Why do humans lose hair? But the hair and private parts are still there, why?

Introduction: Now people say that humans are hairless is not a correct statement. It is said that the density of hair and the number of hair follicles in our body alone, the hair of our body should be almost the same as that of chimpanzees, but our hair is relatively Soft hair, not the relatively hard hair of chimpanzees, and the function of our fine hair is different from that of chimpanzee hair. Human hair is used to regulate the body temperature, however many hairy Animals do not have this function. For example, puppies use their tongues to dissipate heat, not through the long hair on their bodies.

Except for humans, all primates are covered with hair, so humans can be said to be a "naked ape". Why do humans lose their hair genes in the process of development? And why does hair still exist in hair and private parts after the gene is lost? This problem has puzzled many biologists for many years, and there has been no reasonable explanation, only a few guesses.

The effects of sexual selection

I don't know if you have heard of Darwin's book "The Origin of Human Beings and Sexual Selection". In this book, the reason for human hair is caused by "sexual selection".

Just think, is the disappearance of hair a disadvantage? Because the disappearance of hair will make us lose the function of keeping warm, and our skin will also be exposed to the sun, and will also suffer a lot of unavoidable damage, why human hair is obviously a favorable factor, but it is eliminated by natural selection? ? This is a difficult question to understand.

In the history of biological evolution, one has lost the other. While we have acquired some excellent traits, we will lose some secondary traits. For example, after we humans have unlocked upright walking, our hands are more spare, and we can complete some other animals. The impossible operation also promotes the development of the human brain, which is one reason why human civilization can rise. But walking upright also has many bad effects. For example, walking upright will increase the burden on our body, which will lead to diseases of the lumbar spine to a certain extent. At the same time, walking upright also makes it more difficult to produce.

Evidence for Darwin's point is that women tend to have much less hair than men, so Darwin proposed that it was sexual selection that led to the gradual loss of hair in humans.

Conclusion: It may be said that this question will never be answered, but the hair in key parts of our human body is still preserved, which to a certain extent shows that human hair does have a protective effect. Causes hair loss in humans.