Why Do Humans Have Different Skin Colors?

colors? The answer starts with sunlight, and with two vitamins. This video follows the science: why our early ancestors lost their fur and exposed their skin to the sun, how sunlight destroys folate, a vitamin needed for healthy pregnancies, and how vitamin D, which keeps bones strong, pulled evolution in the opposite direction far from the equator. You'll see the evidence behind it: the 1978 research on folate, the 2000 study by Nina Jablonski and George Chaplin that matched skin color to satellite measurements of ultraviolet light in more than 50 countries, and the exceptions that prove the rule, the Inuit and Tibetans. You'll also see the 2017 genetic study led by Sarah Tishkoff, which found that many gene variants for lighter and darker skin are hundreds of thousands of years old and were already in Africa. Cheddar Man, a hunter who lived in Britain about 10,000 years ago, had dark skin and blue eyes. Pale skin in Europe spread much later, with early farmers. Skin color is one of the most visible differences between people, and one of the shallowest. This is the story of one species adapting to the sun above it.