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Essay Melanin

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Melanin

Melanin has played a significant role in human evolution. In this paper I will discuss the importance of melanin in its role in the human biological system and how it relates to the natural selection of suitable human life according to geography and environment.

Human pigmentation is influenced by hemoglobins within blood vessels in the skin, carotene and melanins. Melanin, the basis of pigmentation, can be found in the forms of eumelanin and phaeomelanin. Eumelanin is the brown-black pigment located in the skin, hair, and eyes. Phaeomelanin is a yellow to reddish-brown pigment found in small quantities within the skin, eyes, and red hair. Because of these two pigments, to a greater or lesser degree, we have the variation …show more content…

What does influence skin color variation is the size and distribution pattern of melanosomes as well as other factors.

A major function of melanin is to act as a defensive barrier of the skin against radiation damage. Ultraviolet light between the wavelengths 280-320nm (UV-B) causes sunburn and damages the skin on nonpigmented peoples. Exposure to this degree of light causes their skin to become dry, leathery, and wrinkled in appearance similar to that associated with aging. This can be seen in Whites living in Australia and South Africa, where ultraviolet light intensity is high because of the relative latitude or closeness to the equator.

Melanin is also said to be linked with hearing. Melanocytes are present in the inner ear, the eye, and in the membrane that covers the brain and spinal cord. It has been demonstrated that melanin deposits in these areas are proportional to the amount of melanin found in the skin . These areas of the body, similar to the skin, are exposed to high-energy free radicals that can damage the surrounding cells, and thus causing a lower threshold for hearing.

Evidence shows that black people, on average, hear better than whites, and that within both races, women surpass men. A partial explanation of the differences may lie in the abundance in the inner ear of melanin pigments. Also, numerous studies have found that people with light eye colors, such as blue, green, and hazel, are more

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