Scientists at the University of Copenhagen, Denmark, the University of Greenland and the Institute of Evolutionary Biology in Barcelona, Spain, have determined that sled (or sledge) dogs (for example, Huskies, Malamutes and Greenland Sledge Dogs) are much older than previously believed. This was determined from the analysis of ancient dog bones found in Siberia.
“We have extracted DNA from a 9 500-year-old dog from the Siberian island of Zhokhov, which the dog is named after,” explained Copenhagen University Globe Institute PhD student and joint first author of the study Mikkel Sinding. “Based on that DNA we have sequenced the oldest dog genome to date, and the results show an extremely early diversification of dogs into types of sledge dogs.”
Previously, it had been believed that the Zhokhov dog had been a variety of ancient dog, one of the earliest to be domesticated, and a part of the origin of all dogs. But it has now been established that Siberian Huskies, Malamutes and Greenland Sledge Dogs all share the majority of their genomes with the Zhokhov dog.
“This means that modern sledge dogs and Zhokhov had the same common origin in Siberia more than 9 000 years ago,” pointed out Globe Institute Associate Professor Shyam Gopalakrishnan. “Until now, we have thought that sledge dogs were only 2 [000 years]-3 000 years old.”
As part of their research, the scientists also sequenced the genomes of ten modern Greenland Sledge Dogs and a 33 000-year-old Siberian wolf. They then compared these to the genomes of dogs and wolves from various parts of the world.
“We can see that the modern sledge dogs have most of their genomes in common with Zhokhov,” highlighted Sinding. “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 modern sledge dogs goes back much further than we had thought.”
There is greater genetic overlap between modern sledge dogs and other modern dogs than between the Zhokhov dog and modern non-sledge dogs, but where and when the overlap between modern sledge and non-sledge dogs developed cannot be determined by this research. Of the modern sledge dogs, the Greenland Sledge Dog has the least genetic overlap with modern non-sledge dogs, meaning that it is probably the oldest sledge dog breed in the world today.
The research also determined that modern sledge dogs do not have the genetic adaptations for a sugar- and starch-rich diet that other modern dogs do. On the other hand, they have genetic adaptations for high-fat diets – similar to those in Polar Bears and, indeed, in Arctic people.
“This emphasises that sledge dogs and Arctic people have worked and adapted together for more than 9 500 years,” observed Gopalakrishnan. “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.”
The research has been published in the journal Science.