How Wild Cats First Became Domesticated and Why Dogs are Tamer

Cats and kittens can be found in pet owners' households across the world. But how did these felines first become the cute and cuddly pets that they are today? Cats and humans have shared the same households for the past 9,000 years and now, scientists have studied the cat genome to learn a bit more about how these creatures were first domesticated.

Wolves and, in consequence, dogs were actually domesticated over 30,000 years ago. Ancient humans used these canines and watchdogs and even as hunters. Cats, in contrast, were domesticated far later-if you can even call it domesticated.

"Cats, unlike dogs, are really only semidomesticated," said Wes Warren, one of the researchers, in a news release. "They only recently split off from wild cats, and some even still breed with their wild relatives. So we were surprised to find DNA evidence of their domestication."

The project to sequence the cat genome began in 2007. The original goal was to study hereditary diseases in domestic cats, though the study eventually revealed far more than that. The scientists examined the genomes of both domestic cats and wild cats, finding specific regions of the domestic cat genome that differed significantly.

More specifically, the researchers found changes in areas of a domestic cat's genome that involved memory, fear and reward-seeking.

"Humans most likely welcomed cats because they controlled rodents that consumed their grain harvests," said Warren. "We hypothesized that humans would offer cats food as a reward to stick around."

This isn't all they found. The researchers also compared the cat's genome with those of other mammals, including a tiger, a cow, a dog and a human. The differences in the cat genome helped explain characteristics such as why cats are almost exclusively carnivorous and how their vision and sense of smell differ from other animals, like dogs.

"Cats tend to be more active at dawn and dusk," said Michael Montague, one of the researchers. "So they need to be able to detect movement in low light."

 The findings reveal a bit more about our favorite felines. While the genomes of domestic cats have changed little since their split from wild cats, there is evidence of the species' more recent domestication.

The findings are published in the journal Proceedings of the National Academy of Sciences.