Sled dogs have well-known roots in human prehistory. A 12,500-year-old tool found at an Arctic site suggests its possible use on sleds. And archaeological investigations at a known site on Zhokov Island in the Siberian Sea uncovered dog bones and sledding technology indicating that dogs may have been the first canines bred for a specific task.
Dr. Sinding and his colleagues dug deep into the DNA of one of those dogs, using a jawbone from the site dating back 9,500 years ago. They also sequenced the genomes of a Siberian wolf dating back 33,000 years and 10 modern Greenland sled dogs. They also relied on other canine genomes archived in databases.
They found that the Zhokov dog was closest to modern sled dogs, particularly Greenland sled dogs, which are a “land breed”, bred for a task and sharing an appearance and behavior, but not the type of breed for which breeding books and breeding books are bred. Records are kept.
The Zhokov dog was not a direct ancestor of modern sled dogs, but it shared a common ancestor with modern sled dogs that was probably around 12,000 years old. This evidence suggests that the type of sled dog, bred to carry loads in brutal winters, was already established 9,500 years ago.
The researchers also discovered that sled dogs, ancient and modern, did not show crossbreeding with wolves, despite the fact that other modern dog breeds do, and dog and wolf matings were known in Greenland in historical times. The results suggest that hybrids may not have been very useful for pulling sleds.
The researchers then began looking for genes that were different in sled dogs than wolves and other dog breeds. They found several that made sense. One is involved in a variety of physiological functions, including calcium transport and temperature sensitivity. They don’t know exactly what it does in sled dogs, but they do know that several similar genes are different in mammoths, cold creatures, and elephants, animals from more temperate climates, suggesting some sort of adaptation to arctic life.
Another gene that distinguishes sled dogs from other dogs is involved in coping with low oxygen conditions. It is also found in a group of humans, sea nomads, who have been diving for thousands of years. It could, Dr. Sinding said, contribute to physical fitness for the extreme demands of long sledding.
