Dark skin is a type of human skin color that are rich in melanin pigments, especially eumelanin. The evolution of dark skin is believed to have begun around 1. In the heat of the savannas, better cooling mechanisms were required, which were achieved through the loss of body hair and development of more efficient perspiration. The loss of body hair led to the development of dark skin pigmentation, which acted as a mechanism of natural selection against folate depletion, and to a lesser extent, DNA damage. The primary factor contributing to the evolution of dark skin pigmentation was the breakdown of folate in reaction to ultraviolet radiation ; the relationship between folate breakdown induced by ultraviolet radiation and reduced fitness as a failure of normal embryogenesis and spermatogenesis led to the selection of dark skin pigmentation.
Why Skin Colours Differ
“I’m Not Sitting Next To You”: Education and Racism in Afro-Mexican Communities
Abstract: Today, the biggest concentration of Afro-Mexican communities is found in the Costa Chica region of Guerrero and Oaxaca, although their presence is also important in other areas and states of Mexico. The social, cultural, economic, and political contributions of Africans and their descendants were significant during the colonial period throughout the territory known today as Mexico. Still, historic processes of racism and discrimination have led to their invisibilization and exclusion. This paper is a reflection on racism in schools of Afro-Mexican communities in the Costa Chica region. It presents an analysis of interactions between students, showing how bullying reproduces racism in school, as well as the role of teachers in this process, with some confronting the problem and collaborating to eradicate it and others reproducing racist ideas and discriminatory practices.
Why do some people have dark skin while others have light-coloured skin? The answer lies in the skin's need for protection against solar radiation and the body's need for vitamin D. The skin is our body's wrapping, visible to everyone. Evolution has given us shades of skin colour from black to white, optimally adapted for us according to where we live on Earth.
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