Humans obtain their skin color from a pigment called melanin, which is synthesized from Melanocyte cells. These cells come from melanoblasts that number from 800 to 2000 per cubic millimeter. However, the greatest number of melanoblasts are found in the mucous membranes of the face, penis and extremities (nose, ears, hands, fingers, feet, toes). Every culture (whether the race has light or dark skin) has pigments or melanin in their cells.
Melanocytes create melanin. The melanin is produced by the amino acid tyrosine, which comes from the enzyme tyrosinase
. Exposure to the sun or ultraviolet rays
increases the production of the melanocytes. That is what leads to the production of melanin, which is why Africans
have dark to black skin (more exposure to the sun) and Caucasians skin is very light (less exposure to the sun). Caucasians have melanin and thus under certain conditions will get darker, such as tanning.
In other words, skin color is determinant, not on whether a culture has pigment or melanin, but by the amount of pigment the melanocytes produce and disperse via the amount of exposure to ultraviolet rays.
If an individual produces absolutely no melanin, then that person will be an albino (they cannot tan). If the melanin is abundant, the skin will be dark. If parts of the body lose melanin altogether, the individual will have what is known as vitiligo. With hyper-pigmentation, too much melanin is produced in patches or spots on the skin.
Written by Erica Ruth
Photograph by Erica Ruth