Friday, January 12, 2007

Always Revealing, Human Skin Is an Anthropologist’s Map
In an era of academic hyper-specialization, Dr. Nina G. Jablonski has an amazingly broad résumé. At 53, she heads the anthropology department at Pennsylvania State University. She’s also a primatologist, an evolutionary biologist and a paleontologist.

Last year, Dr. Jablonski led an expedition to China, where she dug for human fossils in an attempt to learn how early man coped with climate change. This month, she’s in Kenya, where she and Meave Leakey are putting together a study on prehistoric monkeys.

For more than a decade, Dr. Jablonski has been trying to get her arms around a ubiquitous and yet mysterious topic: the biology, evolution and social function of human skin. The results of her studies have been published by the University of California Press as “Skin: A Natural History.”

Interview with Jablonski. She says this about skin color:
That it’s not about race — it’s about sun and about how close our ancestors lived to the Equator. Skin color is what regulates our body’s reaction to the sun and its rays. Dark skin evolved to protect the body from excessive sun rays. Light skin evolved when people migrated away from the Equator and needed to make vitamin D in their skin. To do that, they had to lose pigment. Repeatedly over history, many people moved dark to light and light to dark. That shows that color is not a permanent trait.

Seems to me it wasn't all that long ago that someone actually demonstrated empirically that skin tone was, in fact, related to latitude.