Researchers Use DNA to Track Early Humans

From Times Staff and Wire Reports

Humans may have made their first journey out of Africa as recently as 70,000 years ago, according to a Stanford University study of variability in DNA. And the population of these early humans who gave rise to the modern human race was probably no larger than about 2,000, the researchers reported in the American Journal of Human Genetics.

That does not mean there were no other pre-humans alive at the time, they said, but only that the others did not make any genetic contribution to modern humans.