A box full of Ping-Pong balls: My article on inclusive fitness in NY Times

Ant carrierOn Wednesday, EO Wilson and colleagues at Harvard came out swinging at a major concept in modern evolutionary biology, known as inclusive fitness. A generation of scientists has used it to explain how animals help each other–because they’re kin. In the new paper, Wilson and colleagues say it’s superfluous.

I’ve written a story about the paper–and the sparks flying from it in biology circles–for tomorrow’s issue of the New York Times. I very much liked the way Jim Hunt, an expert on wasps, described the debate to me:

“Things are just bouncing around right now like a box full of Ping-Pong balls.”

To see what he means, check out the story.

[Image from Alex Wild]

0 thoughts on “A box full of Ping-Pong balls: My article on inclusive fitness in NY Times

  1. Did you notice how the ‘pro’ side is American (Gould/Lewontin influence?) while ‘con’ side is British (Dawkins/Maynard Smith influence?)? Pluralists vs. genocentrics as “national schools”?

  2. Mmmm…actually, no. Jerry Coyne is all American, and he is super-con. Of course, he has always argued for a more Dawkins-like pattern of evolution and has been critical of Gould. Michael Doebeli, whom I interviewed, was pro, and he’s a mathematical biologist who doesn’t deal much in Gould’s pluralism. He just wants to know if the math makes sense, and he thinks that the math in the new Nature paper does.

  3. If I have to choose, other things being equal, between a theory developed from observing nature and a theory developed from a mathematical model, I would tend to prefer the theory based on observation. I note a comment (Dr Ratnieks) that the new model “does not include how closely related animals are”. I think this is a major shortcoming of the new model.

    To be a better hypothesis, I would have thought the new model has to either prove the old model does not predict the outcome in nature in some situations where the new model does predict nature, or alternatively the new model has to produce an finding the old model does not predict, but which is observed in nature. We don’t seem to have this outcome from the new model yet.

  4. Many species with sterile females, for example, do not have the strange genetics of ants and wasps. And many species with the right genetics have not produced sterile females.

    I’m finding ‘sometimes it works out that way and sometimes it doesn’t’ pretty weak as evidence against inclusive fitness. Why should the necessary conditions for inclusive fitness traits to emerge necessarily lead to them emerging? Evolution seems to push things every which way, often leading to very different endpoints from essentially the same starting conditions. Isn’t that what underpins the creationist canard that evolution is ‘unfalsifiable’?

  5. I am looking forward to see how things develop on the issue. I hope evolutionists, instead of just picking sides based on preconceptions and authority, approach it with an open mind
    For now, I am quite skeptic about Wilson et al’s view. I agree with possum: Dr. Ratnieks observation that that Nowak’s model “does not include how closely related animals are” is a serious one. Maybe I am being simplistic, but I think that it alone lay their study off…
    “[Michael Debeli] just wants to know if the math makes sense, and he thinks that the math in the new Nature paper does”. Good mathematics does not automatically mean good biology

  6. Coturnix, that British/American division is very prominent in this issue, with Stuart West and his intellectual counterparts arguing against E.O. Wilson and David Sloan Wilson (among others on the American side) for some time now. The debate is really about multilevel selection, which West et al. disregard and Wilson and Wilson believe to be critically important. A gene-centric view is insufficient to explain social behaviors, E.O. Wilson and others would tell you, and so selection at higher levels must be invoked.

    The problem is, E.O. Wilson (and others) clearly don’t understand what they’re trying to wage war against. This issue is primarily one of bookkeeping, and I think that will be made abundantly clear in the upcoming response. Expect a lot of vitriol in that response, as well–the conversation about this work will _not_ be helpful, except perhaps to get more people interested in the underlying questions about sociality. I think the fact that it has biologists talking (things are bouncing around like ping pong balls) is the most generous thing you’ll ever be able to say about this paper, Carl. The debate over this paper is not split down the middle, either. There are not and won’t be many evolutionary biologists getting behind this work.

    Also, what outeast says is spot on: ‘sometimes it works out that way and sometimes it doesn’t’ is a terrible way to evaluate evidence for a hypothesis. After all, if every haplodiploid organism was eusocial there wouldn’t BE a haplodiploid hypothesis.

  7. All of these levels of selection in this particular debate over eusociality – kin selection, group selection, individual selection (what Nowak is calling ‘natural selection’) have genes as the unit of selection. Nobody arguing that it is not about differential representation of genes due to traits that are ultimately genetically determined. Whether you look through the parent’s eye view (the paper in question), the gene-carriers’ eye view (inclusive fitness), the colony’s eye view (group selection), or gene’s eye view, that won’t change.

    Tiresomely, this is inevitably going to be related to politics and economics when it really has nothing to do with those things. It’s just another bit of esoterica whose outcome has no wider significance and that the rest of the world can safely ignore. That would be equally true if the debate were on hominid evolution rather than ants. Because ultimate causation, while nice to know (or speculate on, because so much is formally unknowable), is irrelevant for practical purposes. What matters is empirically observable behavior and physiology in the here and now.

  8. I’m having a hard time understanding what Ratnieks is talking about. The “supplemental information” — at 43 pages, it’s basically an article in and of itself — discusses issues of defining and measuring “relatedness” at considerable length. E.g.,

    We can use our model to study the fate of eusocial alleles that arise in thousands of different presocial species with haplodiploid genetics and progressive provisioning. In some of those species eusociality might evolve, while in others it does not. Whether or not eusociality evolves depends on the demographic parameters of the queen (as discussed above), but not on relatedness. The relatedness parameters would be the same for all species under consideration.

    [section 12, p. 38]

    Good mathematics doesn’t necessarily make for good biology . . . but if you’re actually trying to do mathematical biology, it’s important to know whether equation X only works in the weak-selection limit, or if approach Y lacks dynamic sufficiency, or if method Z succeeds on random regular graphs but fails on spatial lattices, and a kajillion other abstruse, dryly technical details. Getting these technicalities right makes for better science but fewer opportunities to get political.

    Once, I thought that the inclusive fitness v. multilevel selection sparring was an interesting intellectual debate to follow. It grew tedious with astonishing rapidity.

  9. I do find it amusing, however, that Nowak et al.‘s summary of their eusociality model reads like it could have come straight out of Dawkins’s Extended Phenotype:

    The queen and her workers are not engaged in a standard cooperative dilemma. The reason is that the workers are not independent agents. Their properties are determined by the alleles that are present in the queen (both in her own genome and in that of the sperm she has stored). The workers can be seen as ‘robots’ that are built by the queen. They are part of the queen’s strategy for reproduction.


  10. it looks like many here have missed what the terms of this controversy are. EO Wilson & coterie’s change of mind was forced by 1999 work by James Hunt who studied multiple origins of sociality in a wasp phylogeny in which all the species had about the same “kin selection potential” and yet he found that sociality evolved only when there were very strong “ecological” incentives (Hunt, J. H. 1999. Trait mapping and salience in the evolution of eusocial vespid wasps. Evolution 53: 225-237). But since ~2005 Wilson, Hoelldobler, etc, have hijacked the controversy.

    Some people have indeed started realizing that crucial for the existence/persistence –and thus for the evolution– of animal societies is not (or not so much) “kin selection” but rather the fact that there are very rewarding ecological niches out there in which biomachines that adopt group-approaches to foraging and interference competition are much more effective trophically than are biomachines which adopt “solitary-consumer/fighter/reproducer” strategies.

    This means that the evolutionary-genetical success of the genetic programs encoding such group behaviors is fully subordinate to the existence of such ecological opportunities!

    In other words: people have begun realizing that, e.g., “altruism” is also a wining ecological strategy, rather than just an example of the promotion, or not, of altruism genes and the rejection (or invasion) of cheater genes.

    The social-ant colony, e.g., is an ecological machine that out-competes at the foraging- and interference-competition level most other organisms in almost any terrestrial ecological setting, i.e., a social-ant colony in the field cannot be reduced natural-historically and evolutionary-historically to just an example of an ESS immune to “selfishness” mutations that may undermine the genetic encoding of its sociality.

    EO Wilson indeed has always made a big deal of the fact that ant species monopolize nearly 70% of the insect biomass on earth, but he did not realize the implications of this until the wasp guy rubbed it to him and his coterie while they were still happily repeating the empty syllogisms of kin-selection numerologists [who meanwhile have even almost managed to deny Darwin (sic!) the credit for explaining the existence of sterile ants, etc., when he mentioned in the Origin Species that an individual’s sacrifice can benefit the reproduction of relatives, i.e., kin selection].

    This 70% means that evolution by “natural selection of individuals” delivers niche-occupancy strategies that suffice to claim only ~30 of the trophic energy monopolized by the insect Bauplan (assuming termites and other social insects are insignificant biomass-wise).

    The situation among many mammals is the same. Wild-dog packs and hyenas, e.g., beat the hell out of tigers and lions, and biomass wise they dominate.

    It is time for gratuitous faux-a-prioristic misused-math arguments to be confronted with ultimate natural-historical facts.

    And it is also time that the too-many cheapo-applied-math peddlers posturing as evolutionary biologists learn that “natural selection” is not the same as “evolution by natural selection”, that differential fitness is always caused by differential ecological performance (and never by “genes”), and that evolution by natural selection is just something that “may” happen to genes when there is differential ecological performance at some level of biological organization, which however does not “prove” that the differential ecological performance is at the level of molecular interactions of genes (or of proteins; genes may suffice but are not necessary for differential ecological performance, but additive genetic variation in ecological performance suffices for evolution driven by differential ecological performance).

    In other words, Sober’s 1984 [1984 sic!] book “The Nature of Selection” should be required reading for every evolutionary biologist. Sober showed first that the “kin selection” oxymoron is a muddled verbal construct to refer to that special case of group-level differential ecological performance in which “selected” groups happen to also be kin groups (most of the time but not always… see mutualism, e.g.).

    PS. I found this very recent paper below that studied this ecological group-performance vs. “kin-selection” issue within a clade of sponge-living shrimp.


    Kin structure, ecology and the evolution of social organization in shrimp: a comparative analysis

    Author(s): Duffy JE (Duffy, J. Emmett)1, Macdonald KS (Macdonald, Kenneth S.)2

    Source: PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES Volume: 277 Issue: 1681 Pages: 575-584 Published: FEB 22 2010

    Times Cited: 2 References: 62 Citation MapCitation Map

    Abstract: Eusocial societies present a Darwinian paradox, yet they have evolved independently in insects, mole-rats, and symbiotic shrimp. Historically, eusociality has been thought to arise as a response to ecological challenges, mediated by kin selection, but the role of kin selection has recently been questioned. Here we use phylogenetically independent contrasts to test the association of eusociality with ecological performance and genetic structure (via life history) among 20 species of sponge-dwelling shrimp (Synalpheus) in Belize. Consistent with hypotheses that cooperative groups enjoy an advantage in challenging habitats, we show that eusocial species are more abundant, occupy more sponges, and have broader host ranges than non-social sister species; and that these patterns are robust to correction for the generally smaller body sizes of eusocial species. In contrast, body size explains less or no variation after accounting for sociality. Despite strong ecological pressures on most sponge-dwellers, however, eusociality arose only in species with non-dispersing larvae, which form family groups subject to kin selection. Thus, superior ability to hold valuable resources may favour eusociality in shrimp but close genetic relatedness is nevertheless key to its origin, as in other eusocial animals.

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