A new genomic analysis of an ancient Taimyr wolf bone reveals that dogs and humans may have been a match far longer than previously believed.

Earlier genome-based estimates have suggested that the ancestors of modern-day dogs diverged from wolves no more than 16,000 years ago, after the last Ice Age, but new 35,000 year-old radiocarbon dating shows the Taimyr wolf represents the most recent common ancestor of modern wolves and dogs.

 The researchers made these discoveries based on a small piece of bone picked up during an expedition to the Taimyr Peninsula in Siberia. Initially, they didn't realize the bone fragment came from a wolf at all; this was only determined using a genetic test back in the laboratory. But wolves are common on the Taimyr Peninsula, and the bone could have easily belonged to a modern-day wolf. On a hunch, the researchers decided to radiocarbon date the bone anyway. It was only then that they realized what they had: a 35,000-year-old bone from an ancient Taimyr wolf. 

An ancient Taimyr Wolf bone from the lower jaw. The animal lived 27,000 to 40,000 years ago.
Credit: Love Dalén

"Dogs may have been domesticated much earlier than is generally believed," says Love Dalén of the Swedish Museum of Natural History. "The only other explanation is that there was a major divergence between two wolf populations at that time, and one of these populations subsequently gave rise to all modern wolves." Dalén considers this second explanation less likely, since it would require that the second wolf population subsequently became extinct in the wild.

"It is [still] possible that a population of wolves remained relatively untamed but tracked human groups to a large degree, for a long time," adds first author of the study Pontus Skoglund of Harvard Medical School and the Broad Institute. 

The DNA evidence also shows that modern-day Siberian Huskies and Greenland sled dogs share an unusually large number of genes with the ancient Taimyr wolf.

"The power of DNA can provide direct evidence that a Siberian Husky you see walking down the street shares ancestry with a wolf that roamed Northern Siberia 35,000 years ago," Skoglund says. To put that in perspective, "this wolf lived just a few thousand years after Neandertals disappeared from Europe and modern humans started populating Europe and Asia."

Citation: Skoglund et al.: "Ancient wolf genome reveals an early divergence of domestic dog ancestors and admixture into high-latitude breeds", Current Biology, DOI:10.1016/j.cub.2015.04.019