On which continents are yellow, white, and black people distributed, and analyze the reasons?

Race refers to human beings who have certain genetic traits (including skin color, eye color, hair color and hairstyle) formed historically in a certain area. , height, face shape, head shape, nose shape, blood type, genetic diseases, etc.). People all over the world are usually divided into four races:

⑴Mongoloid people, also known as yellow people, have yellow skin, straight hair, flat face, flat nose, and wide nostrils;

⑵Caucasoid (Caucasoid) or white people. They have white skin, high and narrow noses, various eye colors and hair types;

⑶ Negroids, or black people, have dark skin, thick lips, wide noses, and curly hair;

⑷ Australians (Australoid), or brown people, have brown or chocolate skin, brown-black and curly hair, wide noses, and well-developed beards and body hair.

There is still no consensus on the classification of modern human races.

Race or ethnicity is a biological classification based on certain physical characteristics, rather than a cultural classification. It should be strictly distinguished from concepts such as "nation". As a biological concept, we must see the following points: First, no human race has a certain or some exclusive genes. The difference between human races is only the frequency of a certain or certain genes. . For example, the IA allele that determines blood type is more frequent in white Europeans, and the IB allele is more frequent in yellow Asians. The II allele is higher in South American Indians. But they all have three alleles: Ii, IA, and IB. Secondly, because of the existence of various intermediate types, there are no insurmountable boundaries between the various races. For example, Ethiopians and South Indians have characteristics between white and black, South Siberians and Urals have characteristics between white and yellow, and Kurilians have white and yellow characteristics. Characteristics of the three main human races: , black race. We should also note that although under certain conditions, geographical isolation and cultural isolation exist between different groups of people, these do not lead to reproductive isolation. Races are genetically "open", and different races can intermarry and produce offspring with strong vitality. Humans are a highly migratory species, and all kinds of isolation will be broken due to interactions caused by migration. It follows that any attempt at “pure” racial classification is misguided.

People usually divide human races based on physical characteristics such as skin color and nose shape. These characteristics are mainly due to adaptation to the climate. The main factors that cause skin color differences are the distribution of blood vessels and the amount of melanin in a given area of ??skin. Skin with a lot of melanin appears black, moderate color appears yellow, and very little color appears light. Melanin has the ability to absorb ultraviolet rays from sunlight. Black people living in Africa across the equator and brown people near the equator in the western Pacific have dark skin, which protects their skin from damage due to excessive ultraviolet radiation. Ultraviolet rays can stimulate the production of vitamin D. Therefore, dark skin can prevent the production of too much vitamin D, which can lead to vitamin D poisoning. On the contrary, white people originally lived in northern Europe, where the sunlight is not as strong as near the equator. The ultraviolet rays in the sun do not harm the body and can stimulate the formation of necessary vitamin D. Therefore, the skin of northern European white people has very little pigment.

The same goes for nose shape. People who live in tropical forests generally have broad nostrils. The climate here is warm and humid, and the function of the nose's warm and humid air is not very important. White people living at higher latitudes have longer, more protruding noses that help warm and moisten the air entering their lungs. The eye folds of yellow people may be related to the climate in the windy and sandy areas of central Asia; the flat face shape and half-full fat layer can protect the face from frostbite.

These racial characteristics were formed approximately during the fossil Homo sapiens stage. Due to the advancement of human material culture, most racial characteristics have long lost their adaptive significance. Today, a black man can live well in northern Europe at high latitudes. He does not need to rely on ultraviolet light in the sun to produce vitamin D, but can obtain the necessary vitamin D from food. White people can also live well near the equator with the help of clothes, hats, houses and other facilities.

The concept of race changes over time. The 18th-century naturalist Carol Linnaeus divided modern humans into seven races.

He divided the world's human races into the savage race - Ferras, the monster race - Monstrous, and the sane race - Sebiens; he further divided the sane race into European whites, Asian yellows, and African blacks. race and the American red race. Europeans, he claimed, were characterized not only by their white skin, but also by their blue eyes and muscular bodies, as well as their ability to invent and rule by law. In contrast, Africans are characterized by "dark skin, cunning, and impulsive personalities." If Linnaeus is to be believed, the different races are so different that they are literally different species; and superficial differences such as skin color are signs of more important and deeper differences in intelligence and character.

Today, no one can divide human beings as extreme as Linnaeus. But the idea that there is a biological basis for racial distinctions remains powerful. Many people still believe that there are fundamental differences between different groups of people based on race. After all, in addition to age and gender, many countries also require each citizen to indicate his/her ethnicity when registering population information.

Biologists with a deep understanding of human genetic differences disagree. Biologists carefully compared the DNA of various people. Their work shows that people are not divided into races. There are indeed many differences between various groups of people, but these differences cannot constitute the biological basis for classifying human races.

The proportion and distribution of the four major races in the world's population:

Caucasians (i.e. Caucasians) are the most populous race, accounting for 54% of the world's population. Mainly distributed in Europe, America, Australia, North Africa, West Asia, South Asia, and the Asian part of Russia.

Although China has a large population, the Mongoloid race (i.e., the yellow race) only accounts for 37% of the world’s population, mainly distributed in East Asia, Southeast Asia, and Central Asia. In addition, some ethnic groups in the Arctic (such as Eskimos) and American Indians are also yellow people.

The Negro race (i.e. black race) only accounts for 8.5% of the world's population and is mainly distributed in Africa. In addition, modern immigrants are also distributed in the Americas.

The remaining 0.5% are Australians (brown people).

There is no absolute classification of race, and there is still a lot of controversy. Some anthropologists believe that there are six major human races in the world; others believe that there are three. In short, the division of human race has not yet been determined, but the Caucasian race (i.e., the Caucasian race) is definitely the largest race in the world.