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This is an accepted version of this page This is the latest accepted revision, reviewed on 28 January 2025. "Skin pigmentation" redirects here. For animal skin pigmentation, see Biological pigment. Extended Coloured family from South Africa showing some spectrum of human skin coloration Human skin color ranges from the darkest brown to the lightest hues. Differences in skin color among ...
It is an autosomal recessive disorder characterized by a congenital reduction or absence of melanin pigment in the skin, hair, and eyes. The estimated frequency of OCA2 among African-Americans is 1 in 10,000, which contrasts with a frequency of 1 in 36,000 in white Americans. [ 55 ]
Pigmentation is used in signalling between animals, such as in courtship and reproductive behavior. For example, some cephalopods use their chromatophores to communicate. The photopigment rhodopsin intercepts light as the first step in the perception of light. Skin pigments such as melanin may protect tissues from sunburn by ultraviolet radiation.
The pigment-producing cells that contribute to the yellow spots of some sub-species are called xanthophores. [30] It appears that the fully-black phenotypes do not ever develop these xanthophores. [31] Alpine salamanders produce a toxin from their skin, and both fully melanistic, black salamanders and spotted individuals produce the compound. [32]
Genetics, sun exposure, and some drugs are the three main factors that contribute to skin pigmentation. [4] The most frequent cause of low melanin concentration (hypopigmentation) is prior skin trauma, which includes skin lesions including blisters, burns, infections, exposure to chemicals, and other wounds. The skin will appear paler than the ...
Pigmentation including tanning is under hormonal control, including the MSH and ACTH peptides that are produced from the precursor proopiomelanocortin. Vitiligo is a skin disease where people lack melanin in certain areas in the skin. People with oculocutaneous albinism typically have a very low level of melanin production.
Skin pigmentation in humans evolved to primarily regulate the amount of ultraviolet radiation (UVR) penetrating the skin, controlling its biochemical effects. [20] The actual skin colour of different humans is affected by many substances, although the single most important substance determining human skin colour is the pigment melanin.
A woman with dark skin. Dark skin is a type of human skin color that is rich in melanin pigments. [1] [2] [3] People with dark skin are often referred to as black people, [4] although this usage can be ambiguous in some countries where it is also used to specifically refer to different ethnic groups or populations.