Dog domestication

Kat - Another story that you highlighted to me was some research from Eric Axelsson and his team in Scandinavia and the US, and this is in Nature. And this is about dogs because I love dogs. We always have some kind of animal genetics thing. What's this about dogs?

Nell - So, I think this is really interesting because essentially, what it's doing is using genetics to go back and try and find evidence to help answer the question about how dogs might have evolved. Obviously, this is a really tricky question because we don't have a lot of evidence. There's no written records, we haven't got any scientists from 14,000 years ago who've published paper on what happened. But instead, we can go back, we can look at the DNA of dogs and we can figure out how that's changed compared to wolves on the assumption that dogs evolved from wolves. So, these scientists have looked at the genetic code of wolves and dogs. They've compared it in loads and loads of detail to see exactly what those differences might be.

Kat - What can it tell us about the relationship of dogs to us and how they evolved?

Nell - So essentially, what they found is there were two main areas where there were obvious differences between the dog DNA and the wolf DNA. One of those was in various brain pathways, so that could be to do with the way that dogs' behaviour is clearly quite different from wolves. The other one that I really was interested in was looking at starch metabolism. So essentially, they found that dogs tend to have many more genes that allow them to metabolise starch in their cells. And this links in quite nicely with the theory that dogs may have evolved by taking advantage of all the waste produced by human societies. So, you can imagine a group of hunter gatherers perhaps. They leave these waste dumps wherever they go, so they have bits of food they don't want anymore, bits of crops maybe if they're farming, and dogs could be able to take advantage of that. So there might have been wolves who'll go, "Okay, here's some food I could eat." The ones who are better able to digest the starch, to digest all these kind of waste food would've been more successful and perhaps could've gone on to evolve into these other species.

Kat - And presumably, with the evolution in the brain as well and giving them characteristics that might make them more amenable to hanging around with humans. It's not a done-deal. It's quite controversial because from what I know, there's another theory that dogs evolved because humans were sort of harnessing wolves for hunting or using wolves for hunting.

Nell - Exactly. I mean, I just like the idea that you could maybe come up with an idea for which of those theories was more accurate using genetics and exactly, you can look perhaps as well at the behaviour because we know that if you breed dogs, you can quite quickly select the ones that are more tamed and are more docile. And there's a theory that that's exactly what happened with wolves. So, if people were using them for hunting, it would be much easier to have wolves that were less aggressive, had better behaviour. And if you ended up selecting those, that could change their behaviour every time.

Kat - I saw an article about this describing dogs is basically more like puppies. They're just grown up puppies and we see these in many species. For example, the human face is basically a baby monkey face and the idea that in behaviour as well, you can preserve those juvenile characteristics into adults.

Nell - Yeah, exactly and that so some of these genes that they were looking at, there's some evidence that that could be maybe what they're doing. But clearly, it's really difficult because we've got all those evidence from a long, long time ago, from thousands of years ago, but there's not a lot to go on in terms of what we know about what happened when. And there's also this theory that dog domestication could have happened multiple times in different ways, in different places. So, it's not necessarily true that there's one answer to that question.

Kat - Well, that's one "ruff" idea. Anyway, thanks very much. That's Nell Barrie science writer.