
© iStockphoto/Warwick Lister-KayeBody hair difference is more pronounced between chimpanzees and humans than within our own species.
Spend a little time people-watching at the beach and you're bound to notice differences in the amount, thickness and color of people's body hair. Then head to the zoo and compare people to chimps, our closest living relatives.
The body hair difference is even more pronounced between the two species than within our own species.
Do the same genes cause both types of variation? Biologists have puzzled over that question for some time, not just with respect to people, chimps and body hair, but for all sorts of traits that differ within and between species. Now, a study by University of Michigan researchers shows that, at least for body color in fruit flies, the two kinds of variation have a common genetic basis. The research, led by evolutionary biologist Patricia Wittkopp, appears in the Oct. 23 issue of the journal
Science.
Wittkopp's group explored the genetic underpinnings of pigmentation differences within and between a pair of closely related fruit fly species:
Drosophila americana, which is dark brown, and
Drosophila novamexicana, which is light yellow.