About 200,000 years ago, in Eastern Africa a Homo group started the evolution towards Homo sapiens, the modern human. About 100,000 years ago, modern humans entered South Asia and by 70,000 years ago they were present in southern China. 40,000 years ago, they entered Europe and this ancestral type was called "Cro-Magnon". About 55,000 humans from southern Asia entered Australia. But all these groups are not what we see today in China and Europe, but more related to the Australian Aborigines.
Almost 25,000 years ago, in Siberia the first humans appeared, and from here, a group that already started to evolve towards the typical Mongoloid race entered 14,000 years ago the North American prairies through Behringia. 13,000 years ago, these people reached central South America.
1. The Han Chinese form the largest ethnic group in the world, 14 % of the planet's population. Due to the cultivation of rice, the world's oldest crop, they could feed large populations, overcoming easily in number the surrounding hunter-gatherer groups. Today, the diet of over 2 billion people is based on rice.
2. Why was rice cultivation such an advantage? It allowed an earlier weaning of the children and this way women could get pregnant more rapidly (hormones that favor lactation impedes pregnancy). At the same time, for a nomad population of hunter-gatherers, having too many children at a time posed a problem and a sedentary group of farmers could not be confronted with such an issue.
Larger families meant more cultivated rice paddies and the process went on, causing a population boom. This also led to the decrease of the territory used by hunter-gatherers to achieve food. Farming societies could also support large armies and were immune to disease originated in and carried by domestic animals.
2. The Han Chinese appeared in the Tibet area (their language is related to the Tibetan) and by about 5,000 years ago started to displace other tribes from modern Eastern China, many speaking Hmong-Mien, Thai and Tibetan-related languages. In fact, even today southern China is home to various minorities from these groups, and from a historical point of view, modern western and northern China was not Chinese at all.
3. 95 % of the members of the Mongoloid race have in the back side of their incisive teeth a small and easily visible groove. Its evolutionary role (if it has any) is not known.
4. The Mongoloid race is the human group with the lowest number of sweating glands. This trait is present in 97 % of them. That's why their body scent is very weak and humans of other races have a strong and unpleasant smell for them. It is known that for the Oriental people, the European perfumes are too strong. Many say that this means they also emit low levels of pheromones, which go out of the body through the armpit's sweating glands.
5. The Chinese and many people of south-eastern Asia have are not fond of milk and alcohol. The intolerance to milk is caused by the lack in the adult stage of the enzyme lactase that breaks down the sugar lactose from milk. When it reaches the thick intestine, bacterial decomposition of the lactose induces digestive issues.
This is due to the fact that cattle and sheep growth has been ignored along the millennia by the Chinese (perhaps because in the center of their civilization, southern/eastern China, pastures are scarce), and as far as evolution goes, individuals adapted to milk consumption were not selected. In Africa, Europe and western Asia, where milk entered the human diet from 10-5,000 years ago, the lactase is active in most adults.
6. Scientists say that gendrift ("sexual preference") is the cause of the evolution in the Mongoloid type of such peculiar traits like snubbed noses or almond eyes: when people in a culture see a trait as desirable, those who do not have it will have lower possibilities of mating and have less offspring.
7. The tendency to less developed genitalia seems to be sustained in this race. A meta-analysis made in May 2007 found the smallest average penis size, in a comparison amongst many areas worldwide, in Korea.
Biologically, this could mean a lower testosterone level in men, a weaker libido, compensated by a higher immune stability (testosterone decreases immunity) and a larger lifespan. In the end, the Japanese people have the highest life expectancy on the planet. The result seems to be this: the Mongoloid race is the most common in the planet.
8. Fossils of 500,000 years old Homo erectus, a human species that lived in Africa, Europe and Asia, were found in China. Some Chinese academics argue that the Mongoloid race would have evolved from Asian H. erectus, and are not a result of migrations of ancestral H. sapiens from Africa.
Their theories are heretic and they argue that because of the skull shape, an inflexion on the lower edge of the cheekbone, the tip of the flattened noses and the incisive teeth's groove. Geneticists disagree, DNA analyses show another story, of a common origin of all Homo sapiens from Africa.
The Chinese even find an explanation why the evolution did not produce two distinct species and why the DNA reveals another story: migrating humans out of Africa produced a continuous inter-change.
9. About 8,000 years ago, all southeastern Asia (Indochina, Indonesia and Philippines) was populated by Black people very similar to Papuans of New Guinea and many tribes of southern India. This distinct race of Black Asians was replaced by the Austronesian (Malayo-Polynesian) migration of Mongoloid people that started from Taiwan. From Taiwan they entered to Philippines, than Indonesia, Indochina and all the islands of the Pacific.
The darker skin of the Mongoloid race in southeastern Asia is rather not the result of a natural selection but of the mix with the Asian Blacks (like is clearly visible in people of Indonesia or Thailand).