Some Thoughts on “Die, Selfish Gene, Die”

I’m often reluctant to get involved in online debates over the philosophy of biology as they usually shed more heat than light. That said, I’m going to do something stupid and comment on David Dobbs’ recent Aeon article “Die, selfish gene, die”. I’ve waited to comment in part because Dobbs’ article has a very different historical perspective (one that I think contains errors) from mine. I was glad to read that Razib Khan also thought that Waddington’s ideas about canalization and genetic assimilation are not in any way new.

In all the chatter, something Larry Moran wrote resonated with me:

The most damning criticism comes from evolutionary biologists who point out that the primary unit of selection is the individual and not the gene. Stephen Jay Gould and Richard Lewontin are prominent opponents of what they see as an unnecessary reductionism in Dawkins’ writing. Clearly, hierarchical theory (Gould) is inconsistent with the selfish gene metaphor because evolution can also operate at the level of groups and species (according to Gould and others). There are plenty of other evolutionary biologists who object to selfish genes for these reasons.

This, for me, is the fundamental problem with The Selfish Gene–at least the earlier versions (for all I know, Dawkins might have changed the book since then). In a population genetics context, Dawkins’ genic selectionism–the gene is the target of selection–never made any sense in light of epistasis. If the fitness effect of variation at one gene depends on the variation at another gene (non-additive effects for the cognescenti), then the gene can’t be the target of selection. You have to consider sets of genes (coadapted gene complexes to use an ol’ timey phrase). This is not a matter of accounting or ‘genetic bookkeeping’: selection targets suites of genes which interact with each other and are distributed around the genome, not individual genes. To call that network of genes a gene stretches the concept of a gene to absurdity. To understand selection, we need to focus on the entity is selected (‘the interactor’) not the entity that replicates (the gene).

For those who consider this a caricature, the earlier editions were staunch genic selectionism. Somehow I doubt think Brandon, Burian, Buss, Gould, Lewontin, West-Eberhard, and Wimsatt (just to name a few) all managed to ‘misuderstand’ Dawkins in the 1970s and 1980s–in the same way. Dawkins does seem to have tempered this view somewhat though (maybe).

The other thing that bothered me about Dobbs’ article was where he placed Williams and Hamilton. From my perspective, they were not genic selectionists in the sense Dawkins was (is?), but rather were arguing that adaptationist explanations, such as ‘for the good of the species’, have to make sense in light of population genetic and dynamic mechanisms:

In the early half of the 20th century, biologists routinely interpreted animal behaviours as adaptations designed to promote the welfare of the whole group (or species), often without realising that ordinary individual-level selection does not necessarily lead to group-beneficial outcomes. Matters changed suddenly in the 1960s, thanks to the work of G.C. Williams, W.D. Hamilton and John Maynard Smith. These authors showed the inherent fragility of group selection as an evolutionary mechanism, and proposed alternative explanations for how pro-social or altruistic behaviour could evolve, such as kin selection, reciprocal altruism, and evolutionary game theory.

Anyway, like I said, more heat than light. Which is why I stay away from this stuff these days (mostly).

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4 Responses to Some Thoughts on “Die, Selfish Gene, Die”

  1. Irit Rubin says:

    Dawkins does expand on how other genes in the same organism are part of the environment of each gene, such that genes undergo selection in the context of other genes with which they temporarily share an organism. Different alleles at the same locus are in competition in the population – other things being equal, including genomic (and epigenetic) environment. IOW One can use a gene-centric view to explain why in a particular locus a particular allele will be favored, knowing what alleles in other interacting loci the competing alleles in question are likely to share organisms with. If locus A with alternative alleles A and a interacts with locus B with alternative alleles B and b, one can make predictions on whether A or a is more likely to increase in prevalence knowing how they do in a population that is entirely BB, one that is entirely bb and the ratio of B:b in the population in question. Something along those lines, in any rate.

    Dawkins makes the distinction that while organisms are the ones that live and die, they are not the ones that persist (at least not in sexually reproducing populations). He sees this as disqualifying organisms as the unit of selection.

  2. Many things can be true, all at the same time:

    * The Selfish Gene is an incredible book that opened the eyes of this chemist to a beautiful new world.

    * The selfish gene metaphor is a great way to introduce people to the weird stuff (to the non-professional’s eye) that goes on within the chromosome.

    * Richard Dawkins has made a career of being a flamboyant dork.

    * Any metaphor or model, when pushed too far, will break down.

    As ever, I think that some people need to settle down and create some space for people to think.

    Fortunately for me, few people have strong opinions about small metal clusters so I never have to fight off hordes of flying monkey enthusiasts who screech ignorantly about my work.

    But it’s nice to see Larry Moran’s name in print again. Back in the mid nineties we would bump into each other in the fight against the creationists.

  3. the long term evolutionary consequence of epistasis is debated. seems like evolutionary genetics on average don’t think it is of much consequence (going back to fisher), though a minority (perhaps a substantial minority, 30% or something?) do think it matters (going back to wright). i would agree there is much to dobbs’ piece, and you almost see what you are looking for.

  4. tmtyler – Boston, MA
    Tim Tyler says:

    Dawkins described the gene as the “unit of selection” – not the “target of selection”.

    “Target of selection” is a term used by E. Mayr – and he did not use it to refer to genes.

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