Melanin, the skin's brown pigment, is a natural sunscreen that protects tropical peoples from the many harmful effects of ultraviolet (UV) rays.
UV rays can, for example, strip away folic acid, a nutrient essential to the development of healthy fetuses.
The DNA, which dates back some 400,000 years, may belong to an unknown human ancestor, say scientists.Variations in human skin color are adaptive traits that correlate closely with geography and the sun’s ultraviolet (UV) radiation.As early humans moved into hot, open environments in search of food and water, one big challenge was keeping cool.“Therefore, the DNA match from the Leicester skeleton could equally be the result of the bones being those of someone descended in the female line from Richard’s mother, Cecily Neville, including her two daughters."It could also be those traceable from the other daughters of Cecily’s mother, Joan Beaufort, any daughters of her grandmother Katherine Swynford, and so on.
The that was favored involved an increase in the number of sweat glands on the skin while at the same time reducing the amount of body hair.