Anthropologists and geographers have exposed the relationship between skin color and spatial layout (Jablonski and Chaplin 2002). Darker-skinned individuals are found closer to the equator than lighter-skinned populations (Jablonski and Chaplin 2002). Having darker skin was initially thought to be associated with an evolutionary defense mechanism regarding protection from skin cancer (Jablonski and Chaplin 2002). However, further investigations suggest that skin pigmentation depends on natural selection responsible for regulating UV radiation (Jablonski and Chaplin 2002). The evolution of early humans was necessary to preserve an optimal body temperature and thus prevent overheating (Jablonski and Chaplin 2002). The body began to adapt by increasing the number of sweat glands and decreasing hair production by establishing a cooler body temperature (Jablonski and Chaplin 2002). When humans began to have bare skin, melanin pigments formed and created a barrier against harmful cancerous UV rays (Jablonski and Chaplin 2002). Melanin absorbs UV energy and counterbalances UV damage by offsetting free radicals (Jablonski and Chaplin 2002). Our earliest ancestors, called Homo sapiens, evolved about 120,000 years ago in Africa (Jablonski and Chaplin 2002). Homo sapiens had dark skin pigments, thus high levels of melanin, which prevented most ultraviolet rays from penetrating the skin (Jablonski and Chaplin 2002). Long-term exposure to UV radiation can cause DNA damage and lead to cancer (Jablonski and Chaplin 2002). Therefore, the dark pigments were an evolutionary adaptation to the high temperatures of the equator (Jablonski and Chaplin 2002). Furthermore, the darker pigments protect...... the center of the paper......n heritage. Works Cited Jablonski, N.G. 2002. “The Naked Truth.” Scientific American 42-49. Print.Lin, J.Y., and D.E. Fisher. 2007."Biology of melanocytes and skin pigmentation." Nature 445.7130: 843-50. Print.Mas, J.S., C.O. Sanchez, G. Ghanem, J. Haycock, J.A. Lozano Teruel, J.C. Garcia-Borron, and C. Jimenez-Cervantes. 2002. “Loss-of-function variants of the human melanocortin-1 receptor gene in melanoma cells define structural determinants of receptor function.” European Journal of Biochemistry 269.24: 6133-141. Print.Rees, J.L. "The genetics of skin and hair pigmentation in humans." The University of Edinburgh: UK 842-843 (2003) Valverde, P., E. Healy, I. Jackson, J. L. Rees and A. J. Thody. 1995. “Melanocyte-stimulating hormone receptor gene variants are associated with red hair and light skin in humans.” Nature Genetics 11.3: 328-30. Press.