Study shows lice were carried from Africa

By Maggie Fox, Health and Science Editor

Genetic tests showed the lice are nearly identical to strains found around the world that have been dated to when humans first began to colonize the rest of the world.

"We know that this parasite was distributed all over the globe along with us," Reed said in a telephone interview.

Clade A is found everywhere, clade B is common in both North America and Europe, and clade C is rare. There had been a theory that clade B evolved separately in the Americas and that European explorers carried A to the Americas and brought B back to Europe with them.

The lice were collected off the heads of two mummies found in the southern Peruvian coastal desert. "The mummies belonged to the post-Tiwanaku Chiribaya culture," the researchers wrote. They were dated to around 1000 AD.

"They were loaded. It was amazing," Reed said. "It really was remarkable how lousy they were."

Reed was able to get intact DNA from the lice and sequencing showed they were all clade A.

Reed believes he can use gene sequencing of lice to track and date human migrations all over the world.

They can also transmit diseases such as typhus. Reed believes some mummified lice will carry the rickettsia bacteria that transmit typhus, and gene sequencing of these bacteria can also help trace routes of human migration.

(Editing by Stuart Grudgings)