Skin color is much more difficult to determine than was previously thought, and it can depend on a different number of different genes for different people, not all of which are known.
For the study of Alicia Martin from Harvard University, about 400 representatives of the Khoisan peoples were selected. These indigenous inhabitants of Africa, Hottentots and Bushmen, never left the continent, did not mix with other Homo and still exist in isolation. This makes them a popular object in linguistics, anthropology, and genetics. For about seven years, Alicia Martin and her colleagues conducted surveys, collected samples for DNA analysis, measured height, weight and accurately assessed skin pigmentation using an OTDR.
Despite the established stereotype, the diversity of shades among the peoples of Africa is much higher than in Eurasia. Their DNA was compared with data from more than 5,000 people from other continents. The analysis showed that skin color is almost 100 percent inherited, but the genetic mechanisms of this inheritance are surprisingly complex and depend on a particular people and person. Scientists write about this in an article published by the journal Cell. They also identified several new genes that determine skin color. “Some of the genes are already known to be involved in the development of skin pigmentation, but there are many that are still unknown,” says Alicia Martin.
In Africans, pigmentation is determined by a much larger number of genes than in Europeans. Until now, scientists have not given them enough attention, which is why the whole complexity of inheriting skin color has disappeared from sight. For example, it is believed that skin pigmentation is determined by directional selection mechanisms, changing in a certain direction over time - that is, becoming generally lighter when moving from the equator to the poles. However, the Khoisan peoples are about 50 percent lighter than other local tribes, and as they move towards the equator, their pigmentation becomes only more diverse, including genetically.
Sergey Vasiliev