Study: Ancient African exodus had more men

BOSTON, Dec. 22 (UPI) -- Men and women who left Africa more than 60,000 years ago were not equal partners in their migration, researchers at Boston's Harvard University reported.

Tracing variations in the X chromosome and in the non-sex chromosomes, researchers found evidence that men likely outnumbered women in the exodus, the university said in a news release.

The scientists said their method of comparing X chromosomes with the other non-gender-specific chromosomes would provide a powerful tool for historical and anthropological studies because it can show differences in female and male populations that were inaccessible previously.

Even though their method can demonstrate a male-dominated migration, the Harvard researchers said they couldn't determine why more men than women participated.

But lead author Alon Keinan said the findings are "in line with what anthropologists have taught us about hunter-gatherer populations, in which short-distance migration is primarily by women and long-distance migration primarily by men."