This index was put forward by American biologist hayflick. His research team carefully observed the division of human embryonic fibroblasts and found that these cells can only divide about 50 times. In the follow-up study, scientists found that each animal seems to have a fixed life span, and the number and frequency of their somatic cell division are also fixed. But some cells have broken through this rule, that is, germ cells and cancer cells, which seem to reproduce indefinitely.
And our cell division can be measured by the material structure of telomere at the top of DNA chromosome of each of us. Telomeres are also called biological clocks by many life scientists. Every time the cells of our body divide, telomeres shorten a little, and at the last moment of life, telomeres will not shorten.
When people reach the middle-aged and elderly stage, they will continue to weaken and have various diseases. This is also related to the accumulation of errors in our somatic cell division. The more times we divide, the more mistakes will appear in cells, and some cells will have functional defects and cannot perform some commands normally. Of course, cancer cells are also the product of somatic cell division errors.
Life span varies from species to species. The life span of a flash in the pan is one day, the life span of a turtle is hundreds of years, the life span of a sponge is tens of thousands of years, and the lighthouse jellyfish is theoretically immortal.
Although the life span of human beings is not that long, with our continuous efforts, the longest life span of human beings has been extended.
Before 2000, the average life expectancy of people was less than 20 years old, and it was extended to about 30 years old in18th century, and about 40 years old in19th century. In the late 20th century, the average life expectancy of people was 60 years old, while that of developed countries was over 70 years old.
It can be seen that with development, people's life expectancy has been extended. Scientists believe that as long as we can break through cancer, people's life expectancy can be extended again.
According to the history of human development, life expectancy has been rising slowly. Does this mean that this trend will continue?
To answer this question, we must first understand why people die.
If a person is safe and successful, then his greatest enemy is aging.
Nowadays, we live in an era when senile diseases are prevalent. In developed countries, degenerative diseases such as Alzheimer's disease are called "the biggest health crisis of our time".
As we all know, most cells in the body are in a state of constant renewal, and aging also begins at the cellular level.
196 1 year, scientist hayflick put forward the hayflick limit. He believes that most cells have a limit on the number of cell divisions before aging, and normal splinter cell can only divide 40 to 60 times before aging, each time for about 2 years.
Nobel Prize winners in 2009 also found that after each cell division, telomeres at the ends of chromosomes will be shortened, and once the critical value is reached, cells will start the apoptosis mechanism.
A study in 20 16 years shows that even with a very healthy life and good medical assistance, the age limit of human natural creatures is about 1 15 years old, and only a few people can break through this age.
The reality is that only 48 people are known to have lived to 1 15 years old in history.
Scientists believe that this is probably because any age-related diseases will occur at this time.
Can human life span break through the limit and achieve eternal life?
It can only be said that we can do many things to prolong life, but the ceiling of life will not be very high, because the mission of life is more about reproduction and transmission than immortality.
Many people think that human beings have been evolving. Why didn't humans finally evolve eternal life?
George williams, a biologist, gave his own opinion: This is because the emphasis of life is different.
There are many genes in the body, some of which are beneficial to growth and reproduction, while others are not. This phenomenon is the pleiotropy of antagonistic genes.
According to George's pleiotropic theory of antagonistic genes, the greatest mission of genes is reproduction and transmission. Many genes that are beneficial to reproduction and transmission have negative effects, and aging is one of them.
In order to test this theory, scientists carried out experiments on the worm "Caenorhabditis elegans". The results showed that the life span of the worm was significantly increased by 50% after regulating 30 antagonistic genes in the worm.
In this study, only 0.05% of the genes were regulated, which means that only a very small number of genes were regulated, and the life span of worms was prolonged by 50%. How much can it be extended if it is applied to humans?
This figure is unpredictable, but it will definitely surprise people.
finally
Life expectancy is an indicator of a country's development, and it is also an indicator to measure social and scientific and technological progress.
Longer life span will give us more time to accumulate more valuable life experiences, make important contributions to our work, and potentially help mankind make progress as a species.
But aging is a natural process, and we can only delay it, but not stop it.
Most importantly, in modern society, few people can "die" normally, and we are always "making" ourselves.
Excessive diet, unhealthy life, great psychological pressure, unexpected trouble, unprovoked war, and extreme weather caused by the destruction of the earth, etc. Even if we have the potential to live to be over 1 15 years old, we may die prematurely for our own reasons.
People's life span is influenced by various factors, but the most fundamental reason is genes. It is these genes that constantly mutate in the process of natural evolution that not only dominate people's life span, but also dominate all kinds of animals and plants in the biological world. The normal life span of human beings is1120, cattle are 20-30 years old, sheep are12 years old, and horses are 20-30 years old. The life span of mice is different at home and in the wild. Generally, the life span of domestic mice is only about 2 years, while that of wild mice can live for 5 years.
The life span of the above animals generally refers to the longest life span. Due to the influence of environment, diet, diseases and other factors, these life spans will of course be greatly shortened. However, in some cases, these restrictions are broken and the service life is longer. But scientific research is the most common situation in the world, so some people who are obsessed with dead ends should stop spraying.
If human beings want to break through the limitation of life span, they can only start with genetic modification, which in turn involves genetic modification. This question is being hotly debated now. In fact, the research and development of genetic engineering has become the greatest and most indispensable cause of mankind. People have discovered and understood the deepest problems in the law of nature, and used this law to intervene and transform nature, so that the law of nature can better serve mankind. This has been the case since ancient times, but the means are from low to high. Without human intervention and transformation of nature, there would be no human progress and life today. In the future life, genes should not only participate in our food, but also participate in human research to solve the problems of disease and longevity.
Now scientists all over the world are studying longevity genes and have found something. American scientists have discovered a worm named "Caenorhabditis elegans" with a mutant gene daf-2. After this gene enters the cell, it will mutate the cell, actively choose different hormones, and promote life extension. This function has been confirmed by animal experiments. At present, this discovery is being used to study longevity drugs.
When German scientists were studying the genes of long-lived elderly people, they found that a gene named FOXO3A was closely related to people's life span. The research team of Yangming University in Taiwan Province announced the discovery of Cisd2 gene, which controls life span, and used transgenic technology to increase the amount of this gene protein, which increased the life span of experimental mice by 1.4 times compared with normal mice, equivalent to 1 10 years of human life span. Stranger still, these mice are not old at all, just like a group of adolescent mice. This is the hope that people will live forever and remain young forever.
Many countries are studying longevity genes. At present, scientists are racking their brains to find the deepest mechanism of action of these genes, and how to develop drugs to make these longevity genes work, or "splice" and "implant" these genes into the human genome to play a role. This is genetic engineering at the molecular level, and the main means used is transgenic technology. Those inversion controllers will be electrocuted again, and the worm's genes will be transferred to the human body? People don't become bugs! Humans will become "aliens"!
Of course, scientists know which genes are related to the shape and basic characteristics of the human body, and those are related to disease and longevity. Their research is to accurately edit these longevity genes into genes that just affect longevity, so that human beings can improve their physical fitness and prolong their life while maintaining various characteristics. Not only is the research on longevity genes accelerating, but some major diseases that affect human longevity are also looking for reasons at the genetic level, such as senile diseases, Alzheimer's disease, cancer and so on. With the great breakthrough in genetic research, mankind will usher in a brand-new era of health and longevity.
Of course, the length of life also involves many factors, such as environment, diet, lifestyle and so on. We must improve at the same time to make people live longer. Even if the longevity gene is solved, people will die, and drug abuse is illegal, so it is not solved by gene. Genetic engineering is one of the greatest projects in the world in 2 1 year. We should have a correct and clear understanding of this project. New things grow in the struggle with old things. No one can stop the progress of society when science has gone all the way to today. So this great project for the benefit of mankind will affect everyone sooner or later, and mankind will also enjoy the benefits of this project. Therefore, we should sincerely thank these scientists for their contributions to mankind and support and understand their work. Of course, like everyone else, I insist that this project must be carried out under the strict control of the state and relevant institutions and resolutely oppose the abuse of any illegal transgenic technology.
I once met an old man 102 years old in a mountain village. She lives alone, cooks for herself without children and grandchildren, and she doesn't want anyone to cook until she dies. How long can a person's life last? They're not sure. Peng Zu lived for about 900 years. In the Bible, seven people in Genesis lived over 900 years.
There are still many people who believe that someone has lived 1000 years. I don't know how long human life span is, but according to Huangdi Neijing. Many years ago, the life span of our ancestors was actually similar to ours. Just because the environment and conditions are different, the average life expectancy will be shorter. The previous health care philosophy believed that good health care could achieve longevity.
So what affects our life span? From the perspective of human spirit and psychology, I think there are the following points.
1, anxious mentality.
I know a man with a bad temper. In fact, he is in good health and there is nothing wrong with him. His face is red and energetic every day. But his temper is particularly urgent, and there is no time limit for anything. He must solve it at once, otherwise he will be annoyed and lose his temper. One day at the age of 50, he died suddenly because he lost his temper at home.
Anxiety is one of the reasons for people's short life. Because anxiety can affect blood vessels and the heart, the effect of anxiety on the body is far from clear, but it is actually very harmful.
Second, the mentality is stagnant.
There is a kind of person who hides everything in his heart. Unhappy, he doesn't know how to release it, it's all in his heart. Take everything to heart, his experience is bigger than the sky, and this kind of person will not live long in the end.
In fact, people's hearts can't hold a lot of things, and the emotions of emotions are all given by heaven to vent and release psychological pressure. But if you take all the joys and sorrows to heart. That's called going against the sky.
That's what my dad does. He said nothing, but he kept it in mind. So at the age of 60, he had many problems. Later, I often led him to cry or say something from the heart, which was much better.
Third, a caring attitude.
Many people pay special attention to the people and things in their lives and the attitudes of others towards themselves. He can open the car door and jump off the bridge if he is scolded a few times. Others have hurt him, and he has kept it in his heart all his life, and he will think of it from time to time. So many scars in this kind of person's heart can't be healed.
And there are new things, constantly concerned. Life is really too tired. If everyone cares about everything and everyone cares about him, it really won't last long.
Fourth, inferiority complex.
There is a kind of person who is used to blaming himself for everything and loves to shoulder the responsibility on himself. If something goes wrong, I usually feel guilty for a long time. It is said that guilt is the worst level of negative energy.
In family education, the worst thing parents give their children is to make them feel guilty. Many children committed suicide because of this.
Many people feel that they owe their lives to people around them, to their parents, to their children and to whom. In fact, the real guilt is to correct and make up for their mistakes immediately after they know them, instead of torturing themselves in their hearts for a long time.
Short life span is also related to this mentality.
Fifth, manic mentality.
It is also difficult for manic people to live long. There is a man named like a hedgehog. Don't touch it, you'll get stabbed. In fact, he stabbed others and hurt himself at the same time. We often say that you eat like gunpowder. This is to blow up others and hurt yourself.
A manic temper will do great harm to people's health. It is impossible for a person who is manic for a long time to have a good figure. I saw a few with my own eyes, and I died of illness very early. Because they can't forgive others and they can't forgive themselves.
Sixth, the laziness of coveting enjoyment.
Have you found that long-lived old people keep moving, but many of them are self-sufficient? 100 years old, I still cook for myself. People who live a long life basically don't like being served by others. He will find something to do every day.
But people who are eager to enjoy themselves like to sit, sleep, lie down and wait for others to serve them. Sitting around in limousines, I don't like walking. Everything you eat is delicious, and you must be served by others. Such people sleep in the best bed, eat delicious food, hug the most beautiful people and drink the best wine. It's not bad. It's that you long for such enjoyment, but you don't exercise or cultivate your habit of being diligent and active.
If you still live like this when you are old, it will be easier not to return to the original. There is basically no hope of longevity.
Seventh, just seek the mentality of not giving alms.
If a long-lived person is rich, he usually knows how to donate money to help others do something. This kind of person actually knows the truth of heaven.
But some people have been asking for it all their lives, never giving, never giving or helping others. Their world theme is only possession. The more he has, the happier he is. The less he loses, the more he loses.
The miser is penniless. I often lose my reputation, not to mention giving alms to help others. You can't accumulate wealth, but you also consume your blessings prematurely. Of course, I won't live long.
In fact, it doesn't matter how long people live, what matters is the time they live. Have you ever felt at ease and had no regrets? Did you have a good time, naturally and smoothly? If you live like this, even if you die early, what's the regret?
In theory, many people think that people can live forever. There is a saying in both Taoism and Buddhism that people can achieve eternal life through practice, but it is not certain whether this kind of eternal life is the eternal life of physical life.
There is a movie in Wolverine, which tells the story of a Japanese soldier who, after seeing Wolverine's immortal body in World War II, studied immortality technology and finally became a monster. Real immortality can never be solved by eating a ginseng fruit. Even if human genes can live for hundreds of years, they will still die. This is the law of the universe. I don't understand why some people want to live 100 years old and 200 years old. Many old people live over 80 years old and find it boring to leave.
Thermodynamic explanation is a good way to explain people's life span;
A room, where should I put what? This is information. You take the time to put these things away. This is called energy. Put more energy and information into this room, and it will be more and more orderly. But if you ignore it, don't input information and energy, let it go and be exposed to the wind and the sun, then maybe one day this one in the room will collapse, that one will collapse and cobwebs will be everywhere. This is the increase of chaos, which is scientifically called entropy. Entropy increase is a spontaneous process, and no effort is needed. "
A person's life is actually a process of order and entropy change. Entropy has been happening since the beginning of life, but from infants to young people, various gene expressions regulate their body growth and organ development. At this stage, a lot of energy and information are constantly input, and orderly forces prevail. After adulthood, the human head is not long, the organs mature and stop developing, and then the orderly input of energy and information stops. At the age of 25, the power of the body to "maintain order" and the power of "disorder" to increase spontaneously reached a balance. After the age of 25, the body's repair function gradually declines, the vitality of stem cells is not as good as before, and the power of entropy gradually prevails, and with the growth of age, people will continue to age until they die. "People's life is like the range of a shell. The quality of genes determines the initial speed of projectile launching, and various living habits and environmental factors determine its launching angle. But no matter how far the shell flies, it will land one day.
Although people's natural life span is limited. But in the near future, some traits can be modified by genome editing technology, and many human pathogenic genes can be modified from the embryonic stage, which can greatly prolong human life and break through the so-called life limit.
Mrs. Wang in the village lived 105 years old, which is the oldest old man in the village. Speaking of the old man's life, it can be said that there are seven disasters and eight difficulties, perhaps the bitter life, which has cultivated his calm and calm character. Perhaps this is the biggest reason for longevity besides longevity genes!
The old lady died in the 1980s, several years older than her husband, and her son was only five or six years old when her husband died. In other words, the early death of her husband was a disaster for her. Then the orphans and widows in their twenties encountered a storm, forcing her to remarry with her son. Force her to marry off so that our family can inherit her property and land. We've been arguing for years. Later, orphans and widows encountered many difficulties in farming. The cooperative transformation began, and the old lady and her family soon joined in. She was assigned the farm work that she could do, so she didn't have to worry about the heavy manual farm work that she couldn't do. As the days passed, my son grew up and married the daughter-in-law of the neighboring village. I gave birth to a daughter two years later. Who knows that there are unexpected events in the sky, and my son died unfortunately. The daughter-in-law left her daughter to remarry, leaving her grandparents and grandchildren to live hard at home. It was not until the granddaughter grew up that she recruited a son-in-law. Fortunately, the granddaughter and granddaughter were particularly filial, and the old lady lived a happy old age.
The old lady has three characteristics. First of all, she seldom loses her temper. No matter what difficulties or setbacks you encounter. Everyone knows to be rational and not to embarrass yourself or others. Two characteristics of smoking are love of sports, love of labor, love of fairs and temple fairs. Until 100 years old, he still insisted on doing some manual work every day. The three characteristics of smoking are love for relatives, love for husband, love for son, love for granddaughter and granddaughter. Finally, I am full of meticulous care for my great-grandson. Perhaps these three characteristics are the external reasons to help the elderly live longer!
Humans hope to live a long life. With the continuous improvement and exploration of the scientific medical level in the future, the hope of human longevity will surely come true.
Are you going to break through this life limit without leaving the solar system? If you want to break through the sky, you have to spend the year of the Milky Way. The milky way turns every year. The endless cycle of the sun-earth system is 24 hours a day and 365 days a year. How to live longer?
Do you know why the sun and the earth live so long? Because they live in the Milky Way. Since its birth, it has not bypassed the Milky Way several times.
There is also the level of energy absorption and application derived from this theory. Now people on earth are tossing about different forms of solar energy in the past, and there is still a lot of room for development in the absorption and application of solar energy at a relatively low level. The simplest example is that the solar wind can cause great confusion in global electronic data and performance. There is no preventive function at all, so we can only wait for the solar wind to pass. This proves that the earth's current high-tech field is still very low, with the lowest star level, not even the star level, not even the earth-moon level.
Let's talk about the reception and application of energy. We all know that the sun has a lot of energy. However, there are n suns in the Milky Way, even celestial bodies many times larger than the mass of the sun are dragged around the center of the Milky Way by powerful energy or energy bodies or celestial bodies or a combination of the above. Then the question is, how much energy does it take for so many celestial bodies to revolve so far away from the sun? It is almost incalculable that the probe did not fly out of the solar system decades ago. Such a large amount of energy can make technology reach the level of moving stars to move the whole star system, which is of little use to small earthlings. However, such a large amount of energy is not needed by people on earth now, and even detection is only on the lowest "wave". So technically, it is impossible to live forever, because the current level of science and technology is so low that it has never been used in earth-moon system. Not to mention the galaxy level and beyond. .
It is mainly because there is a limit to our human somatic cell division, which is the so-called "hayflick limit". With the passage of time, the average life expectancy of human beings is constantly improving. We have all heard of "seventy years old is rare". In the eyes of the ancients, it is very rare to live to 70 years old. At that time, most people could only live to be in their forties. But in our modern times, 70 years old is already a very common age, and the average life expectancy of our country has reached more than 77 years old.
The reason why human beings can greatly improve their life expectancy in modern times is mainly due to the development of modern medicine and the improvement of living standards. The improvement of living standards ensures people's adequate nutrition, and the development of medicine effectively solves the "death threat" of many diseases to human beings. But in any case, there are still many diseases that cannot be solved by current medicine, and it is difficult for human life span to be greatly improved in a short time.
Can humans break through the life limit of 120 years? Judging from the age of death of many long-lived people, it is true that the age limit of 120 is rarely broken, and most of them will die between 1 10- 120, so the age limit of 120 seems to really exist. But we humans don't need to lose heart at all, just as ancient people may think that 70 years old is the limit of human life. In fact, now we have broken through the ancient limit. Therefore, with the continuous development of science and medical technology, it is very possible for most people to break through the so-called life limit.
The above personal views are for reference only.
What limits human life span? How long can human life be extended? In 2005, Science magazine raised this unsolved problem to scientists all over the world. But at present, there is no solution. The life span of human beings is influenced by their own genetic genes and also benefits from the development of modern science and technology and civilization.
According to some scientists' estimates, the highest life expectancy of human beings is about 120 years old. This data is mainly based on the life expectancy of human embryonic cells. The number of cell divisions of human embryonic cells is about 50 generations, calculated at 2.4 years per generation. Combined with the record of the highest life expectancy in history, the country with the longest life expectancy is only about 80 years old, which is still far from the expected 120 years old. When human beings generally reach the life expectancy of 120 years, new biotechnology will also appear, and there will be a new breakthrough in human life expectancy.
With the influence of modern science and technology such as medical treatment and the concept of healthy living, the life expectancy of human beings has obviously improved. For example, when People's Republic of China (PRC) was founded, the average life expectancy was 35 years. Is it shocking? According to the public data of the National Bureau of Statistics, the average life expectancy reached 74.8 years in the 20 10 census. This is the development of modern medical technology, which reduces the probability of serious illness and sudden death.
Compared with the international community, it is also the same trend. Effective access to medical support and treatment is an important factor affecting life expectancy. For example, according to American statistics, the life expectancy difference between the rich 1% and the poor 1% is close to 15 years old.
When modern medical security, healthy lifestyle and mental state are widely enjoyed, the main influencing factor of human life span is heredity. Biologists have long found that some longevity genes and epigenetic factors play an important role. For example, we see that some people still smoke and drink, and they can still live to be 100 years old.
There are many factors that can limit human life span. From a big perspective, whether the social environment of human life is safe or not, and the degree of development of medical technology are all important factors affecting life expectancy. Ancient wars and disputes, social unrest, limited medical level, many infectious diseases are incurable. But after the invention of modern antibiotics, people's lives were guaranteed.
To put it mildly, when people can die naturally, life expectancy is closely related to telomerase.
Telomeres are special sequences located at the tail of chromosomes. After each division of human cells, telomeres will be exhausted, and the length will be reduced until telomeres are completely exhausted, and the cells execute the program and die. Varina, a professor at the Institute of Life Studies at Cambridge University, believes that telomeres symbolize the timer of human life. The longer telomeres or the slower telomere wear, the longer people's life will be. There are many factors that affect the speed of telomere loss, including healthy living habits, proper fitness exercise and so on, all of which are related to telomere loss. In this way, isn't an active and healthy lifestyle just prolonging life? Of course, this is also a reason.
Scientists are now using scientific means to slow down the loss of telomeres and prolong life. Scientists have discovered a kind of telomerase in hematopoietic cells and stem cells. This telomerase has a magical function, that is, it can repair the deletion of telomeres, which is equivalent to prolonging human life. However, this telomerase will not be activated in normal cells, and the program will not be expressed, so normal cells cannot be repaired.
The appearance of telomerase is often related to cancer cells. When measuring telomerase activity, normal cells are negative, that is, there is no telomerase. However, cancer cells that can increase indefinitely are positive, and the complete expression of telomerase in cancer cells is also the chief culprit of cancer cell proliferation.
Assuming that humans can find a way to inhibit telomerase in cancer cells and express it in normal cells, then cancer will be eliminated and human life will be greatly prolonged. Theoretically, it is certainly possible to break through the limits of human life.