Why didn't chimpanzees with high genetic similarity to humans become human?

Genes and Experience Maurice Goodman, a biologist at Wayne State University in the United States, and others published a paper in the Proceedings of the National Academy of Sciences, proposing that chimpanzees (including common chimpanzees and bonobos) should be classified into human genera (the classification of organisms is domain, kingdom, class, order, family, genus and species). The reason is that they choose people, chimpanzees, gorillas and species. In view of the fact that genetic similarity accounts for the vast majority, and the difference accounts for only a small part (0.6%), they think that chimpanzees should belong to the genus of human beings, that is, the brothers of human beings.

Obviously, this view has had a strong impact on human-centered biological classification, and then it has caused widespread controversy among scientists and related personnel all over the world, both positive and negative. In fact, this is also an old saying. Why are most of human genes similar to primates such as chimpanzees, but their behaviors and intelligence are so different? Because humans and chimpanzees are obviously two different creatures, there will be no debate about whether chimpanzees and humans belong to the same genus or not. Will a genetic difference of 0.6% make a big difference in behavior and intelligence between humans and chimpanzees?

Obviously, the answer must be found outside the gene. Now, the answer has a clue beyond genes, that is, the experiences of humans and chimpanzees are different, which makes the two creatures very different. Because different experiences are the keys to different genes. Only by turning on specific genes can the intelligence, behavior and thinking of organisms develop and produce great differences. "Experience is wealth" is a fact or truth recognized by many people. According to past experience, the cognition that "experience is wealth" means that if a person experiences something that should be experienced in life and some unique events, he/she will learn from these experiences, become mature, become particularly wise and find the key to success.

"Experience is wealth", turning genes on or off through experience can also have another deeper explanation today, that is, experience is a key to turning genes on. With countless experiences or unique experiences, we can turn on all kinds of genes that we already have and are sleeping, and these genes are shared by all people, even primates. Experience will make everyone mature and unique, not everyone is the same person.

The relationship between life experience and genes can not only solve the difficult problems of "which came first, the egg or the chicken" and "whether human intelligence is innate or acquired", but also help to explain why the number of genes and the number of gene differences do not play an important role in the differences between intelligence and behavior, just as people have always wondered why the genetic differences between humans and chimpanzees are so small, but the ways of intelligence and behavior are so great. For the problems caused by the same and similar number of genes between humans and chimpanzees, gene hunter Venter, who participated in and promoted the early completion of the human genome project, believes that there are not so many genes supporting biological determinism; The wonderful diversity of human beings is not inherent in the genetic code. Our environment plays a decisive role. Other researchers' explanations are more firm. They believe that even if there are huge differences between humans and chimpanzees, only 33 genes are needed. The key is how the environment and experience turn these genes on or off.

A well-known parenting principle is that pediatricians always take pains to remind families who are just fathers and mothers not to stop babies from touching and exploring the world with their hands, and not to interfere as long as they are not touching dangerous things such as boiling water and fire. Because by touching, babies can turn on a variety of gene switches in the human brain early and widely, which is conducive to nerve development and understanding the world. Touch is a kind of learning or experience, which can expand the ability of human beings to choose their own path. The latest research proves that the human brain can be changed only by expressing 17 genes at the right time. Some of these genes are turned on and some are turned off to change the connection state of nerve cells in the brain, thus storing long-term memories. However, the turn-on or turn-off of these genes is dominated by human behavior. For example, babies feel the world with their hands, and all kinds of experiences after they grow up, whether positive or negative, will turn on or off some genes.

Therefore, experience is an effective key to unlock genes. It is behavior and experience that determine human genes, not the genes that determine behavior and experience. Only rich and complicated experiences will turn genes on or off, so as to acquire all kinds of knowledge and store all kinds of different knowledge in the brain.

The enlightenment of the mouse experiment is that success is not only about cars, houses and money, but also a perfect personality and spirit, full of compassion, and of course, if possible, it will be "a man of great talent who learned from five cars." If a good personality or personality (a part of emotional intelligence) is regarded as the key to success, it will be helpful to know how a mouse obtains a good personality.

Experience, whether active or passive, will turn on some genes, thus making people gain some wealth. A study by researchers such as Michael Minnie of McGill University in Montreal, Canada, found that mice that were often licked by their mothers in infancy were more calm and calm than those that were left out in adulthood. That is to say, whether there is maternal love or not, and the amount of maternal love will lead to great differences in the personality of life individuals in adulthood, which is exactly the same as human personality. This difference is due to the fact that the licking of the mother mouse activates the genes in the mouse to relieve the physical and mental stress in an emergency.

Minnie and others used more than 65,438+000 mice for experiments. All female mice feed and nurse their children normally, but there is a different behavior. Different mothers lick their children in different ways. Between the two groups of mice, the number of female mice licking mice was 4-5 times that of other female mice. The results show that in adulthood, mice that have been licked many times rarely have fear when encountering dangerous situations, and they also produce less stress hormones when teasing them, showing a calm temperament and personality characteristics. This is exactly one of the successful people that people pursue: fearless in times of crisis, calm and comfortable, especially "no anger for no reason, no surprise and no danger suddenly"

So, how did the mouse become a good character after being licked by its mother many times? It is found that there are many kinds of biomolecule receptors in the biological brain, among which there are receptors that feel stress hormones such as cortisol. The more such receptors in the brain, the more sensitive it is to cortisol, and the easier it is to send instructions to the adrenal gland of the human body to stop producing hormones, so there will be fewer stress hormones such as cortisol in the body, reducing the impulse of cortisol, thus maintaining a peaceful psychological state. Michael found that mice licked by their mothers had more cortisol receptors in their brains. The DNA of 50 mice that were frequently licked and 50 mice that were rarely licked were examined. It was found that the growth of cortisol receptors in the brain originated from specific DNA, that is, genes. These genes encoding cortisol receptors are much more active in mice that have been licked many times than in mice that have been licked less often.

This shows that the licking action of the mother mouse leads to the opening of cortisol receptor gene, that is, the maternal licking experience of the mouse leads to a large increase of cortisol receptor, thus reducing the production of cortisol and maintaining a calm personality. Separate the female mice from the young mice in the above experiment, and give the children of the female mice with licking hobbies to the female mice who seldom lick the mice, and the mice will be more nervous when they grow up; Conversely, if the children of mothers who lick their young mice less often are given to mothers who have licking hobbies, the mice will show less psychological tension when they grow up, and the genes that control tension will be more active.

More interesting and powerful evidence is that the young mice are all isolated from the mother mice, and the "licking" mice are replaced by manual touch-soft brush. The result is the same as that of a female mouse licking a mouse. The more brush contacts, the lower the psychological tension of mice when they grow up, and vice versa.

Consequences of Bad Experience The above experiments accurately detected the behaviors experienced by the offspring, especially whether the mother's behavior can produce different reactions in the offspring and the brain, and lead to personality differences in adulthood. But some people will argue that this is only the result of animal experiments. In fact, the same truth is reflected in every child's growth process. Children who grow up in loving families are full of kindness, and children who grow up in violent and abusive families also have too much violence and cruelty. This is all related to the opening or closing of genes.

Even if the formation of a child's personality and temperament has nothing to do with the genetic changes acquired in his growing experience, even adults will encounter such changes. The following is a small experiment about people's bad experiences.

Researchers at Chilters University in Buckinghamshire, southern England, found that working under an unfair or unreasonable boss can raise employees' blood pressure and increase their risk of heart disease or stroke. Employees feel nervous when they work under the supervision of bossy bosses, so their blood pressure will rise. The researchers recruited 28 female nurses from British hospitals, and measured their blood pressure every half hour during their working hours, 12 hours a day for three consecutive days.

Of the 28 nurses, 13 is supervised by two different people in turn on weekdays. One of them is a nurse's favorite, kind and reasonable. The other party is not liked by nurses and is bossy and unreasonable. In addition, the 15 nurse was supervised as a control group, but was supervised by one person and two bosses who were either kind and reasonable or bossy. The results showed that the blood pressure of the first group 13 people was significantly different. When they work under the supervision of a bossy boss, their systolic blood pressure is 2 kPa higher than normal, and their diastolic blood pressure is 0.93 kPa higher. But when they work under the supervision of an impartial boss, their blood pressure will return to normal or drop a little. When the control group 15 people work under the supervision of two just and unfair bosses, the systolic blood pressure is only 0.4 kPa, but the systolic blood pressure is almost the same.

This study shows that there will be great differences in blood pressure when working under the supervision of different bosses. However, previous studies have shown that when a person's systolic blood pressure increases by about 65,438+0.33 kPa and diastolic blood pressure increases by 0.67 kPa, his/her risk of coronary heart disease and stroke increases by 65,438+06% and 38% respectively. Coincidentally, in June 5438+ 10, 2002, a similar study in Finland proved that people who are strictly supervised at work, have low wages and lack career development opportunities are twice as likely to die of heart disease as their colleagues under normal circumstances. Therefore, nadia Weijie, a British doctor, said in Occupational and Environmental Medicine, a magazine sponsored by the British Medical Association, that an unpopular supervisor is an effective stressor in the workplace, and he may have a significant clinical impact on the supervised person.

Although these studies have not pointed out which genes are turned on and off by environment and experience, which leads to the increase or decrease of hormone secretion, stress response, high blood pressure and heart disease, they are similar in principle. That is to say, people's bad experiences are also a kind of "wealth", which can make people realize the negative impact of bad experiences on people as soon as possible, so as to take corresponding countermeasures, such as checking their weaknesses or giving play to their strengths to change the environment, or actively changing their jobs and working environment, or even changing their career, so as to turn bad experiences into wealth.