This is part 5 of a ten part series on the myths surrounding melanin. This myth is the one suggesting skin Melanin levels are related to sunlight. Are skin melanin levels related to sunlight?
There are six different skin types. Four of them burn. If skin melanin levels were related to sunlight NO ONE WOULD BURN. That is, melanin levels would increase with increased sunlight. There are people whose skin melanin remains the same year round. There are people whose skin melanin level fluctuates with the amount of sunlight or UV Radiation.
If melanin levels are related to sunlight, everyone in the same environment would have the same level of skin melanin. So when Europeans go to say, Africa, the higher levels of sunlight would, eventually, change their skin melanin levels to match that of the rest of the people there. We know that does not happen. Even in Africa, people living in the same environment have different skin melanin levels. There are even different people in the same family in Africa with different skin melanin levels. Melanin production in skin is based on a number of factors.
α-Melanocyte Stimulating Hormone aka Alpha MSH aka Melanotan-II in sufficient levels will produce higher levels of melanin in skin.
African albinos. Yes, there are albinos in Africa. If there can be people in Africa without melanin in their skin then UV radiation must not be the reason we produce melanin. When humans first rose as a species in Africa there was no Sahara Desert. Hundreds of thousands of years ago Africa was lush forest. How did albinos come to exist? In a dense forest UV radiation was absorbed mostly by the trees and plants. Yet people with high levels of skin melanin manifested anyway. Why are albinos born in an environment with high levels of UV radiation?
The answer could be simple genetics. The genes TH, SLC24A5, SLC45A2, ASIP, TYR, and OCA2 all have an effect on melanin levels in skin, hair and eyes. The amount of sunlight does not change their effect. Our physical appearance is the result of these different genes producing our melanin levels in hair, skin and eyes. African albinos are literally proof of random chaos in the human gene pool.