How the modern dog came to be
A major new study of prehistoric dog
DNA has revealed how rapidly man’s best friend spread around the world following domestication, and how the animals’ changed as they followed their two-legged masters. Researchers sequenced and analyzed DNA extracted from the remains of 27 ancient dogs unearthed in Europe, the Near East, and Siberia. They found that by 11,000 years ago, just after the Ice Age and before the domestication of any other animal, there were already five different types of dogs with distinct genetic ancestries scattered across the world. The study suggests that domestication may have begun about 20,000 years ago, some 5,000 years earlier than previously thought. Some of the researchers also believe the genomes show that all dogs evolved from an extinct and as yet unidentified form of wolf, though others say the evidence is not conclusive. The team made a pack of other findings, including that today’s dogs are much less genetically diverse than their ancient ancestors, presumably because breeders have prioritized powerful genes; that no new wolf DNA has entered dog genomes since wolves became dogs more than 15,000 years ago; and that dogs’ geographic spread didn’t always correlate with human migration. “In many cases humans would simply bring their dogs with them as they migrated and moved across the world,” co-author Anders Bergstrom, from London’s Francis Crick Institute, tells CNN .com. But “perhaps sometimes dogs were traded between human groups.”