Skin color and climate in Central Africa: A comparison of three populations

In order to test the hypothesis that in Central Africa variation in melanin concentration in the human skin largely results from adaptation to ultraviolet radiation, skin reflectance of the inner surface of the arm was measured at 685 nm in three samples: a sample of 415 Sara, who have a long history of habitation in the very sunny savanna of Chad; a sample of 278 Oto, a Konda caste that migrated to the equatorial forest of Zaire less than two millennia ago;and a sample of 122 Twa, a Konda caste that has been in the equatorial forest longer than the Oto. The predicted Sara-Oto-Twa sequence was confirmed and is at least partly genetically based.The study presented here is a part of an International Biological Programme/Human Adaptability Program project, which has been supported by the French and Belgian International Biological Programme committees, by Recherche Coopérative sur Programme 117 of Centre National de la Recherche Scientifique, in the Chad by Institut National Tchadien pour les Sciences Humaines, and in Zaire by Office National pour la Recherche et le Développement and Institut pour Recherche Scientifique au Congo.