In the fall of 2015, professors of Anthropology at the University of Cincinnati stood alongside students fighting against racism on campus.
"Anthropologists know there is no biological basis for race," one of their signs read, "but that racism is real."
There isn't any real reason to group people based on the shade of their skin. And yet, that doesn't mean skin color itself is meaningless. On the contrary, skin color is dynamic and its diversity is a beautiful examples of recent human evolution.
Our skin is our first line of defense against the environment, including damage from the rays of the sun. When people first emerged in Africa, where sun exposure in powerful and constant, dark skin was crucial to staying healthy. After our ancestors left the continent, however, things started to get interesting.
At northern latitudes, people had less exposure to sunlight. The darker skin tones made it harder to create vitamin D with help from the sun and caused health problems, so those with lighter tones had an advantage. Over time, lighter skin became predominant among these groups, though it left them at an increased risk of burns and skin cancer.
As human populations settled around the globe, the exposure to sunlight at various locations has shifted the body's constant balancing act between protecting against UV rays and getting enough vitamin D.
Angela Koine Flynn of TED-Ed has explained the science of skin color in an easy-to-understand way. Check it out and celebrate diversity here:
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