The skin color diversity in primates over the last 20 million years showcases the adaptability of primates. The melanin levels in primate skin vary significantly based on the varying levels of UV radiation exposure in different climates. In high UV regions, darker skin evolved to protect against UV damage and folate degradation, while in areas with less sunlight, lighter skin developed to facilitate vitamin D synthesis through the skin. This adaptive trait is not static; it can change over millennia as populations move between different UV environments.