shhhhhhhh don't tell the kkk (or for that matter the 'intelligent' designers)

Clue To White Skin: One Gene Mutation Found Among Europeans
By WILLIAM HATHAWAY
Courant Staff WriterDecember 16 2005

The skin color of Europeans may have turned white after their ancestors migrated from Africa because of a single mutation among the 3 billion genetic "letters" that make up the human genome, scientists reported Thursday.The mutation explains part of the lingering mystery of how human skin colors evolved during the last 50,000 years as modern humans migrated across the world after leaving Africa, according to research published today in the journal Science."This really calls into question our ideas about race," said Mark Shriver, professor of anthropology and genetics at Penn State University and an author of the paper. Cancer researchers discovered the mutation in zebra fish while investigating a gene they suspected might play a role in malignant melanoma, a skin cancer. Researchers found that a mutation of a gene called SLC24A5 seemed to explain why golden zebra fish had lighter pigmentation in their stripes than other zebra fish.In humans as well as fish, variations in skin color are caused by melanin, or specifically the size and number of pigmentation granules called melanosomes within cells. People of European descent - and the golden zebra fish - have few, smaller and lighter granules within skin cells.While scores of genes have been identified in development of skin pigmentation, there is still confusion about which ones are most important in humans. So scientists at the Penn State College of Medicine in Hershey, Pa., wondered whether the mutation of a single specific gene might account for lighter pigmentation in humans as well as in the zebra fish. "When you run into something incredibly interesting, you have an obligation to do the best science you can do," said Dr. Keith Cheng, a cancer researcher at the Penn State Cancer Institute and senior author of the Science paper...........