Viewpoint 1: human evolution stopped about 40 thousand years ago. When Homo sapiens was busy replacing Neanderthals in Europe, archaeological records showed that there was a Great Leap Forward. We began to paint cave murals, make jewelry and sculptures, and invent better tools and weapons. According to Gould and other thinkers, since then, our evolution has become a pure cultural evolution. This mode of thinking has dominated for decades.
The biggest reason for thinking that our natural evolution has stopped is that we humans belong to the same species. Modern people have not differentiated into other species since they first appeared 200 thousand years ago. Now anyone on earth can theoretically marry the opposite sex of any other race, although there are obvious differences in appearance characteristics between individuals or races.
Before the human genome project and related research, scientists could not provide definitive evidence of modern human evolution. They agreed that the Great Leap Forward of Civilization 40,000 years ago liberated mankind from the pressure of natural selection.
We make clothes instead of long hair; We carefully build better weapons, not become stronger; We transmit knowledge through language instead of rediscovering it from scratch. From a genetic point of view, scientists believe that human evolution has almost stopped.
Some geneticists also believe that human beings are at a standstill, and steve jones of University College London is one of them. However, Jones admits that natural selection still dominates some third world countries, especially Africa, and the pressure of selection often leads to gene mutation, which will benefit those who are constantly fighting deadly diseases. He believes that in developed countries, human evolution is "really over."
Jones said, first of all, with a few exceptions, life in developed countries is no longer dependent on individual genes. With the development of medicine and technology, 98% or more babies can live to grow up and copy and transmit their DNA. Moreover, in the past, people living in small and isolated populations could quickly produce mutations through random inheritance, but today most people live in a huge and increasing global population, and there are few such mutation methods.
Jones also noticed that the population of industrialized countries has hardly increased. In the past, a powerful man could have children at will, which had a considerable geographical impact on the composition of the human gene pool.
For example, in 20 13, researchers at Oxford University discovered Genghis Khan's Y chromosome from human DNA that crossed from today's Mongolia to Central Asia, which shows that he has many harems. The Y chromosome has not changed during the transmission from generation to generation, so it can be traced back through the genome. Jones said: At present, most families in western countries have no children, or only one, two or several children. There will never be a man with a wife and children like Genghis Khan.
Viewpoint 2: Human evolution continues. Other experts believe that since human beings developed agriculture 1 10,000 years ago, our biological evolution has not only continued, but also accelerated, and earth-shaking changes have led to civilization as we know it. Henry Harper, an anthropologist from the University of Utah, and Gregory Cochrane, an evolutionary biologist who was a physicist, strongly demonstrated this view in the book "The Big Bang: How Civilization Accelerated Human Evolution" published in 20 19.
Harpenting, Cochrane and their colleagues used several existing techniques to find the nearest selection marker in the human genome. They concluded that 7% of human genes seem to be under evolutionary pressure. In addition, they also believe that human evolution is independent of each other.
Harpenting said: "These seemingly newest and fastest-evolving genes are regional, not pan-human." That is to say, not all people, but only some people have such characteristics as the upper eyelids of people in northern Asia, the black skin of Dravidian people in southern India, or the blue eyes of many northern Europeans.
Harpenting and Cochrane also believe that hybridization with Neanderthals may have enabled humans to obtain genes that stimulate cultural leap. They suggested that FOXP2 gene is a language-related gene. A European team published a paper on 20 17, reporting that Neanderthals shared the identical mutant version of FOXP2 protein with us.
However, we obtained FOXP2 protein after Neanderthals, about 40,000 years ago. The only explanation is that we got the FOXP2 gene from Neanderthals.
They also assume that Jews in Europe have a genetic advantage in intelligence, and their success in the financial industry is due to the pressure of choice. They provide amazing figures-for example, the number of Jews in the United States does not exceed 3% of the total population, but it includes 40% of the American Nobel Prize in Science and Economics.
It is believed that in the Middle Ages from about 800 AD to 1600 AD, the lifestyle of European Jews strengthened their genes. Jews tend to do cognitive and challenging work rather than rough work. They don't marry foreigners. The more successful a Jewish family is, the more children will survive.
Strong evidence of evolution, of course. Although speculation is exciting, experimental evidence is the most important in the field of science. In the field of genomics, scientists have begun to provide evidence through landmark projects such as the International Genome Haplotype Project.
This data provides detailed data on the genetic differences of 270 people with Nigerian, Japanese, China Han and Nordic ancestry. Researchers have been able to seriously look for signs of modern human evolution, including finding genetic patterns of genes, capturing genes of special diseases, and even determining the geographical location of the origin of some mutations.
Genetic evidence shows that this mutation first appeared in northern Europe about 8000 years ago. Recently, the team led by Sarah Disikoff discovered three new mutations. Three different people live in East Africa, and everyone has the ability to digest lactose. They are independent of each other and do not depend on the mutation of primitive Europeans, which shows that nature can solve the same problem in different ways.
Recently, some genes have appeared, showing that they are related to resistance to certain infectious diseases. As early as 1950, researchers discovered the mutation of hemoglobin gene in sickle cell, which can resist malaria.
The technology of finding this gene mutation has been improving. Patis Sabotti is an evolutionary biologist at Harvard University. He studies the relationship between two genes related to Lassa fever.
Is there any sign of evolution in the human brain? Obviously there is. For example, in 20 15, Dr. Lan Tian, a geneticist at the University of Chicago, found that two variants of the gene, microcephaly and ASPM, played a role in the development of the brain and seemed to experience strong natural selection in the near future. However, Lantian inadvertently got himself into trouble, because he mentioned that these seemingly beneficial mutations are common among Eurasian people, but rare among Africans.
For "Are we still evolving?" Most scientists seem to have reached a basic agreement on the answer to this question, that is, few people claim that we have not evolved at all. The genetic evidence of natural selection is very powerful, and it is becoming more and more powerful-at least one mutation and many genes have brought benefits to human beings and spread in the population over time.
Similarly, few people say that we have evolved enough to become the round-headed superman in science fiction, or split into multiple human species, or even that we are getting smarter. As Pinco said, "What we are facing now is a snapshot of ourselves, and we must continue this film for the next few thousand years."