domestication

But the new research shows that the shrinking genetic diversity associated with domestication happened much faster in horses.

"Up to now relatively little has been known, however, about how the root system developed over this period of domestication and afterwards."

A little more than 10,000 years ago, they cleared the hurdle with one of the most transformative innovations in history: plant and animal domestication.

No breed stood out, and all were bested on the same tests by wolves and coyotes-perhaps, the study's authors say, because domestication slackened the evolutionary pressure for a sharp olfactory sense to find food.

Having a strong sense of smell can be metabolically costly, Bird notes, so it’s possible that domestication and reliance on humans for food slackened the evolutionary pressure to maintain such a sharp olfactory edge.