Men significantly outnumbered women in the"out-of-Africa" migration some 60,000 years ago that eventually populated the rest of the world, according to a new study.

Africa is known to be the cradle of human evolution, and recent studies show that the peoples today inhabiting other continents originate from a relatively small band of Homo sapiens sapiens who moved through the Near East, into Europe and beyond some 50,000 and 70,000 years ago.

But until now no one had figured out a way to determine what the sex-ratio of this so-called founding population might have been.

A quartet of researchers led by Alon Keinan at the Harvard Medical School thought that the secret might be locked inside differences in genetic code across distinct geographic regions....