Skin Deep: Nina Jablonski\'s Theory of Race (video summary) PDF

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summary on the video called "Skin Deep: Nina Jablonski's Theory of Race" . Video focues on the evolution of skin color ...

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Skin Deep: Video Summary In this video, Professor Nina Jablonski sets out to discover the reason why human skin variation exists and how skin color evolved. This video begins by explaining that melanin is a biomolecule that exists in every human and the amount varies for everyone. The amount of eumelanin and pheomelanin helps determine the shade of skin color. But it also serves as a protection from the UV rays of the sun. In Africa it is notable that the climate is hot and dry and that the population is dark skinned. But millions of years ago, our earliest ancestors that lived in a green Africa had light skin and body hair. Thus, humans had to adapt to this new environment by losing body hair and developing dark pigmentation to protect the skin from the sun. It is important to note that UVB and UVA wavelengths affect human skin. Because UVA penetrates more into the skin and to the bloodstream, this was a cause of birth defects. To add on, folate is a water-soluble vitamin that is important for the reproduction of DNA but exposure to intense UV radiation can destroy folate. Folate is especially important for men because it makes healthy sperm and so that is why folate is added in bread, in countries with intense UV radiations and light skinned populations. But despite the negative affects of UV rays, it is required for producing vitamin D. This caused light skin to evolve to allow UVB radiation make vitamin D. On the other hand, dark skin evolved to block UVA. But our skin can respond to biological needs. For example, an African baby was lighter than his parents because he required vitamin D from UV radiation. Nowadays many people are not in sync with the appropriate UV radiation their body requires and this could lead to health problems. In conclusion, despite the different skin colors, only 50 genes contribute to skin color. As a result, people are genetically almost identical and even though we have different labels, we all have the same ancestry....