 Since pigmentation appears to be not entirely advantageous to life in the tropics, other hypotheses about its biological significance have been advanced, for example a secondary phenomenon induced by adaptation to parasites and tropical diseases.Early humans evolved to have dark skin color around 1.2 million years ago, as an adaptation to a loss of body hair that increased the effects of UV radiation.Before the development of hairlessness, early humans had reasonably light skin underneath their fur, similar to that found in other primates.