The historic levels of melanin in human populations have changed due to migration by mixing of populations with different levels of melanin. As humans migrated to different regions of the world with different levels of UV exposure, the adaptation to the local environment led to changes in the levels of melanin in the population. For example, populations living in regions with higher UV exposure developed higher levels of melanin to protect against sun damage, while populations living in regions with lower UV exposure developed lower levels of melanin to allow for greater absorption of vitamin D. This has resulted in a range of skin colors and levels of melanin in human populations around the world.
