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).