What geneticists have found is a pattern of dispersal that suggests ancestors of modern cats probably used land bridges created by climate-related low sea level stands to cross into the Americas from Asia.
Then, the cats crossed from North America to South America when volcanoes rose up and connected the two continents just three million years ago.
One of the things that has made the history even more complicated is that there appears to have been several backward migrations, with cheetahs moving from North America all the way to Africa, for instance, and pumas from South America back to North America.
This new history was constructed, in part, by matching the rates of change in genes between cat species — a sort of genetic clock — to known climate changes and geological events over the last 11 million years.
By combining the two histories, the researchers have been able to make educated guesses at when various cats moved from continent to continent.
"I think what's driving (cat) evolution is opportunity," said geneticist Stephen O'Brien of the National Cancer Institute, one of the authors of the
Science report.
The need for food, room and the opening up of new lands via land bridges all provided opportunities for the cats to move into new places and adapt to new environments.
A prime example is the ocelot. Before the Isthmus of Panama emerged, there were no cats or any other large predators in South America.
When ocelot cats finally got in about three million years ago, they rapidly evolved into seven new species — the ocelot, margay, Andean mountain cat, Pampas cat, Geoffrey's cat, Kodkod and Tigrina — and took over.
