Man in a civilized society lives more and more socially and less and less biologically. He successfully overcomes the restrictions that nature has imposed on him: he lives in any climate, develops new food resources, and has learned to fight infectious diseases. Many factors that used to kill a human being have now ceased to be fatal to him. Doctors have learned to nurse premature and weak newborns; vaccination protects against dangerous infections, and in case of infection, antibiotics fight the infection; society takes care of the sick and disabled. Even though all this does not work perfectly, civilization has radically increased the biological fitness of man - his survival in the environment. But a person cannot get away from his genetics, and we are not yet able to change the processes taking place under these conditions. We tried to understand what is happening with a person today and what awaits us in the future with the help of an evolutionary biologist, Doctor of Biological Sciences Alexey Kondrashov, professor at the University of Michigan and the Faculty of Bioengineering and Bioinformatics of Moscow State University, who gave a public lecture at the All-Russian Festival of Science - 2012.

In terms of evolutionary biology, modern man natural selection acts less and less, that is, such a force that removes less adapted individuals from a population, leaving more adapted ones, since the latter leave more offspring. " There is positive and negative selection., - explains Alexey Kondrashov. - Positive selection favors some new useful trait. For example, everyone in the population was white, then a black mutant appeared, this feature turned out to be useful, and after a while the descendants of this black mutant can flood the entire population. And negative selection, on the contrary, favors old and common traits. Everyone is white, and being white is good, but a mutation occurred and black appeared, and being black is bad. Accordingly, the offspring of this mutant will not survive, and the "black" gene will fly out of the population. Darwin was mainly interested in evolution, i.e., slow change, and he mainly thought and wrote about positive selection. And Ivan Ivanovich Schmalhausen thought and reasoned a lot about negative selection". It is this selection that is weakened in modern man - unfavorable genes do not fly out of the population, but accumulate. At the level of the general concept, this became clear a long time ago, but in last years thanks to the development of modern methods of research, data have appeared that make it possible to quantify this process.

Errors in biomolecular machinery

Mutations are constantly taking place in our DNA - changes. This does not require exposure to radiation or chemical mutagens - the process is spontaneous. " As the Buddha said, everything that is made up of parts is destroyed, - says Kondrashov . - Before leaving for nirvana, he gathered the students and said these four words. With regard to biological molecules, the Buddha was completely right, indeed, they are made up of parts and can be destroyed. And the mutation process is a manifestation of the tendency of the entire material world to chaos.". Mutations are inevitable, since DNA is a very long molecule (the total length of all genomic molecules in a human cell is about one meter) one nucleotide thick - naturally, it cannot be perfect.

There are three main sources of mutations. The first is the errors that occur during replication - the duplication of the DNA molecule. The main actor in this process is the enzyme DNA polymerase. After the DNA double helix unwinds into two separate strands, DNA polymerase goes along each strand and assembles a pair to it, using the old strand as a template. That is, if she sees the letter A (adenine) on the old thread, then she attaches the letter T (thymine) to the new thread. " But about one in 100,000 times she puts in the wrong letter, explains Alexei Kondrashov. - And the most remarkable thing is that after she attaches the letter, she immediately tries to tear it off. As a result, it turns out that the letter is attached incorrectly with a probability of approximately 10 -5, and if the letter is incorrectly attached, then it will not be torn off with a probability of 10 -5 too. So the probability of mutation is about 10-10 per letter per replication. Try typing and agree that DNA polymerase works great».

However, replication errors that occur with a probability of 10 – 10 per letter is the main source of mutations. The second source of mutations is errors in DNA repair. Repair is the repair of damage, and damage is that which breaks the chemical structure of the molecule so that the DNA becomes corrupted. We are talking, for example, about breaking one or both threads, stitching the threads together not by weak hydrogen bonds, but by covalent bonds, so that they cannot separate, etc. " In every human cell, several hundred thousand spontaneous injuries occur every day, - says Kondrashov. - And they must be repaired, because otherwise the cell will die. And if some error occurred as a result of the repair, this will also be a mutation". The third source of mutations is errors during recombination during meiosis - a reduction cell division leading to the formation of diploid cells with a double set of chromosomes, haploid cells with a single set of chromosomes. This is a necessary stage in the maturation of germ cells, and during recombination - when chromosomes exchange pieces - errors can occur.

What and how much

99% of mutations are nucleotide substitutions, says Alexei Kondrashov, for example, when cytosine (C) changes to guanine (G). This is the source of single nucleotide polymorphism ( single-nucleotide polymorphism, SNP). In addition, there may be short drops of several letters or, conversely, short insertions of one, two, or three nucleotides. Big events happen less often - dropouts or insertions of 100 or more, sometimes up to a million nucleotides, or a turn of some piece of DNA by 180 °. It must be understood that mutations are not always bad. This is the source of genetic variability, and without mutations there would be no evolution, as a result of which all the diversity of the living world arose.

With the advent of next-generation sequencing methods, the cost of sequencing whole genomes has drastically decreased. And there are new opportunities to quantify the rate of occurrence of mutations. If earlier, as Kondrashov recalls, he had to spend several years painstakingly studying the wings of fruit flies and selecting mutants, now for $ 300 it is possible to sequence the genotypes of a mother fly, a father fly, and a daughter fly and compare them. As a result, all new mutations that occurred during the generation change will be detected, which means that they arose in the germ cells of the parents. As far as humans are concerned, the rate of mutations in the human genome, as scientists have calculated, is about 10–8 per generation per nucleotide.

Pitfalls in the genome

All people differ from each other in many external and internal signs. And genetically, two human individuals differ by one letter of the genetic code for every 1000 nucleotides. One difference in 1000 is not much, considering that, for example, Drosophila has one difference in 100, and the fungus schizophyllum has one difference in 10, and this is today an absolute record of genetic diversity. And still, this is a lot and means that between two human individuals there are 35 million short differences, one-letter substitutions. But since each amino acid is encoded by three nucleotides (a triplet, or codon), not all nucleotide substitutions in DNA lead to a substitution of an amino acid in a protein, but only the so-called non-synonymous ones. And there are about 10 thousand such non-synonymous substitutions, leading to a change in the protein molecule, in each person in protein-coding genes. Approximately 10% of them are not useless, but harmful, which reduce fitness. Some of them are deadly. Biologists have found that both Drosophila and vertebrates have, on average, one or two lethal mutations per genotype. The organism does not die because these mutations are in a heterozygous state, that is, the mutant gene is duplicated by a normal gene on a paired chromosome. In addition, the human genotype, on average, carries about 100 large DNA insertions and drops, the total length of which is about 3 million nucleotides. Genotype Nobel laureate, co-inventor of the double helix model of DNA, James Watson, was sequenced to carry the usual number of mildly deleterious mutations and 12 highly deleterious mutations that hide behind normal genes in the heterozygous state. Obviously, they did not affect the fitness and success of James Watson. But if there are even more harmful mutations and they are not cleaned out by selection, the balance will be disturbed, and fitness in the human population will inevitably decrease.

As Aleksei Kondrashov emphasized, this problem was understood even by Darwin, who wrote: “ Among the savages, those who are weak either in body or in mind perish quickly. And those who survive usually show strong health. And we civilized people do our best to prevent this process of elimination: we create shelters for the mentally retarded, the disabled and the sick, we make laws that support the poor, and our doctors try their best to save the life of every person to the last possible. There is reason to believe that vaccination has saved hundreds of lives that would otherwise have died from smallpox. Therefore, even the feeble-minded members of civilized societies continue to multiply. Anyone who has been interested in breeding domestic animals will have no doubt that it is extremely harmful to the human population.».

Fly model of humanity

Interestingly, it turned out to be possible to confirm in the experiment. Such an experiment - to exclude selection - Kondrashov and his colleagues set up 15 years ago. They modeled the living conditions of modern man on Drosophila flies. Pairs of flies - a male and a female - were settled in separate "apartments" - test tubes, where they did not compete for food with other flies, as happens with "communal" resettlement. The couples produced offspring, with biologists limiting the number of eggs laid to prevent competition between the larvae. From each “family” of flies, young male and female were taken, mixed and settled in pairs in new “separate apartments”. The exclusion of selection was expressed in the absence of competition and in the fact that each pair, regardless of its genotype, brought the same number of offspring. And so for 30 generations. Every 10 generations, scientists assessed the fitness of the larvae - their competitiveness for food in harsh conditions. As a result, during the experiment (for 30 generations), the fitness of the larvae fell by more than half. And in one generation, the researchers calculated, it fell by 2%. Aleksey Kondrashov believes that in nature it would decrease even more than in the laboratory. " I would like to repeat this experiment and stretch it for at least 100 generations, because there is a hypothesis that after 100 generations the flies will all die».

It is hoped that in the near future, scientists will be able to directly see what is happening with the human genome. When the 1000 Genomes project is completed, they will have 1000 fully sequenced individual genomes (genotypes) in their hands, which can be compared for mutations. And in ten years there will be a million of these genomes. " Negative selection is more common by several orders of magnitude than positive selection. Therefore, the reasoning that after some time due to positive selection we will have a huge head and small hands and we will all be very smart, etc., is all the subject of science fiction.”, - specifies Alexey Kondrashov. But what will happen to our health is the question. However, in ten years it will be possible to answer it more or less accurately, because we will be able to quantify the changes taking place in the human population.

About the risks of late fatherhood

To reiterate, the mutation rate in humans, as geneticists have calculated, is about 10–8 per generation per nucleotide. But it is interesting that men and women contribute differently to the mutation of their children. Namely, the child receives several times more mutations from the father than from the mother. The first to show this difference was the English geneticist John Burdon Sanderson Haldane ( John Burdon Sanderson Haldane), one of the creators of the synthetic theory of evolution. He explored the genetics of hemophilia, a hereditary disease expressed in blood incoagulability. It is known that the gene responsible for hemophilia is located on the X chromosome. Therefore, women who carry an X chromosome defective for this gene do not suffer from hemophilia, since they compensate for it with a normal gene on the paired X chromosome, but they pass on their X chromosome to their sons along with the disease. But the question is, where does this mutation occur, in female or male germ cells? Haldane considered both options and, comparing their probabilities, came to the conclusion that most hemophilia mutations occur in male germ cells. A carrier woman receives this mutation from her father and passes it on to her son, who becomes ill.

Later, researchers analyzed several more hereditary diseases associated with X-chromosomal genes, such as multiple endocrine neoplasia, acrocephalosyndactyly. And it turned out that in the vast majority of cases, the mutation first occurs on the male X chromosome. As James F. Crow writes, article in PNAS, 1997), higher primates, including humans, have on average five times more male mutations than female ones.

The reasons for this inequality is that male and female germ cells are formed differently. Oocyte precursors undergo normal cell division (mitosis) only in the embryonic period. A girl is born with a ready set of immature oocytes (oocytes of the first order), which, with the onset of puberty, alternately enter into a reduction division - meiosis - and form eggs (oocytes of the second order). The precursors of spermatozoa - spermatogonia - are actively mitotically divided in the testes from puberty to old age. As a result, the egg cell goes through 25 mitoses, ending with meiosis, and the number of mitoses through which the spermatozoon passes before meiosis depends on the age of the man: if he is 18 years old, this is about 100 mitoses, but if he is 50, about 800 mitoses. And the more cell divisions, the more DNA replications, the more mutations.

It follows from this that the number of mutations that a child receives from his father is largely influenced by paternal age. This conclusion is not new. As Alexey Kondrashov explains, Wilhelm Weinberg first came to him ( Wilhelm Weinberg), a German physician, one of the discoverers of the basic law of population genetics (the Hardy-Weinberg law). But now this pattern can be confirmed by direct studies, since it has become possible to sequence the genome and count the number of mutations. In August 2012 in Nature an article by Icelandic scientists was published (the first author was Augustine Kong ( Augustine Kong)), which describes the results of a genome-wide analysis of 78 families. In each family, the genomes of the father, mother and child were sequenced. And, comparing them with each other, they calculated how many new mutations the child acquired. It turned out that a child receives an average of 15 mutations from a mother, regardless of her age. And from the father - depending on age: if the father is 20 years old - 25 mutations, if 40 years old - 65, and if 50 years old - 85 mutations. That is, every year of the father's life adds two new mutations to the child. The conclusion of the authors of the work: men who postpone the birth of a child at a later age should reconsider their life plans. And just now in the world there is a trend of ever later paternity. If in 2004 average age fathers was 35 years old, then in 2007 he had already approached 40 years. Almost every tenth newborn has a father over 50 years old.

The more mutations, the more harmful among them, associated with diseases. Several studies have found evidence that late fatherhood puts the child at risk for neurological and psychiatric illness. So, according to data obtained at the Brain Institute in Queensland, children of 50-year-old fathers are twice as likely to suffer from schizophrenia and autism than children of 20-year-old fathers. In an experiment on mice, scientists have demonstrated that the offspring of old males have mutated genes that in humans are associated with schizophrenia and autism. And according to researchers from Tel Aviv University, fathers aged 55 and older are five times more likely to give birth to a child with Down syndrome, a 37% increase in the risk of manic-depressive psychosis in a child, and every subsequent 10 years, a 30% increase in the risk of schizophrenia in the child. In a paper published three years ago in nature, graphs of the dependence of the cognitive indicators of the child on the age of the parents are given. It turns out that a too young mother is undesirable for the intellect of a child - up to 20 years old, and in the future her age has practically no effect on this level. But with the age of the father, the cognitive performance of the child falls: if the father is 60 years old, then the expected mental development of the child is 5% lower than for a 20-year-old father. The results can be trusted, as they were obtained on a very large sample - more than 30 thousand children. An elderly father passes on 60 additional mutations to a child compared to a young one, Kondrashov specifies. And it reduces intellectual abilities by about 5%. It seems to be not much, but for the population as a whole, common small defects are much more terrible than large, but rare defects. There is practically no selection against weakly harmful mutations in humans; they certainly do not affect the number of children in any way. And as a result, they accumulate in the population.

The question arises: what about Down syndrome - a consequence of an extra chromosome - the likelihood of which, as you know, increases with the age of the mother? Apparently, this is because nondisjunction of chromosomes occurs during the last division of meiosis, Alexey Kondrashov answers. Recall that this division occurs already in the adult body of a woman. But it can also happen in the sperm, and it is a fact that a certain number of Down syndromes do not come from the mother, but from the father: “Recently, an article was published - they took 90 individual spermatozoa and sequenced them, two of them turned out to be aneuploid - they carried an extra chromosome. So all this happens all the time, only we don’t see it, because usually such spermatozoa die in the early stages. ”

Well, what to do?

How to deal with this problem is a difficult question, primarily because it involves ethical issues. “I do not want to make any recommendations as a matter of principle, because in ethical matters scientists do not have any special knowledge,” says Professor Kondrashov. - I know the facts, and what is good and what is bad, I know or do not know to the same extent as any other person. The application of artificial selection to people is fascism, and the forced sterilization of about 400 thousand people in Nazi Germany was recognized as a crime against humanity. Another thing is genetic counseling, which will make it possible to avoid the birth of a child with a hereditary disease, although today only the most severe of them can be cut off in this way. In the future, it will probably be possible to learn everything about a child, including his intelligence and life expectancy.

Perhaps, Kondrashov believes, we will someday learn how to “cleanse” the genome from harmful mutations, returning it to an “ideal state”: “It sounds like science fiction now, but 50 years ago, $2,000 sequencing was science fiction.” In his opinion, humanity will face this problem in the near future and will be forced to somehow solve it. In the meantime, you can at least spare your child the risks of late fatherhood - men can freeze their sperm at a young age, so that they can use it later when they need it. And throughout life to be "forever young" fathers.

Alexey Kondrashov, Nadezhda Markina
"Trinity option" No. 23 (117), November 20, 2012

The main purpose of a person is, with the help of our Imagination, the further expansion of the Universe, conducting into it the corresponding vibrations or energy that we have accumulated.

The purpose is the same for every soul and different. The difference lies in how the Imagination is realized in the world: someone draws, someone designs, someone builds, sings, cooks food, teaches children, takes care of animals, etc. The main goal of a person is to be the right people! The meaning of life for each of us is to turn our whole life, every moment of it, into a kind of creative act! Indeed, in each of us there is a piece of the Creator himself, therefore we are essentially co-creators, and not servants of God.

It is necessary to fill every day with Imagination - be it cleaning the house, washing dishes, peeling potatoes, traveling in transport, talking with others, etc., through all this you can multiply and expand the Divine essence. The main thing is to create everything with the soul and in any business it is necessary to go from creation, and not from destruction!

Any human action must be spiritualized, i.e., it must be based on spiritual and moral principles, and not evil! The biggest goal of life is to live every moment not automatically, half asleep, but with Imagination, with love for what you do!

Thus, we will return our debt to the world. After all, how much they took from life, the same amount must be returned in the form of physical or intellectual labor, otherwise our behavior will be subject to correction through various diseases, troubles and misfortunes.

Any event that happens to us is a sign! Therefore, we must always stop and try to comprehend what is happening to us, because there are no accidents in life.

The main test of our wrong behavior or action is the observable inhibition in the implementation of our goals and plans. At this time, Nature herself, as it were, gives us a pause to comprehend that we are going the wrong way and doing it the wrong way!

It is required to understand and realize the possible reasons for their failures. If this continues further, then the natural principles of natural selection of biological species will turn on, and, due to various circumstances, a person finds himself on the side of the road of life, ending it with a downtrodden homeless person, a drunkard, a drug addict, a chronic loser and suicide!

A person in his life goes through three stages of his development:

Animal stage;

The stage of a rational animal, when in his life he is guided by natural instincts;

And the stage of the person himself, when he consciously continues his development.

A person who is not motivated to develop is subject to slow extinction! He becomes unable to fulfill his mission on Earth, and therefore leaves as unnecessary.

Change value orientation After the collapse of the USSR, it led to the fact that money began to play the leading role in people's lives, and not spiritual and moral principles, which are the basis for the development of all human civilization on Earth. Today we do not have a single law that defines the principles of the spiritual and moral development of man and society. All laws are aimed only at satisfying the needs of the body and there is not a single law that concerns the human soul. And this cannot form in our youth the proper respect for their parents and the elderly. After all, there is a good folk wisdom: “He who does not honor parents and elders does not walk in good!” Since young people cannot imagine themselves in old age, they automatically program themselves for a short-term life, so they don’t live to old age, but die young. There is something to think about here!

Today, the majority of our population lives only by the instincts of self-preservation, stuck in its development at the stage of a “reasonable animal”, not actually reaching out to a person. So what do we want from each other - what feelings, what justice, what love and what human relations? After all, under capitalism, "Man is a wolf to man!" We were taught this in the Soviet school!

A person in life must necessarily have a long-term goal, divided into stages, striving to achieve which he must realize himself more fully and be in demand by people. Since the goal is being energetically fixed “from above”, for this a person is given certain forces and opportunities for its subsequent realization. For the successful phased implementation of the goal, a person determines what he lacks for this: what knowledge, skills, skills, professionalism, etc., trying to acquire and master all this. The universe will always help him in this, it is only necessary that the thoughts of a person be pure.

Currently, the country, and the world as a whole, has an unfavorable economic situation. People lose their minds, lose their jobs, begin to behave inappropriately, the space is saturated with human aggression, manifested in various forms. There is a formation of a resonance of social evil due to the social disorder of people. People who, due to various circumstances, are thrown out today to the backyards of society are ready-made material for protests.

In order to survive in such conditions, one must try to develop strong-willed qualities in oneself, the ability to adapt flexibly to a rapidly changing environment, and you cannot learn this while sitting at a computer. It is necessary to gain life experience, as well as the practice of real, and not virtual, communication with people, not to shy away from any work, but to consider all this as a kind of training for one's endurance and gaining experience. You need to treat any work with soul, develop your personal and business qualities, otherwise you will fall under the millstones of natural selection. We must learn to structure ourselves from the inside and accustom ourselves to order in everything! After all, “God helps those who strive for order!” - so says popular wisdom.

It is high time to understand that no one but ourselves will solve our problems for us! If you don’t have your own brains, then you can’t add strangers! Such people simply do not have an inner core, and over time, if they do not work on themselves, they will fall under natural culling.

And it's good if such people have their own corner and those who can support them in old age? Otherwise, there is only one road - to where souls rest.

Don't be lazy today! Just think now - what will you live on in old age? Pull yourself together and go! Acquire new specialties, take care of your health, because no one needs you in our hospitals! Seek and find! And everyone will be rewarded according to his deeds - so, it seems, is written in the Gospel.

Compiled by B. Ratnikov

Struggle for existence- complex and diverse relationships of individuals within a species, between species and with adverse conditions of inanimate nature. Ch. Darwin points out that the discrepancy between the possibility of species to the infinite and the limited resources is the main reason for the struggle for existence. The struggle for existence is of three kinds:

Intraspecific - leads to the preservation due to the death or non-participation in reproduction of the least given species.

fight for territory
prey competition
intraspecific cannibalism
struggle for dominance in the pack
fight for possession of a female

Intraspecific struggle is the most cruel type of struggle, since individuals compete with each other for the same conditions of existence, the same food sources, the same reproduction opportunities. The result of this struggle is the preferential right for the reproduction of more adapted individuals and the death of the less adapted.

Interspecific - leads to the victory of more viable individuals or populations of one species over a less viable individual or another species.

Interspecies struggle is an example of a direct struggle for existence. In addition to these examples, there may be a struggle for a niche between representatives of different species. In this struggle, no one directly destroys anyone, but those less adapted to the conditions of existence find themselves without a source of food, a suitable territory for reproduction. As a result, less adapted populations die.

Fight against adverse conditions of inanimate nature- leads to the survival of the most adapted individuals, populations and species in the changed conditions of inanimate nature.

seasonal change of fur (molting) in mammals
summer and winter hibernation in animals
seasonal bird migrations
modification

Fight against abiotic factors takes place in nature constantly, since there are no absolutely stable conditions in nature. Environmental conditions are constantly changing and the body is forced to either adapt to them or die.

Natural selection is the driving factor. It lies in the fact that in the struggle for existence, the most adapted individuals are preserved and leave offspring and the less adapted die. Various forms of selection have been well studied:

driving selection- ensures the adaptability of the population and species to a unidirectional change in the habitat. As a result of this form of selection, individuals with an average and one of the extreme manifestations of a trait are rejected. Individuals with another extreme manifestation of the trait survive and reproduce.

After all, the end result of selection is: on the one hand, the preemptive right to reproduce, and on the other hand, sooner or later, the death of the organism, and, accordingly, the destruction of its genes from the population of the species as a whole.

Natural selection increases the chances of survival and continuation of the whole genus, it is on the same level as mutations, migrations and transformations in genes. The main mechanism of evolution works flawlessly, but on the condition that no one interferes with its work.

What is natural selection?

The meaning of this term was given by the English scientist Charles Darwin. He established that natural selection is a process that determines the survival and reproduction of only those adapted to the conditions. environment individuals. According to Darwin's theory, the most important role in evolution is played by random hereditary changes.

• recombination of genotypes;
• mutations and their combinations.

Natural selection in humans

In times of underdeveloped medicine and other sciences, only a person with strong immunity and a stable healthy body survived. They did not know how to care for premature newborns, they did not use antibiotics in the treatment, they did not perform operations, and they had to cope with their illnesses on their own. Natural selection in humans has selected the strongest representatives of humanity for further reproduction.

In the civilized world, it is not customary to acquire numerous offspring and in most families there are no more than two children, who, thanks to modern conditions life and medicine, may well live to a ripe old age. Previously, families had 12 or more children, and no more than four survived under favorable conditions. Natural selection in man has led to the fact that most of the hardened, exceptionally healthy and strong people. Thanks to their gene pool, humanity still lives on earth.

Reasons for natural selection

All life on earth developed gradually, from the simplest organisms to the most complex ones. Representatives of certain forms of life that failed to adapt to the environment did not survive and did not reproduce, their genes were not passed on to subsequent generations. The role of natural selection in evolution has led to the emergence of the ability at the cellular level to adapt to the environment and quickly respond to its changes. The causes of natural selection are influenced by a number of simple factors:

1. Natural selection works when more offspring are produced than can survive.
2. In the genes of the body there is hereditary variability.
3. Genetic differences dictate the survival and ability to reproduce offspring in different conditions.

Signs of natural selection

The evolution of any living organism is the creativity of nature itself and this is not a whim, but a necessity. Acting in various environmental conditions, it is not difficult to guess what signs natural selection preserves, all of them are aimed at the evolution of the species, increasing its resistance to external influences:

1. The selection factor plays an important role. If in artificial selection a person chooses which features of a species to preserve and which not (for example, when breeding a new breed of dogs), then in natural selection the strongest wins in the struggle for his existence.
2. The material for selection is hereditary changes, the signs of which can help in adapting to new living conditions or for specific purposes.
3. The result is another stage of natural selection, as a result of which new species were formed with traits that are beneficial in certain environmental conditions.
4. The speed of action - mother nature is not in a hurry, she thinks over her every step, and therefore, natural selection is characterized by a low rate of change, while artificial selection is fast.

What is the result of natural selection?

All organisms have their own degree of adaptability and it is impossible to say with certainty how one or another species will behave in unfamiliar environmental conditions. The struggle for survival and hereditary variability is the essence of natural selection. There are many examples of plants and animals that have been introduced from other continents and have adapted better to new living conditions. The result of natural selection is a whole set of acquired changes.

• adaptation - adaptation to new conditions;
• variety of forms of organisms - arise from a common ancestor;
• evolutionary progress - the complication of species.

How is natural selection different from artificial selection?

It can be said with certainty that almost everything that is eaten by humans sooner or later was subjected to artificial selection. The fundamental difference is that by conducting "his" selection, a person pursues his own benefit. Thanks to selection, he received selected products, brought out new breeds of animals. Natural, natural selection is not focused on the benefit for humanity, it pursues only the interests of this particular organism.

Natural and artificial selection equally affect the lives of all people. They fight for the life of a premature baby, as well as for the life of a healthy one, but at the same time, natural selection kills drunkards frozen on the streets, deadly diseases take the lives of ordinary people, the mentally unbalanced commit suicide, natural disasters fall on the earth.

Types of natural selection

Why are only certain representatives of species able to survive in different environmental conditions? The forms of natural selection are not written rules of nature:

1. Driving selection occurs when environmental conditions change and species have to adapt, it keeps the genetic heritage in certain directions.
2. Stabilizing selection is aimed at individuals with deviations from the average statistical norm in favor of average individuals of the same species.
3. Disruptive selection is when individuals with extreme indicators survive, and not with average ones. As a result of such selection, two new species can be formed at once. More common in plants.
4. Sexual selection - based on reproduction, when the key role is played not by the ability to survive, but by attractiveness. Females, without thinking about the reasons for their behavior, choose beautiful, bright males.

Why is a person able to weaken the impact of natural selection?

Medical progress has come a long way. People who were supposed to die - survive, develop, have their own children. By passing on their genetics to them, they give rise to a weak race. Natural selection and the struggle for existence clash hourly. Nature comes up with more and more sophisticated ways to control people, and man tries to keep up with her, thereby preventing natural selection. Human humanism leads to the weak appearance of people.

Jan. 7th, 2007 | 02:34 p.m.

What is natural selection? The process by which offspring are reproduced by the most adapted individuals to the environment. Adaptation to the environment can also be understood as adaptability to intraspecific competition, including for the possession of sexual partners. That is, a strong and healthy individual is more likely to pass on its genes to future generations than a weak and sick one.

The important thing here is that these traits are uniquely determined by genes. The principle of natural selection is based on this - external attractiveness (strength, fitness) also testifies to the quality of the genetic material. It cannot be otherwise in the animal world.

Another thing is a person. He, unlike other living beings on our planet, managed to create his own habitat, changing the existing one for himself. This, of course, does not mean that the question of the need for adaptation to this environment of each individual individual has disappeared. Simply by creating an environment, a person has created his own criteria of fitness, which are different from natural ones. More precisely, only one - money.

Indeed, let us consider such concepts as "adaptation to the environment", "adaptation to intraspecific competition", "sexual attractiveness" in relation to modern man.

The impact of the environment on a person in civilized countries is minimized every year. Of course, it has not yet been possible to achieve a complete absence of influence, but this influence ( natural disasters, outbreaks of epidemics of intractable diseases, etc.) is episodic and cannot be considered as a factor that can radically affect our species. In order to bear any fruit, the factor must act in appearance constantly, for a long period of time, which is not observed at the moment.

Now with regard to intraspecific competition. The use of physical force and aggression is maximally limited by moral and legal norms, so physical force does not at all indicate an advantage over other people. And what does it testify? The answer does not need to be looked for long - of course, money.

At first glance, it may seem that money does not guarantee sexual attractiveness. True, but sex appeal in the human sense has no of great importance for natural selection. What matters is not the desire to have sex, but the desire to have children, to pass on the genes. And in order to raise a child, no doubt, money is needed, therefore, it is their presence that increases the likelihood of passing on one's gene further.

And here the main difference between animal selection and human selection is manifested. In animals, as mentioned above, strength and attractiveness are determined by genes and only by them. This means that more “quality” genes will be passed on. In the human world, the possession of money has nothing to do with the genes of the individual. Moreover, money can be obtained in many ways: by intellectual work, by strength, by beauty, by some special talent needed by society, and so on. Thus, money does not express anything. But at the same time, they are the main criterion for the transfer of their genes further.

What kind of natural selection among people can we talk about then? Its supporters often compare modern man with the remains of ancient people or talk about acquired resistance to various diseases. But this is all the influence of the external environment, which is becoming less and less significant and can no longer influence our appearance. And intraspecific competition and sexual selection already have a certain direction, because their criteria are in no way connected with human genes. If a species more adapted to life on Earth appears, then certainly not as a result of natural selection.

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Comments (14)

(no subject)

from:
date: Jan. 14th, 2007 03:29 pm (UTC)

The main selection criterion in human society is intelligence, money can play as a factor that determines the advantage of an individual in certain conditions, but it can also play the role of an eliminating factor. In a period of stability, yes, money implies a number of advantages, for posterity, only theoretically, one cannot renounce "from prison and from the bag" ... Money is energy that can both pull up and down, and even destroy it .. .

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(no subject)

from:
date: Jan. 15th, 2007 12:35 pm (UTC)

Revolutions and upheavals sometimes happen in society, and then the richest part of the population traditionally suffers, remember after the 1917 revolution how expropriation was carried out?
This also happened after french revolution. After the change of power, there is often a reason to ruin a particularly rich part of the population.
thus, the monetary part of the population runs the risk of being destroyed along with the descendants and genes (eliminated) by both the power-holding and the criminal part of the population.

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(no subject)

from:
date: Jan. 15th, 2007 07:10 pm (UTC)

However, this does not go against what I wrote. Of course, the possession of money does not solve all problems, and cannot guarantee a cloudless life, but it is money that is now the main criterion for competitiveness. Not ideal. But the closest to this of the existing ones.

Intelligence is the main selection criterion in human society.
Intelligence by itself is as useless as (roughly speaking) a screwdriver without screws is useless. Let's say that a tiger can provide itself with everything necessary only by force, directly. And in order for a person to provide himself with intellect, he cannot do without an intermediary, and this intermediary is money. And money is obtained not only by intellectual labor.

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(no subject)

from:
date: Jan. 15th, 2007 07:32 pm (UTC)

Yes, you are certainly right, I just wanted to add that money is an unconditional advantage in the selection process, however, not absolute when transferring this advantage to descendants. How many generations of people can enjoy the benefits of wealth - money? money can contribute to the transfer of genes, but descendants do not always have money and, accordingly, the same advantages, by the way, money without intelligence is not a big advantage either.
As for the strength of the tiger, if it is due to dominant genes, then at least 50% of the tiger’s descendants, or even all 100%, inherit it and pass it on to their descendants.
Money probably plays the role of a selection factor in society, such as the amount of game for a tiger, little game - little power ...
Of course, I simplified a lot of things :))

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(no subject)

from:
date: Jan. 15th, 2007 09:01 pm (UTC)

And the advantage should not be absolute. Enough to be overwhelming.

Money without intelligence? Slippery concept. Do you know many people without intelligence? The intellect is so multidimensional that it is impossible to say: “Here he is with intellect, but he is not.” In any case, I have not heard clear criteria.

And the point is that there is no natural selection now. The main criterion of competitiveness - money - has nothing to do with genes, which means that there will be no transfer of any specific genes. Unlike the tiger with its strength.

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(no subject)

from:
date: Jan. 15th, 2007 09:22 pm (UTC)

natural selection in human society is a very deep and controversial topic, it seems to me that it exists, the question is in the selection criteria
artificially determined selection criterion - money, this is a natural criterion for society, society is a population of people, and money is a product of society, everything is natural ...

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(no subject)

from:
date: Jan. 16th, 2007 11:48 am (UTC)

when we talk about conscious selection, we call it "artificial",
money is a product of society, created consciously,
they are the selection criteria
Nevertheless, this selection criterion arose within the human population, and therefore is a natural process, and therefore it does not run counter to the theory of natural selection ...

and in general, there is a lot of interesting things on this topic
http://alvarets.livejournal.com/24381.html
I liked Maiskuryan's works in the library, inquire
here: http://community.livejournal.com/darwiniana/6924.html
in addition to unokai , there were interesting thoughts in this direction, look, if you wish, in his journal