Human skin color is primarily due to the presence of melanin in the skin. Skin color ranges from almost black to white with a pinkish tinge due to blood vessels underneath. Variation in natural skin color is mainly due to genetics, although the evolutionary causes are not completely certain. According to scientific studies, natural human skin color diversity within populations is highest in Sub-Saharan African populations, with skin reflectance values ranging from 19 to 46 (med. 31) compared with European and East Asian populations which have skin reflectance values of 62 to 69 and 50 to 59 respectively. The term "range" is loosely defined in this case, as African albinos have obviously not been taken into consideration when calculating the "range".
The natural skin color can be darkened as a result of tanning due to exposure to sunlight. The leading theory is that skin color adapts to intense sunlight irradiation to provide partial protection against the ultraviolet fraction which produces damage and thus mutations in the DNA of the skin cells. Other factors that can modify skin color include protection from ambient temperature, infections, skin cancer or frostbite, an alteration in food, and sexual selection.
The social significance of differences in skin color has varied across cultures and over time, as demonstrated with regard to social status and racism.
... According to classical scholar Frank Snowden, skin color did not determine social status in ancient Egypt, Greece or Rome ... as more significant in a person's status than was their skin color ... The preferred skin tone varies by culture and has varied over time ...
... the tiny muscles that are contracting are causing a "bunching" of the skin surrounding the hairs, which results in the "bumps" in goosebumps ... body's way of preserving its own heat by causing the hairs on the skin to stand up, thus reducing heat loss ... As the perspiration accumulates on the skin, it naturally evaporates ...
... scab") is a slough or piece of dead tissue that is cast off from the surface of the skin, particularly after a burn injury, but also seen in gangrene, ulcer, fungal ... A newly identified human rickettsial infection, R ... if a skin graft is to be conducted) ...
... Look up skin in Wiktionary, the free dictionary. ...
... In computing, a skin is a custom graphical appearance achieved by the use of a graphical user interface (GUI) that can be applied to specific software and websites to suit the purpose ... A skin may be associated with themes ... Software that is capable of having a skin applied is referred to as being skinnable, and the process of writing or applying such a skin is known as skinning ...
Famous quotes containing the words human and/or skin:
“In great misfortunes, he told himself, people want to be alone. They have a right to be. And the misfortunes that occur within one are the greatest. Surely the saddest thing in the world is falling out of loveif once one has ever fallen in.
Falling out, for him, seemed to mean falling out of all domestic and social relations, out of his place in the human family, indeed.”
—Willa Cather (18731947)
“Ive been opened and undressed.
I have no arms or legs.
Im all one skin like a fish.
Im no more a woman
than Christ was a man.”
—Anne Sexton (19281974)