How have the historic levels of melanin and human population change due to migration humans that produce more melanin became more common as populations and immigrated towards the equator?
Historically, as human populations migrated towards the equator, where there is increased exposure to UV radiation, individuals with higher levels of melanin were more likely to survive and reproduce. This is because melanin provides protection against the harmful effects of UV radiation, such as skin damage and skin cancer.
As a result, populations living closer to the equator tend to have higher levels of melanin, as it offers a survival advantage in that environment. Over time, through natural selection, individuals with higher levels of melanin became more common in these populations.
Migration patterns have also played a role in the distribution of melanin levels among human populations. For example, populations that migrated out of Africa to regions with lower UV radiation levels, such as Europe and Asia, experienced a decrease in melanin production due to reduced selection pressure for protection against UV radiation. This led to populations with lighter skin tones in these regions.
Overall, the historic levels of melanin in human populations have been influenced by both environmental factors, such as UV radiation levels, and migration patterns. As populations have moved and adapted to different environments, the prevalence of melanin production has changed to better suit the local conditions.