Ancient wolf mummies reveal the origin of domestic dogs

An international team of geneticists and archaeologists, led by the Francis Crick Institute, has found that the dog's ancestry may have come from at least two ancient wolf populations.

The team used samples taken from an 18,000-year-old young wolf mummy in Yakutia. (Photo: Sergey Fedorov)

In the study, published June 29 in the journal Nature, scientists looked at the genomes of ancient wolves to better understand where the first dogs evolved. They analyzed 72 wolf genomes dating back to the last 100,000 years from Europe, Siberia and North America. The specimen in the study came from ancient coyotes excavated previously. Archaeologists from 38 institutes in 16 different countries participated in the study. Among the specimens, the most notable is the fully preserved head of a Siberian wolf that lived 32,000 years ago. Nine DNA labs collaborated to generate DNA sequence data from wolves.

Through genome analysis, the team found that both ancient and modern dogs were genetically more like wolves in Asia than in Europe, indicating that they were domesticated in the East. However, they also found evidence that domestic dogs possess DNA from two separate populations of wolves. The first dogs from northeastern Europe, Siberia and the Americas appear to have originated in the East. But the ancestors of dogs in the Middle East, Africa and southern Europe seem to be related to wolves in the Middle East.

One possible explanation for the double ancestry finding is that wolves undergo domestication more than once with different populations, then mix. Another possibility is that domestication was a one-off and the first dogs crossed with wild wolves, resulting in two ancestors.

"Through the project, we have significantly increased the number of genomes sequenced in ancient wolves, allowing us to create a detailed picture of the canine ancestry over time," said Anders Bergström, researcher Postdoctoral fellow at the Ancient Genomics Laboratory in Crick, said.

The team is continuing to look for more canine ancestors, which may reveal more precisely where the domestication process took place. Now, they're focusing on genomes from other locations, including in the South. Because the 72 ancient wolf genomes spanned some 30,000 generations, the team was able to construct a time frame that reflects how wolf DNA has changed and the role of natural selection.