COPENHAGEN, DENMARK—NBC News reports that researchers have compared the genome of a 9,500-year-old dog who lived at a site on Siberia’s Zhokhov Island, where archaeological evidence of dogsleds was also recovered, with DNA extracted from a 33,000-year-old wolf’s jaw found in northeastern Siberia, and the genomes of 134 modern sled dog breeds, including Alaskan and Siberian huskies, Alaskan malamutes, and Greenland dogs. The study found that the ancient dog had long fur and thick foot pads, and shared many genes with modern sled dog breeds. The Greenland dogs, long thought to be the closest modern breed to ancient sled dogs, were found to be genetically closest to the wolf, while the modern sled dogs were more closely related to the Greenland dogs than other dog breeds. The study also suggests that the sled dog lineage may date back some 15,000 years. “Dogs already had different populations 10,000 years ago, and one would imagine that domestication happened quite a bit of time before that,” said population geneticist Shyam Gopalakrishnan of the University of Copenhagen. To read about the specialized breed of sled dog brought to North America by the first Inuit migrants, go to "Around the World: Arctic."