Why are westerners all white and we are all yellow?

Because when God created man, he put the first clay figurine in a boiler and burned it. Later, due to inexperience, it became black.

Burning the second one, because I learned the last lesson and didn't burn enough, turned out to be white, so both of them are stupid.

I was very careful when I burned the third person. As a result, I burned into a yellow person, so the yellow person is very smart! We are the best race, yellow race!

These are all jokes!

Black, yellow and white are the three primary colors of the human body. However, after tens of thousands of years of evolution, it now emits colorful light. Scientific investigation has confirmed that there are 60 different races on the earth today. In order to accurately divide the skin color of races, it is necessary to understand the law of skin color formation and uncover the mystery of skin color formation. A person's skin color is related to many factors, such as skin refraction, capillary distribution, blood flow and so on. But the most important thing is the pigment in the skin. Pigment is located on the pigment cells at the base of human epidermis. Under the microscope, pigments are tiny brown particles. The more and denser the pigment distribution, the darker and heavier the skin color will be; On the contrary, the less and thinner the pigment distribution, the whiter and lighter the skin color will be. According to statistics, the number of pigment cells in different skin colors is different. Within 1mm2, white people have about 1000 pigment cells, yellow people have about 1300 pigment cells, and black people have about 1400 pigment cells.

People's skin color has a stable heredity, and the skin has a certain primary color at birth. Even if the skin is exposed to the sun for a period of time, the pigment will increase, or the blood flow will increase because of blood vessel dilation, which will make the skin turn black and red, but it will still recover its original characteristics after a period of time. It can be seen that human skin color is controlled by genetic material and has a stable genetic basis. At present, it is difficult to draw a clear conclusion about the genetic factors that control skin color, but the biochemical process of pigment production has been clear. The formation of pigment is mainly related to a protease called tyrosinase. Under its action, intracellular tyrosine can be converted into pigment components. Without this enzyme, pigment cells will lose their function and cannot produce pigment substances. If a person lacks the genetic factor produced by this enzyme in the genetic material obtained from both parents, he will suffer from pigment deficiency, that is, albinism. Due to congenital lack of pigment, the patient's skin and hair are white and his eyes are red because there is no pigment covering. According to the clinical statistics of genetics, one hereditary patient in about 20,000 newborns suffers from this albinism.

The role of pigment is to participate in protecting the skin. Pigment determines the color and hiding power of skin. It can prevent too much sunlight and ultraviolet rays from harming the body and prevent too much infrared radiation from reaching the deep part of the body. Therefore, the skin color of the human body is controlled by the internal genetic material, and at the same time it is also subject to the pressure and choice of the external sunlight. In tropical areas with strong sunshine, blacks with heavy pigments are more adaptable than whites with less pigments. Under intense photothermal radiation, white people have a higher risk of skin cancer. On the contrary, if dark skin color is a disadvantage in the cold north of the earth, relevant data prove that blacks are more likely to get frostbite than whites on the Korean battlefield. It can be seen that the change and distribution of skin color depth are related to the choice of external environment, and the production and activation of pigments are often inseparable from the stimulation and induction of the environment. For example, ultraviolet rays in sunlight are invisible short-wave rays, which can kill tiny cells in the human body, promote the production of vitamin D in the human body, and make alcohol substances (such as ergot, etc.) in the human body. ) under the action of ultraviolet energy, it can be converted into vitamin D, which can promote the absorption of calcium and phosphorus by human bone tissue, thus hardening bone development. If the lack of necessary ultraviolet radiation affects the production of vitamin D, it will lead to rickets and rickets. Therefore, in most parts of Europe that are often cloudy and cloudy, white people with lighter skin color are also a favorable adaptive feature. They can absorb enough ultraviolet rays from the sun to reduce the occurrence of diseases. When babies grow up, doctors often tell them to get more sunshine.

The change of human skin color depends on the change of pigment content in skin, and the change of pigment content is the result of long-term adaptation to external light intensity. It can be said that a person's skin color is the brand left by nature on the human body. On the earth, the changing trend of skin color distribution of different races and human pigment depth basically corresponds to the intensity of sunlight radiation. People with more pigments and darker skin are mostly concentrated near the equator of the sunny earth. As the latitude of the earth goes on, the farther away from the equator, the weaker the sunlight and the lighter the skin color of the human body. In Asia, South Asians are darker than North Asians; In Europe, too, southern Europeans are darker than northern Europeans.

In the early stage of human development, people lived in one place for a long time, influenced by the environment, passed down from generation to generation, and their bodies gradually formed the characteristics of adapting to the environment. The farther south, the darker the skin color. Near the tropical equator, people who are exposed to direct sunlight for a long time in a year have strong illumination, high temperature, strong ultraviolet rays and high melanin content in their skin, which can absorb ultraviolet rays from the sun and protect their skin; The nose is low and wide, the nostril passage is short, and the body hair is less, which is convenient for heat dissipation; Hair curls, air fills the gaps in the hair, forming a heat insulation layer, which plays a role in protecting the head. It is called men in black.

White people are mostly distributed in northern cold regions or temperate high latitude cold regions. The sun is oblique, the light is weak, the temperature is low and the ultraviolet rays are weak in this area. The local residents have low melanin content and light skin color. The nose is high and narrow, and the nostril passage is long, which can make cold air slowly enter the lungs; Thick body hair can prevent cold, and so on. The yellow race is between the two, mostly distributed in temperate zone, mainly distributed in Asia with mild climate, so the skin color and physical characteristics have the transitional characteristics of the above two races.

The history of recent hundreds of years has proved that the mixture of the above three major races can be stable in a certain area for a long time, and new races can also be produced. For example, African Americans, whose ancestors came from Africa, have long been mixed with white Americans who went to Europe. At present, there are more than 20% white genetic factors among African-Americans, so they are obviously different from African-Americans in physique and constitute a new race. In Brazil, it is a mixture of Indians, Spaniards, Portuguese, Japanese and China. After a long period of time, a new race-mixed race has also formed.

The national characteristics of China people have largely adapted to the geographical environment in the middle latitudes of East Asia. Their average height and skin color are in line with the mid-latitude sunshine and temperature. "Mongolian eyes" and nose collapse may be related to the cold and windy climate in Central Asia. However, the ethnic composition of China people is not single. The inhabitants of Dawenkou culture in the lower reaches of the Yellow River may have Polynesian elements, while Hemudu culture and some human bone fossils found in Guangdong have obvious Australian and nigro elements. The human skulls found in Yin Ruins of Shang Dynasty also contain people of several different races. Because, before the Stone Age, human beings were in a long-term large-scale migration. Only when mankind has entered the historical era and formed a regional nation, the sighing life is relatively stable. Therefore, in the process of the Chinese nation and Chinese civilization forming an independent whole, there are always many elements that need to be integrated, and even after the formation of the Chinese nation, new elements are constantly being absorbed.