Our world is a wonderfully diverse and beautiful place, with millions of species of animals and plants, capped off by the most dominant species – human beings. We consider the human race that is spread across the globe as members of a single species, Homo sapiens, but we certainly don’t all look the same. From language, culture and clothing to height, eye shape and hair color, human beings have many things that make us unique from one another.
However, if we all belong to the same species, shouldn’t our basic skin color be the same? Why are some people fair and others dark?
To start with, variety is the spice of our life, such as variety in food, colours, from white to yellow and to black. Our living environment accounts for the different skin colours we have.
What is Melanin?
Our skin color is determined by a pigment called melanin, and while everyone has melanin (both fair and dark-skinned people), it comes in different forms and ratios. The two forms of melanin are called EUMELANIN and PHEOMELANIN.
Eumelanin comes in primarily brown and black hues, while pheomelanin appears as red and yellow hues. It is produced by a specialized group of cells called MELANOCYTES.
How does it affect our Skin Colour?
Before we can find out why we have different skin colors, we should first understand the basic science behind our skin. First of all, there is no such thing as “black”, “white”, “red”, or “yellow” in terms of skin color. There are simply mixtures of colors and variations, depending on your genetic makeup.
For example, someone with very dark skin would primarily produce eumelanin, while pale-skinned Europeans might produce a majority of pheomelanin. PERHAPS MORE IMPORTANTLY, THE SIZE AND NUMBER OF MELANIN PARTICLES IS ALSO A FACTOR IN DETERMINING SKIN COLOR.
Melanin is produced in specialized cells called melanocytes, but these do not behave the same way for all people. Some people naturally produce less melanin, which means less pigment and lighter skin. Other people possess fewer melanocytes than normal, which also results in less overall pigment and lighter skin. Clumps of melanocytes in fair-skinned people often appear as freckles, while areas lacking freckles will usually be extremely light. People can temporarily change the color of their skin by tanning (or getting sunburnt), which essentially stimulates the production of melanin and inflames the area to protect against adverse UV exposure. So you can see the darkening of the skin under certain conditions like exposure is a God given mechanism of the skin to protect us from the dangerous ultraviolent UV rays of the sun. Melanin is the best form of sun protection that ever existed.
Skin lightening agents work primarily by preventing melanin production so the natural protection against UV rays and other insults is lost…….FOOD FOR THOUGHTm
FACTORS WHICH AFFECT MELANIN PRODUCTION
Exposure to UV radiation: Melanin is produced as a response to UV radiation in order to prevent damage to the DNA in the integument. Individuals, who are exposed to UV light, such as the sun, will produce more melanin for protection. Little wonder when we migrate to the sunny North in Africa, we get darker.
Genetic makeup: Different ethnicities and cultures are genetically pre-disposed to producing particular shades and amounts of melanin due to inheritance. This is, essentially, one of the primary indicators used in determining race in the human population. It is important to note that this is, and has historically been, a controversial form of human identification.
Size of melanocytes: Melanocyte size varies in different individuals and may lead to a difference in the amount of melanin produced per cell.
Disease conditions: Several diseases may affect melanin production, including albinism, a genetic inability to produce melanin, and vitiligo, a progressive loss of melanocytes.
Others include Irritants, pregnancy, pollution, stress etc.