The genetic basis for skin color has finally been identified

This is interesting news due to it's social implications. In a recent article they have announced the result of an experiment which has identified the genetic basis for skin color. While it is not widely known, there is a lot of skin tone diversity among Africans scaling from pale "white" skin to the darkest "black" skin. On most continents the skin tones aren't quite as diverse as Africa and scientists wanted to determine why different groups of African people have vastly different skin tones.

By David Berkowitz from New York, NY, USA [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons

In Africa, Nilo-Saharan Africans have amongst the darkest skin tones in humans. On the other hand the Berbers also in Africa in some cases have some of the lightest skin (commonly associated with Europeans) as well as some of the darker skin tones. So we can see that in Africa the whole palate of skin tones are represented.

Through analysis researchers have discovered where light skin came from and how it arrived in Africa:

The region with the strongest associations was in and around the SLC24A5 gene, one variant of which is known to play a role in light skin color in European and some southern Asian populations and is believed to have arisen more than 30,000 years ago. This variant was common in populations in Ethiopia and Tanzania that were known to have ancestry from southeast Asia and the Middle East, suggesting it was carried into Africa from those regions and, based on its frequency, may have been positively selected.

Another region, which contains the MFSD12 gene, had the second strongest association to skin pigmentation. This gene is expressed at low levels in depigmented skin in individuals with vitiligo, a condition where the skin loses pigment in some areas.

The team found that mutations in and around this gene that were associated with dark pigmentation were present at high frequencies in populations of Nilo-Saharan ancestry, who tend to have very dark skin, as well as across sub-Saharan populations, except the San, who tend to have lighter skin. They also identified these variants, as well as others associated with dark skin pigmentation, in South Asian Indian and Australo-Melanesian populations, who tend to have the darkest skin coloration outside of Africa.

"The origin of traits such as hair texture, skin color and stature, which are shared between some indigenous populations in Melanesia and Australia and some sub-Saharan Africans, has long been a mystery." Tishkoff said. "Some have argued it's because of convergent evolution, that they independently evolved these mutations, but our study finds that, at genes associated with skin color, they have the identical variants associated with dark skin as Africans.

So they found that darker skinnied people are genetically linked even when on different continents. How the genes moved to these different continents are unknown but it is now a fact that it is the same gene. Something even more strange is that the most ancient lineage in Africa has the gene for lighter skin:

Also of interest was that genetic variants at MFSD12, OCA2, and HERC2 associated with light skin pigmentation were at highest frequency in the African San population, which has the oldest genetic lineages in the world, as well as in Europeans.

So the light skin genes are among the oldest African genes. It is possible the light and dark skin genes came from Africa and spread to Europe and other locations.

Choose your benefits and adapt to the skin you have

Both light and dark skin pigmentations confer benefits: Darker skin, for example, is believed to help prevent some of the negative impacts of ultraviolet light exposure, while lighter skin is better able to promote synthesis of vitamin D in regions with low ultraviolet light exposure.

So it would appear if you are born with very dark or very light skin you are genetically lucky in the natural sense. The sun will not harm you as much if you are born with very dark skin and if you are born with very light skin you wont have to worry about vitamin D deficiency as much. On a social level because of pseudo-science concepts like "race" we have taken what may have been a natural genetic advantage and adaptation and turned it into something political to fight over. The truth seems to be in the genetics and the more we learn about genetics the more we understand humanity and ourselves (without political distortion).

If you liked this article feel free to comment. If you are an African then please share your knowledge if you have any on these topics.

References

University of Pennsylvania. (2017, October 12). Genes responsible for diversity of human skin colors identified. ScienceDaily. Retrieved October 13, 2017 from www.sciencedaily.com/releases/2017/10/171012143324.htm