Reply To: science question — atavism, reversion and pariah morphs

[Jennifer]

Thanks, Kathryn, for the informative answer. I’ll have to add that Coppinger book to my reading list. I’d never thought about it quite that way before…that if you’re conceptually lumping all non-purebred dogs in the world into one arbitrary “mongrels” category, you’ll probably tend to come up with some pretty far-fetched theories trying to account for the tendency of longstanding “pariah” populations to look a certain way. I think it was that Dunbar quote that really threw me for a loop, because I thought, OK, well here’s someone with serious credentials, and even he seems to be saying there really is some sort of “reversion” effect intrinsic to mixing different breeds that’s destined to generate a “primitive”-looking population in pretty short order. To be fair, the quote is 30 years old, and in context he was discussing the unreliability of breed ID in bite statistics, not trying to explain why “village dogs” look the way they do. Still, I find it hard to read it as anything other than implicit support for the “mutts morphing into pariahs” scenario, and indeed that’s why the person I saw post it chose to cite it. Of course, it’s completely true that housepet-descended “First World” shelter mutts, like many of us own, often have no overall resemblance to any breed in them, and also that the loss of “type” relative to their purebred ancestors tends to be especially pronounced when those ancestors were phenotypically extreme (which seems to be a theme with Dunbar’s chosen example breeds). But at least to the best of my limited understanding, that’s not because these mutts are “reverting” towards any particular predestined form or forms, and certainly not because natural selection was substantially in play for their near ancestors.