Evolutionary Advantages of Straight and Curly Hair

 

Evolutionary Advantages of Straight and Curly Hair

Evolutionary Advantages of Straight and Curly Hair

Multiple theories exist as to why human beings who left Africa developed the straight hair phenotype. These include improved comfort while hunting and improved ultraviolet (UV) light absorption for vitamin D production and healthy bone development, and sexual selection. A further theory is that human hair was reduced in response to parasite infestation, wherein human nakedness is based on the principle that a hairless primate would carry fewer parasites. It may be that ability to grow long, straight, densely packed hair provides an evolutionary advantage in a cold climate and a distinct disadvantage in a hot climate, when compared to loosely packed, spongy, closely cropped hair.

Whatever the evolutionary pressure, straight hair presumably provided some biological advantage for hair health, but only in humans who had left Africa despite greater genetic diversity than in the rest of the world suggests that this phenotype has an evolutionary advantage.

This is reinforced by this phenotype existing in peoples living at the Equator who have recent Asian lineages. The current varied phenotypes of human and their hair around the world may be explained by both genetics and the adaptations that occurred after the first migrations (diaspora) of modern humans out of Africa about 90,000 years ago. Hair morphology rose from the original tiny clans, and as much as skin color, denotes our subgroup association.