Since When Were Sled Dogs Domesticated By Humans?

 

Today's sled dogs are descended from an ancient dog that helped ancient people migrate across the Arctic, new research suggests.

Since ancient times, more than 10,000 years ago, frost-resistant dogs have helped humans survive in the Arctic. A study just published in the US journal Science compared the genomes of today's sled dogs (including Alaskan, Siberian, and Greenland huskies) with the DNA of a dog that lived just a few years ago. There is archaeological evidence of dog sledding 9,500 years ago on Zhokhov Island, above the Arctic Circle in Eastern Siberia.

The researchers believe that these sled dogs and ancient dogs shared many genetic traits, forming a unique lineage. This shows that their genetic traits span many generations to the present, and we can see how important they were to human survival when our ancestors migrated to the area of the Arctic at the end of the Ice Age.

The ability of these dogs to transport large quantities of utensils and food across large areas with complex terrain would be very helpful, says lead author Shyam Gopalakrishnan, a geneticist at the University of Copenhagen in Denmark. They may have helped to help humans settle the Arctic.

The team compared the DNA of the ancient Siberian dog to that of 134 dogs today, including 10 Greenlanders -- the breed believed to be most similar to the ancient sled dog. They also compared DNA from the jawbone of a wolf that lived in northeastern Siberia 33,000 years ago, which is similar to the original wolf genome in dogs today. The results showed that the Greenlander was the most similar to that wolf, while other sled dog breeds were more similar to the Greenlander than the other canines.

The researchers determined that today's sled dog breeds have ancestry genes that existed at least 9,500 years ago, and that sled dogs may be genetically different from other breeds that lived long ago (about 15,000 years ago).

The ancient Siberian dogs had adaptations to environmental conditions that allowed them to survive extremely cold weather, for example, they had longer and thicker fur on their feet, which allowed them to run great distances on icy and snowy ground. Today's sled dogs also retain these genetic traits.

Other evidence also suggests that today's dog canines can thrive on the high-fat and low-carb diet that was the norm for thousands of years for humans in the Arctic, when they mainly hunted aquatic mammals such as seals, seahorses, and whales animal. Most of the food source was hunted, so it's possible the dogs ate human leftovers. This may be an adaptive trait resulting from dogs living with people.

The study also strengthens the idea that humans domesticated dogs about 35,000 years ago, much earlier than previously thought. Previously, scientists believed that humans domesticated wolves into domestic dogs around 10,000 to 15,000 years ago, but genetic evidence suggests it was much earlier. Geneticist Gopalakrishnan said there have been many different breeds of dog since 10,000 years ago, so instead of 10,000 to 15,000 years for domestication, it had to be longer.

Archaeologist Robert Losey of the University of Alberta in Edmonton, Canada, who has extensively studied sled dogs in Russia and North America, said these ancient dogs adapted to the cold arctic conditions in which they lived alongside humans. Today, trailers are laid out with several people sharing a vehicle pulled by multiple dogs, sometimes as many as 20. In the past, there may only be one or two dogs, and they can only pull the cart, humans bring the stuff on their shoulders, or dogs pull the sled have person all.

Professor Ben Sachs, an animal geneticist at the University of California, Davis, said the study shed light on the origins of Neolithic dog breeds, including the Greenlander, Inuit, and wild dogs of Australia and New Guinea. Both Native American dogs and dingoes are at risk of local extinction, so this research could help advance conservation efforts for these rare breeds.