How did humans evolve?

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How did apes with raised skulls and protruding faces become modern humans? This question has been debated for hundreds of years, and there is still no convincing perfect answer. But most scientists agree with Darwin’s theory of evolution, which holds that organisms are gradually evolved from their ancestors, and the ancestors of modern humans are australopithecines. One of the top ten scientific advances selected by the American journal Science in 2011 was the new discovery of australopithecines by scientists from many countries, who considered it to be the best species of human ancestors.

Humans are the highest form of animals, capable of walking upright, having large heads, using language to communicate, making tools, having consciousness and sociability. According to fossil data, scientists believe that about 4 million years ago, apes evolved into australopithecines, 2.5 million years ago, habilis appeared, 2 million to 250,000 years ago were erectus (ape-men), 250,000 years ago were sapiens, and modern humans did not appear until more than 100,000 years ago.

Early sapiens had obvious differences from modern humans in their skulls and facial features, but their cranial capacity was very close, averaging around 1440 milliliters. By more than 100,000 years ago, late sapiens were indistinguishable from modern humans.

The hypothesis of evolutionary biologist Meyer and zoologist Kingdon holds that between 7 million and 5 million years ago, due to the dry climate and dead trees, the forest area on the earth continued to shrink, and the apes who had lived in the forest for generations faced the danger of their home being broken.

In order to reproduce their race, these apes who could climb and forage flexibly in the forest had to find another way out. In addition to the forest, the grassland is also a relatively ideal place to rest. However, when the apes first arrived, they were only outsiders on the grassland. The original inhabitants there, such as elephants and wild oxen, did not welcome these uninvited guests. Once they met on a narrow road, the apes could only run away. If they failed to escape, they would either die or be injured.

On the grassland, in addition to elephants and wild oxen, there are also fierce carnivores such as lions, tigers, leopards and wolves. When they see this group of unfamiliar forest visitors, they will open their mouths and pounce on them. The apes will die in an instant. Except for leaving a pool of blood stains, their bones and flesh will become a feast for the beasts.

In this dangerous situation where there is a life-threatening danger at any time on the grassland, if the apes can stand upright and look around to observe the enemy situation and prepare for escape early, they can survive in danger. Therefore, under these conditions of life and death survival, those who survived were naturally those apes who could stand upright and look around. Their forelimbs must be shorter than their hind limbs. These apes reproduced continuously and became a population of upright walkers. This is Australopithecus.

The upright walking Australopithecus no longer needs four limbs to walk on the ground. Their hands are liberated. The free hands can be used for predation and self-defense as well as caring for infants. When encountering natural enemies, they can also run away with their children.

According to the research on human brain and ape brain development, it can be known that human brain and ape brain differ greatly in cranial capacity. Human brain is larger than ape brain, so humans are smarter than apes.

But ape brain development is obviously faster than human brain development. The brains of newborn apes have basically developed completely. Otherwise, young apes cannot actively survive or actively grasp their mothers.

Just out of the mother’s body baby, except for crying loudly, there is no survival skills, if not taken care of, there is only one way to die. The upright walking Australopithecus can actively use their free hands to take care of their offspring, which is conducive to reproduction, thus evolving into a larger cranial capacity habilis and erectus.

What is the future of human development? This is a question that everyone cares about. In history, so-called "end of the world" predictions have been constantly rising and falling, endless.

In fact, in the history of biological evolution, there have been many large-scale biological extinction events, among which, 250 million years ago and 65 million years ago, two biological extinctions were particularly severe.

Campbell, a researcher at the Australian National University’s Institute of Earth Sciences, has shown that 250 million years ago, Siberia had experienced the largest volcanic eruption on Earth so far, resulting in 95% of animals and plants being destroyed. And 65 million years ago, a near-Earth asteroid with a diameter of more than 10 kilometers hit the Earth, which directly led to the extinction of dinosaurs.

Gott III, an astrophysicist at Princeton University, published an article in the British journal Nature on May 27 , 1993, entitled "The Implications of the Copernican Principle for Our Future Prospects". He proposed the following equation based on probability theory: (1/39) × past time < future time < 39 × past time.

He cited the literature report that adopted the average time that most species appeared on Earth: 1 million to 11 million years, of which humans have lived for about 2.5 million years, and substituted this equation to get: (1/39) × 2,500,000 years < future time < 39×2,500,000 years.

From this it can be calculated that humans may become extinct between 641,025 and 97,500,000 years in the future, with a probability of 95%. Anyway, humans still have a long time to live!

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