Saturday, October 8, 2016

Study: Europeans better adapted to cold climates, Africans better adapted to hot climates


Caucasians are evolutionarily adapted to cold climates, Africans not.  Source: Wikimedia


Daanen and Van Marten Lichtenbelt report that Europeans differ markedly from other populations in heritable adaptations to cold climates, whereas Africans have marked physiological adaptations to hot climates.

People who have black skin such as Africans have more sweat glands than people with white skin who are native to northern climates.
Thus Africans are better adapted to hot climates, as evolutionary theory predicts.

When exposed to cold air temperature of 17 ℃, Caucasians and Eskimos display a rise in metabolism more than double that of Africans:

Compared to Africans, Caucasians and Eskimos have higher basal metabolic rates producing more heat, making Africans better adapted to hot climates and Caucasians and Eskimos to cold climates.
As an aside, the lower average metabolic rate of Africans makes them more susceptible to obesity in an environment full of high energy density foods.  Put otherwise, Caucasians are probably adapted to a diet having a higher energy density than would have been possible in Africa, while Africans are probably adapted to a diet having a lower energy density than would have been possible in Europe.

Africans have better heat loss capacities than Caucasians, while Caucasians and circumpolar peoples have better heat generating and cold tolerance capacities.  


Africans have slower and reduced cold-induced vasodilation compared to Caucasians:

It seems there exist substantial physiological differences between races and these differences arose as specific adaptations to ancestral habitats

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