Where is the birthplace of mankind (high score)

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Where human beings come from seems to be our eternal mystery. Now some geneticists claim that all of us modern people had a pair of common ancestors 654.38+500,000 years ago. The clue that the root-seeking journey can be based on is our body. Through consanguinity, we tried to travel through time and space to find our ancestors 6.5438+0.5 million years ago.

The man who discovered the ape.

In 2004, a strange human skull was found on an island in Indonesia. Experts believe that his brain is only 380ml, and his height is1.08m. This dwarf star, 18000 years ago, was called one of the greatest discoveries in the past 50 years.

1992, in Artamura, Italy, paleoanthropologists found a primitive human skull embedded in a rock wall 80 meters above the ground in a labyrinth cave formed by the erosion of underground rivers for 500,000 years. Experts determined that this is the best preserved Heidelberg fossil.

1924, workers found a child's skull fossil when blasting in Dunn quarry in South Africa. Experts believe that he lived from 120000 to 400000 years ago, which was a transitional period between apes and humans, and named him Australopithecus. Judging from the paw prints on the skull, the 3-year-old child died at the hands of an eagle. He is the earliest ancestor discovered by mankind so far. It is found that Australopithecus originated from a family of Australopithecus with gene mutation. This mutant gene enables them to walk upright and survive more easily.

Australopithecus is not the only Australopithecus found. As early as 189 1 years ago, du bois, a Dutch anatomist, discovered an ape-man fossil that could walk upright 20,000 years ago in Java.

The first great migration

1984, scientist Richard Ritchie led a research team to dig the dry riverbed in Turkana, Kenya at a high temperature of 60 degrees Celsius. Near noon, an unusual human skeleton fossil appeared on the surface, and then they found more fossils. Fossils all belong to one person. This 16-year-old boy was10.5 million years ago, and was nearly 2 meters tall as an adult. He is undoubtedly the earliest direct ancestor of modern people.

The emergence of Homo erectus is the watershed between man and ape. Compared with other primates, Homo erectus is the earliest Homo erectus animal, with a height of 1.8m, and it is also the earliest animal that can be called human. He is both a hunter and a scavenger, and high-protein food directly nourishes the brain. Homo erectus' brain is the largest among the known primates, and the evolution of intelligence gave Homo erectus a choice of survival, that is, conquering the world.

654.38+0 million years ago, the ice age that lasted for 90,000 years completely dried up Africa and formed the African prairie. Homo erectus had to choose new animals and plants as food. At this time, their groups have been able to organize migration with the change of seasons. They are the earliest hunting people. Tens of thousands of years later, driven by hunger and curiosity, some Homo erectus walked out of Africa and came to Asia. This is the first human migration, but it is by no means the last.

evolution of mankind

Both Europe and Asia have found humans of the same ancestor, which proves that Eurasian humans are related. In terms of time, European Homo erectus was earlier than Asian Homo erectus and was a descendant of African Homo erectus.

From 1.2 million years ago to 800,000 years ago, Homo erectus from Africa spread all over non-Eurasia. Some experts believe that 800,000 years ago, Homo erectus became the first human to come to Europe and enter the Iberian Peninsula. At the same time, Homo erectus in East Asia, represented by Beijingers, began the road of independent evolution. Their brains began to get bigger. Finally, 200,000 years ago, a homo erectus named Neanderthal had almost the same brain as modern people. Neanderthals were kings of the Ice Age. They cooperate with each other and live together, perfectly adapting to this harsh world.

According to the theory of polycentric origin, Neanderthals in Europe evolved into advanced races, and Homo erectus in Asia also expanded its brain capacity and evolved into modern humans together with primitive people in Africa. But according to this theory, modern people should evolve three species with different forms. However, from a genetic point of view, the differences in skin color and hair of modern people are very small changes. Biologically, we all belong to the same species. How do you explain this?

Some experts believe that in the process of evolution, the genes of people in various regions have become closer and closer through 500,000 years of communication. If this theory holds, it means that these independent people meet and mate through mobility, thus exchanging genes. Can this theory be confirmed by genetic science?

Adam Hewa

The earliest evidence of African Eve theory or single origin hypothesis comes from genetic research. Professor Wilson of the University of California, Berkeley, is interested in genetic variation between people.

Wilson and others believe that genetic variation can explain the evolutionary history of all animals. For example, chimpanzees that look the same may have great differences in gene types, because there will be a lot of genetic changes in their 3 million-year development history. Moreover, there should be more than 6.5438+0 million years of genetic differences between races. From 65438 to 0987, Rebecca Kahn of the University of Hawaii purified DNA samples from women all over the world to find a unique substance called mitochondria. Mitochondria exist in cytoplasm and are called energy supply stations of cells. It has its own DNA and can replicate independently. The next generation of mitochondrial DNA generally comes only from the mother and is passed down from generation to generation, so it is a good genetic marker.

The result of the experiment is surprising. The results show that all the genes of modern women come from a woman who lived about 148000 years ago, and the difference between Africans and Asians is only about 65438+ million years ago. In this case, multi-regional origin becomes impossible.

Subsequently, geneticists successfully deciphered the Y chromosome code of male genes again. They come to the conclusion through research that all modern people have a father like him, and he should have lived 6.5438+0.5 million years ago.

This is well-deserved Adam and Eve, the ancestors of mankind.

* * * Tongzu

If human evolution is compared to a tree, the process of searching for Adam and Eve by geneticists is like searching for roots through fruits, and roots have the greatest genetic variation because of a long time. So geneticists judge that Africans are the source of modern human evolution.

The discovery of Indonesian dwarfs proves that Asians and Europeans are the same race and share a common ancestor. They come from the African continent.

Homo erectus once spread all over the world, but why did African Homo erectus finally stand out? 1997, paleoanthropologists discovered three ancient human skulls160,000 years ago in Ethiopia, no different from modern people. They were named Old Homo sapiens. They lived in an era similar to Eve, and they are probably our immediate ancestors. At that time, the earth was in the ice age and Africa was facing severe drought. The expanding desert divides human beings into isolated small communities and lives independently in the small forests around the coastline. A new genetic mutation changed all this. There are new human beings on the earth, that is, our ancestors, who have brand-new thinking.

If we compare the 5 million years of human evolution to a day, in the last few minutes of this day, the earliest intelligent human caveman stood out from the apes. Homo sapiens is not alone. In Europe, Neanderthals were still fighting for life and death during the Ice Age, and in Asia, Homo erectus gradually became stronger. There is not only one kind of human beings, and soon they will be close to each other, which will be an encounter that will determine the fate of our species.

Journey of conquest

In the 1980s, anthropologists discovered early human sites 654.38+200,000 years ago in blombos cave. In the cave, experts found a large number of stone tools, as well as a large number of shells and large fish bones, which shows that Homo sapiens ate marine animals and even cooperated in hunting big fish.

Wooden spears and stone knives give them a stable daily diet, mainly seals, penguins and fish. Red ochre is a treasure collected by Homo sapiens and should be a pigment. Homo sapiens used it to decorate themselves in celebrations, which showed that they had the ability of abstract thinking. The developed brain combined with superb hunting skills soon made primitive people embark on the path taken by their ancestors Homo erectus: migration. 654.38 million years ago or even later, a small number of them hoped to find a better living environment. They left Africa and the human conquest began.

For ancestors living by the sea, the world is a long coastline, and they migrated along this coastline from generation to generation. In order to outline their migration routes, scientists began to search through 60,000 years from the perspective of genetics in the 1990s. But now the vast majority of people are mixed-race, which is the result of a variety of origins, and the difficulty of pursuing it can be imagined.

Long pursuit road

The human gene consists of 300,000 base pairs, and each of the 6 billion modern people has its own unique gene. Finding a unique set of markers in these genes is like looking for a needle in a haystack.

After careful selection, the experts selected the main male gene Y chromosome as the main direction of attack. According to experts, the advantage of Y chromosome is that its size is much larger than that of mitochondrial DNA, which is only 16000 nucleotides. For Y chromosome, if you can use non-recombinant fragments, it is about 600 million nucleotides, so its information is much larger and the theoretical results are much more reliable. On the other hand, mitochondrial DNA only reflects maternal inheritance or maternal migration. Y chromosome is just the opposite, reflecting the origin and migration of paternal line, so geneticists began to study Y chromosome systematically from 1993 and 1994.

Mitochondrial DNA has opened a door for us, and the Y chromosome has been studied more accurately. By comparing the changes of two groups of genes, geneticists will outline the route of human migration for us. People can finally begin to understand how Eve's descendants will cross Wan Li and finally unify the world and form our modern people.

two

No matter what color we are, our ancestors came from Africa. 2000 years ago, human beings landed on the American continent, and about 80 generations later, they came to South America from Alaska, which put a perfect end to the great migration of human beings-from then on, human beings ruled the whole world. ...

In 2003, there was a sensational news in the Institute of Genetics of Fudan University-people tried to find traces of people of independent origin in East Asia, and the conclusion was very surprising: all the people studied 1200 were of African descent.

This conclusion is the most adequate annotation to Adam and Eve's theory-no matter what color we are, our ancestors came from Africa.

Since 1980s, geneticists have made an evolutionary clock by analyzing people's DNA all over the world. By comparing the genetic differences, they came to a conclusion: we are all descendants of a pair of parents 6.5438+0.5 million years ago, and we are veritable Adam and Eve.

However, some paleoanthropologists have put forward different views on this. According to Wu Xinzhi, the question is whether the genetic variation that can be detected now can be equal to all the genetic variations handed down from the same ancestor. He doesn't think so, because many individuals in the descendants of * * * have ancestors, and many small groups can't get the chance to pass on, so the genetic variation of those ancestors in Zhi Zi is all lost.

Geneticists believe that the loss of genes just verifies the evolutionary footprint of ancestors. For example, Li Jing said that if the source population is Group A, assuming that the genetic components of this group are mainly green balls and red balls, then a small number of them have left Group A and established their residence in a new place, and they happen to be a family or related by blood, then it is very likely that the genetic components they represent are different from the original group, for example, they all have red balls or green balls, because there are few people in this group. In addition, in the new population, especially in the struggle for existence of this population, there will be a mechanism mutation, so in the B population, in addition to the red ball, there are new genetic variations such as blue ball. If some people in Group B moved to another place, according to the same principle, most of them just moved out with blue balls, and only a few of them were red balls, then blue balls can be regarded as a major genetic variation in Group C.

Geneticists believe that about 654.38 million+years ago, Eve's descendants began to go out of Africa and migrate to all parts of the world, replacing the local Homo erectus and eventually evolving into our modern people. Compared with modern people, they are just a small group, and it is impossible for them to have more complicated genetic variation in a short period of tens of thousands of years. In a sense, Eve is the luckiest person in the world. After other people's genes finally disappeared for various reasons, only her descendants stubbornly survived and passed on their own genes to modern times.

At that time, there were all kinds of Homo erectus all over the world. In Europe, Neanderthals were the king of snow, in Asia, Homo erectus became stronger, and in Africa, Homo sapiens painted themselves with ochre and made a living by fishing and hunting. Three races, one world. How did Homo sapiens conquer the world? Experts try to use genes to find the footprints of our ancestors. Li Jing speculated that the route of human ancestors' migration always followed the route of rich products and the environment more suitable for their lifestyle. For our ancestors, the coastline was their lifeline. About 60,000 years ago, most Homo sapiens went all the way along the coastline to the Middle East, such as the two river basins in Iraq, and lived there for quite a long time. The rich products in the Middle East made the population of Homo sapiens expand again, which made some Homo sapiens decide to migrate again. About 50,000 to 60,000 years ago, some people moved out of the Middle East and went to East Asia along the routes of Southeast Asia and the Indian Ocean. They crossed India to Southeast Asia, and then entered the hinterland of East Asia such as China from the south. They are the ancestors of East Asians and China people.

After sorting the fossils of ancient humans in East Asia, Li Jing and his colleagues made a discovery: from 654.38 million+years ago to 40,000 years ago, there were no human fossils in East Asia.

Li Jing and others believe that compared with the yellow race, primitive Southeast Asians are genetically older, and they are the first modern people to come to East Asia. This view is welcomed by linguists.

For a long time, East Asian languages have been traditionally divided into four language families: Sino-Tibetan, Miao-Yao, Dong-Tai and Southern, which is based on the multi-regional origin theory of paleoanthropologists. However, the research of linguist Pan Wuyun found that all four language families actually came from the same language. Through language comparison, Pan Wuyun reached the same conclusion as Li Jing. The language families in East Asia come from the same race. They first came to Southeast Asia and became the ancestors of early brown people. They expanded from south to north, and then more Homo sapiens followed. The species expansion of East Asian people is not completed by a migration.

Geneticists believe that after the early brown people came to East Asia, the ancestors of modern yellow people also entered East Asia. Among them, there is not only the war of survival, but also the exchange of genes. We are the descendants of blood and fire between them. So where are the East Asian Homo erectus who came to the East Asian continent earlier and once flourished?

Like Africa, Asia is an ancient continent. From early ape-man to late homo erectus, ancient human fossils of various stages have been found in various regions of East Asia, showing its unique evolutionary model. From the early Beijingers to the late Neanderthals, they all have similar skeletal characteristics to modern East Asians, especially Neanderthals. Judging from the tools and decorations found on the spot, they have a fairly high degree of civilization.

After sorting out the fossils of ancient humans in East Asia, Li Jing made a discovery: from 654.38 million years ago to 40,000 years ago, there were no human fossils in East Asia.

Because this fault happened to be an ice age in East Asia, geneticists concluded that severe cold probably killed Beijingers and their descendants, but this inference was questioned by paleoanthropologists. Wu Xinzhi said that animal fossils from the same period showed that it was not so cold in Asia at that time. How did Homo erectus freeze to death?

On the origin of East Asians, paleoanthropologists use fossils to speak, while geneticists can't find the evidence handed down by Homo erectus in East Asia. So far, this issue will continue to be debated.

According to geneticists, our DNA was not imprinted by Neanderthals. We are descendants of Homo sapiens. If our ancestors intermarried with Neanderthals, their descendants will also be extinct from this earth.

Experts believe that Homo sapiens made a great leap in Eastern Europe 40,000 years ago. The new environment has greatly improved their tool manufacturing technology, and new tools such as bone spears and stone knives have appeared one after another. This is the first technological revolution.

New tools mean more successful hunting, larger tribes and expansion in the interior of Europe. Li Jing said that about 300,000 years ago, some people entered Europe and may become the ancestors of modern Europeans. But with the arrival of the last ice age, they were pushed to the south by glaciers and then established settlements on the northern shore of the Mediterranean.

European immigrants soon found themselves in other people's territory. As early as 200,000 years ago, there were primitive homo erectus in Europe. In the 1980s, France filmed a prehistoric feature film "The Battle of Fire", in which Neanderthals gathered in caves in southern Europe. They are strong and hairy, guarding the bonfire. Among them, the concept of tribe has been formed, and tribal members care about each other and live together. 1997, an archaeologist found a skeleton in weller, laga, Portugal. Judging from the bones, this is a 4-year-old child. Because the child's bones are very fragile, they would not be so complete if they were not intentionally preserved. The child's skull was broken, which is estimated to be the cause of his death. Judging from the excavation site, he should have been buried ceremoniously. By identifying these bones, experts found that he had the characteristics of Neanderthals. On the boy, the expert also found a shell necklace. Ornaments are one of the symbols that distinguish Homo sapiens from Neanderthals, and their burial methods are also very close to the custom of Homo sapiens. Will this child with Neanderthal skeletal characteristics be a hybrid? Does he have genes inherited from modern society?

People compared the DNA of modern people and Neanderthals, trying to find out the differences between them. The result of verification is that the difference between them is about 600,000 years, that is, they were separated 600,000 years ago or earlier, indicating that Neanderthals were indeed descendants of Homo erectus who moved out of Africa early, but the Neanderthals' genes were not seen in modern people.

Geneticists have determined that our DNA does not bear any Neanderthal imprint, and we are descendants of Homo sapiens. If our ancestors intermarried with Neanderthals, their descendants will certainly be extinct from this earth. Neanderthals survived and evolved during the ice age, but they were not so lucky when they met modern people.

40,000 years ago, Europe was the first time that modern people met Neanderthals. Modern people with darts and other new tools met local people. Although Neanderthals were small in size, their muscles were extremely developed. Tall and thin Homo sapiens are no match for them physically, but they have great advantages in the competition. For a long time, Neanderthals made many exquisite stone tools and used them widely. But for some reason, the stone tools stopped after reaching a certain height. Experts speculate that this may be related to the brain evolution of Neanderthals. Corresponding to them, Homo sapiens made more kinds of tools, and they began to make tools from bones, antlers and ivory that had never been used before. This wisdom is the key to their ultimate survival.

37,000 years ago, Homo sapiens entered the cold south of France with all kinds of new tools. The local Neanderthals tried to copy these inventions, but when Neanderthals struggled to catch up with Homo sapiens, Homo sapiens made another leap, that is, art.

37,000 years ago, the ice age deteriorated, the area covered by ice and snow became larger and larger, and winter was more difficult than before. Winter is the enemy of Neanderthals and Homo sapiens, and isolation means starvation or even extinction. In order to survive, our ancestors need to deal with their compatriots far away, and they provide more information about food. They began to communicate, and besides tools, shell carvings, stone statues and other works of art were also very popular. Through exchange, Homo sapiens got the food necessary for survival, and works of art helped them tide over the difficulties in the most difficult times.

According to experts, it is through some trinkets that Europe has become a big market, so all modern people can establish their own initial network, exchange all useful information and improve their tools. It is by relying on these that they can occupy the broadest and richest territory. Homo sapiens used their tools and culture to gradually expand in Western Europe and occupy the best caves and valleys. From warm Turkey to cold France and Germany, the communication network of our ancestors in the Stone Age enabled them to thrive wherever they wanted to go. Homo sapiens is a nomadic people, they are looking for a new hunting ground every season, while Neanderthals live in a fixed cave. These ice age groups with single skills were defeated by shrewd foreign brothers, which was a victory of wisdom.

28,000 years ago, Homo sapiens outnumbered Neanderthals. A few Neanderthal tribes are still in Spain, but they are doomed to perish. 27,000 years ago, Neanderthals disappeared forever, and their homes fell into the hands of smarter people. Before 2000, human conquest reached a new stage. Homo sapiens left their familiar warm hunting grounds and entered areas they had never set foot in. The lure of food led them to follow the wild animals to the cold forest in Siberia. The sea level drop during the ice age provided an excellent opportunity for mankind. Today, Asia and America are separated by oceans, but 2000 years ago, a land bridge closely linked the two continents and brought mankind into a brand-new world.

Li Jing said that human beings have migrated to the so-called marginal areas, one is America and the other is Oceania, and they all use Asia as a springboard. People who entered the United States came from Asia and entered the United States through the land bridge in the Bering Strait. His lineage is now relatively certain, that is, Siberian, and Siberian is from Central Asia.

For five million years, no animal with such high intelligence as human beings has set foot on American soil. For the first people who set foot on this vast land, it is full of mystery and danger. Geneticists compare the DNA of Native Americans with that of people around the world. Surprisingly, Native American genes contain a unique mutation, which may appear in only one person at first, but now it appears in millions of people. Experts believe that the first person to land on the American continent may only have a family from Siberia, but their ability has greatly exceeded that of their ancestors who left Africa. In less than 2000 years, that is, about 80 generations, they came to South America from Alaska, which brought a perfect end to this great migration of human beings-from then on, human beings ruled the whole world.