Why do n’t humans have different species like other animals such as dogs? And humans have only one?
Human beings are not just our race. Two million years ago, there were several humanoid species living in this land in Africa. Some of them looked surprisingly similar in appearance, while others had obvious appearances.Different characteristics.
In September 2015, another human species was added to the list. Hundreds of bones found in a cave in South Africa are now considered to belong to a new species, the Naledi. There may be more extinct ancient humansSpecies are waiting for us to discover.
Our own species Homo sapiens, modern humans appeared about 200,000 years ago, and there were several other human races on the planet at the same time. However, today, only we survived. Then why are all our close relatives extinctIs it just us?
First of all, it is worth pointing out that extinction is a normal part of evolution. In this sense, it is not surprising that the extinction of humanoid species is called "primitive humans".
However, there is not enough evidence to show that only one human species can exist in the world's living space, and the earth is fully capable of accommodating multiple human species. Our closest relatives are human apes, now there are six species: chimpanzee, bonobo,Two gorillas and two orangutans.
Millions of years ago, when many genus species lived together, they mainly fed and picked plants. Scientists believe that there is no evidence at this time that humans systematically predated large animals.
△ Southern Ape Skull
But as the environment changes, the forest is degraded in a large area, and the vast grasslands are rising rapidly. Primitives are forced to migrate from forests and trees to dry and vast prairie and start to kill animals.
Although they hunt animals, there are not many plants to eat, so in general, there is less and less food around, and the living environment is worse. This competition has indeed led to the differentiation and even extinction of some species.. But this has not left only a single race on the planet.
△ Southern Ape Skull left, Hobbit skull found only on one island left
Back to 30,000 years ago. In addition to modern humans Homo sapiens, there are three other races: Neanderthals in Europe and West Asia, Denisova in Asia, and Flores from Indonesia.Island Hobbit.
The Hobbit may have lived until 18,000 years ago. According to the geological evidence of the area, they may have been extinct during a large volcanic eruption. Living on an island will also make a species more vulnerable to disaster.Easily extinct.
We do n’t know much about Denisova, even why they are extinct. Because we only found a small phalanx and two teeth of Denisova
However, we know a lot about Neanderthals because we know them longer and have a lot of fossil evidence. To understand why we are the only surviving human species, we must figure out why they areWill go extinct.
The diversification of modern tools is more suitable for breeding in open grasslands
Gibraltar was the home of the last Neanderthals.
Archaeological evidence strongly suggests that Neanderthals are more suitable for hunting in woodland environments than modern people, but Neanderthals have lost to modern people to some extent. In modern times, humans have occupied their habitats.He was soon forced to migrate.
The Neanderthals evolved earlier than we did, and lived in Europe long before we arrived. When we arrived in Europe, more than 40,000 years ago, the Neanderthals were already there successfullyHaving lived for more than 200,000 years, they have enough time to adapt to the cold climate. They are dressed in warm clothes, have precise stone tools, and are intimidating hunters.
Some researchers believe that when Europeans began to experience rapid climate change, Neanderthals may already be struggling with colder climates.
Neandertals lived in Europe long before we were
But temperature should not be the main issue. Instead, it is because the colder climate has changed their living environment, and they have not changed their hunting style to adapt to the changing environment.
But when the European climate began to fluctuate, the forest became more open and more like the African savannah that modern humans are used to. The forest provides most of the food for Neanderthals, but the forest area shrinks, no moreCannot survive.
But modern humans are more able to adapt to the vast grassland life, and the range of animals they hunt is also wider.
Neanderthal axe made of flint
In addition to killing large prey, modern humans also hunt small animals such as hares. In contrast, according to an analysis of the Iberian archeological site, there is little evidence that the Neanderthals have hunted similar small groundsmammal.
Neanderthal tools are more suitable for hunting larger animals, so even if they try to hunt small animals, they may not be successful. Although there is evidence that they have eaten birds, they may have used other animal carcassesThe wreckage entices the capture rather than using more innovative tools to actively hunt birds in the air.
And modern people have more extensive innovations in tools, and modern people seem to be more adaptable under the pressure of survival. This ability to innovate and adapt may explain why modern people have replaced Neander so quickly.Special person.
Because faster innovation can improve the efficiency and utilization of the environment, thereby increasing the success rate of reproduction. And scientists believe that modern humans have something intrinsic to help us quickly adapt to the environment. There is some evidence.
Modern people are better than Neanderthals in terms of culture, and our brains are more flexible
Neandertals like to hunt in the forest
We know that Neanderthal tools are very effective in their jungle hunting, but when modern people reach Europe, our tools are better than them. Archaeological evidence shows that our tools are more extensive and more deadly.
But tools are not the only things made by modern humans. We have also created other things that help us defeat all other species on Earth, that is, the more advanced culture and art of living of modern people.
Shortly after modern people left Africa, there is ample evidence that they have created some culture and art. Archeologists have found decorations, jewelry, descriptions of mythical animals, and even musical instruments.
When modern people settled in Europe, the population grew rapidly. As the number of people increased, we began to live in a more complex social unit and required more sophisticated communication methods.
Prehistoric Lion Statue has a history of more than 30,000 years
40,000 years ago, humans in Europe have created sculptures that any of us can recognize as art. The most famous and oldest one is a "Lowenmensch" found in a cave in Germany.Sphinx statues. Sculptures of a similar period have been found elsewhere in Europe.
This shows that we have shared information between cultural groups in different regions a long time ago. Culture and art seem to be an important part of human identity, helping to bring different groups together.
In other words, symbols are a social glue. It helps people organize social and economic affairs with each other. In sharp contrast, Neanderthals do not seem to need these arts or symbols. LimitedEvidence shows that they did some decoration, but not as much as we do. Neanderthals hunt, cook, sleep, eat, sex and entertain every day. They don't seem to need a lot of symbolic art.
We have many ancient humans
For humans, the sharing of symbolic information is vital to our success. Every new idea we learn has the opportunity to pass on from generation to generation. For example, this is how language is transmitted.
In fact, any art work created by our modern people is done with the hands of making tools. You may think this is nonsense, but it shows our unique ability to change behavior. We can use our hands to do anything,Solve any problem, not just one thing.
We modern people do more than one specific way to do everything. We can design solutions for one problem, but also other solutions to solve the same or other problems. Modern people do particularly well in this area..
And other ancient humans seem to be doing the same thing over and over again. It seems that they do not understand the changes and still adopt the old, already used methods to solve different problems.
Do we modern people have a more advanced brain? The genes of modern people have changed
It takes only a few simple steps from ape to human
This has always been a popular point of view. The above illustration of human evolution shows the evolutionary process from apes to modern humans. Over time, human brains have grown larger.
In fact, our evolutionary story is more complicated than this. We know that Homo erectus has survived for a long time and is the first ancient human species to leave Africa, even before the Neanderthals, but theirThe brain is very small.
Therefore, some anthropologists are uncomfortable with the idea of a big head to solve the problem. The huge brains of modern people may have played a role in success, but the Neanderthal brains are compared to their size.The same size. Not smaller than ours.
Scientists have a more precise explanation.
Modern humans thrive on the African savannah.
We know that our behavior, or our environment, can change our genetic makeup. There are important differences between us and Neanderthals and Denisovans.
For example, when our ancestors began to consume more dairy products, most European talents became resistant to lactose. It also occurred under the threat of devastating diseases such as the Black Death of the 14th centuryUnnatural changes in genes, because the Black Death changed the genes of survivors.
Similarly, some scientists have proposed that modern people benefit to some extent from key genetic changes. During the first 100,000 years of human existence, modern people have behaved much like Neanderthals. So certainWhat has changed. Makes our tools more complex and diverse.
We now have genetic evidence that our DNA changed at some point after we separated from our common ancestor with Neanderthals.
Neanderthals are not as primitive as they once thought. They are also very smart, but still a little worse than modern people.
In studying the genetic makeup of modern people, geneticists have found dozens of unique points in our genome, of which several are related to brain development. That is, key genes appear in our modern peopleBefore the change, modern people and other humans were evenly matched in survival. No one is better than anyone.
This also shows that although the size of Neandertal's brain may be similar to ours, it may be that the way the modern brain develops determines the success of modern people.
But some people also think that from language and culture to war and love, the most unique behaviors of our human beings have social factors. It is our supersocial, cooperative brain that sets us apart. It may be our social lifeThis tendency leads to our ability to use symbols and create art.
Gorham Cave of Gibraltar, once a place where Neanderthals lived
In the past tens of thousands of years, the abilities of modern people and other primitive people were relatively balanced. Any other species may replace our place.
But the result: they didn't, and we eventually defeated them. As the modern human population exploded, other species faded and eventually disappeared completely. If these are true, our survival may be thanks to our creativity.
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