The dark pigmentation protects from DNA damage and absorbs the right amounts of UV radiation needed by the body, as well as protects against foliate depletion. Foliate is water soluble vitamin B complex which naturally occurs in green, leafy vegetables, whole grains, and citrus fruits. Foliate is needed for normal sperm production in men. Furthermore, foliate is essential for fetal growth, organ development, and neural tube development. Foliate breaks down in high intense UVR. Dark-skinned women suffer the lowest level of neural tube defects.
Dark skin is primarily influenced by the production and distribution of eumelanin, a dark pigment, by melanocytes. Tyrosinase, an enzyme crucial for melanin synthesis, plays a key role in this process. According to research, individuals with dark skin have higher levels of active tyrosinase, resulting in increased production of eumelanin [1].
Light skin, on the other hand, is characterized by reduced levels of eumelanin and higher levels of pheomelanin, a lighter pigment. This is attributed to lower tyrosinase activity, leading to decreased eumelanin production. Pheomelanin is less effective at protecting against UV radiation, hence individuals with light skin are more susceptible to sun damage [2].
Albinism is a genetic condition caused by various mutations that affect the genes involved in melanin production, including the tyrosinase gene. It is associated with high levels of tyrosinase inhibitors. These mutations can lead to a partial or complete absence of melanin, resulting in little to no pigmentation in the skin, hair, and eyes [3].
Albinos are therefore not the ancestors of white people. Having high levels of tyrosinase inhibitors produces the light skin tone but the cause of albinoism is different to the reason for other “white” skin tones.
Determining the exact timeline of when white skin first emerged is challenging due to limited scientific evidence. The emergence of lighter skin tones is believed to have occurred gradually over tens of thousands of years as human populations migrated and settled in different regions. It is estimated that white skin pigmentation began to emerge in Central Europe around 8,000 to 6,000 BCE. The spread of lighter skin to Western Europe, the Middle East, and North Africa likely followed, but the specific timing and extent of this process can vary based on population dynamics, migration patterns, and natural selection pressures [4].
According to specialist scientists, the knowledge of the genetics of skin tones in Africa is less mature than the knowledge of the genetics of skin tones in Europe. This is due to academics having dedicated a higher volume of research to European specimens. Scientists have found that genes which they thought are only present in “white Europeans” and which they thought were indicators of “whiteness” exist in some black Africans too. [5]
African Albinos are beautiful Africans; they are not cursed. There are also albinos in Europe, Asia such as fashion model Connie Chiu and America. It is just caused by being born with high levels of tyrosinase inhibitor.
Our black skin is not some kind of indication that we can’t govern ourselves. People need to learn facts about the world so that they don’t internalised racism.
References:
[1] Jablonski, N. G. (2004). The evolution of human skin and skin color. Annual Review of Anthropology, 33, 585-623.
[2] Rees, J. L. (2003). Genetics of hair and skin color. Annual Review of Genetics, 37, 67-90.
[3] Oetting, W. S., & King, R. A. (1999). Molecular basis of albinism: mutations and polymorphisms of pigmentation genes associated with albinism. Human Mutation, 13(2), 99-115.
[4] Beleza, S., Santos, A. M., McEvoy, B., Alves, I., Martinho, C., Cameron, E., ... & Rocha, J. (2013). The timing of pigmentation lightening in Europeans. Molecular Biology and Evolution, 30(1), 24-35.
[5] Ed Yong (2017). The Ancient Origins of Both Light and Dark Skin: A study of diverse people from Africa shows that the genetic story of our skin is more complicated than previously thought. The Atlantic Magazine. Published 12 October 2017. Last accessed 23 May 2023.
No comments:
Post a Comment