How correlated are pigmentation and climate?

[cyberlorian]

For example, yesterday, I have thought that French are usually darker than Bosnians because France is usually warmer than Bosnia. How correlated are pigmentation and climate?

[manu15151513]

They tend to be correlated, given that often the inhabitants of a nation having a certain climate derive from populations that have been present in those areas for thousands of years, and that over time have been subject to biological adaptations that have also involved the variants allelic determinants the color of the complexion.
I doubt that there is perfect parallelism between the color of the skin and the specific climatic conditions of the environment in which the individuals considered live, but surely there is a correlation.
Southern Italians have a slightly darker complexion than northern Italians, but it does not seem very reasonable to believe that it is due to changes in the allelic frequencies induced by the peculiar environmental conditions of southern Italy.
It seems less misleading to believe that it is due to their proximity to today's Mediterranean populations, which in turn derive largely from Middle Eastern populations, who have acquired a relatively dark skin thanks to gene flows and gene mutations favored by natural selection.
I maintain that it is right to believe that southern Italians have a darker complexion, on average, than their northern compatriots, because of the notable quantity of single nucleotide polymorphisms that they have in common with Middle Eastern peoples, and among these are also included gene variants not considered by genetic calculators that play a role in determining skin color.




You must not think this way, think of the biological adaptations to which the ancestral populations from which they derive may have been subjected, and when the modern peoples considered by the aforementioned derive.