Dark skin evolves
With the fur gone, exposed skin needs protection, and melanin production increases sharply.
- When
- —
- Duration
- 400 thousand years
- Known to
- ± 200 thousand years
- Era
- Early Pleistocene, Quaternary
A chimpanzee has pale skin under dark hair. Once hominins lost their body hair on the open, high-UV African savanna, exposed skin was under strong selection, and genetic evidence from the melanocortin 1 receptor gene indicates the shift to heavily pigmented skin occurred well over a million years ago. Melanin protects folate — required for cell division and neural tube development — from UV degradation. The much later lightening of skin in high-latitude populations is a separate, far more recent reversal driven by vitamin D.