Various as human hair, although it is made of the same components, it can still come in many textures and sizes. As we see, hair can be straight, wavy straight, wavy, wavy curly, very curly and kinky. People predominately from Africa have kinky hair, while European and Asian people’s hair is normally straight or wavy straight. The kinky hair can be mostly found in Africa, and most of them have very curly hair and dark skin. What’s so puzzling is that even though Africa has the greatest genetic diversity, two traits that are ubiquitous are the skin color and hair texture.
But why? Why do black people have different hair? Someone says that it is a result of weather and climate. Thousands of years ago, as people started to migrate and populate the world, they evolved and changed to adapt to their environments just like other animals. Those who moved to much colder areas need more vitamin D in their skin and don’t require much melanin so they look pale. While their hair got less kinky so it can keep warm.
However, as the equator crosses Africa, people in this mainland lived in an extremely hot climate. The denser the hair is on the top of the head, the more it protects your scalp from the sun. So when you are out gathering food or water all day, the sun won’t scorch your brain. Thus, the ancient people, because of where he was located, evolved to have extremely kinky hair to protect them from the sun’s heat. While there is a different opinion that one of the functions of hair is to insulate heat.
In fact, there are people in other places having dark skin but not curly hair. For example, the Indians can have skin colors as dark as people from Africa, but don’t have curly hair like black people. In places like Melanesia, many people have dark skin, yet a variety of hair textures. Thus, we can get a conclusion that kinky hair has no relation to skin color, but is related to the continent that is Africa or not.
Maybe you have noticed that when people with straight hair sweat, their hair tends to cling to them? In a place like Africa, the hottest continent of earth, sweating definitely helped our ancestors to cool off. However, hair texture could have possibly been an obstacle for our body’s natural way of regulating temperature. As sweat was our body’s way of cooling off, but straight hair had more of a clinging ability to the body than curly hair, straight hair would seem like a disadvantage. Maybe the natural selection basically drove out straight hair, just because it interfered with the body’s ability to cool off.
Therefore, natural selection left a population of mostly people with kinky hair, producing offspring with even more curly hair than the previous generation until everyone in that population had the same gene of kinky hair.