When We Met Other Human Species

WHAT DOES CLIMATE CHANGE HAVE TO DO WITH MELANIN? Heat is not the issue except in regards to studies showing caucasians and non melanated populations have lower birth rates and shorter life expectancies in tropic climes.—The real issue is the ability of the skin to absorb sunlight and vitamin D while blocking out solar radiation more likely to lead to cancer and photolysis or reduced sperm production and healthy female reproductive organs. And the operative event is natural selection—people whose skin color is more amenable to local climate will produce more offspring that survive this is because melanin is the protective factor specifically Eumelanin in black and brown people that guards against high UV radiation which is invisible thus the UV index meter/reader or app on all cell phones. The evidence is that all homo sapiens were dark skinned initially, and that lighter skin provided advantages as archaic human (specifically neanderthal) early populations moved North into climates where sunlight and fertile nutrient rich vegetation was not a constant.The UV in sunlight is independent of the air or water temperature.

Melanin on skin blocks near UV, affecting the nutritional balance. Near UV on skin produces vitamin D. The same UV on skin destroys folate, The deficiencies in the two vitamins can be lethal. Deficiency of vitamin D causes rickets, a bone disease that especially kills young women in childbirth. Folate deficiency causes neural tube defects in newborns and causes miscarriages.So  basically temperature change although being a significant problem in agriculture and availability of crops as well as animal extinction will not be the catalyst for demographic of phenotype changes rather it will be the UV radiation levels in climate change and sea level rises that will affect all continents more adversely than Africa.Beauty is a social construct, not purely a biological one, but one based in searching for the most advantageous qualities for survival as the climate warms the subconscious realization that dark skin is key to survival will cause the zeitgeist of humanity to seek out darker skinned partners. Regardless of social and political constructs like white supremacy the need for survival with supersede the current accepted social dynamics of preference towards lighter skin in all cultures.Those who adhere to the previous archetype of preferred caucasian phenotypes will do so at the risk of the survival of their progeny and soon disappear.