Scientists at Trinity, University of Copenhagen, University of Greenland, and the Institute of Evolutionary Biology – Barcelona have sequenced the oldest complete dog genome, showing that sledge dogs adapted to Arctic conditions much earlier than previously thought.
In a study from the QIMMEQ project, DNA was extracted from a 9,500-year-old dog from the Siberian island of Zhokhov, which the dog is named after. Based on this DNA, these scientists have sequenced the oldest complete dog genome to date. According to Mikkel Sinding, from the Globe Institute and a Postdoctoral Fellow in Trinity’s School of Genetics and Microbiology, “the results show an extremely early diversification of dogs into types as sledge dogs”.
To learn more about the origins of the sledge dog, researchers sequenced genomes of a 33,000-year-old Siberian wolf and ten modern Greenlandic sledge dogs. They compared these genomes to genomes of dogs and wolves from around the world.
Through this, it can be seen that modern sledge dogs have most of their genomes in common with Zhokhov, and are more closely related to this ancient dog than to other dogs and wolves. Additionally, traces of crossbreeding with wolves can be seen, but not with modern wolves. This further emphasises that the origin of the modern sledge dog goes back much further than once thought.
“This means that modern sledge dogs and Zhokhov had the same common origin in Siberia more than 9,500 years ago. Until now, we have thought that sledge dogs were only 2-3,000 years old,” stated Sinding.
The study shows that modern sledge dogs such as the Siberian Husky, the Alaskan Malamute and the Greenland sledge dog share the major part of their genome with Zhokov. However, the study also outlines differences between sledge dogs and other dogs. For example, most dogs have genetic adaptations to a sugar and starch rich diet, whereas sledge dogs have adaptations to high-fat diets, with mechanisms that are similar to those described for polar bears and Arctic people.
Sinding stated: “This emphasises that sledge dogs and Arctic people have worked and adapted together for more than 9,500 years. 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.”