Science fiction writers have suggested a future Earth populated by a blend of all races into a common human form. In real life, the reverse seems to be happening. People are evolving more rapidly than in the distant past, with residents of various continents becoming increasingly different from one another, researchers say.
"I was raised with the belief that modern humans showed up 40,000 to 50,000 years ago and haven't changed," explained Henry C. Harpending, an anthropologist at the University of Utah. "The opposite seems to be true."