Study Finds Dogs Were Domesticated Twice In Different Parts Of The World
ROBERT SIEGEL, HOST:
Where did dogs start their evolution from wolves to the dear beasts that curl up at the end of our beds? That question is at the heart of a new study published today in the journal Science. And according to the study, there are multiple answers. The researchers say dogs were domesticated separately on the east and west sides of the Eurasian landmass.
Joining us to talk about these findings is Greger Larson. He's a professor of evolutionary genomics in the archaeology department at Oxford University and was an author of this study. Welcome to the program.
GREGER LARSON: Thank you.
SIEGEL: Tell us about these two points of domestication. How far apart were they in time?
LARSON: We know from the archaeological record that the first appearance of dogs is in Western Europe at about 15,000 years ago, and we have dogs in Far East Asia at about 12-and-a-half to 13,000 years ago.
So - but we're not entirely certain when the process itself took place. We can just - that's the first time we can see the differences between dogs and wolves in the archaeological record.
SIEGEL: Because you're at the mercy of what bones happened to remain from those times.
LARSON: Partly that, but we're also at the mercy of being able to distinguish dogs from wolves, which requires there to be to be changes on the skeletons, which is certainly going to be the result of a long-term selection process. So when that selection started, how much before you visually can recognize the difference between a dog and wolf - does it require you to start selecting for something different between the two populations is an open question.
SIEGEL: And do the dogs from the East and the dogs from the West, to the extent that you can see their genomes - are they the same creatures. Are they - is it the same species?
LARSON: Absolutely. I mean, it's really no different than, you know, people on different sides of the planet as well. We're all the same people, but if we get together at a bar and have a few drinks, there's no reason that we can't create offspring from that encounter.
SIEGEL: (Laughter) Do you have any idea; why would dogs have developed from wolves and suddenly been domesticated?
LARSON: I think often, you know, people ask why, but I think why is the wrong question. Why implies an intentionality or a kind of goal-directed process that people sought to domesticate something because they saw in the wild wolf the potential to have a puppy that they could bring back and not eat their 3-year-old.
And we - because they were the first domestic animal, there is no model. There's nothing that you can compare it to. So I think the how question is the more important one, and what you require for a how question is, how does a population of wolves become much more closely related to and then initiate a relationship with humans whereby it becomes not so much antagonistic but almost a partnership?
So one idea is that very similar to how some wolf populations follow caribou across a landscape and have a very different culture, if you will, from the wolves that hang out in forests and have a very other - different ways that they go about procuring nutrients from the landscape, we think that there may be something to do with a wolf population that instead of following caribou, starts following us around and gets very used to our niche and the waste products that we're creating.
And then we get used to them as centuries or whatever else - and that can then kick start this process whereby those pups are under much more heavy selection for tameness, which we know is a major factor in domesticating anything. And that might be just the kind of beginnings that we require before then, many, many generations later, people start imparting a much more direct selection pressure on them.
SIEGEL: So we shouldn't think in terms of a pair of hunter gatherers saying, the kids have all moved off into caves of their own, and why don't we domesticate a wolf?
LARSON: Boy, that would be great. It would make all our jobs very much easier.
LARSON: But I kind of prefer the actual biological narrative over the one that we invent for ourselves.
SIEGEL: (Laughter) OK. Professor Larson, thanks for talking with us today.
LARSON: Thank you very much.
SIEGEL: Greger Larson - professor of evolutionary genomics in the archaeology department at Oxford University.
(SOUNDBITE OF SONG, "I WANNA BE YOUR DOG")
THE STOOGES: (Singing) And now I want to be your dog. And now I want to be your dog. And now I want to be your dog. Transcript provided by NPR, Copyright NPR.