Ancient dogs adapted for the freezing cold helped primitive humans survive in the Arctic more than 10,000 years ago, according to research published Thursday in the journal Science.
The study compares the genetics of modern breeds of “sled dogs,” including Alaskan and Siberian husky dogs used for dog sledding, as well as Alaskan malamutes and Greenland dogs, with the DNA of a dog that lived 9,500 years ago on the island of Zhokhov, above The Arctic Circle in Eastern Siberia, where archaeological evidence of the first dog sleds has been found.
The researchers found that sled dog breeds and the ancient dog share many of the same genes, forming a distinct lineage that reveals the antiquity of sled dogs and hints at their importance to human survival as humans spread to the world. Arctic near the end of the period. last ice age.
“Being able to move large amounts of material, killings and food across large spaces in such difficult terrain would have been a great advantage,” said Shyam Gopalakrishnan, a population geneticist at the University of Copenhagen and lead author of the study along with the geneticist. Mikkel Sinding. “It may have been instrumental in the humans who established the Arctic.”
Gopalakrishnan and his colleagues compared the DNA of the ancient Siberian dog with the DNA of 134 modern dogs, including 10 dogs from Greenland, a breed believed to be close to the ancient sled dogs.
They also compared DNA from the jawbone of a 33,000-year-old wolf found in northeast Siberia, which is similar to the original wolf genome from which modern dogs descended.
Their results showed that among dogs, Greenlandic dogs were genetically closer to the wolf, while the other sled dog breeds were genetically closer to Greenlandic dogs than other dogs.
They determined that modern sled dog breeds share a genetic lineage that is at least 9,500 years old, and suggested that sled dogs may have been genetically distinct from other dogs about 15,000 years ago.
The ancient Siberian dog showed various adaptations that would have helped it survive in very cold conditions, including longer fur and thick pads on its paws, which could have helped it run more in snow and ice.
Modern sled dog breeds retain these adaptations, Gopalakrishnan said.
There is also evidence that modern sled dog breeds can thrive on a high-fat, low-starch diet, which became normal for humans in the Arctic several thousand years ago when they focused on hunting marine mammals, like seals, walruses and whales.
“Most of the food came from hunting, so these dogs were probably being fed the leftovers from the human population that lived there,” he said. “It could be that this adaptation is a reflection of the fact that [the dogs] they are living with them. “
Research also supports the idea that dog domestication occurred about 35,000 years ago, much earlier than previously thought.
Scientists used to believe that humans domesticated wolfhounds 10,000 to 15,000 years ago, but genetic evidence supports the much earlier date.
“Dogs already had different populations 10,000 years ago, and one could imagine that domestication occurred long before that,” Gopalakrishnan said. “So the original 10,000 to 15,000-year idea for domestication simply doesn’t work.”
Robert Losey, an archaeologist at the University of Alberta at Edmonton, who studied ancient dog sledding in Russia and North America, said the research delays the earliest date for dog sledding at least 10,000 years ago. “These dogs have adapted to live with people in the Arctic, in these cold environments, very soon.”
Losey said the old dog sled was probably not like the modern dog sled, where as many as 20 dogs pull large sleds and multiple people.
“I guess there was only one or two dogs, maybe pulling a sled, or pulling a sled in combination with people,” he said. “And they probably had packages on their backs.”
Animal geneticist Ben Sacks of the University of California at Davis said the study shed light on the origins of Neolithic dog breeds, including Greenland and Inuit dogs and wild dogs from Australia and New Guinea.
“Both Native Americans [dogs] and Australasian wild dingoes are under great threat of extirpation, so the study should boost efforts to conserve these populations, “he said.
