Lice Mark Meeting With Pre-Humans

A study of an ancient human pest -- head lice -- suggests that the ancestors of today’s American Indians may have met and fought with pre-humans long extinct elsewhere, scientists said Tuesday.

Researchers said one type of lice is found worldwide and must have evolved on the ancestors of our species, Homo sapiens. A second type is found, so far, only in the Americas. That type is thought to have come from Homo erectus in Central Asia.

“The lineage in Africa that led to Homo sapiens left Africa 100,000 to 200,000 years ago and very quickly, it seems, moved around the world,” said Dale Clayton, a biology professor at the University of Utah who led the study.

It could be that migrating Homo sapiens ran into groups of Homo erectus -- and their unique family of head lice.

“It is amazing to know that we had physical contact with another species of human,” said David Reed, an assistant curator at the University of Florida.