Cat fanciers have long known that their feline friends have wild origins.
Now scientists have identified the house cat's maternal ancestors and traced them back to the Fertile Crescent.
The Near Eastern wildcat still roams the deserts of Israel, Saudi Arabia, and other Middle Eastern countries. Between 70,000 and 100,000 years ago the animal gave rise to the genetic lineage that eventually produced all domesticated cats.
"It's plausible that the ancient [domestic cat] lineages were present in the wildcat populations back as far as 70,000 or 100,000 years ago," said study co-author Stephen O'Brien of the National Cancer Institute in Frederick, Maryland.
The wildcats may have been captured around 10,000 or 12,000 years ago when humans were settling down to farming, he added.
"One of nearly 40 wild cat species existing at that time, the little wildcat that lived in the Middle East had a genetic variance that allowed it to sort of try an experiment—let's walk in and see if we can get along with those people," O'Brien said.
One Hell of an Experiment
A research team led by geneticist Carlos Driscoll of the National Cancer Institute and scientists at the University of Oxford in England found five matriarchal lineages to which modern domestic cats belong.
"This tells us that domestic cats were sort of widely recruited, probably over time and space," Driscoll said.
But people probably weren't going out and catching—or herding—cats.
"The cats just sort of domesticated themselves. People today know that you can't keep a cat inside [without barriers], and 10,000 years ago in the Fertile Crescent you couldn't just shut the window."
Farmers were likely the first to domesticate wildcats. The animals may have been helpful in hunting mice and other pests that plagued farm fields in the early human settlements, which had just sprang from the first agricultural development.
Agriculture led to cities and towns, as well as a new ecological environment that cats were able to exploit.
There are some 600 million house cats around the world, study co-author O'Brien added.
"Domestication was one hell of a successful natural experiment."
Cats on the Move
Once the formerly wild felines became household companions, the same cats appear to have accompanied human tribes as they gradually migrated and spread throughout the ancient world. (Related: Check out our ancestors' journey.)
"It's sort of analogous to the 'out of Africa' theory that people talk about for humans," Driscoll said. "In the same way, domestic cats from Europe are really the same as domestic cats from Israel or China or wherever."
The earliest archaeological evidence for domestic cats has been found in Cyprus and dates back approximately 9,500 years.
(Read: "Oldest Known Pet Cat? 9,500-Year-Old Burial Found on Cyprus" [April 8, 2004].)
Cat studies of all types are hindered by the many physical and behavioral similarities between domestic cats and their wild relatives. In fact, it is often difficult or impossible for even the trained eye to tell them apart, and interbreeding has created many hybrids of the two.
Driscoll's study began because genetics may be one of the only ways to determine which cats are truly wild. His group managed to successfully herd about a thousand wild and domestic cats and sample their DNA to produce the genetic study, which will appear in tomorrow's issue of the journal Science.
In search of cats' wild ancestor, the team studied modern wildcat subspecies including the Near Eastern wildcat, the European wildcat, the Central Asian wildcat, the southern African wildcat, and the Chinese desert cat.
The sampling of feline genes revealed that the Near Eastern wildcat and domestic cats fell into the same genetic clade, a group of species with the same ancestor. This meant the ancient ancestors of the wildcats were likely the first cats to be domesticated.
The genetic diversity of living cats revealed that they must have existed for some 70,000 to 100,000 years to produce that degree of diversity.
Related: Cat Day: Our Archival Pictures of Felines