What makes an animal a pet?

Turns out it's not just close association with humans tat makes a species a good pet. It's a long period of acclimation and breeding that actually puts companionship in the genes. Biologist Dmitry Belyaev and his colleagues have compressed thousands of years of such evolution into decades, producing foxes that "naturally" love human company. This is more than just domestication, too. Geneticist Greger Larson says that while "domestication" "implies something top down, something that humans did intentionally...the complex story is so much more interesting."