This paper takes part in the series essay competition of “great science” of Recordunkown.
The earth is a world rich in life, and the earliest life was born 3.8 billion years ago. After continuous evolution, simple primitive life has become more and more complex. Until the emergence of mammals, after a long period of evolution, there was the birth of human beings.
According to the research of scientists, the ancestor of modern human is Homo sapiens 100000 years ago. In the era of Homo sapiens, Homo sapiens was not the only human species on the earth. There were at least six other human species evolved from Homo erectus, including denisovans, Neanderthals, Heidelberg and siblano.
Since there were at least six kinds of human beings on the earth at that time, why did only Homo sapiens, the ancestor of human beings, survive in the end? What happened in the meantime? To understand this problem, let’s first understand the evolutionary history of life on earth and the evolutionary process of human beings.
As we said earlier, the most primitive life on earth was born 3.8 billion years ago. After the birth of primitive life, after billions of years of long evolution, it finally ushered in a big explosion 500 million years ago. The explosion of life has enriched the species of life on earth, and also entered the cycle of mass extinction.
After three mass extinctions, dinosaurs were born 230 million years ago, along with mammals. However, in the 160 million years when dinosaurs dominated the earth, mammals, because of their small size, were at the bottom of the food chain, far from being able to compare with dinosaurs. So they can only come out at night for food and activities.
About 90 million years ago, mammals evolved and early primates were born. This time is still the age of dinosaurs. Primates are no better than dinosaurs, and it’s not easy to survive. 65 million years ago, a turning point appeared, and an asteroid with a diameter of 10 kilometers hit the earth.
The impact caused ecological upheaval, dinosaurs could not adapt to this upheaval environment, and began mass extinction. The extinction of dinosaurs led to the emergence of a large number of niches on the earth. After the extinction of dinosaurs, mammals naturally had more chances to survive, making up for the vacant niche. Since then, mammals have officially stepped on the stage of hegemony and replaced dinosaurs.
The rise of mammals laid the foundation for the birth of human beings. After tens of millions of years of development, about 25 to 33 million years ago, the common ancestor of human beings and monkeys appeared. In the later evolution process, this common ancestor divided into two branches, one branch evolved into monkeys, and the other branch evolved into apes.
By 18-20 million years, apes continued to differentiate into gibbons and human ancestors. Six million years ago, the ancient ancestors of human beings continued to differentiate, one to evolve into human ancestors, the other to evolve into chimpanzees. That’s why chimpanzees and humans have the most probing DNA, because we share a common ancestor.
In the following years of evolution, that is, about 4 million to 1.8 million years ago, the ancestors of humans first evolved into Australopithecus, and then Australopithecus evolved into Homo sapiens. And Homo erectus is the first species that can be called human. Homo erectus learned to walk upright and became Homo erectus. Since Homo erectus, the ancestors of human beings have really moved towards the road of intelligent evolution. They have liberated their hands and learned to make and use tools.
There is no direct relationship between Homo erectus and modern humans, because Homo erectus is just the beginning of the evolution of human wisdom. In the later years of evolution, they also differentiated into many kinds of human beings, of which Homo sapiens was only one. The differentiated human beings lived together on the earth and continued to evolve.
Although different races are intelligent life, there are still some differences in the development and evolution of intelligence. In particular, 100000 years ago, in addition to Homo sapiens, there were at least six kinds of human beings on the earth. These six kinds of human beings have their own characteristics. Compared with Neanderthals, they are the descendants of Homo erectus who came out of Africa earlier, and their bodies are much stronger than Homo sapiens.
According to scientists, a Neanderthal can challenge at least two Homo sapiens. Theoretically speaking, this powerful constitution can better adapt to the living environment of the earth and survive in the cruel nature. In fact, in the era of coexistence with Homo sapiens, the scale of development of Neanderthals was larger than that of Homo sapiens.
But because the intelligence of Neanderthals is much worse than that of Homo sapiens, we can say that Neanderthals are human beings with simple minds and limbs. With the continuous development of the scale of Homo sapiens, the physical weakness has been made up with intelligence. In the later struggle for survival, Homo sapiens relied on more developed wisdom and made more powerful tools.
We need to know that the main guarantee for human survival in nature is that we have powerful tools. As long as we have more powerful tools, then the probability of survival will be higher. So in the later period of Homo sapiens, the development of Homo sapiens is getting better and stronger. On the contrary, Neanderthals have been in a very primitive stage, using primitive sticks and stones.
The huge gap in tools makes Homo sapiens constantly replace Neanderthals and become the master of the earth. In addition, other kinds of human also disappeared for various reasons, and only Homo sapiens was left. After tens of thousands of years of evolution, Homo sapiens has become a modern human being and become really powerful.
Of course, this is just a simple result of our natural evolution. But in fact, Homo sapiens, the ancestors of human beings, can eliminate other races. Besides natural factors, there may be a more important factor, that is war. We should know that there are no two tigers in one mountain. There are several kinds of human beings on the earth. Naturally, there will be competition among them, and they are not willing to share the earth with other human beings.
Especially between Neanderthals and Homo sapiens, there have probably been racial wars for many times. Although Neanderthals have absolute advantages in physique, they can only be eliminated in the end in the face of the more powerful tools of Homo sapiens. Only the human ancestor Homo sapiens is left.
Through the above analysis, we can also see how difficult it is for natural creatures to compete and survive. Scientists once said that there are many lucky elements in the birth of human beings. Let’s not talk about the impact of gene mutation. Let’s take the disaster 65 million years ago. If there had been no asteroid impact at that time, the ecology would have changed dramatically and the dinosaurs would not have been extinct.
If the dinosaurs did not die out, the mammals would have no chance to rise. Mammals can’t rise, so it’s hard for them to evolve into human ancestors. Therefore, the birth of human beings is very grateful to the asteroid 65 million years ago, which completely changed the fate of mammals.
Of course, for today’s humans, we don’t welcome asteroids to come to earth again. Because we are already advanced intelligent life and have entered the era of science and technology. If there is a global ecological disaster, then human beings may not be able to be alone