Dogs are descended from two populations of ancient wolves

Modern dogs have ancestry from wolves in Asia and Europe, according to a study analysing DNA from 72 ancient wolves going back 100,000 years

By Jason Arunn Murugesu

Modern dogs are closely related to two populations of ancient wolves, one from Asia and one from Europe, according to a study looking at ancient DNA.

Dogs are thought to be descended from Eurasian grey wolves (Canis lupus lupus), but the story of when and where they were domesticated is still shrouded in mystery.

Anders Bergstrom at the Francis Crick Institute in London and his colleagues analysed the DNA of 72 ancient wolves from skeletal remains that were found in Europe, Siberia and north-western America, some of which were up to 100,000 years old.

The researchers sequenced the DNA of these ancient wolves and compared it with the genome of modern-day dogs. They hoped to find out whether any of the wolves were more closely related to modern dogs than the others.

Finding an ancient wolf that is particularly related to a modern dog would give researchers a better idea of when exactly dogs evolved. “This is one of the biggest questions in human prehistory,” says Bergstrom.

He and his team didn’t find such a wolf in this study, but they did learn that modern dogs were more genetically similar to ancient wolves in Asia than European ones.

Bergstrom says they can’t be more specific than that because they don’t have enough ancient wolf samples. “There are still big parts of the map where we don’t have many samples.”

This is largely to do with the fact that DNA is preserved for longer in colder climates, he says. Most of the samples that the team studied came from the northern hemisphere and were found in permafrost and caves, which preserve genetic material well.

Bergstrom says the direct ancestor of modern dogs is probably somewhere in Asia. “It’ll be somewhere where we don’t have any samples yet.”

The results also support previous work suggesting that modern dogs may have dual heritage. Early dogs in places like Israel and the African continent were found to be closely related to ancient European wolves, unlike dogs found in Siberia, the Americas and Europe.

That suggests wolves contributed DNA to the dogs that arrived in this region, says Bergstrom. This could mean dogs were independently domesticated in eastern and western regions and later merged, or they could have first been domesticated in Asia and then reproduced with wolves in western areas.

All modern dogs seem to have this dual heritage now. The earliest dogs that were found to have this dual ancestry are 7000 years old and were discovered in Israel. But this heritage from European wolves could have come far earlier in the region and we just don’t have the samples to prove it, says Bergstrom. “Ideally, we would have a dog from Israel that is 15,000 years old.”

“Although previous studies have also postulated the involvement of either western or eastern – or both – Eurasian wolves as the ancestors of modern dogs, this large study, though far from definitive, tips the balance again towards the east,” says Keith Dobney at the University of Sydney in Australia.

“Frustratingly, we’re still no closer to identifying the actual – now almost certainly extinct – ancient wolf populations that are the direct ancestors of our pampered pooches,” he says. “The hunt is still on for the smoking gun samples.”

Journal reference: Nature, DOI: 10.1038/s41586-022-04824-9