120,000 years ago, Neanderthals, close relatives of modern humans, ruled all of Europe, western Asia, and northern Africa. They have flat foreheads, huge teeth, and small cheekbones. They are only about 1.5 to 1.6 meters tall. They are short, stocky, and sturdy. However, 10,000 years after modern Homo sapiens left Africa and migrated to Eurasia, Neanderthals disappeared, and modern Homo sapiens became the only surviving ancient humans.
Although the reason for the extinction of Neanderthals is still controversial, many scholars believe that our ancestors were smarter than Neanderthals and thus won the fierce competition. However, some recent archaeological evidence indicates that Neanderthals may be smarter than we think. They will choose volcanic craters as a place to live. They know how to bury the dead and take care of the injured or sick. They also have aesthetic ideas, such as Neanderthals will apply colored clay on their faces to make up for themselves.
However, we cannot go back in time to meet with Neanderthals and understand what happened. However, some scientists are working hard to answer this question: Why can modern Homo sapiens survive, but Neanderthals are extinct?
Organ culture class
natural selection favored intelligence, because the higher the intelligence, the brain will be able to handle more complex information, people can work, live in larger groups. And new technologies and ideas can spread better among larger groups.
The size of a social group is related to the cerebral cortex, because the ability of communication and interaction between mammals is controlled by the front part of the cerebral cortex. In order to further understand the brains of modern humans and Neanderthals, geneticist Allison Modiri of the University of California, San Diego, cultivated Neanderthal organoids (mini brains) in the laboratory.
Some new technologies have made it possible to cultivate Neandertal brain-like organs. These technologies include: DNA extraction from fossil bones, gene editing technology, and cell reprogramming technology (which can induce skin cells to transform into stem cells). In 2010, a team led by Professor Sfant Pabo from the Max Planck Institute for Evolutionary Anthropology in Germany sequenced the Neanderthal genome for the first time. (Currently, the laboratory is also creating Neanderthal organoids.) After comparing human DNA and Neanderthal DNA sequences, Modiri replaced humans with designed Neanderthal gene fragments. The genes in the cells are edited to obtain stem cells carrying Neanderthal genes to cultivate organoids.
By comparing the brain organs of modern Homo sapiens and Neanderthal human brain organs, Modiri found that there are more gray matter (brain cells) and white matter (branch fibers of nerve cells) in the cerebral cortex of Neandertals. There are also more folds in the cortex. Neanderthal brains are actually bigger than ours, especially the occipital and parietal areas (a certain area of the cerebral cortex) responsible for processing visual and spatial information.
However, the brain resources are limited. The stronger the ability to process visual and spatial information, the weaker certain other abilities. This is a trade-off of the brain. Scientists speculate that in order to find high-calorie food in cold climates, Neanderthals obtained excellent visual and spatial perception capabilities (for hunting) in order to find high-calorie food in cold climates, but they reduced the processing of social information and The ability to live in a group. The lack of these abilities prevented Neanderthals from building larger groups, and their skills and ideas could not be improved. Although modern Homo sapiens have poor vision and perception of space, they are able to build larger social groups and have an advantage in survival.
Clone Neanderthals?
Although brain-like organs provide us with some Neanderthal information, some scientists still believe that this information is not comprehensive enough to better reveal the cause of Neanderthal extinction. Scientists believe that the cerebral cortex is not the only factor that affects the disappearance of Neanderthals. Many daily activities, such as walking and talking, will affect the survival of Neanderthals, but these are all related to procedural memory. Memory is stored in the area below the cerebral cortex, which we cannot observe in brain-like organs.
Therefore, studying the cerebral cortex alone has great limitations. Scientists including Modiri hope to cultivate a real Neanderthal brain. To this end, scientists are considering how to make all brain regions and put them together.
However, even if scientists have created the entire Neanderthal brain, this brain may not be enough to provide complete information for Neanderthal life, because behavior will be affected by both genetic differences and the environment. In addition, Neanderthals and modern Homo sapiens lived in the same era and on the same continent. There was no reproductive isolation between the two races. Except for Africans, modern humans carry about 2% of the Nian. Detite genes. Scientists still don’t know what kind of influence these genes have on us, such as whether humans will get type 2 diabetes because of Neanderthal influence. To solve such problems, it is also necessary to bring Neanderthal babies to modern society for raising, and to do comparative research.
Therefore, some scientists think: If our purpose is to understand Neanderthals’ thoughts and their influence on future generations, why don’t we cultivate a complete body through cloning?
The famous geneticist Professor George Church once proposed the cloning of Neanderthals. Technically, cloning a Neanderthal requires a lot of gene editing to create a Neanderthal embryo, which also needs to be implanted in the womb of a human mother. Ethically, the birth of a Neanderthal baby means the resurrection of this species. But this is an anti-evolutionary behavior. Many questions will follow, such as: how should we treat Neanderthal clones.
Some scientists believe that humans may currently be discriminatory and resentful towards Neanderthals. Moreover, Neanderthals live in an agricultural society, and their digestive system is probably not adapted to the food of modern society. At the same time, they also lack the ability to deal with some modern germs, and whether the Neanderthal clones can survive is also a question. And is the cloned Neanderthal just a sample of human scientific research? Can he enjoy the same rights as people? For example, does he have the right to reject any research done by humans on him because of his right to privacy?
On the one hand, it is the need of scientific research, on the other hand, it is the constraint of morality and ethics. Should we resurrect the Neanderthals? The discussion on this issue may go on for a long time.
