How Cats Took Over the World
That kitty sitting on your lap can now boast of her own family history. A research team, lead by Warren E. Johnson of the National Cancer Institute, studied the DNA of 37 species of cats and traced the cat family line to one animal who lived in Central Asia nearly 11 million years ago. Until this study, cat ancestry was hard to pin down because cat fossils look pretty much alike except for differences in size. The scientists published their findings in the journal Science in early January 2006.
As cats flourished they needed more room to hunt and they migrated throughout the world. When sea levels were low, the felines could cross over land bridges to other territories. Rising sea levels trapped the animals who then adapted and evolved in their new lands. When the sea returned to lower levels, they were again able to roam around. At least ten of these intercontinental migrations are believed to have happened.
That fast sprinter, the cheetah of Africa, can trace its family to North America. An ancestor trooped across the Bering Strait about three million years ago and finally made it to Africa where it developed into the cheetah we know today.
One member of the team, Stephen O'Brien, also attributes the cat's legendary curiosity to these travels and said, “If there were land bridges, the youngest animals—the teenagers—saw an opportunity to migrate.”
The same reason cats originally roamed and evolved—needing more hunting space—has contributed to their dwindling numbers as they clash with the humans they meet. Other than house cats and some other small cats, most species are endangered or threatened. It is estimated that fewer than 15,000 tigers, cheetahs, and snow leopards are left in the wild.