Although many animals have a coat of hair, none of them have hairs that take the form of curls – except for humans. This is a by-product of our intelligence, for among all the hairy creatures, only humans have two critical factors associated with it. First, we have a large volume of the brain, vulnerable to overheating. Secondly, due to upright posture, it is the cranium that receives the greatest amount of solar heat, and therefore is prone to overheating.
Experiments by scientists from the University of Pennsylvania on mannequins with sensors have convincingly proved that it is the curly hair structure that is most effective for cooling the head. The complex structure of the hair in the composition of the curls creates a large number of air pockets that form a kind of thermal filter around the head. And it is no coincidence that hard, but curly hair is a characteristic feature of the peoples of hot Africa, where all of humanity came from.
Animal wool in its mass is designed to keep warm and protect the skin from various negative factors. In humans, on the other hand, hair serves as a protection against overheating, since, from the point of view of evolution, our species originated and lived almost all the time in a very warm climate. If hair is removed, a person begins to sweat much more to cool the body, but this leads to catastrophic dehydration, so this mutation did not take root. As people settled in areas with a different climate, people began to change, but too little time had passed for these changes to be fixed in our genotype.
