Can modern apes become human?

origin of man

Author: Wu Xinzhi

Today, I want to tell you about "the origin of mankind". Speaking of the origin of mankind, what do you care about most? Maybe one is when the earliest people on earth appeared. Can anyone give an answer? Just say something.

Student: I think it should be between 3 million and 4 million years. It first appeared in Africa.

Expert: Three million years, in Africa, what else?

Student A: I think it should be Yuanmou, China's Yuanmou. I don't quite remember the time.

Expert: There is another mastermind.

Student: About four million years ago, it should be in Africa.

Expert: Four million years, one million years more. All right. In fact, several students just now have a certain truth, that is, it depends on when to say this. It seems that it is not right to say it today, because our understanding of this issue has a process, so I will start from the beginning.

What kind of people were the earliest in the first half of last century? It was a Javanese ape-man and a Peking ape-man, so at that time, the age of Peking ape-man was determined according to the accompanying animal fossils. Everyone in the biology department knows that biological evolution is different from one period to another, and its form is also different. So according to the change of biological form, we can make a timetable to know what this animal looks like and what animals there are, for example, 500 thousand years ago. The animal fossils of Beijingers were set 500,000 years ago, so Beijingers were 500,000 years ago, so the historical record of human beings at that time was only 500,000 years. It was shorter before that, that is to say, in the19th century, the earliest human fossils were Neanderthals in Europe, and the earliest age of Neanderthals was less than100000 years, so the earliest historical record of mankind was100000 years.

Therefore, after Beijingers, the historical record of mankind is about 500,000 years, so Beijingers were the earliest people at that time. He sat on this throne for more than 20 years. From the end of 1920s to 1959, a human skull was found in Tanzania, Africa. This is the old lady. Her name is mary leakey. She and her husband have been searching for human fossils in the wilderness valley of Tanzania for more than 20 years. Nearly 30 years later, an important skull was found in 1959, which is the middle one. As we all know, stone tools are made by people, but they are all stone tools. The stratum where this stone tool and this skull are located was 6.5438 0.75 million years ago, which was measured by radioactive isotope method of potassium and argon. Therefore, the historical record of mankind has been extended by 6.5438+0.75 million years, that is, 654.38+0.959, so it was selected as the top ten news in the world that year. In the 1960s, an English girl named Jane Goodall graduated from high school and came to Beijing a few years ago. Now she is engaged in animal protection. She is very interested in studying ancient humans. When she arrived in Africa, she asked the gentleman, Louis Leakey, to give her money. She lives in a dense forest and observes the life of chimpanzees. After a long period of observation, she found that chimpanzees can make tools and put grass. After removing it, insert the straw into the ant nest, because the ants in Africa are very big, and their nests are like graves, so we call it the ant grave, insert it into that ant grave, catch the ants and eat them, that is to say, it can change the shape of natural objects and use them for its own use, which is the beginning of making tools. So she found such a manufacturing tool. What is the significance of this discovery? This means a lot. Before that, what was the definition of man? It is an animal that can make tools, so we found the earliest tool, 1.75 million years old, so we can know that there are still people at this time. The Javanese ape-man was discovered in 189 1 year, but it has been argued for a long time for decades, and it is still impossible to decide whether he is a human or an ape. Why? It is because there is no tool to find with him that his brain is between the size of modern humans and modern apes, so he can't decide. So at that time, 1959, according to the definition of such a person, the history of people reached1750,000 years, because the earliest tool was1750,000 years. So now that jane goodall has discovered that chimpanzees can also make tools, it is not feasible and appropriate to use making tools as a historical symbol of the boundary between humans and apes, so people have to discuss whether to use another symbol to distinguish humans from apes. Everyone knows that apes have become human beings, but in what state did they become human beings? If you don't reach this state, you are not a person, and this sign is even more difficult to determine.

Then at this time, people will think that in ancient Greece, there was a Plato who once defined people. What does he say about people? It is an animal that walks on two feet and has no hair. One day, his students pulled out a goose and asked the teacher, is this a person? Of course, it is not a person, so it was later called Plato's goose in the book, saying that people are Plato's geese. So this definition was abandoned and no one adopted it. So up to now, jane goodall found that chimpanzees can also make tools, and people, as tools-making animals, can't use this definition. Then people will recall Plato's definition at that time, and if there is any place available, they will feel that there is still some truth. Then, if we modify it, it will walk on two feet. In addition, the body should be straight, that is, walking with two feet upright, so as to be considered as a person. As long as this can be done, it is considered as a person, so everyone agrees to adopt such a sign, and there is another advantage. At that time, using stone tools as the dividing line between man and ape was, after all, a thing apart. You can't find a man's fossil and catch the stone tools in his hand. Impossible, right? It's something outside. Now it is better to define the boundary between man and ape with his own body structure. It is better to change the definition of such a man and extend his historical record to more than three million years. Later, in the 1970s, some Australopithecus fossils more than 3 million years ago were found in Ethiopia, which were also determined by the methods of radioactive isotopes potassium and argon. He was named Australopithecus afarensis at that time. Because it was found in Afa, a relatively complete skeleton was dug up later, which is what you see now, accounting for 40% of the whole skeleton. On the day of discovery, they celebrated in the camp at night, because it was such a complete skeleton three million years ago, and everyone put a record at the party called "Lucy in the Diamond Sky", so after that, they simply called this skeleton Lucy. So when I talk about Lucy, maybe some students will know. It refers to this thing, so Lucy's discovery has extended the historical record of mankind to more than three million years.

Then in the 1970s, mary leakey discovered East Africans. In the 1970s, her husband passed away. She took a British high school graduate and found these footprints in another part of Tanzania. From the study of footprints, we can know that he walks upright on two feet, and the amplitude between each step can be measured and calculated. Look at the size of this footprint.

It is the footprints of two people walking on volcanic ash, which will accumulate in the future, so this lithology is different. After it becomes a fossil, it can be selected. At this time, the history of mankind is more than three million years, so the classmate just said it was more than three million years. In the 1970s, this answer was correct.

Then in the 1990s, in Ethiopia from 65438 to 0994, a group of American scientists discovered some fossils, which were 4.4 million years ago. This is the ancestor species of Australopithecus, which is 4.4 million years, so some students just said it was more than 4 million years. This time is right, it is 1994, so the human history is extended to 4 years. In the Millennium of 2000, French scientists also found some fossils in Africa. The newspaper said that millennials, fossils with thigh bones, can be studied. He was able to walk upright on two legs and was called Millennials at that time. Later, after research, he gave a formal name. This genus was called Primitive Man. According to the place where he found it, his species was called Tugen Mountain, so we translated it into Tugen Seed, which is Primitive Man.

Seven million years ago, so up to now, human history has reached six.

Seven million years ago, but this is about people who walk upright on two legs. Making tools? The earliest tools are only 2.5 million years old, and there is nothing earlier. So all the fossils are in Africa, so just now my classmates said that human beings originated in Africa. Now it is generally understood that this is the case, but is it definitely in Africa? I'm afraid I can't make a final judgment. Why? Because the earliest fossils can be seen in history, people tend to think where the origin of human beings is. At the beginning, the Javanese ape-man was discovered in Java by 189 1, the Peking ape-man was discovered by 192 1, and the first skull of Peking ape-man was discovered by 1929, so at this time. In the 1920s, anthropological theory believed that the origin of human beings was because the uplift of the Himalayas prevented the humid sea breeze in the Indian Ocean from blowing to the north of the mountain, so the area in the north of the Himalayas became dry, and at this time, the forest in that place became thinner and thinner, so the ancient apes who once lived in the forest had to go down to the ground and become people. This was the theory at that time, so the discovery of Beijingers further confirmed this theory.

As mentioned just now, East Africans were found in Africa in 1959, with fossils of1700,000 years ago. At this time, the wind turned to Africa, but after all, in the southwest of China, especially Yunnan, at the time of human origin, that is, the Miocene, its climatic and environmental conditions were suitable for the transformation of apes into humans and the generation of humans, so the possibility of finding human ancestors in Yunnan was not completely ruled out. So it is still worth looking for, but before it is found, it is only possible, but we can't say that this possibility means that human beings originated in Asia, so we still say that we are currently in Africa. Therefore, with the discovery of fossils in recent years, the understanding of human origin has gradually changed.

Ok, let's introduce several stages of human evolution. The earliest were Chadians and primitive people, followed by Australopithecus and Australopithecus. This started 4.4 million years ago and is currently only found in Africa. Australopithecus lasted until1400,000 years ago, and then disappeared. But more than 2 million years ago, a new species appeared in Australopithecus, that is homo habilis, and more and more fossils of homo habilis were found. Some people think that he is divided into two parts and two species, one is homo habilis and the other is Rudolf. Then from 1.8 million years ago, a new species called Homo erectus appeared, which lasted for more than 200,000 years. About this time, another kind of people appeared on the earth, called Homo sapiens. Homo sapiens has continued until now, and we are all ourselves. His culture is more complicated. Physically, his culture is more detailed. Although it is only over 200,000 years old, it is divided into two parts, one is called early Homo sapiens and the other is called late Homo sapiens.

So the first stage of human evolution just now included Chad, primitive man, ape and Australopithecus. There are many species of Australopithecus. So far, there are seven kinds. Will each of them become us in the future? That's not true. There may be only one, or even none. Our immediate ancestors haven't discovered it yet. It's possible.

So what does this phenomenon mean? In other words, in the process of human evolution, its pattern is shrub-like. Before this, people found a fossil, saying that it was100000 years ago, and later found a Beijinger 500000 years ago. So they said that this person 500,000 years ago became a person100,000 years ago, became a person now, and then another person 400,000 years ago and 500,000 years ago became a person 400,000 years ago, then a person 200,000 years ago, and then a person now. In other words, a line is stepped, step by step. Therefore, after discovering so many species of Australopithecus, people changed their understanding and realized that in the process of human evolution, it was not stepped, but shrubby, and it was divided into many branches. These branches went extinct at different times, and there were no descendants, only one stood out, and then it became like us. Are these branches theoretically impossible to merge with each other? Why? Because they are different species, it is well known that different species cannot mate to produce fertile offspring, so they will not mate. So the understanding of human evolution has changed from ladders to bushes.

Here are some specimens. These are all specimens of Australopithecus, and this is also Australopithecus. It's just that Australopithecus is round now Now these two apes have a ridge on their heads. This ridge means that the masticatory muscles are so large that there is not enough room for them. They grow to the top of their heads like gorillas. This kind is called pudgy. That one was called slim. It is generally believed that.

This picture is an imaginary picture of the life of Australopithecus at that time. This is the skull of homo habilis. You can see that the head is bigger and closer to us modern people. Therefore, according to the existing fossils, humans probably originated in Africa, and apes may be in Africa or East Africa. Long-term upright walking has broadened their horizons, used tools and developed their brains, so they have become adults. About 2.5 million years ago, mankind began to make the most primitive tools, which is the second stage of human development.

Now when it comes to the third stage, the third stage is Homo erectus. Homo erectus has homo erectus in Java in Southeast Asia, and there are many places in China, such as Zhoukoudian, the Yuanmou man in Yunnan mentioned by that classmate just now. He was homo erectus, about 6.5438+0.7 million years ago. This is the earliest Homo erectus fossil discovered in China, later than Yuanmou. China has the skull of Gongzhuling in Lantian, Shaanxi, and Yunxian in Hubei and Tangshan and Nanjing in Anhui have two skulls. Later, Homo erectus fossils were discovered one after another. Of course, the most important place for Homo erectus was Zhou in Beijing.

This is the skeleton of African Homo erectus,1600,000 years ago. /kloc-It was not easy to have such a complete skeleton 0/600,000 years ago. With this skeleton, you can measure its length. As a result, he is about 1.6 meters long. This skeleton is a child, because according to his skeleton, he is about ten years old, so if the child grows up, it can reach at least 1.8 meters, then1600,000 years ago. As I said just now, when we see a footprint, it is very small. In other words, people at that time more than 3 million years ago were much shorter than now, that is, more than one meter. So from that time to1600,000 years ago, people's bodies have been growing taller. From1600,000 years to now, it seems that people's bodies have basically not changed much, but only fluctuated up and down. So some people used to think that people were tall, but now people are shorter, according to the ancient shirts in the museum. Some people say that the early Australopithecus was short three million years ago, so people grew taller slowly, so neither was comprehensive. On the whole, it was two million years ago that human beings gradually became taller, from more than one million years ago to the present.

This is a brief introduction to our Chinese fossils. This is our Homo erectus in China, and what we saw just now is Homo erectus in Africa. These are two teeth of Yuanmou. These four are because there are two sides, just different sides. This is the skull of Lantian ape-man. It is a fragmentary fossil, but it can be pieced together. This is a Beijinger, and this is a restored image. As we all know, the Peking man fossils were lost before the liberation of the Pearl Harbor incident in 194 1 year. So I've been looking for it all these years. As soon as some clues appear, it is always a suspense to pursue them and finally fail. But after liberation, we found some fossils in Zhoukoudian, and the number was very small. These five teeth were discovered in the early days of liberation. These two bones are limbs, one is the arm and the other is the calf, which were also found in the early days of liberation. Later, a mandible was found in 1959, two skulls were found in 1966, and a tooth was found in 1966. These are the only Peking man fossils in China. Others have been looking for it, but they haven't. In addition, Sweden has three teeth It was excavated in Beijing in the 1920s and then transported to Sweden for restoration, so what existed there later has not been discovered until now. This is the only Peking man fossil in the world.

Okay, what about after Homo erectus? Now let's introduce early Homo sapiens. Early Homo sapiens was also called Ancient Homo sapiens in China. It is found in many places, such as Dali in Shaanxi and Jinniu Mountain in Liaoning. It's also a skull in India. In Europe, mainly Neanderthals. This is China's early Homo sapiens, and this is the skull of Dali, Shaanxi Province, which is relatively complete. This was found in Yingkou, Liaoning Province. This skull is relatively complete. They were all early homo sapiens, more than 200 thousand years ago.

Then the last stage of human evolution is the late Homo sapiens, and we are part of the late Homo sapiens. At this time, human beings are more capable, so they are more widely distributed, not only in Europe, Asia and Africa, but also in Oceania, America and many islands.

As human beings evolve, so do their tools. The earliest human tools were simple, that is, hitting another stone with a sharp edge, and you can use it. The latter is sharp-edged, allowing you to dig things, as long as you do it, you can use it. Therefore, this beating technology is called the first mode. Later, a second pattern appeared 1.7 million years ago, and the stone tools in the second pattern were more regular and made into very regular shapes according to certain rules. By 200,000 years ago, a third model appeared in Africa. You see, this pattern has become more regular. Professionally speaking, it has a set of rules and is very particular about the way of fighting. This is called the third mode. Later, 350 million years ago, in addition to stone tools, people also used bones to make exquisite bone tools, including harpoons and barbed forks, which can be used to fork fish, and can be ground into needles to sew clothes, draw pictures, murals and sculptures. This is called the fourth mode.

In the process of human evolution, we can see that this brain is getting bigger and bigger. On the right are the brains of chimpanzees and gorillas, and on the left are the brains of humans three or four million years ago. So this brain is about the same size, not much better than chimpanzees, and it is gradually developed, because in the process of human evolution, the brain is getting bigger and bigger, and people's intelligence is getting smarter and smarter. Therefore, it is easy to think that the evolution of the brain is directly proportional to the growth of intelligence, which is not unreasonable.

Finally, I still have a little time to introduce the origin theory of modern people. In other words, we are modern people. Where do people like us come from? This is also a hot topic in recent years.

One is from Africa, that is to say, about 200 thousand years ago, there appeared people in Africa who look like us now. About100000 years ago, their descendants went out of Africa, to Europe, to Asia, and then to China about 60000 years ago, replacing the descendants of those people in China who were earlier than 60000 years ago. Those descendants have no descendants and are extinct. So we are descendants of African immigrants 60 thousand years ago. This is a theory from Africa. You see, this is from Africa. In other words, after he came out of Africa, he went to various places. There used to be fossil people in those places. For example, Beijingers are one of them, and Dali people mentioned just now are one of them. However, the descendants of these people became extinct and were replaced by these people from Africa. This is such a model. Another model is multi-regional evolution, that is, our ancestors first came from Africa. Take China as an example. More than a million years ago, a group of people from Africa came to China, and these people gave birth to descendants. Later, they grew up to be Beijingers and Dali people. Up to now, of course, in Europe, it has evolutionary lines, as well as in Southeast Asia and Africa, but these few. We paleoanthropologists in China, including myself, believe in the latter. The evidence of this theory is that many fossils have been found in China. These fossils contain incisors, that is, upper incisors. These upper incisors are all shovel-shaped. What do you mean by shovel shape? Look at this front tooth. It protrudes from the back and sinks in the middle like a coal shovel, and this shovel-shaped front tooth is yellow in China now. At present, less than 5% of people in Europe are shovel-shaped front teeth, about 10% in Africa, and more than 20% in Australia. Fossil people in Europe also have shovel-shaped incisors, but the frequency of their appearance is much less than that in China. China may not say 100%. At least so far, no case has been found. So the same front teeth have been going on for so many years, which proves that human evolution in China has been going on.

In other words, China's human skull fossils, as early as ten thousand years ago, we found a lot of skulls, all with a series of * * * characteristics. One is flat face, the other is flat nose, and the eyes are basically rectangular. If the race is changed in the middle, some characteristics should be changed, but these characteristics remain unchanged, so it may be continuous evolution. At the same time of continuous evolution, a few features are different from most skulls in China. As you can see here, the bridge of the nose in Nanjing No.1 Middle School is particularly high, and the bridge of the nose in Dali is relatively low. That is to say, there are a few fossil skulls with high noses in China, so what does this mean? These characteristics are determined by genes. Like Maba's round eyes, the genes that determine his eyes are definitely different from those of most people in China, but the same as those of Europeans. So this gene probably came from Europe and the West, so the snub nose just now is also like this, that is to say, in the human evolution in China, a small number of foreign genes were embodied, so a hypothesis was formed, that is to say, the human evolution in China is mainly continuous evolution, with hybridization with other regions, which is a hypothesis of continuous evolution and hybridization. Of course, this is a hypothesis. According to the existing materials, this induction can be strengthened, enriched and even overturned with the discovery of new fossils in the future. So this hypothesis has evidence of ancient culture. I just showed it to you. In the world, the development of stone tools comes from mode one, mode two, mode three and mode four, in Africa and Europe. This is not the case in China. For a long time, China has been a model one, a model three and a model two, and there are few places with this model. Up to now, Paleolithic tools have been found in nearly 1,000 places in China, but most of the 900 places are of type I, while there are few types III and II. Therefore, it seems that the development of China's ancient culture is mainly based on continuity, supplemented by communication with the West. So the other hypothesis mentioned at the beginning, the Eve hypothesis, comes from Africa. What is its main basis? According to 1987, three scientists extracted mtDNA from human placenta. It turns out that the DNA variation of Africans is particularly large, while that of Asia and Europe is very small. How did the variation come about? It is precisely because of mutations in the genetic process that the longer the genetic process, the more mutations accumulate and the more mutations there are. Therefore, the more mutations in Africa means that its history is relatively long, while in Asia and Europe, the history is relatively short. Therefore, it is believed that modern people first appeared in Africa and gradually walked out of Africa. When did modern people appear in Africa? According to the speed of mutation, the rate of mutation occurs once every ten thousand years. This calculation is 200 thousand years.

This is a pattern map, that is, modern people migrate from Africa to these places, so if this pattern is correct, then you can see that the main road out of Africa now is this place in the Near East, which is this place in Israel. Some stone tools have been found in this part of Israel. These stone tools were100000 years ago, and they are the third model stone tools. If this is the case, then the descendants of those who mastered the third mode technology came to China 60,000 years ago, replacing the descendants of those who used the first mode in China. That is to say, 50,000 years ago, 40,000 years ago, the tools of Paleolithic in China should generally become the third mode, or even go further, instead of the first mode, because the third mode is more advanced than the first mode.

But this is not the case. Just now, China really reached the fifth and fourth modes very late, only 30,000 years, so from this perspective, the theory that modern people came from Africa seems to be inconsistent with the materials found in China stone tools. A lot of work has been done in the past few years, and the results are also interpreted in various ways. Because of the time, I won't go into details.

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