What does pigmentation correlate with?

Pigmentation, particularly skin color in humans, is closely related to latitudes and levels of UVA radiation due to the adaptation of populations to their environments over thousands of years. Near the equator, where UV radiation is more intense, higher levels of melanin provide protection against the harmful effects of UV rays, such as skin cancer and folate degradation. Conversely, in regions with lower UV radiation, such as higher latitudes, lighter skin pigmentation is advantageous for the synthesis of vitamin D in conditions where sunlight is less abundant. This biological response reflects an evolutionary adaptation to varying environmental conditions, showcasing how human populations have developed differing physical traits based on their geographic locations and the corresponding levels of UV exposure.