Not elder law: our ancestors were were one, then two, then one species. Hmmm....

Ancient humans started down the path of evolving into two separate species before merging back into a single population, a genetic study suggests. The genetic split in Africa resulted in distinct populations that lived in isolation for as much as 100,000 years, the scientists say. This could have been caused by arid conditions driving a wedge between humans in eastern and southern Africa. Details have been published in the American Journal of Human Genetics. It would be the longest period for which modern human populations have been isolated from one another. But other scientists said it was still too early to reconstruct a meaningful picture of humankind's early history in Africa. They argue that other scenarios could also account for the data. At the time of the split - some 150,000 years ago - our species, Homo sapiens, was still confined to the African continent.