LONDON, ENGLAND—According to a Cosmos Magazine report, a new study of ancient DNA spanning 100,000 years and 30,000 generations indicates that dogs came from two different populations of wolves. Pontus Skoglund of the Francis Crick Institute and his colleagues sequenced the genomes of 72 ancient wolves whose remains were found in Europe, Siberia, and North America. The scientists also analyzed data from the genomes of 68 modern wolves, and 169 modern and 33 ancient dogs. Early dogs in Siberia, the Americas, East Asia, and Europe appear to have descended from an eastern Eurasian species of wolf, while early dogs in the Middle East, Africa, and southern Europe came from this eastern Eurasian species and a second, distinct population related to modern wolves in southwest Eurasia. The study also suggests that wolves were either domesticated more than once and the dogs were eventually mixed together, or the eastern Eurasian species of wolf was domesticated just once, but then some of these early dogs then mixed with their wild relatives. “We found several cases where mutations spread to the whole wolf species, which was possible because the species was highly connected over large distances,” Skoglund added. In particular, a gene related to the shape of the skull and jaw spread to every wolf in just 10,000 years, between 30,000 and 40,000 years ago. This change may have allowed the predators to adapt to the prey available during the Ice Age, he said. Read the original scholarly article about this research in Nature. To read about dog and wolf bones unearthed at a Bronze Age site on the Russian steppe, go to "Wolf Rites of Winter."