Lice is nice, at least when studying human evolution

William Atkins
Monday, 12 March 2007 22:27

Science - Biology

The article “Pair of lice lost or parasites regained: the evolutionary history of anthropoid primate lice”, which appears March 7, 2007, in the journal BMC Biology (BioMed Central Biology), contains the results of a study performed by University of Florida researchers.

David L. Reed, one of the article’s authors and assistant curator of mammals at the Florida Museum of Natural History, says of their result: "These lice really give us the potential to learn how humans evolved when so many parts of our evolutionary history are obscure. Lice also can serve as a model in understanding how parasites move from one species to another." [The Post Chronicle]

The scientific team (consisting of Reed, Jessica E. Light, Julie M. Allen, and Jeremy J. Kirchman) collected human pubic lice (Pthirus pubis) from a public health clinic in Salt Lake City, Utah, and compared it to gorilla lice (Pthirus gorillae) from the Mountain Gorilla Veterinary Project (Rwanda, Africa). Differences in DNA (deoxyribonucleic acid), the substance that carries an organism’s genetic material, showed that the two species of louse (singular of lice) diverged between three and four million years ago.

Lice are known to have evolved along with primates for at least 25 million years. They are parasitic wingless insects that live on humans and other animals.

The collaborators within the study say that their results show that humans had lost most of their body hair by that period of time, except for the head and groin areas. The lice transferred from gorillas to humans by a number of possible means. Some of the possible ways include humans sleeping in gorilla nests, eating gorilla meat, or in close contact with gorillas (even sexual contact).