Scientists still don’t know how dogs became dogs – but they might be close to finding out

Blue enjoys his reward for sniffing out explosives material on a moving target. CREDIT: Jahi Chikwendiu

You might know that the German shepherd curled up at the foot of your bed – and even the English terrier yipping in the yard next door – descended from wolves. You might also know that dogs were the first domesticated animal.

But if you don’t know when or where that predator-to-pooch transformation happened, don’t fret. Neither do scientists.

Sure, they’ve published lots of studies suggesting they do. In the past four years, researchers have identified Siberia, Europe, Central Asia and southern East Asia as dog domestication’s ground zero. They’ve said it occurred at least 15,000 years ago, or possibly 18,800 years ago, or 33,000 years ago.

Note the conflicts? That’s the problem. To say this is a hotly debated topic in the dog-eat-dog world of canine science would be a huge understatement.

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But a massive global study is making a bold attempt to settle things by bringing together nearly all major canine researchers to gather and analyze thousands of ancient DNA samples and canine skulls. The first findings of the project, run out of the University of Oxford in Britain, are expected to be rolled out this year.

The results should help determine the wheres and whens – plural, because dogs might have been domesticated in different places at different times – said Greger Larson, an American evolutionary biologist who is a leader of the effort. And from that, he said, scientists will be able to infer the answer to another controversial question: Did ancient humans tame wolves, or did wolves become our pals by following ancient humans and scavenging their scraps?

The reason for the confusion, Larson said in an interview, is that much of canine genetics research is based on modern dogs, which are the result of thousands of years of mixing and, more recently, rampant breeding by people.

“All of which means that the global population of dogs is essentially one large bowl of tomato soup,” he said. “If all you have is the soup to go on, how do you infer the initial process of making that soup?”

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The answer, he said: “Look at the past and watch it happen.”

Those involved in the project are doing that by creating a database of more than 1,500 DNA samples from ancient canine fossils collected all over the world, most of them housed in museums and universities. They are also uploading thousands of photos of canine skulls to create computer-generated images of their morphology, or shape. That’s key because wolves’ faces changed – their snouts shortened, for example – as they evolved into dogs.

The result will offer something of a timeline and a map of that transformation, and patterns that emerge will lead to answers, Larson thinks.

“Like anything evolutionary, it’s a continuum,” he said. But the idea is to end up with a representation of the “time and space of dogs and wolves across the old and new world.”

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The mystery of precisely how domestication happened is likely to continue sparking battles, he said. One theory is that ancient humans had a eureka moment when they decided to tame wolves, nabbed some puppies and went from there. Larson thinks that’s preposterous, partly because people hadn’t yet domesticated other animals or plants 15,000 years ago – by which time scientists generally agree dogs had come into being – and partly because wolves probably wouldn’t have made that easy.

“Our imaginations don’t really grasp onto this idea of a long, slow, accidental process. We like to think of ourselves as smart, and we’ve always been smart,” he said. What’s more, he said: “Even wolves that are hand-reared by people from birth . . . they’re completely unruly.”

Larson favors a theory that he said “absolves humans of forethought and intention” and puts it in the paws of the wolves. According to this idea, the canines followed hunter-gatherers around and scavenged their scraps, and over time the gentler ones got to stick around.

Even while the jury is still out, Larson is getting praise for having gathered the sometimes snarling forces of the competitive dog research world, some of whose bold claims might end up undermined.

“It’s not dog-specific. It’s just science . . . If there’s a lot of potential answers, then you’ll have people fighting in their corner for their answers,” he said. “I just want to know the answer.”

On its face, that answer would be about the beginnings of the dog at the end of your leash. But Larson said it is also key to nothing less than human civilization itself. Before they began domesticating other living things, people were mobile and maybe smarter than other creatures. But they were certainly not in charge, he noted.

“Everything about the way that humans now live and exist in the world,” he said. “It’s all because of domestication.”