Scientists say there are more than 30 different skin colors. The colors range from almost black to pinkish white. Sunlight caused this variety.
Long ago, our ancestors lived in Africa and had a few shades of dark skin. Dark skin protects best against sunburn in tropical heat. It also helps protect against skin cancer, which is dangerous changes in skin cells. Skin cancer is usually caused by getting too much of the sun’s ultraviolet light.
Then, about 100,000 years ago, some people left Africa for other continents. In places with little sunlight, lighter skin color evolved. Darker skin was no longer necessary to protect against ultraviolet light. Light skin lets more sunlight through. This allows more production of vitamin D, which we need for calcium absorption and bone growth.