Early humans may have evolved black skin to protect against a very high risk of dying from ultraviolet light-induced skin cancer, a new analysis concludes. Skin cancer has usually been rejected as the most likely selective pressure for the development of black skin because of a belief that it is only rarely fatal at ages young enough to affect reproduction. But a new paper cites evidence that black people with albinism from parts of Africa with the highest UV radiation exposure, and where humans first evolved, almost all die of skin cancer at a young age.
I didn’t realize that this was still a controversial notion. The idea that skin color was a factor of the latitude that your ancestors lived is fairly well established. But it appears that the exact mechanisms maybe weren’t fully established.
In warmer climates, the sun is beating down more directly on you, and dark skin is thought to be protection from skin cancer. In colder climates, aside from receiving less sun, you’re more likely to be covered up except for limited body parts, and dark skin becomes a liability limiting vitamin D production.
This study seems to support the benefits of dark skin. From what I understand, the vitamin D connection has also been established.