How did our ancestors evolve?

According to foreign media reports, scientists have always believed that homo habilis, the ancestor of human beings, evolved from Homo erectus. However, when American scientists studied an ancient human fossil, they found that Homo erectus and Homo habilis probably evolved from the same ancestor, and there was no evolutionary relationship between them. This new discovery has seriously impacted the current theory of human evolution.

In the August 9th issue of Nature, American scientists published their latest research results. American scientists say that an ancient human fossil discovered by scientists in Kenya shows that long before humans and Neanderthals lived side by side in Europe, the other two early races had lived together in Africa for many years. Scientists working in Kenya have found evidence that Homo habilis lived peacefully with another early species, Homo erectus, for hundreds of thousands of years, which is much longer than scientists expected. Ian Tesal, an anthropologist at the new york Museum of Natural History, said that the newly discovered fossils strongly proved that there was more than one race in Africa 6.5438+0.5 million years ago, which forced scientists to rethink the evolutionary relationship between the two races.

Have a common ancestor.

"Homo habilis" is the earliest known ancient human, while "Homo erectus" is an ancient human with more advanced morphological characteristics than "Homo habilis" and similar to modern human. Because of their anatomical overlap, scientists once thought that Homo erectus evolved from Homo habilis. However, the latest findings show that homo habilis probably shared a common ancestor with Homo erectus.

In 2000, scientists found two fossils in the ashes of an ancient volcano in Hileret. Through identification, the researchers determined that a jawbone fossil belonged to an "able person" who was 654.38+0.44 million years ago. Before this time, the recently discovered "homo habilis" fossil was the famous "Turkana Boy", a human fossil dating back to 1.60 million years ago, which was discovered by paleoanthropologist Richard Leakey and his research team in 1.984. Another fossil unearthed is a skull dating back to 1.55 million years ago. There is no doubt that this skull belongs to Homo erectus. Compared with other known Homo erectus skulls, this skull fossil is much smaller, which means that Homo erectus is bisexual, and males are larger than females. Researchers say that most bisexual primates, such as gorillas and baboons, have multiple mating partners, and this phenomenon may also be common among Homo erectus.

According to the traditional theory, homo habilis lived from 3 million years ago to 6.5438+0.5 million years ago, and should be the earliest ancient human who could skillfully make stone tools. "Homo erectus" lived about10.8 million to 200 thousand years ago, and was a more advanced ancient human than "homo habilis" but more primitive than Homo sapiens. "Homo erectus" evolved from "homo habilis" and may have gone through the evolution stage of craftsmen. So far, the relationship between Homo erectus and Homo sapiens is unknown. According to the mode of human moving out of Africa, "Homo erectus" was the first human to leave Africa in large numbers, and Homo sapiens, who later replaced it, also embarked on a journey out of Africa. However, according to another theory of human origin, some "Homo erectus" who left Africa were scattered everywhere and then evolved into Homo sapiens all over the world at the same time.

Peace after half a million years.

In the eyes of scientists, Neanderthals and modern people competed with each other. In the end, our race won in the struggle and became the only surviving human member on earth. On the contrary, homo habilis and homo erectus can live in peace for 500,000 years and try to avoid any conflict. Miff Leakey, the wife of Richard Leakey, believes that the fact that "Homo habilis" and "Homo erectus" are scattered as individual species shows that they have their own niche, so they can avoid direct competition. By analyzing the jaws and teeth of these two species, scientists suspect that Homo habilis may have more vegetables and less meat than Homo erectus, which is similar to the situation of gorillas and chimpanzees now: although these two apes live in the same habitat, gorillas eat much more hard vegetables than chimpanzees who specialize in hunting other animals.

Frank Brown of Utah State University said, "There is a relationship between Homo erectus and Homo erectus, which refutes the theory that Homo erectus evolved from Homo erectus. They have lived in the same river basin for 500 thousand years, but they can exist as independent ethnic groups, suggesting that they have their own ecological areas and avoid disputes. Maybe there are differences in food between the two nations. The most important conclusion is that there was more than one human race in the early history of East Africa. The parallel existence of several' able people' ethnic groups is very normal in history, and the Neanderthals who perished 28,000 years ago are one of them. " Brown added: "The fossil discovered by scientists probably belongs to an adult woman. But today, there is only one kind of Homo sapiens living in this world, and that is us modern people. "

There are still questions.

Newly discovered fossils prove that Homo erectus and Homo habilis may have evolved from the same ancestor who lived 2 million to 3 million years ago. However, Tim White, a paleoanthropologist at the University of California, thinks that Homo erectus may have evolved from a few isolated homo habilis, and then the two species lived together for hundreds of thousands of years, because he did not fully believe that the unearthed fossils of the lower jaw bones must belong to homo habilis. White said: "A very simple question that people are likely to ask is: Since their chins and teeth are so similar, how do you know that this is not the upper jaw of Homo erectus?" Another problem is that even though it has been discovered for 50 years, people have not really understood "capable people" and have no exact definition. "