A millennium-long story about Greenland is written in the genes of the island’s sled dogs. A new genomic analysis, published July 10 in Science, suggests that humans (and their sled dogs) arrived in the region roughly 1,000 years ago — centuries earlier than previously thought. The results weave new threads into the story of humanity’s 20,000-year-long relationship with dogs, highlighting how through domestication, dogs mirror what humans value.
“If we have any curiosity about ourselves, about us as humans, we have to understand dogs,” says Audrey Lin, an evolutionary biologist at the American Museum of Natural History in New York City.
The Qimmeq (plural Qimmit) is a large, thick-furred Arctic sled dog, akin to huskies and malamutes. “A lot of working dogs are now just companion animals,” says Tatiana Feuerborn, a paleogeneticist at the National Human Genome Research Institute in Bethesda, Md. “But the Greenland sled dog is pretty much exclusively still used as a sled dog today.”
The Qimmit remain crucial to the culture of the Greenlandic Inuit people, having been bred as “high tech technology” to thrive in the unforgiving Arctic, says Anders Johannes Hansen, an evolutionary microbiologist at the University of Copenhagen. “[The Greenlandic Inuit people] know what a good dog looks like,” he says. “They’ve selected really hard on what they believe a good sled dog should look like.”
To explore the ancient origins of this sled dog, Feuerborn, Hansen and their colleagues sampled DNA from 92 Qimmit, analyzing each dog’s genome — its full set of genetic instructions. Many samples were taken from saliva swabs from dogs working all over Greenland, while others came from bones, skin and fur in museum collections, some dating back about 800 years. The team compared the Qimmit genomes with those of other dog breeds — both modern and ancient — as well as wild canids.
The researchers found that Qimmit had limited interbreeding with European dog breeds, reflecting their long-term isolation. The dogs also fell into four genetic groups that match the main geographic and cultural groups of humans on the island, suggesting a close relationship between the Qimmeq and humans.
Those findings confirmed expectations. And that’s helpful, Feuerborn says. “You just never know when a dog is going to scamper off and change the story for you.”
The genomic analyses revealed that while one group of Qimmit from northeast Greenland has gone extinct, all the groups shared a common ancestor with that extinct population roughly 1,000 years ago. Because humans would have accompanied their sled dogs to the island, this evidence pushes the first known human presence in Greenland back by a couple of centuries. The finding bolsters the long-debated idea that the Inuit arrived before the Norse, Feuerborn says.
The research also tells a story about the broader archaeological history of the Arctic. The Qimmit are closely related to a 3,700-year-old dog found in Alaska, suggesting a rapid Inuit migration from Alaska to Greenland, possibly within a few generations. “The tight genetic connection between these Greenlandic dogs and the Alaskan dogs just goes to show how tight the histories across the Arctic are,” Feuerborn says.
Unfortunately, the Qimmit are declining in the face of shrinking sea ice from climate change and competition from snowmobiles, with their numbers halving to about 13,000 individuals from 2002 to 2020. The data from this study establishes a baseline on their population genetics, which may aid future conservation efforts.
The Qimmit have signatures in their genomes suggesting low genetic diversity but also limited inbreeding. Most modern inbred dogs have a predisposition for substantial health problems. But not the sled dogs, Lin notes.
“They’re healthy dogs,” she says. “They’re clearly able to survive in the Arctic and to perform as well as they do as working sled dogs. This shows that there are sustainable ways of maintaining a population of healthy working dogs.”