Do australian aborigines have tanned skin,(without mixing with europeans), or have they always been dark skinned?
Maybe this will explain: Why no white aboriginals? John Hawkes reviews a Jared Diamond review of some literature on the evolution of human skin color variation. It seems plausible that on a world-wide scale skin color variation is a reaction to a variety of environmental selection pressures, relaxation of functional constraints and social/sexual selection. Diamond focuses on the idea that balance of catabolism of folate and synthesis of vitamin D as a function of ultraviolent radiation (UVR) exposure is the primary determinant. But then he asks, what explains the dark skins of Australian Aboriginals and Tasmanians? In The Third Chimpanzee Diamond opined that sexual selection, not enviornmental selection, was the primary factor in diversifying human skin coloration. This was a qualitative assertion, and I do not not believe it has stood the test of time, seeing as how a strong positive quantitative correlation between UVR levels and melanin levels as well as evidence that purifying sele
