What should I do if I roam the Chinese world or pursue the origin of mankind?

In chronological order (non-professional answers):

1, the origin of Asia (before the 20th century)

2. Early theory of "African origin"

3. "Multi-regional origin theory" (or direct evolution theory)

4. "Eve hypothesis"

5. "African origin hypothesis" (or single regional origin theory)

6. A new theory on the origin of modern human beings "regional continuity"

The following are from Beijing and history:

First, the origin of mankind

The development of science and technology has changed human life and people's view of the world. The change of these viewpoints involves the change of people's understanding of themselves. Darwin, who was born two hundred years ago, put forward his theory about the origin of species after a long journey around the world as a naturalist. He wrote in the introduction of the Origin of Species: "I firmly believe that species are not immutable; Those so-called homologous species are the direct descendants of another usually extinct species, just as the varieties of one species are identified as the descendants of that species. In addition, I also think that natural selection is the most important way of mutation, although it is not the only way. " Darwin believed that his theory was correct. In fact, today, the evolutionary theory of natural selection has become an immortal basic idea in life science. This theory has also become an obvious truth.

The theory of evolution provides the most fundamental theoretical basis for scientists to explore the origin of mankind. The motivation to explore the origin of human beings may come from human curiosity. Humans are almost the most curious animals. Where do we come from? Who is the ancestor of mankind? These questions are probably the most interesting. However, any mystery of nature is not easily presented to people. In order to solve the mystery of human origin, scientists all over the world are trying to find new evidence. Like detectives, they never let go of any clues and kept looking for human ancestors and their footprints. It's like a big puzzle, but most of the pieces are lost forever. People want to get the whole picture of human evolution, but what we know now is only fragmentary fragments, and the story of human origin still feels as hazy and elusive as looking at flowers in the fog.

The exploration of the origin of human beings has a history of more than a century. Before the 20th century, human beings knew little about their origins, but now, people's scientific research achievements in anthropology, archaeology, biology and geology have enriched our understanding of early human ancestors. This knowledge tells us that human beings, like other animals, are the product of natural selection and evolved from Pleistocene primates. It is generally believed that this primate first appeared on the savanna in eastern and southern Africa more than 4 million years ago. In 1990s, a group of American scientists discovered fossils about 4.4 million years ago in Ethiopia, which are considered as the ancestors of Australopithecus and the earliest human fossils. So people come to the conclusion that human ancestors appeared more than 4 million years ago. However, in 2000, French scientists discovered some fossils in Africa that may be the ancestors of earlier humans. The thigh bones in these fossils suggest that this species may be able to walk upright on two legs. These fossils are very old, about 67 million years ago. So our ancestors went through a long period of millions of years, and it was on this long evolutionary road that human ancestors gradually evolved into modern humans.

In the vast universe, the earth itself is like a humble dust. Scientists tell us that the earth has a history of about 4.6 billion years. Life on earth was born about 4 billion years ago, and began to develop from the ocean to the land about 300 million years ago. Mammals have dominated the biological world since 60 million years ago. Scientists believe that human beings belong to primates of mammals in the animal kingdom. Primates also include lemurs, tarsiers, monkeys and apes (including orangutans, gorillas, chimpanzees, etc. Anthropologists' research on human fossils shows that human beings evolved gradually from ordinary apes, and these fossils can continuously show the evolution process of human beings.

At the beginning of the 20th century, the scientific community thought that the cradle of human origin was in Asia, but later discoveries changed this view. Now the scientific community generally believes that human beings originated in Africa, which is the early "African origin" theory. This theory holds that the earliest human beings originated in Africa and then migrated to Asia, Europe, America and Oceania.

It is generally believed that the earliest ancestors of human beings lived in the tropical grasslands of eastern and southern Africa. The study of human fossils is an important and direct way for anthropologists to reveal the mystery of human origin, while molecular biologists use test tubes and other instruments in the laboratory to infer the specific age of human evolution. The analysis provided by molecular biologists shows that human beings originated from apes who lived in Africa millions of years ago and have the same ancestors as orangutans, gorillas and chimpanzees. The line separated from the branch that evolved into human beings 654.38+0.5 million years ago and developed into an orangutan; The next separation took place five million years ago, which is a branch of the gorilla; The closest relationship with humans is chimpanzees. Chimpanzees and humans may have only begun to separate and evolve four or five million years ago.

Therefore, more than 4 million years ago, human ancestors appeared in the savanna of eastern and southern Africa, and they belonged to the primates of that period. After roaming the African plains for more than 2 million years, this primate began to spread from Africa to other continents. It is generally believed that the earliest time for human ancestors to walk out of Africa was about 2 million years ago, and then Homo erectus appeared. Anthropologists' speculation about these dates is based on the fact that human fossils 2 million years ago are currently found only in Africa, while human fossils 2 million years ago have already appeared in other continents. The early "African origin" theory holds that the earliest human beings originated in Africa and then migrated to Asia, Europe, America and Oceania. So far, it is generally accepted that the earliest human beings originated in Africa. Therefore, it is believed that Homo erectus distributed in Asia, Europe and Oceania originated in Africa. Their ancestors left Africa about 2 million years ago and migrated to other continents. Later, some of these homo erectus may have evolved to the early homo sapiens stage.

At present, people are not very clear about the migration of early humans, but anthropologists have discovered the fact that human fossils 2 million years ago were only found in Africa, while human fossils 2 million years ago have appeared in other continents. Human fossils of 2 million years ago have been found in many places outside the African continent. For example, the Peking Man (Homo erectus subspecies) fossil was found in Zhoukoudian, Beijing (about 50 kilometers southwest of Beijing) in the 1920s. Beijingers lived about 500,000 years ago and belonged to Homo erectus. Although it is generally believed that Beijingers are a sideline in the process of human evolution and eventually extinct, they are not the direct ancestors of modern people, but in anthropology, Beijingers are generally considered to belong to the category of human beings.

So, how did modern humans develop? Did the early humans who migrated from Africa 2 million years ago and evolved there finally evolve into modern people?

Although modern humans have racial differences (yellow race, white race and black race), that is, they have obvious characteristics in skin color, hairstyle and face shape, in fact, racial differences occur very late. It is generally believed that the formation of racial differences is mainly due to different races adapting to different environments during migration. Therefore, the emergence of race occurred after the formation of human beings in the full sense, which means that modern human beings originated from the same ancestor very late. It is precisely because of this that different races in the world can marry; There is not much difference in innate intelligence between different races. In fact, anthropologists basically agree that "primitive people in the late Paleolithic period or contemporary Australian aborigines, like any other race, have the hope of graduating from college as long as they have the opportunity to receive education."

In recent decades, the intervention of molecular biology has injected fresh vitality into the study of human origin. 1987, American geneticist Rebecca Cann and others studied the mitochondrial DNA extracted from the placenta of 147 women of different races around the world, and found that the mitochondrial DNA from African women was the oldest race, so they proposed that all modern races originated from the same ancestor in Africa. According to the mutation rate of mitochondrial DNA, they calculated that African female ancestors lived about14-290 thousand years ago, with an average of 200 thousand years ago. Her descendants went out of Africa about 13000 years ago and scattered all over the world, completely replacing the original locals. This is the so-called "Eve hypothesis". Eve hypothesis is the beginning of exploring the origin and evolution of human beings by genetic methods.

For the origin of modern people, Eve hypothesis and other genetic analysis results support the "African origin hypothesis". The hypothesis of African origin (or the theory of single geographical origin) holds that human beings with modern human anatomical characteristics first appeared in Africa, and then spread all over the world, replacing local Homo erectus or early Homo sapiens. In the process of diffusion, there is almost no fusion or genetic communication with local residents, and there is no anatomical or genetic continuity. For example, white Europeans invaded from Africa and wiped out indigenous Nigerians. The same is true of people who invaded Asia, replacing the early humans in the region and evolving into modern yellow people. The research results of molecular biology really support the African origin hypothesis, which encourages the supporters of this hypothesis. They believe that molecular biology provides genetic evidence for modern human single-region origin theory.

However, on the whole, the origin of modern people is controversial. On this issue, the view opposite to the African origin hypothesis is "multi-regional origin theory" (or direct evolution theory). This hypothesis holds that modern humans evolved from local early homo sapiens and even apes, and there is anatomical or genetic continuity between them, but there is gene exchange between different regions. For example, the white people in Europe evolved gradually from the local Nepalese, and the yellow people in Asia evolved from the local early Homo sapiens and apes. The support of multi-regional origin theory mainly comes from archaeologists and paleoanthropologists. The continuity and wide geographical distribution of unearthed human fossils make them think that there is an evolutionary process of "Homo erectus → Early Homo sapiens → Modern Humans" in Asia and Africa, that is, the origin of modern humans is multi-regional.

In addition to the above two theories, some people put forward a new theory of modern human origin, which is called "regional continuity". According to this theory, Homo erectus originated in Africa migrated to other regions outside Africa in the past 6.5438+0.5 million years, forming different branches. These branches began from 6.5438+0.5 million years ago, and evolved into modern people in Africa, Europe, East Asia and West Asia through hybrid breeding.

Scientists are still exploring the question "Who are our ancestors". At present, the African origin hypothesis about the origin of modern people seems to be more accepted by people. This hypothesis was put forward by molecular biologists and geneticists. They think that modern people are a single species, but the early apes found in different places are very different and belong to different species. Not all of them have evolved into modern people, and only the apes in East Africa have embarked on the road of evolution to modern people. Specifically, the theory of African origin holds that modern people originated in Africa about 250,000-200,000 years ago (most likely in East Africa), and then some modern people left Africa about 654.38 million years ago and migrated to Asia and Europe, completely replacing other ancient people there. According to this hypothesis, all early humans (including Beijingers) in China earlier than 654.38+ million years ago are considered doomed to extinction, leaving no descendants and not belonging to the ancestors of China people. Now China people are descendants of the African woman "Eve".

At the end of last century, some geneticists in China cooperated with foreign scholars. By studying the DNA of modern human groups in China, they put forward that Eve theory is applicable to the historical situation of China, and further put forward that African immigrants arrived in southern China about 60,000 years ago, and then extended to northern China, completely replacing the human beings living in this land at that time.

So, now we can summarize the process of human evolution. Humans evolved from Pleistocene primates and first appeared in Africa more than 4 million years ago or earlier. About 2 million years ago, human ancestors first walked out of Africa, and then Homo erectus appeared. Homo erectus, which spread from Africa to Asia, Europe and Oceania, evolved into early Homo sapiens, but did not evolve into modern humans. Modern people originated in Africa about 200,000 years ago and spread to Europe and Asia about 654.38 million years ago. About 40 thousand years ago, Homo sapiens with thinking ability finally appeared. About 1 0,000 years ago, after the last glacial retreat, the distribution of human races was basically formed, and the distribution of all races on the earth was almost the same as it is now.