Some wolf puppies are unexpectedly willing to play fetch, according to scientists who saw young wolves retrieve a ball thrown by a stranger and bring it back at that person’s urging.

This behavior wouldn’t be surprising in a dog. But wolves are thought to be less responsive to human cues because they haven’t gone through thousands of years of domestication.

Exactly how dogs emerged from a now-extinct population of ancient wolves is a mystery. Wolves are large, dangerous carnivores, and yet they were the first animals that humans tamed. More than 15,000 years ago, when humans were still hunter-gatherers, this large predator somehow began cozying up to people, eventually becoming their “best friend.”

To try to get clues about how that happened, scientists such as Christina Hansen Wheat of Stockholm University in Sweden have been studying the differences between dogs and modern wolves. As part of her work, she raised litters of wolf puppies, feeding them and acclimating them to her presence but not playing with them or training them.

via Wolf Puppies Willing To Play ‘Fetch’ Stun Researchers : NPR