with the addition of more workers.

This seems completely unrealistic, for why wouldn’t two workers add more offspring than one, and why, over the threshold, wouldn’t more workers help produce more offspring by defending the nest better and tending more brood? Further, why would workers in large colonies remain in those colonies, since their presence adds nothing according to the “threshold” model? They should, instead, join smaller colonies, pushing them over the threshold. And indeed, when Liao et al. added more realistic assumptions to Nowak et al.’s model—a “stepwise” feature whereby, up to some limit, each worker adds an increment to the offspring production of the colony—eusociality evolved more readily.

*******

So what is the upshot? First, that kin selection, i.e., the relatedness between queen and her offspring, plays an important causal role in the evolution of eusociality.  Nowak et al. were dead wrong in denying this. And since the subsequent statements of both Nowak and Wilson on the evolutionary worthlessness of kin selection were based on a model that could not show what they claimed to show (because relatedness wasn’t allowed to vary), we should not take their dismissal of kin selection seriously. Kin selection remains a viable and valuable view in evolutionary biology—indeed, one of the most important advances since the 1950s—and, as I’ve shown in my earlier posts, has helped us understand a wide variety of biological phenomena.

The other points are less important, but still show that Nowak et al.’s model was too narrow to support their generalizations about no conflict between queens and workers, or about the “difficulty” of evolving eusociality. Yes, it may indeed be hard to evolve such a bizarre system, and it may require uncommon ecological and/or genetic circumstances, but it’s not as hard, at least in theory, as Nowak et al. maintained.

The final lesson is that one’s biological conclusions from a model are only as good as the biological assumptions built into it. Because Nowak et al.’s assumptions were flawed, and because they failed to examine the robustness of the model to varying its assumptions, they arrived at faulty conclusions. But because Nowak and Wilson were already famous evolutionary biologists (particularly Wilson, who is an iconic figure in the field), and because the paper was published in Nature, their conclusions were taken far too seriously. The paper should have been reviewed by more critical reviewers in the field. Even I, who do not work on the evolution of eusociality, could see that you can’t dismiss the value of genetic relatedness from a model in which relatedness isn’t allowed to vary!

_________

Hughes, W. O. H., B. P. Oldroyd, M. Beekman, and F. L. W. Ratnieks. 2008. Ancestral monogamy shows kin selection is key to the evolution of eusociality. Science 320:1213-1216.

Liao, X., Rong, S., and D. Queller, 2015. Relatedness, conflict, and the evolution of eusociality. PLOS Biology | DOI:10.1371/

Nowak, M. A., C. E. Tarnita and E. O. Wilson.  2010.  The evolution of eusociality.  Nature 466: 1057-1062.

 

64 Comments

  1. Posted March 27, 2015 at 11:47 am | Permalink

    What a great paper and interesting coda to a really bizarre episode. I think I first learned about kin selection from Richard Dawlins’s The Selfish Gene, which, unless I’m mixing up his books now, used bee evolution to demonstrate the math. I am much cheered to hear Sir Richard got it right, especially since he’s “just a journalist.”

    • Diane G.
      Posted March 27, 2015 at 9:40 pm | Permalink

      😉

  2. darrelle
    Posted March 27, 2015 at 11:50 am | Permalink

    It is a bit surprising to me, and disappointing, to read about this . . .

    ” . . . they didn’t vary relatedness in their model.”

    It just doesn’t seem possible that this could have been simply a mistake or oversight. This is so obviously something that is key to their claim. It sure seems like it must have been neglected knowingly, and if that is so, very disappointing. Not to mention, did they think no one would see that issue and call them on it?

    • Mark Sturtevant
      Posted March 27, 2015 at 1:08 pm | Permalink

      I am sure that many will speculate about why they pushed out such a badly construed idea, and why they have been doubling-down on it lately. A possibility that comes to mind is overconfidence in their ability to be right all the time b/c everybody hangs on their every word. We have also seen a similar-ish thing with Jane Goodall and her views about Big Foot and some other wonky ideas.

      • Posted March 27, 2015 at 4:01 pm | Permalink

        It always appeared to me a bit like they went out looking for data to support their favored conclusion; and of course, they found it. They seemed to have forgotten Feynman’s rule of fooling yourself.

  3. Posted March 27, 2015 at 11:51 am | Permalink

    Awesome!!! How a smart guy like Wilson got involved in this denial of kin selection seemed bizarre to me. Doubt this will change his mind, but it is still excellent that Hamilton has been vindicated!

    • Posted March 27, 2015 at 1:24 pm | Permalink

      Maybe Wilson got involved because he sees the limitations of kin selection. Hamilton was a nice guy, but his inclusive fitness theory, and the kin selection that grew out of it is so flawed as to be useless.

      http://blog.uvm.edu/cgoodnig/2014/04/23/why-i-dont-like-kin-selection/

      Importantly, Hamilton was a group selectionist at the end of his life, and kin selection is a product of Maynard-smiths deep misunderstandings of multilevel selection. Since then MLS theory has developed into a rich and productive (if ignored) tradition, while kin selection theory has foundered and is still stuck in the 70s

      • reasonshark
        Posted March 27, 2015 at 3:14 pm | Permalink

        Maybe Wilson got involved because he sees the limitations of kin selection. Hamilton was a nice guy, but his inclusive fitness theory, and the kin selection that grew out of it is so flawed as to be useless… Since then MLS theory has developed into a rich and productive (if ignored) tradition, while kin selection theory has foundered and is still stuck in the 70s.

        This paper would suggest otherwise:

        http://onlinelibrary.wiley.com/doi/10.1111/j.1420-9101.2007.01458.x/epdf

        “In our social semantics review (J. Evol. Biol., 2007, 415–432), we discussed some of the misconceptions and sources of confusion associated with group selection. Wilson (2007, this issue) claims that we made three errors regarding group selection. Here, we aim to expand upon the relevant points from our review in order to refute this claim. The last 45 years of research provide clear evidence of the relative use of the kin and group selection approaches. Kin selection methodologies are more tractable, allowing the construction of models that can be applied more easily to specific biological examples, including those chosen by Wilson to illustrate the utility of the group selection approach. In contrast, the group selection approach is not only less useful, but also appears to frequently have negative consequences by fostering confusion that leads to wasted effort. More generally, kin selection theory allows the construction of a unified conceptual overview that can be applied across all taxa, whereas there is no formal theory of group selection.

        And this one:

        http://onlinelibrary.wiley.com/doi/10.1111/j.1420-9101.2011.02236.x/epdf

        “Natural selection operates both directly, via the impact of a trait upon the individual’s own fitness, and indirectly, via the impact of the trait upon the fitness of the individual’s genetically related social partners. These effects are often framed in terms of Hamilton’s rule, rb ) c > 0, which provides the central result of social-evolution theory. However, a number of studies have questioned the generality of Hamilton’s rule, suggesting that it requires restrictive assumptions. Here, we use Fisher’s genetical paradigm to demonstrate the generality of Hamilton’s rule and to clarify links between different studies. We show that confusion has arisen owing to researchers misidentifying model parameters with the b and c terms in Hamilton’s rule, and misidentifying measures of genotypic similarity or genealogical relationship with the coefficient of genetic relatedness, r. More generally, we emphasize the need to distinguish between general kin-selection theory that forms the foundations of social evolution, and streamlined kin-selection methodology that is used to solve specific problems.”

        Not to mention the OP and the 100 or so biologists who took the original paper to task.

        I’d be interested to see what Jerry has to say about your claims, considering he knows a lot more about the field than I do, but I suspect your confidence is greater than the substance behind your claims.

      • Torbjörn Larsson, OM
        Posted March 27, 2015 at 3:48 pm | Permalink

        [*looks at article*]

        (Who notes consensus, so usefulness; and which referenced paper if correct supports that yet again, while seemingly makes reject group selection altogether (for the first time?).)

        [looks at comment*]

        You remind me of a certain Black Knight:

        “I’ll bite your legs off!”

        Except that you fight with the strength of very few men indeed.*

        Disclaimer: I’m a layman, but with an astrobiology interest. So I need to know that selection acts on.

        * I briefly browsed that blog post, and I see it refers to “unpublished ideas” of “the phenotypic approach”. Not a stellar reference, especially compared to a peer review paper.

        (And I don’t grok how kin selection is more of an optimality approach than other kinds of selection.

        I did find “the origin of life (hint: the phenotype always comes first)” remark somewhat interesting, but unfortunately it came in a long line of similar simple “solutions” to deep problems. :-/)

      • Posted March 28, 2015 at 4:47 am | Permalink

        Sorry Charles, but you cite a blog post as showing the flaws of kin selection? GIve me a break and at least be intellectually honest enough to cite the many papers (Stuart West; the group-signed letter) that were PEER REVIEWED and showed the advances that kin selection has led to.

        Your rewriting of history is just flat wrong, and distorted in favor of your own prejudices.

  4. Posted March 27, 2015 at 11:55 am | Permalink

    Thank you for this.. Your explanations are very much appreciated.

    • Delphin
      Posted March 27, 2015 at 9:35 pm | Permalink

      Yes indeed. You can’t find lucid explanations of issues like this easily.

      • slandermonkey
        Posted March 28, 2015 at 8:50 am | Permalink

        We do read the science posts, not just the cute cat ones.

  5. lkr
    Posted March 27, 2015 at 12:01 pm | Permalink

    Re: one of Nowak et al.’s “wonky assumption” that “below a certain colony size no worker can add anything to the offspring production of the colony”.

    Tell that to the scrub jays in my backyard — the one or two yearlings feeding their sibling nestlings and harassing my cat aren’t adding anything to offspring production?

  6. NewEnglandBob
    Posted March 27, 2015 at 12:03 pm | Permalink

    I am heatened that Nowak, Tarnita and Wilson’s paper was dismissed by further research. The paper had bothered me ever since I first heard about it.

    I will always now question anything further from any Wilson (D. S. or E. O.)

  7. quiscalus
    Posted March 27, 2015 at 12:06 pm | Permalink

    COuld anyone explain how this might play out within eusocial, polydomous, polygynous ant species such as Tapinoma sessile. T. sessile, aka the odorous house ant (when crushed, smells like coconut-flavored rum to me.) How is it that a colony of these ants can have more than one reproductive queen combined with other colonies who also have multiple reproductive queens, but not be violently competitive (not killing the other colony’s queens or the other queens within their own)? I mean beyond the obvious more complicated genetic maths, but an explanation as to what benefits (versus costs) there are to this type of living arrangement, other than it makes it damn hard to eliminate all the ants in a person’s house (which, honestly, I don’t mind too much, they’re quite charming, but guests seem bothered by them)

    • quiscalus
      Posted March 27, 2015 at 12:14 pm | Permalink

      actually, come to think of it, I’ve no idea how related each colony is or how related each reproductive queen is in polydomous, polygynous T. sessile nests, so I guess knowing that would allow for understanding how they tolerate each other, and I don’t know how much inter- and intra-colonial resource competition has been observed…so many questions!

    • Mark Sturtevant
      Posted March 27, 2015 at 1:14 pm | Permalink

      It is still an interesting question. There are other ants that do this, and other hymenopterans, I believe.
      My hand-waving answer is that a queen’s control over the colony is limited by its size. They produce a hormone that controls the other castes, and tie them to her. Farther away, in a big colony, the hormonal control peters out and that is where a new colony can start.
      This might work more easily if the multi-queens were genetically related.
      One can also expect that these huge colonies would be pretty competitive against other colonies who might want to muscle in, while also being able to mount a stronger defense against predators.

      • quiscalus
        Posted March 27, 2015 at 1:33 pm | Permalink

        a quick perusal of the poor-person’s university, wikipedia, gives links to papers about T. sessile’s non-aggression towards other ant species. They have apparently been known not only to exist in multi-queen colonies, but also with other species of ant. Likewise they seem to prefer to avoid rather than confront other species at food sources. They will alter their foraging times to avoid competition, and one study, Buckowski and Bennett, 2008, showed they “fought collectively in 6 out of forty interactions”, even when they outnumbered the other species, so they aren’t fighters much at all, but still doesn’t explain why they don’t avoid each other. Curiouser and curiouser.

        • Mark Sturtevant
          Posted March 27, 2015 at 10:35 pm | Permalink

          That is interesting. Curiouser indeed.

    • John Scanlon, FCD
      Posted March 28, 2015 at 7:04 am | Permalink

      I’m no hymenopterist, but while I’m sure it’s an interesting case, the issue in question in the kin/group-selction argument is how eusociality originates, not how it can vary once established.

      • bees_are_cool
        Posted March 29, 2015 at 6:39 am | Permalink

        There is a lot of interesting variation in eusociality. John is correct in that variation can occur post origin that seems to not fit. For example, honey bees mate with many males (as many as 50), leading to relatively low relatedness among sisters. However, honey bees were locked into eusociality likely long before multiple matings evolved. Other eusocial bees like bumble bees typically queens mate with one male and are primitively eusocial.

        Bees are a great system to study the origin of eusociality actually. Only about 15% or so of species are eusocial. There are also some really interesting bees in the Halictidae that are facultatively eusocial.

  8. Randy Schenck
    Posted March 27, 2015 at 12:10 pm | Permalink

    Always glad to get further explaination of this important topic. Within the scientific world I wonder if Wilson or the others will say anything on this. He certainly had a few things to about it and Richard Dawkins in the past.

  9. Posted March 27, 2015 at 12:21 pm | Permalink

    thanks – from a former beekeeper.

  10. sgo
    Posted March 27, 2015 at 12:26 pm | Permalink

    I wonder two things:

    – Will the paper now be retracted (I doubt it but still)? Or will it get even more citations, except that all those citing the paper will say how wrong it is (I sometimes joke about this with colleagues)?

    – What do the reviewers who originally reviewed the paper think now? Obviously that isn’t going to be answered but I wonder.

    • Mark Sturtevant
      Posted March 27, 2015 at 1:19 pm | Permalink

      I do not think a paper is retracted when proven wrong. It simply starts to become a historical footnote as scientific progress moves in a different direction. Retracted papers are generally done after misconduct is discovered.

      It is possible that the reviewers (or some of the reviewers) saw the problems but decided to let it be published to let science sort things out. It would be tough to be the one who rejected an E.O. Wilson paper.

      • sgo
        Posted March 27, 2015 at 1:49 pm | Permalink

        Double blind peer review! Which I think Nature is offering now, at least for some of its other journals in their group. And I know, often it will still be obvious who the authors are (check the reference list), but still, it might be a step in the right direction.

        I don’t really think the paper will be retracted indeed, but it just makes me wonder. You’re probably right that most retractions are done after misconduct, but it does not necessarily have to be the case, does it? If later on it is proven that the paper was conceptually wrong (as opposed to having new and better data available that would disprove a theory; that’s the way science works, indeed), why wouldn’t it be retracted? Especially if it happens so short after publication.

        I am not necessarily arguing for it to be retracted, but I think it would be good to have some kind of indication that certain papers have been refuted. Especially if it’s a high profile paper, the refutation might be less visible, which might mean people will, unjustly, keep citing the original high profile paper. Yes, reviewers should be able to point this out to the new authors but it just doesn’t seem to work that way.

        Just thinking out loud.

        • Torbjörn Larsson, OM
          Posted March 27, 2015 at 2:52 pm | Permalink

          Since we are thinking out loud, it is obvious (to me) that flawed papers should not be retracted.

          We see too little of above all negative results but also the trial & error that is science (and technology). It becomes much harder to see where we are (lack of publications of negative results) and where we went (lack of bungled attempts), in order to see where we should go.

          A markup system would be good (for newspapers too), where papers could be retroactively qualified or at least linked to reviews where they are (of should be) mentioned. But I don’t think it is realistic to expect it would happen, or work very well.

          In my mind blogging is a way to do ongoing peer review, and spread the info wider and faster.

          [Which reminds me, there is a markup system for blog articles reviewing papers.]

          • winewithcats
            Posted March 29, 2015 at 1:01 pm | Permalink

            Any links describing this markup system, or do you at least know the acronym it goes by?

        • John Scanlon, FCD
          Posted March 28, 2015 at 7:10 am | Permalink

          “I think it would be good to have some kind of indication that certain papers have been refuted.”

          Isn’t that the function of review articles, textbooks and histories of science? ‘Truth is the Daughter of Time’ and ‘Funeral by funeral…’; it’s rarely if ever been possible to round up all copies and burn, pulp or correct them.

  11. Dominic
    Posted March 27, 2015 at 12:41 pm | Permalink

    I am going to have to digest this after dinner… but thanks for explaining this.
    Of possible related interest –
    http://journal.frontiersin.org/article/10.3389/fgene.2015.00032/abstract

  12. Mark Sturtevant
    Posted March 27, 2015 at 1:24 pm | Permalink

    A very interesting and well presented input on this ongoing story.
    My question is that given that eusocial societies confer greater reproductive success than more individualized reproduction in social societies, why has not eusociality become the norm? Although common, most social species are not eusocial.
    Could it be b/c they tend to mate with multiple partners?

  13. peepuk
    Posted March 27, 2015 at 2:08 pm | Permalink

    “Even I, who do not work on the evolution of eusociality, could see that you can’t dismiss the value of genetic relatedness from a model in which relatedness isn’t allowed to vary”

    I wonder, why did it take so long?
    Personally I suspect the cold materialistic worldview against a more warmer and friendly view of reality that’s easier to sell.

  14. Steve Pollard
    Posted March 27, 2015 at 2:54 pm | Permalink

    Many thanks for another fascinating piece of science.

    This is one of those occasions when I wish I had been a failed biologist rather than a failed chemist!

    • mrtoads
      Posted March 30, 2015 at 2:55 pm | Permalink

      “Failed biologist” is such a harsh term – I prefer “repurposed academician”. After all, God, he knows there’s an unGodly amount of biology out there just begging to be explored and described, if not elucidated. We maybe can’t all be Margaret Morse Nice (especially us men), but given that almost everything we see has been very lightly studied (at best), there’s tons of possible basic observation to do.

  15. Torbjörn Larsson, OM
    Posted March 27, 2015 at 3:06 pm | Permalink

    As I noted at the time, their dismissal of relatedness and kin selection from their model seemed bizarre, since they didn’t vary relatedness in their model. If you don’t do that, how can you say it’s unimportant in evolving eusociality?

    Thanks! I read about this (yesterday I think) and it awoke a remembrance that “someone said this at the time”. But it was a stressful week* and I couldn’t connect (or figure out) that it was of course you, Jerry!

    *Thanks CC that it is now meowing close to Caturday!

  16. Keith Cook or more
    Posted March 27, 2015 at 4:08 pm | Permalink

    “..you can’t dismiss the value of genetic relatedness from a model in which relatedness isn’t allowed to vary”
    I’m glad that was said, I can move on.
    Thanks for the post.

  17. Diego
    Posted March 27, 2015 at 4:32 pm | Permalink

    I can’t say that I’m surprised, but I am gratified to see a solid refutation of such a tenuous and unnecessary hypothesis.

    P.S. I love many of the subjects that Jerry covers on this website, but I am always happiest to read some good evolutionary biology discussion.

    • Posted March 27, 2015 at 10:20 pm | Permalink

      Can I add my signature to this?

  18. Posted March 27, 2015 at 5:25 pm | Permalink

    While I do not doubt the occurrence and importance of kin selection, I am always puzzled why its supposed importance in the evolution of eusociality is stressed so much. On the one side, there are many species of eusocial hymenoptera that mate with numerous males, so the average worker wouldn’t be very related to the average larva, but they still don’t evolve workers going their own way.

    On the other hand, does any group of eusocial animals except the hymenoptera have haploid males? Termites, naked mole rats, or those beetles, thrips and crustaceans that have become eusocial? (In that context, wouldn’t the observation that eusociality is easy to evolve be a mark against the supreme importance of kin selection in the evolution of eusociality?) I am surely not an expert on eusociality and thus cannot really judge, but I have read that the need to defend an enclosed nesting space may be a much more important driving factor.

  19. Posted March 27, 2015 at 5:53 pm | Permalink

    Very cool; thanks for this report. I am curious to read both the original Nowak, et al. and the new Liao, et al. papers now. It’s great to see people performing detailed sensitivity analyses to justify causal claims.

    As for people with big names getting shoddy or short-sighted work published in major journals with lots of fanfare, I guess that happens in every field. Still drives me nuts though. I would like to see a double-blind peer review system where the names of all reviewing parties – and their referee reports – are published alongside the article itself. I think this could at least mitigate the problem somewhat.

  20. thh1859
    Posted March 27, 2015 at 6:30 pm | Permalink

    What happens when eggs from one ant colony are replaced by eggs from another colony of the same species? Are the incoming eggs and, later, larvae tended by the workers? Do they reach maturity, and if so, do the ants become fully integrated members of their ‘adopted’ colony?
    Does the answer vary with the species chosen?

    • mrtoads
      Posted March 30, 2015 at 2:57 pm | Permalink

      Maybe some of the work on slave-takers and other such raiders would help with that question. Not my field, unfortunately, so I don’t know what’s been published.

  21. Posted March 27, 2015 at 9:03 pm | Permalink

    Nowak and I have a forthcoming formal comment on this article, which should appear in a few weeks.

    Summary: Liao et al. vary relatedness in a way that likely doesn’t occur in nature. They suppose that either workers migrate between nests or that queens regularly lay eggs in each others nests. There is little evidence that either mechanism occurs often enough to affect the evolution of eusociality in nature.

    Liao et al. basically admit this when they say “Our goal is not to exactly model eusociality in any particular organism but to examine the logic and truth of [NTW’s claims]” But Nowak et al. didn’t that relatedness never matters in theory.

    What Nowak et al. (2010) says is that (1) inclusive fitness theory has severe mathematical limitations, and (2) high relatedness is better viewed as a consequence, rather than a cause, of eusociality, since it follows naturally from colony structure.

    As for the mathematical limitations of inclusive fitness theory, my 2013 paper with Nowak and Wilson in PNAS has yet to meet with any rebuttal: http://www.pnas.org/content/110/50/20135

    • µ
      Posted March 28, 2015 at 9:32 am | Permalink

      RE “my 2013 paper with Nowak and Wilson in PNAS has yet to meet with any rebuttal”

      Not sure I agree. Like here, from Jan 2015:
      http://bioscience.oxfordjournals.org/content/65/1/22.short

      Perhaps not a formal rebuttal, but at least a qualification of your work.

      I do agree that the field at large has not thought carefully about the assumptions that underly prevalent formulations of kin selection, that we need to develop better ways of teaching the evolution of cooperation to avoid oversimplifications, and that we need to clarify causality in the selection process favoring cooperation.

    • Posted March 28, 2015 at 9:41 am | Permalink

      Re “vary relatedness in a way that likely doesn’t occur in nature.”

      I disagree (e.g., see the literature on egg dumping and worker drifting in primitively eusocial halictids or bee-eaters; or queen supersedure in primitively eusocial polistine wasps; or migration of individuals between naked-mole-rat colonies; etc). Such reshuffling of related/unrelated individuals between colonies/nests is relevant to both the origin and the maintenance of sociality.

    • Peter Nonacs
      Posted March 28, 2015 at 10:57 am | Permalink

      I was a reviewer for Liao et al, and strongly supported its publication. However, I don’t for a moment think that the matter is settled. Let’s start with the about dozen pages of criticisms in Martin Nowak’s review of the manuscript. So yes, I’m expecting an extensive (mathematical) reply soon. And in defense of Nowak et al (NTW) let me make the following points. First, they never claim that relatedness is unimportant or irrelevant to the evolution of cooperation; only that its importance has been overemphasized. Wilson’s argument is that high relatedness can arise as byproduct of group living and not be the causative factor. True enough at least in theory. And the mathematics of measuring inclusive fitness are a minefield. Don’t believe it – try publishing a test of kin selection using field data and experience the many ways reviewers have of dismissing your data (see our lament in TREE at http://www.cell.com/trends/ecology-evolution/abstract/S0169-5347(15)00047-6 ). Also note that the studies that are being published are far from unanimous in supporting the idea that helpers help in order to maximize their fitness. Furthermore, obvious conclusions from Hamiltonian inclusive, such as monogamy is always more favorable for the evolution of cooperation, do not hold up when placed in the context of a population genetics model (see my papers – peer reviewed (!) – in J. Evol. Biol. and Biology Letters). So NTW gives the field a much needed kick in arse. However… Liao et al are absolutely right about the NTW model. It says nothing about relatedness because they never varied it! And their internal assumptions about how fitness is accrued were fantastical. Hence, I find it amusing that Ben complains about Liao et al not reflecting the natural world. It is a very, very black pot calling a grayish pot, black! Finally, and most importantly. I grant that Nowak & Allen do their sums correctly, but where they fail is in showing where a single prediction arising from a Hamilton-type model is just flat out wrong. One can carp about the inadequacies of the math all you want, but until you show exactly where and how kin selection models give us the wrong predictions, I and everyone else will continue to use them.

    • Posted March 29, 2015 at 7:19 am | Permalink

      Fascinating that both sides in this argument can purposely use the same model and by tweaking the variables both prove and disprove the points they are trying to make. Some useful(?) model this is. It brings to mind the old adage that goes “why describe something we don’t understand with a model that we don’t understand”. The lovely thing about inclusive fitness theory is the relative simplicity of both the concepts and the models…. and of course how very predictive that the models turned out to be. And isn’t that what theoretical biology should really aim to achieve?

      • thh1859
        Posted April 2, 2015 at 5:49 am | Permalink

        “Fascinating that both sides in this argument can purposely use the same model and by tweaking the variables both prove and disprove the points they are trying to make.”

        Reminds me of ‘Climate Change’.

    • Posted March 31, 2015 at 12:43 pm | Permalink

      There are workers unrelated to the queen in the primitively eusocial wasp Polistes dominulus. I know, I’ve analyzed the microsatellite gels for such nests. Without reviewing the literature, I can’t say how often this occurs in other taxa. I did this work as an undergrad. Also, as you might expect, this is a well known observation, e.g.:

      http://www.nature.com/nature/journal/v405/n6788/full/405784a0.html
      http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0011997

      The workers either got there by migrating or by a queen from another nest laying an egg in that nest. I’m at a loss for other ways they could get there.

  22. Posted March 27, 2015 at 9:28 pm | Permalink

    My understanding of the subject is too shallow to contribute anything of merit, however I wanted to express my appreciation of your elaborations on science subjects (too). 🙂

  23. marksolock
    Posted March 27, 2015 at 11:32 pm | Permalink

    Reblogged this on Mark Solock Blog.

  24. Dale Franzwa
    Posted March 28, 2015 at 12:11 am | Permalink

    Beautiful post, Jerry. Even I, a non-biologist, can understand it.

  25. Posted March 28, 2015 at 5:58 am | Permalink

    Wasn’t Nowak et al’s paper peer-reviewed and published in Nature?

    • Posted March 28, 2015 at 6:03 am | Permalink

      Yes, but that’s no guarantee that it’s correct; reviewers screw up all the time, or review a paper perfunctorily. How many of them would do the mathematics described in the paper in this post.

      Lesson: just because something is published in a peer-reviewed journal, even an important one, that doesn’t mean it’s right. Lessons: cold fusion (in Nature) and arsenic-based life (Science; really, really wrong).

      • Posted March 28, 2015 at 6:09 am | Permalink

        So this train of thought applies also to Liao et al’s at PLoS Biology (Open Access)?

        • Posted March 28, 2015 at 6:18 am | Permalink

          Now you’re just being obstreperous. Yes, if 120+ people find errors in the paper, and someone reanalyzes it and finds a mistake, then by all means it should be published. But your train of argument here goes beyond that: you’re implying that if Nowak et al is wrong, then it’s just as likely that the Xiao et al. paper is wrong. That’s just dumb. We”ll see how the papers fare, but at the present time there have been well over a hundred people, working in this precise field, that have found errors and misleading statement in the Nowak et al paper. I don’t know how you’re trying to defend something like that by saying, “Well this one critical paper could be wrong.” Yes, it could, and so could the 120+ people who criticized the Nowak et al. paper. But if you want to defend Nowak et al., do so scientifically instead of trying to run down their critics.

  26. John Scanlon, FCD
    Posted March 28, 2015 at 6:54 am | Permalink

    Can I be the first to note that not even Rong agreed with Nowak et al.?

  27. Posted March 28, 2015 at 8:21 am | Permalink

    I remember how astonished I was when the Nowak, Tarnita and Wilson paper was first published. This was in part because I had read or seen video presentations by Nowak himself where he so positively endorsed the concept of inclusive fitness in earlier times. Example: Hamilton is the most highly referenced author in Nowak’s “Evolutionary Dynamics” text which had been my “bible” on developments in evolutionary mathematics (not that I claim to be able to follow all the mathematics in it). Now, scientists are not expected to maintain their opinions throughout their career, but what was astonishing to me was the vehemence with which Nowak’s paper and subsequent comments attacked Hamilton’s work. The same goes for E.O. Wilson. Wilson did this with even more venom, extending his attack to figures who were principal supporters of Hamilton’s work (his personal attack on Dawkins being a case in point) It’s all rather disheartening – not the way I’d like to think of scientific endeavour. So it’s rather nice to see the paper of Liao, Rong, nd Queller directly take on the specific proofs that Nowak employed and effectively invalidate them. It’s sort of like seeing the home team -the nice guys- win the match.

  28. durakje
    Posted April 2, 2015 at 5:28 am | Permalink

    Almost 🙂 Myers wasn’t the one who wanted to comment. Apparently Ben Allen was not permitted to follow up his original comment on this post. Myers just gave Allen a place to put the comment he wanted to post here, on the assumption that many people read both sites.

    As PZ notes, he’s actually more on Jerry’s side in terms of the science. The putative banning, not so much.

    • durakje
      Posted April 2, 2015 at 5:31 am | Permalink

      Odd. The comment I responded to has now (been) disappeared. I’m assuming supernatural intervention at this point 😉

  29. thh1859
    Posted April 2, 2015 at 5:57 am | Permalink

    Are kin and group selection mutually exclusive?

  30. Peter Nonacs
    Posted April 28, 2015 at 7:51 pm | Permalink

    And here is the response, and the response to the response…

    http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002134

    http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002133


3 Trackbacks/Pingbacks

  1. […] Kin selection still stands. […]

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