Ancient humans started down the path of evolving into two separate species before merging back into a single population, a genetic study suggests.That's one possibility, anyway; the reporter adds that "other scenarios could also account for the data." The paper, published in the American Journal of Human Genetics, is available here.
The genetic split in Africa resulted in distinct populations that lived in isolation for as much as 100,000 years, the scientists say.
[Via The Art of the Possible.]