The hypothesis of multiple origins of human beings (I)

Biologist charles robert darwin first put forward the hypothesis that human beings originated in Africa. In his book "The Origin and Sexual Selection of Human Beings" published by 187 1, he clearly pointed out that human beings evolved from apes and probably originated from the African continent.

It is conceivable that such a shocking view at that time was severely criticized not only by religious forces, but also by many scientists who supported the "evolution theory".

Therefore, in the midst of opposition, western scholars began to look for evidence and fossils of human origin in the soil layers of Europe and Asia. To their excitement, an ancient human fossil surfaced from Eurasia.

1856, several miners dug up some human skeleton fossils in the Neanderthal Canyon in Germany. The skull is very similar to modern humans, but there are also obvious differences. The brow bone is prominent, the forehead is flat, the forearm and calf are shorter than those of modern people, and the elbow joint and knee joint are unusually thick. He was named Neanderthal and lived about 654.38 million+50,000 years ago. Therefore, western scholars believe that human beings originated in Europe. Moreover, at most, it will be 10 million years.

At the same time, some western scholars are also exploring in Asia.

More than half a century later, Budasheng, a Canadian who was then the head of the Anatomy Department of Peking Union Medical College Hospital, organized a team to excavate in Longgushan, Zhoukoudian, Beijing, and found an ancient human tooth fossil. According to calculation, the owner of this tooth lived about 500,000 years ago and was later referred to as "Beijinger" or "Beijinger" for short.

Shortly afterwards, on February 2, 1929,/kloc-0, the team of Peking University Geology Department Pei Wenzhong continued to dig in Zhoukoudian Cave and found a complete skull. The discovery of Peking man's skull shocked the world. Archaeologists believe that Beijingers not only moved the origin of human beings from Europe to Asia, that is, human beings originated in Asia.

However, nearly half a century later, the origin of human beings has shifted again.

At the northernmost tip of the Great Rift Valley in East Africa, in an archaeological camp in the Afa Triangle in Ethiopia, that is, on the day of1974165438+1October 24th, a team composed of American paleoanthropologist Donald Johnson dug up a skull fragment, as well as fossils such as mandible and trunk bones, which can be assembled into a roughly complete human skeleton. She is a woman. The age of existence is about 3.3 million to 2.8 million years ago. Later, she was named "Lucy"

The discovery of "Lucy" enlivened the ancient and mysterious continent of Africa, and more and more scientists who abandoned prejudice came here to explore the secrets of human origin.

Subsequently, the continuous discovery of ancient human fossils in Africa extended the history of human beings again and again, and confirmed Darwin's genius prediction again and again. The distant ancestors of human beings did originate in Africa, but more and more questions followed. Which kind of ancient apes evolved into human beings? Why choose Africa as the stage of evolution?

1984, Chris stringer, a British anthropologist, collected the most complete fossil data of ancient humans in the world at that time from 197 1 and entered it into a computer to build a model. By analyzing and judging the data by computer, the conclusion is that all human beings in the world today are descended from African Homo sapiens.

And put forward the viewpoint of "the second time out of Africa hypothesis", or the theory of "substitution hypothesis"; He said that African Homo erectus walked out of Africa for the first time 2 million years ago, and some Homo erectus walked out of Africa and started a long expedition, which eventually spread all over Eurasia. Among them, those who entered Europe later became Neanderthals, arrived in a branch of Asia, and later evolved into early humans such as Peking man.

About 65,438+million years ago, Homo sapiens in Africa went out of Africa for the second time, replacing all human beings in other regions, because Homo erectus in other regions had long since become extinct. Therefore, African "Homo sapiens" have no genetic communication with the local races in Europe and Asia. This is the "substitution hypothesis" theory of African Homo sapiens at that time.

By 1987, geneticists such as Allen Wilson of the University of California put forward a brand-new viewpoint by analyzing the DNA of women of different races all over the world. Today, all human beings on earth come from a female ancestor who lived in Africa about 200,000 years ago. Her descendants went out of Africa about 6,543,800 years ago and spread all over the world. Replaced all ancient humans outside Africa. This is the "Eve Hypothesis" theory in Africa, which further affirms the "African Origin Hypothesis" theory of human beings.

Starting from 1998, some geneticists further proved that the theory of "Eve Hypothesis" in Africa was established, and supported the view that "human beings came from Africa", indicating that Homo sapiens in Africa left Africa about 654.38+million years ago and went to Southeast Asia, and then to the Yangtze River in Asia about 60,000 years ago, all the way to Northeast Asia. Became the ancestors of China people.

But is this really the case? Don't! Many scientists question this.

Wu Xinzhi, an academician of the China Academy of Sciences, and many other scientists questioned it. And put forward the viewpoint of "multi-regional origin and evolution hypothesis"

For example, the hypothesis that the origin of human beings should originate from Asia, Europe, Oceania and Africa at the same time. This theory of "multi-regional origin hypothesis" was proposed by Academician Wu Xinzhi in 1984.

By 1998, after years of research, Academician Wu Xinzhi put forward a new viewpoint of "continuous evolution of reticulation and hybridization", which further clarified the theory that human beings originated from many regions and interbred with other continental races. This theory of "network evolving with hybridization" is commonly known as "multi-point water wave diffusion crossing" theory. In other words, human beings are like multi-point origins on the water. When waves are generated randomly, they will spread around. Then, multi-point waves will inevitably cross and meet. Therefore, the origin of human beings must be multi-point origin, and then meet and hybridize due to migration. This is the reason why human genes exist later, which is a biological form of mutual hybridization and fusion. Therefore, the "multi-point origin hypothesis" is very PK "African origin hypothesis"

With the further development of ancient DNA analysis technology, it is possible for scientists to extract DNA directly from fossils. Thanks to the emergence of high-throughput sequencing technology, scientists can obtain accurate ancient DNA information.

In 20 10, the Institute of Evolutionary Anthropology under the Max Planck Institute in Germany, after analyzing the DNA genes of Neanderthals, found that modern people and Neanderthals shared 1% to 4% of the * * * genes; This explains the possibility of multi-point origin hybridization.

In 20 14, American scientists published an article in Science magazine, saying that 20% of Neanderthal genes were still preserved in modern human genes, which means that modern Homo sapiens had gene communication with ancient European humans.

Therefore, the African school of origin revised the Eve hypothesis into the assimilation hypothesis, that is, indirectly recognized the viewpoint of Academician Wu Xinzhi's "multi-source hybridization hypothesis".

According to its viewpoint, in the process of human migration, protozoa have always been in a dominant position, and outsiders have played a certain role in transformation, but there has been no substitution of human beings as a whole.

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The hypothesis of multiple origins of human beings (I)