for National Geographic News
A common type of head lice picked from thousand-year-old Peruvian mummies suggests the pesky parasitic insects accompanied modern humans on their first migration out of Africa, according to a new study.
Researchers had thought Europeans brought the widespread louse species to the Americas about 500 years ago, said David Reed, who studies the parasites at the University of Florida's Museum of Natural History in Gainesville.
Hundreds of lice were found on two mummy heads dating from the ancient Chiribaya culture that were excavated from the southern Peruvian coastal desert between 1999 and 2002.
Reed and his colleagues expected the lice collected from the mummies' braided hair to be of a kind called type B, which is abundant in North and Central America.
"We thought the type B lice might have their origin here in the Americas and perhaps have been the only one here prior to European influence," Reed said.
The team was surprised to find the more widespread louse, type A. This supports the notion that the lice "spread around the globe with humans as they emerged out of Africa," he added.
Where and when the type B louse originated remains a mystery.
Reed and colleagues reported the finding this week in an online edition of the Journal of Infectious Diseases.
The presence of type A in the Americas prior to European arrival also raises the possibility that a louse-borne disease called epidemic typhus may have originated in the New World.
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