Fresh ideas emerge about the origins of humans’ relationships with their favorite species
One lab full of rats looks pretty much the same as another. But visiting a lab in Siberia, geneticist Alex Cagan can distinguish rats bred to be tame from those bred to be aggressive as soon as he opens the lab door.
“It’s a completely different response immediately,” he says. All of the tame rats “come to the front of the cage very inquisitively.” The aggressive rats scurry to the backs of their cages to hide. Exactly how 70 generations of breeding have ingrained friendly or hostile behaviors in the rats’ DNA is a mystery that domestication researchers are trying to solve. The rats, along with mink and silver foxes, are part of a long-running study at the Institute of Cytology and Genetics in Novosibirsk, Russia. The aim is to replay domestication to determine the genetic underpinnings that set domesticated animals apart