Sled dogs from Siberia are significantly older than we once thought, based on the genome of a 9,500-year-old dog called Zhokhov.
Researchers from the University of Copenhagen, University of Greenland, the Institute of Evolutionary Biology in Barcelona and Trinity College Dublin (TCD) have made a surprising discovery about humankind’s best friend. Working as part of the Qimmeq project, the researchers extracted DNA from a 9,500-year-old dog from the Siberian island of Zhokhov.
This, the researchers said, is the oldest complete dog genome to date and helps reveal an extremely early diversification of dogs into sled dogs. Until now, it was though that the dog Zhokhov, named after the island, was an ancient kind of dog – one of the earliest domesticated dogs and a version of the common origin on all dogs.
However, this study found that modern sled dogs, such as the Siberian husky, the Alaskan malamute and the Greenland sled dog, share the major part of their genome with Zhokhov.
According to TCD’s Mikkel Sinding, first author of the study, it was previously thought that sled dogs originated no more than 3,000 years ago, long after Zhokhov was around. The researchers then compared Zhokhov’s DNA with a 33,000-year-old Siberian wolf and 10 modern Greenland sled dogs.
Traces of crossbreeding
“We can see that the modern sled dogs have most of their genomes in common with Zhokhov,” Sinding said.
“So, they are more closely related to this ancient dog than to other dogs and wolves. But not just that – we can see traces of crossbreeding with wolves such as the 33,000-year-old Siberian wolf, but not with modern wolves. It further emphasises that the origin of the modern sled dog goes back much further than we had thought.”
However, among modern sled dogs, the Greenland sled dog has the least in common with other dogs, meaning it is probably the most unique of its kind in the world. It was also discovered that sled dogs don’t have the same adaptations to a sugar and starch diet as other dogs.
Instead, they have adaptations to high-fat diets, with mechanisms that are similar to those described for polar bears and Arctic people.
“This emphasises that sled dogs and Arctic people have worked and adapted together for more than 9,500 years,” Sinding added.
“We can also see that they have adaptations that are probably linked to improved oxygen uptake, which makes sense in relation to sledding and give the sledding tradition ancient roots.”