Here's a strange fact I recently found out:
"Scientists have long known that Africa is the cradle of human civilization​. There, our ancestors shed most of their body hair around 2 million years ago, and their dark skin protected them from skin cancer and other harmful effects of UV radiation. When humans began leaving Africa 20,000 to 50,000 years ago, a skin-whitening mutation appeared randomly in a sole individual, according to a 2005 Penn State study. That mutation proved advantageous as humans moved into Europe. Why? Because it allowed the migrants increased access to vitamin D, which is crucial to absorbing calcium and keeping bones strong. "