Africa is where modern humans evolved and is the starting place for the global expansion of our species (Campbell & Tishkoff, 2008, p. 403). African populations also have the highest levels of genetic and phenotypic variation among all humans (Beleza et al., 2005, p. 366). Archaeological evidence indicates that the continent has been inhabited by humans and their forebears for some 4,000,000 years or more (Stringer, 2011, p. 20). Anatomically modern humans are believed to have appeared as early as 200,000 years ago in the eastern region of Africa (Tishkoff & Kidd, 2004, p. 133).
Africa has the most physically varied populations in the world, from the tallest peoples to the shortest; body form and facial and other morphological features also vary widely (Hiernaux, 1975, p. 15). It is the continent with the greatest human genetic variation, reflecting its evolutionary role as the source of all human DNA (Campbell & Tishkoff, 2008, p. 405). Naturally blonde hair is often associated with white or Caucasian people (Loomis, 1967, p. 25). However, there are groups of dark-skinned people who have naturally blonde hair also (Beleza et al., 2005, p. 370). Some of these groups include the Aboriginal Australians (Aborigines) and the Melanesians (Friedlaender, 1975, p. 30). "The Aborigines are thus direct descendants of the first modern humans to leave Africa, without any genetic mixture from other races so far as can be seen at present (Friedlaender, 1975, p. 35). Their dark skin reflects an African origin and a migration and residence in latitudes near the equator, unlike Europeans and Asians whose ancestors gained the paler skin necessary for living in northern latitudes (Jablonski, 2006, p. 40). Similarly, the Solomon Island Melanesians have dark skin, blue eyes, and blonde hair (Friedlaender, 1975, p. 40). The children often have curly blonde hair which may turn darker when they get older (Loomis, 1967, p. 30). Blonde hair is also found in many of the women as well (Beleza et al., 2005, p. 375).
When people think of skin color in Africa, most would think of darker skin, but there is a huge amount of variation, ranging from skin as light to the darkest skin on a global level and everything in between (Jablonski, 2006, p. 45). Populations of indigenous people in southern Africa like the San people carry a gene that causes lighter skin, and scientists have now identified the rapid evolution of this gene in recent human history (Tishkoff & Kidd, 2004, p. 135). Africans are known to mostly have brown or black eyes, while Caucasians are mostly known to have varieties of colors (Loomis, 1967, p. 35). However, contrary to the popular belief, having blue eyes is not limited to Asians or Europeans; a significant number of Africans are known to have blue eyes (Beleza et al., 2005, p. 380). “Originally, we all had brown eyes, but a genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a ‘switch’ which literally ‘turned off’ the ability to produce brown eyes” (Eiberg & Troelsen, 2011, p. 20).
References
(1). Campbell, M. C., & Tishkoff, S. A. (2008). African genetic diversity: Implications for human demographic history, modern human origins, and complex disease mapping. Annual Review of Genomics and Human Genetics, 9, 403-433.
(2). Beleza, S., Gusmao, L., Amorim, A., Carracedo, A., & Salas, A. (2005). The genetic legacy of western Bantu migrations. Human Genetics, 117(4), 366-375.
(3). Stringer, C. (2011). The origin of our species. Penguin Books.
(4). Tishkoff, S. A., & Kidd, K. K. (2004). Implications of biogeography of human populations for 'race' and medicine. Nature Genetics, 36(11), 133-137.
(5). Hiernaux, J. (1975). The people of Africa. Scribner.
(6). Loomis, W. F. (1967). Skin-pigment regulation of vitamin-D biosynthesis in man. Science, 157
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