My explanation of human evolution suggests increased testosterone in human males and females, compared to chimpanzee males and females, is directly involved in human evolution. Therefore, I decided testosterone could be linked to skin color. In 1996, I found limited support of a connection, so I left further work on this connection for later. The article concerns UV light and skin color. This indicates to me that testosterone, as I first suggested in 1996, may be directly involved in skin color.
Blacks produce more testosterone than other races, hence, blacks have darker skin.
Jablonski and Chaplin just found that In all populations for which skin reflectance data were available for males and females, females were found to be lighter skinned than males. This would support my hypothesis. The obvious question quickly returned in response at the news group. The following is my answer to the question and is an extension of my original hypothesis that testosterone is directly involved in skin color and human evolution. I suggest the difference results from effects of testosterone on melanocytes in utero.