Scratch, scratch, scratch, scratch. Head lice can be a real pain, and they can keep you out of school until you get them out of your hair.
Now, it appears that head lice and their cousins, body lice, might help solve a longstanding mystery: When did people start wearing clothes? Was it half a million years ago, or was it perhaps only in the last 30,000 years?
One type of human louse lives on the scalp (left), and the other lives on clothes (right).
|S. Tuepke/Max Planck Institute for Evolutionary Anthropology|
Scientists in Germany think they’ve found an answer by looking at the history of human lice, those tiny critters that make us all cringe and grab the medicated shampoo.
Head lice dwell among the hairs on your head, and they like to feast on the tiny flakes of dead skin on your scalp. Body lice, however, live on your clothes and eat dead skin on the rest of your body. So, to have body lice, you need to have clothes.
The researchers say that, at one time, there were just head lice. Body lice diverged from head lice about 70,000 years ago, give or take 40,000 years. The appearance of body lice suggests that people started wearing clothes at roughly the same time.
Not everyone agrees with this view, though. Some say that people living in northern Europe half a million years ago would have needed clothes to survive the cold weather. Other scientists say they aren’t sure that head lice and body lice really are separate species.
Whatever the case may be, it seems there’s one sure cure for body lice: going around naked!—S. McDonagh
Travis, John. 2003. The naked truth? Lice hint at the recent origin of clothing. Science News 164(Aug. 23):118. Available at http://www.sciencenews.org/20030823/fob7.asp .
You can learn more about head lice at http://www.kidshealth.org/kid/ill_injure/sick/lice.html and http://www.kidshealth.org/kid/ill_injure/aches/louse.html (KidsHealth for Kids).
You can look for information on the history of clothing at http://www.historyforkids.org/learn/clothing/index.htm (History for Kids).