Dogs' special friendship with humans may go back 27,000 to 40,000 years, according to genomic analysis of an ancient Taimyr wolf bone reported in the Cell Press journal Current Biology last week. That's a dramatic increase from 11-16 thousand years ago when dogs were previously thought to have diverged from their wolf ancestors, after the last Ice Age.
The genome from this ancient specimen, which has been radiocarbon dated to 35,000 years ago, reveals that the Taimyr wolf represents the most recent common ancestor of modern wolves and dogs.
The Taymyr is a peninsula in northern arctic Russia that forms the northernmost part of the mainland of Eurasia. The indigenous people living there are called the Nenets people, also known as Samoyeds (that’s where the Samoyed dog’s name comes from!).
"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 the first author of the study Pontus Skoglund of Harvard Medical School and the Broad Institute.
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.
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."