Essay about The Evolution of Human Skin Color

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According to Darwin and his theory on evolution, organisms are presented with nature’s challenge of environmental change. Those that possess the characteristics of adapting to such challenges are successful in leaving their genes behind and ensuring that their lineage will continue. It is natural selection, where nature can perform tiny to mass sporadic experiments on its organisms, and the results can be interesting from extinction to significant changes within a species.

Human beings are no exception to biological evolution. Like other organisms around the world, humans have significantly changed overtime and have developed all sorts of diverse characteristics. One noticeable characteristic of human beings is the variation of skin
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However, like humans today, the ancestors of modern humans did not stay in one place and various groups moved to various regions of the world. Moving to new regions meant coping and adapting to a new environment.

Geographical isolation in the past has caused a variation in skin color; natural selection selected specific skin pigments depending on environmental factors. Early humans who moved to Europe were introduced to a place that had less sunlight than their former place of residence. Overtime, light skin (skin with lower levels of melanin) was selected for since there were not as many UV rays that the skin needed protection from. But, what was wrong with having dark skin in Europe? How is extra melanin a disadvantage in this case? One thing to remember is that even though the sun can provide UV rays, sunlight is also a great source of natural vitamin D (Jablonski; Kirchweger). Vitamin D helps bones absorb calcium and is particularly essential for developing embryos in pregnant women. The adaptation for lighter skin was important because the skin needed to absorb as much sunlight as it could in order to receive optimal amounts of vitamin D (Kirchweger). However, too much vitamin D can be fatal. So as high amounts of melanin protected the skin from excessive UV rays in Africa, they also protected it from excessive vitamin D (Kirchweger).

Lighter skinned
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