If light skin is so desirable, why do white people get tans?

[magical thyme]

89. actually, yes it does, sort of...

The same mutation responsible for red hair apparently triggers a pathway associated with malignant melanoma. Ok, not race, but red hair leads to significatnly higher risk.

http://hms.harvard.edu/news/how-red-hair-may-increase-melanoma-risk-8-22-13

A person’s skin pigment, which determines hair color and skin tone, is influenced by the melanocortin-1 (MC1R) gene receptor. For the population’s 1 to 2 percent of redheads, a mutation in MC1R accounts for their red hair color and typical light skin.

Now researchers from Harvard Medical School have discovered that the same MC1R mutation responsible for the red-hair phenotype also promotes an important cancer-causing pathway. The new findings, reported online August 22 in the journal Molecular Cell, help to explain the molecular mechanisms that underlie redheads’ well-known risk of developing melanoma, providing new insights for treating and preventing this dangerous type of skin cancer....

...“In this current study, we have demonstrated that the mutation MC1R-RHC promotes the PI3K/Akt signaling pathway when a red-haired individual is exposed to UV radiation,” explained co-senior author Wenyi Wei, an HMS associate professor of pathology at Beth Israel Deaconess Medical Center. PI3K/Akt is a well-known cancer-causing pathway that has been implicated in breast cancer, ovarian cancer and lung cancer. ..

...“Together, our findings provide a possible molecular mechanism as to why red-haired individuals harboring MC1R mutations are much more susceptible to UV-induced skin damage than individuals with darker skin, resulting in a 10- to 100-fold higher frequency of melanoma,” said Wei.