Question

Explain why different populations have similar genes: examples alleles that code for light skin color in European populations also exist within African populations why?

Answer 1

From the discovery of HGT (human genome project) it was predicted that humans have around 20 thousand to 25 thousand genes. Every individual carries two copies of both genes, one hereditary from each of their parent. Most of the genes are similar in all individuals, but a very small amount of genes approximately less than 1 percent of the total genes are somewhat different among individuals.

The MC1R (melanocortin 1 receptor) gene is responsible for the color of the skin. It provides instructions for the production of a protein known as MC1R. This receptor plays a significant role in normal skin pigmentation. This receptor is primarily to be found on the melanocytes surface, which are the specific cells that lead to the production of a pigment named melanin. The pigmentation of the skin is the result of genetics. The end product of both of the genetic makeup of the parents and exposure to the sun results in different skin color or pigmentation.

The geographic supply of UVR (ultraviolet radiation) and the sharing of native skin pigmentation in the region has a direct connection between them. The region that receives high amounts of UVR is generally situated nearer to the equator region and be likely to have a darker-skinned color or pigmentation populations, whereas the regions that are distant from the tropics and nearer to the poles will receive low-intensity UVR, which results in the lighter-skinned color or pigmentation populations.

The MC1R gene is mainly responsible for determining whether eumelanin and pheomelanin and are expressed in the human body. The high UV exposure results in the expression of eumelanin (darker skin color) in the African population and low exposure to UV result in the expression of pheomelanin (lighter skin color) in the European population.