Why Do Cats Hang Around Us? (Hint: They Can't Open Cans)

Both fingerprints showed that domesticated cats around the world are most closely related to the wildcat subspecies (called lybica) that lives in the Near East. (War prevented the sampling of Iraqi wildcats, but the researchers believe those animals are of the same species as animals they collected samples from in Israel and on the Arabian Peninsula.)

One might think that people in each region would have domesticated their local wildcats. In that case, European pet cats today would genetically most closely resemble European wildcats and Chinese cats would be descended from East Asian wildcats. But that isn't the case.

Why not?

Genetics can't answer the question, but history and archaeology can provide a good guess.

Large-scale grain agriculture began in the Near East's Fertile Crescent. With the storage of surplus grain came mice, which fed on it and contaminated it.

Settled farming communities with dense rodent populations were a new habitat. Wildcats came out of the woods and grasslands to exploit it. They may have lived close to man -- but not petting-close -- for centuries.

Eventually, though, natural selection favored individual animals whose genetic makeup by chance made them tolerant of human contact. Such behavior provided them with things -- a night indoors, the occasional bowl of milk -- that allowed them to out-compete their scaredy-cat relatives.

For people, it was a great package -- agriculture, food surplus (and all the civilizing effects that came with it), with domesticated cats thrown in to protect the wealth by eating the mice.

"When that technology was transferred to other cultures, so were the cats," said Robert Wayne, an evolutionary biologist at the University of California in Los Angeles. Therein lies the reason other cultures didn't domesticate local wildcats, he said. "Why reinvent the wheel?"

This is not true with other acts of animal domestication.

Genetic studies have shown that cattle, goats, sheep, pigs and water buffalo were all domesticated at least twice in independent events. With horses, it happened many times.

The consequence of one other feline behavior -- the average cat's uncertainty about whether it wants to be indoors or out -- was also written in the genes Driscoll studied.

He found that a significant fraction of wildcats in Europe, southern Africa and central Asia were hybrids. They carried genetic evidence of having tomcatted around from time to time with their domesticated relatives.