Human-Lice Relationship a Long One

By Joe Rojas-Burke, The Oregonian October 07, 2009

Earlier this year, Italian scientists identified head lice and pubic lice on the mummified corpse of a 15th century king, Ferdinand II of Naples — a reminder that lice are equal-opportunity blood suckers, preying on rich and poor. Lice and combs used to remove them also have turned up in royal Egyptian mummies and tombs.

But the oldest direct evidence of our long association with head lice comes from 10,000-year-old human remains at an archaeological dig in Brazil. Archaeologists in 2000 recovered a well-preserved louse nit attached to a human hair.

Genetic studies make clear that lice have been with us much farther back than recorded history. University of Utah researchers used gene sequences from human head lice and lice that afflict chimpanzees to work out a louse family tree. The lineage goes back 5.5 million years, to the last common ancestor of humans and chimps.

Now scientists are using lice as a way to explore and verify important milestones in human history. David Reed, a scientist at the Florida Museum of Natural History, and colleagues have analyzed lice genes to corroborate the “out of Africa” theory that the human species emerged from a small band of early humans who ventured from Africa more than 50,000 years ago.

Another group used lice to come up with a date for the origin of clothing. Mark Stoneking and colleagues at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, tracked down the origin of body lice, a species related to head lice that split off to occupy a different niche: clothing. The researchers calculated that body lice originated about 72,000 years ago and no sooner than about 114,000 years ago — evidence that clothing may have been a surprisingly recent innovation in human history.