The mysteries of the human body are different skin tones7
Hi guys!I am He Jingzhi, the founder of the Transforming Profession, dedicated to studying human behavior and promoting human growth.
In the previous article (different skin tones6), we mainly talked about the effects of vitamin D deficiency on humans, and humans "love and hate" vitamin D!Guess.
According to the usual practice, I will first answer the previous reflection (what are the other effects of vitamin D on humans).
For example, height, cardiovascular disease, hair growth, intake of other nutrients, mental development, etc. may all be affected by vitamin D.
Okay, let's move on to a new explanation.
Continued: Dragged down by chronic renal failure.
In this way, there is a more good reason to explain the black ** of Africans: the abundance of melanin not only filters out excess ultraviolet rays, thereby preventing the development of **cancer, but also prevents the synthesis of too much vitamin D.
This also seems to be able to explain the different colors in different regions
Humans who have left Africa have only been able to synthesize melanin flexibly, in order to be able to shield themselves more flexibly from the sun's ultraviolet rays.
Due to the different intensity of sunlight rays in different regions, the melanin content of local residents must also be different. After all, the right melanin means the right amount of UV light, as well as the right amount of vitamin D. According to observations and statistics, the natural distribution of the existing human skin color on Earth seems to be the best empirical evidence: the inhabitants of the equatorial regions** are dark;**Residents of zone and temperate zones have a slightly less complexion, are yellow or brown, and are prone to tanning;People in Europe and around the polar regions have lighter skin tones and distinctly white stars, because the sun is milder there. Therefore, in order to get more sunlight, people in those areas not only turn white, but also their hair has changed from black to golden, gray or silvery-white, such light-colored hair is easier for sunlight to pass through, better promote vitamin D conversion, and can even heat the head more directly to save energy.
On the other hand, Africans' curly black hair is used to keep out the sun.
Vitamin D also explains very well why women are fairer than men. Regardless of the corners of the world, women of almost all races have a whiter skin color than local men. This phenomenon has caused a lot of controversy, and it continues to be debated today.
Common sense tells people that women need to get more calcium than usual when they are pregnant and breastfeeding, not only for their own use, but also for their children, so they need more vitamin D than men, that is, they need more ultraviolet rays, so they have a reason to make ** whiter.
Further bold reasoning, after a long period of evolution, the ultimate reason for men's preference for white** women is that white** women are more able to provide more calcium to the next generation.
At this point, is the explanation of the skin color phenomenon made by the vitamin D theory convincing you?Are you satisfied?
Reflections on this issue: Do you support existing theories about vitamin D?
The only two references:
A History of Madness Human Evolution