CHICAGO, ILLINOIS—A new analysis of dog and wolf DNA collected from animals in areas of the world thought to be centers of dog domestication suggests that dogs and wolves split from a common ancestor between 9,000 and 34,000 years ago. This date is before the human transition to agricultural societies, indicating that the earliest dogs may have lived with hunter-gatherers. The study also shows that dogs are more closely related to each other than to wolves. Any genetic overlap between modern dogs and wolves is probably the result of later interbreeding. “We also found evidence for genetic exchange between wolves and jackals. The picture emerging from our analyses is that these exchanges may play an important role in shaping the diversification of canid species,” said John Novembre of the University of Chicago.