It’s the species so nice, we tamed it twice.
Scientists have found that ancient humans must have domesticated dogs at least twice in their history—once in Asia and once in Europe or the Near East.
“Comparing ancient dogs to a modern worldwide panel of dogs shows an old, deep split between East Asian and Western Eurasian dogs,” the new study in Science says. “Thus, dogs were domesticated from two separate wolf populations on either side of the Old World.”
The team of geneticists made their discovery by sequencing the entire nuclear genome of a 5,000-year-old dog, using only a bone from its inner ear.
Then, combining that data with the DNA of 605 modern dogs, they mapped out a family tree of dog species—and what they found surprised them.
“I was like, ‘Holy shit!’” the study's leader, Greger Larson, told Science. “We never saw this split before because we didn’t have enough samples.”
Even more interesting, the split occurs around the same time dogs first started appearing in Europe and Asia. That’s why the scientists think these divergent evolutions were caused by humans’ efforts to domesticate and breed the animals, changing them from wolves to dogs—twice.