Due to the explanation of African nouns

Out of Africa

Regarding the origin theory of modern people, many people don't like to go out of Africa, but prefer the theory of multiple origins. But it is undeniable that the theory of going out of Africa is the mainstream theory now, and it is supported by more and more molecular biological evidence.

There are two main types of evidence:

Mitochondrial DNA (maternal inheritance only)

Y chromosome (patrilineal inheritance only)

The theory of going out of Africa holds that "modern man" in anatomical sense appeared in East Africa about 6.5438+0.5 million years ago, and then spread all over the world. Molecular biological evidence shows that the successful migration from Africa occurred about 55,000-85,000 years ago.

Non-molecular biological evidence:

The oldest people show the greatest diversity: Africans are the most different people.

After the same species is isolated in space, the gap between species should become larger and larger with the evolution of time. However, in the past 6.5438+million years, the species differences among Homo erectus, Early Homo sapiens and Late Homo sapiens found around the world have not increased, but narrowed.

The Long March of Genes: From East Africa to the World

Scientists have found convincing new evidence that the ancestors of modern people originated in Africa, not independently in different parts of the world. This discovery may help to solve a long-term anthropological debate, or it may be used to challenge the view that human beings can be divided into different races.

The origin of modern people is a controversial topic. A mainstream theory holds that all modern people originated in East Africa and then left the continent 654.38 million years ago. Since then, they have moved around the world, replacing the Neanderthals who used to live in Africa. So far, the best evidence of this theory is that the genetic diversity of African population is higher than that of other continents (so it can be inferred that African population is older).

The Long March of Genes: From East Africa to the World

A minority theory holds that modern people evolved from ancient human populations in different parts of the world at the same time, and they all contributed to today's human gene pool. Therefore, modern Homo sapiens is considered to be the result of sharing genes and behaviors between ancient people and modern people.

In this new study, Fran? Ois Balloux and his colleagues proved that the geographical distance from Ethiopia is related to the genetic diversity of 565,438+0 human groups in the world today. This study supports the theory that as humans leave Africa, some versions of their genes are gradually lost in the process of immigration. Therefore, the population far away from Ethiopia has low genetic diversity.

The research team published their results in the journal Current Biology on March 9th. They further observed that along the ancient migration route, with the increase of distance from Africa, the genetic diversity declined very smoothly. Balloux said that according to the multi-regional origin hypothesis, it is impossible to find that this genetic diversity decreases with the increase of distance.

"We were surprised that such a simple analysis produced such a clear result," Balu said. He added that the genetic diversity between adjacent populations declined steadily. There is no leap-forward difference, which shows that human beings cannot be divided into discrete ethnic groups or races on the basis of heredity.

Max said, "The correlation between genetic diversity and geographical location seems so simple and monotonous. I really find this result fascinating? Svante p, director of the Planck institute of evolutionary anthropology? Bo, say it. " This is very consistent with our belief in our understanding of human distribution. "

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