Cancer may have driven the evolution of black skin early in human history, a study suggests.
Scientists believe dark skins appeared more than a million years ago to prevent our African ancestors dying from skin cancer.
The change occurred after ancient humans shed most of their body hair and ventured out into the sun-drenched African savannah.
Only those individuals with darker, more protected, skin would have escaped dying young from skin cancer.
Lead scientist Professor Mel Greaves, director of the Centre for Evolution and Cancer at The Institute of Cancer Research in London, said: "Other investigators have dismissed cancer as a selective force in evolution.
"But the clinical data on people with albinism, particularly in Africa, provide a strong argument that lethal cancers may well have played a major role in early human evolution as an important factor in the development of skin rich in dark pigmentation."
The research is published in the journal 'Proceedings of the Royal Society B'.