Geodakyan evolutionary theory. Dictionary of gender terms. Evolutionary Sex Theory
Why do men and women exist? Why don't we be, like amoebas, asexual? Or, like earthworms, hermaphrodites? Why are there two sexes, not three? Scientists find it difficult to answer this question. All are difficult, except for one. Doctor of Biological Sciences, Leading Researcher at the Institute of General Problems of Ecology and Evolution of the Russian Academy of Sciences Vigen Artavazdovich Geodakyan has been developing a theory for forty years to explain the meaning of the division of living beings into two sexes. And everyone who had to get acquainted with this theory opened their mouths in surprise.
Guinea pigs
The whole theory of Geodakyan can be expressed in one phrase - men are the guinea pigs of nature. As you know, life on earth develops from amoeba to dinosaurs, and from dinosaurs to humans, and this happens because living beings acquire new signs and properties in the process of evolution. But changes in living organisms can be not only beneficial, but also harmful. Another careless mutation can generally lead to the extinction of a biological species. That's why most biological beings will be divided into men and women, and all the risk associated with the change is taken by men, who can be safely called the pioneers of evolution. After all, if the mutation turns out to be harmful, and most of the men die - this will not affect the fate of the species, not numerous surviving men can, using numerous women, easily restore their numbers. Thus, for some time, men try new mutations on themselves, and if they survive, they pass on a new trait to women.
In accordance with Darwin's theory, which has not yet been rejected, the evolution of living beings occurs as a result of natural selection. Suppose a global cooling has come on earth, and it would be good for all animals to acquire thick fur. The selection acts rudely - all those who do not have enough fur die, the most woolly ones remain, which give rise to a new generation of frost-resistant animals. Nature acts like a breeder: she chooses sheep with the thickest wool and makes them the founder of new, thick-haired breeds. The trouble, however, is that the more “thoroughly” the selection takes place, the fewer individuals remain alive. If after the first frosts there are too few sheep left, then even if they are very woolly, they simply will not be able to restore the number of their species. But if there are too many left alive, then new signs - ("thicker hair") will not appear clearly enough. That is, every biological species is between two dangers - it is necessary to maintain its numbers and ensure a high rate of evolution.
And here the division into two sexes comes to the aid of sheep, as well as all other living beings. Women are responsible for maintaining the numbers of their species. Men, on the other hand, are constantly dying, but they pass on to their offspring new traits that have resulted from the most severe selection.
Male and female talents
Of course, the question arises - how do women manage to survive in changing conditions, say, among the same cold weather? But each gender has its own talent. Men have the talent to change genetically, acquire new mutations that they pass on to their children. Women, on the other hand, adapt much more easily to new conditions, but their genes remain unchanged. Women survive more easily in both cold and heat, but that is why natural selection does not act on them, and they have nothing to pass on to their offspring. As Vigen Artavazdovich says, if a man is poorly fed from childhood, he will die, if a woman is poorly fed, she will grow smaller. When cold weather sets in, a sheep, unlike a ram, easily acquires wool itself, but this trait is not transmitted to offspring. That is why dairy bulls play a much greater role than dairy cows in the maintenance of dairy cattle.
Having based his theory on the principle of conjugated subsystems, Geodakyan noted that adaptive systems evolving in a moving environment significantly increase their overall stability, provided that they are differentiated into two conjugated subsystems, with conservative and operational specialization, which belong to female and male individuals, respectively. How does it happen?
Initially, the female organism has a wider reaction rate than the male. So, if a man in conflict behavior, for example, usually behaves in an explosive way, then it will hardly be possible to make him tolerant and peaceful. And a woman can combine several strategies in her behavior, using them flexibly depending on the situation. Due to this, the adaptive abilities of females are much higher, and learning is better. (Studies in educational psychology have noted that boys tend to have higher levels of ability initially, but plateau faster as they learn, while girls, starting from lower levels, pick up the pace and overtake boys.) If If we come to a school class and look at the performance of children, it turns out that girls (like boys) are equally divided into excellent students, poor students and mediocre students. However, if we put the question differently: who is the most notorious loser and bully, who is the most talented student? - then it turns out that these groups are filled, as a rule, with boys. That is, the male subsample has more specialized behavior, which generally hinders adaptation at the individual level. All extremes are more pronounced in men, but women are more trainable.
The next question that needs to be resolved is: why do men keep new signs “in themselves” for a long time, sometimes for many generations, and only then pass them on to women? Geodakyan solves this problem at the genetic level. As is known from genetics, in the cells of men there are so-called "Y-chromosomes" - in fact, it is the presence of these chromosomes that distinguishes men from women. According to Geodakyan's theory, new genes appear at one end of the y chromosome, and they can only pass to women from the other end. With each successive generation, the gene moves from the beginning of the chromosome to the end. But until it reaches the opposite end, the new trait is passed only from father to son, never to daughter. And while this is happening, the new sign stands the test of time.
The recent decoding of the human genome has brought yet another confirmation of Geodakian's theory. It turned out that most mutations in human genes do occur "on the Y chromosomes." That is, male chromosomes are really an experimental laboratory where new genes are produced.
Men as a compass of evolution
It follows from Geodakyan's theory that women go in evolution with some lagging behind men. Amazing evidence of this was found in Israel. Skeletons of ancient people were found in the caves of Mount Carmel, and all women are typical Neanderthals, without a chin and with a low forehead, and all men are Cro-Magnons, that is, modern people. Scientists believe that the Cro-Magnon tribe captured Neanderthal women. But Geodakyan chuckles at this: where did they put those men, and even more so - their own women?
According to Geodakyan, this is a typical example of how men have already received new signs - a chin and a high forehead, while women have not yet pulled themselves up behind them.
By studying how men differ from women (except for the actual sexual characteristics), one can understand in which direction evolution is going. As you know, in higher animals, males are always larger than females. This means that these creatures gradually increased in size as they evolved. Indeed, the ancestors of an elephant were no more than a pig, and the ancestors of a horse were slightly larger than a cat. But according to Geodakyan's theory, the males were the first to increase their size, and the females followed them with some delay. That is why stallions are always larger than mares - and the mare is a little closer to her small, cat-like ancestor.
In insects, the opposite is true - women are much larger than men. What does it say? The fact that evolution followed the path of reducing the size of these creatures. In ancient times, dragonflies with a meter-long wingspan lived on earth, but their “husbands” gradually became smaller, and women kept up with their husbands, but with a lag, reluctantly parting with luxurious sizes.
But evolution continues today. For example, the data of anthropometric measurements say that, as a rule, in men, the ring finger is longer than the index finger, and in women, on the contrary, it is usually longer than the index finger. According to Geodakyan's theory, this means that evolution follows the “male” version, and that in centuries to come, all people, without exception, will have longer fingers on their ring fingers.
However, - I ask Vigen Artavazdovich, - civilization has given everyone food and shelter, today people do not die from the cold, and, in any case, they do not grow their own wool to fight the weather. Has human evolution stopped?
Why? - Geodakyan is sincerely surprised. - It's just that before a man died from a meeting with a tiger, but today he is being worked on at the academic council or the party committee - and a heart attack.
Like this. According to Geodakyan's theory, party committees acted as an instrument of natural selection.
Men to the right, women to the left
But Geodakyan goes even further. He believes that the division of living beings into two sexes is only a partial example of the division of everything that exists in living nature into left and right halves. All innovations appear on the right. In fish, the heart is strictly in the middle, but when the fish came to land and instead of gills the first lung appeared, the heart crawled to the left to make way. Relatively speaking, the right half in any living body is “male”, and the left half is “female”. New evolutionary traits follow the path from right to left, and from males to females. Any innovation in the human body appears on the right side in men, and ends up on the left side in women. For example, in the process of evolution, the eyes gradually crawled from the sides (like those of horses) to the face. But if you measure it exactly, you can see that on average men have eyes a little closer to the nose than women. Women often have the "hair-eyedness" that amazed Eastern poets - widely spaced eyes, but from the point of view of evolution, this is a relic sign. In this case, the right eye is always a little closer to the nose than the left, as well as the right ear is usually a little higher than the left.
When a person begins to artificially breed dogs with long ears, then the ears of males grow faster than those of females, and the right ears of both of them - a little faster than the left. The longest ear is in the male on the right, the shortest is in the young lady on the left. Moreover, Vigen Artavazdovich even undertakes to derive a mathematical law, according to which the sum of the lengths of the male right and female left ear should be equal to the sum of the lengths of the male left and female right.
People's teeth are gradually getting smaller. Therefore, if you put a man and a woman, approximately the same in height and build, next to each other, then the smallest teeth will be in the man on the right, and the largest in women on the left.
However, women should not be offended that they are “lagging behind”. After all, changes are not only beneficial. And as Vigen Geodakyan says, although there are more geniuses among men than among women, there are also many more complete idiots among them. It’s better to remember the funny song that Oleg Yankovsky sings in the movie “Pipe” in the voice of Anatoly Solovyanenko:
Men, I want to remind you
What a test specimen was Adam!
God worked on him to the best of his ability,
At first he gained experience on it.
Bibliography:
All world literature.
Based on the article by K. Frumkin et al.
What can be the reason for individual differences between males and females? Obviously, to answer this question, it is necessary to go beyond psychology and turn to the theories and hypotheses that exist in ethology and biology.
The question of why gender exists at all has been around for a long time. The simplest answer - for reproduction - cannot be considered satisfactory. In the living world, in addition to dioecious, there is also asexual (vegetative) and hermaphroditic reproduction, and there are no obvious advantages over them in dioecious reproduction. On the contrary, the combinatorial potential (combination of genes) in hermaphrodites is twice as large, and the number of offspring (reproductive efficiency) is higher in asexual ones. However, all progressive forms reproduce sexually (3, 5).
To clarify the role of dioecious reproduction in 1965, the Russian biologist V.A. Geodakyan (under the obvious influence of cybernetics and systems theory) created the so-called evolutionary theory of sex, in which the author argued that sex differentiation is associated with specialization in two main aspects of the evolutionary process - preservation and modification of genetic information as a form of informational contact with the environment that is beneficial for the population (3). Obviously, only male (or only female) individuals are not enough to ensure the continuity and development of the species. They must coexist.
Having based his theory on the principle of conjugated subsystems, Geodakyan noted that adaptive systems evolving in a moving environment significantly increase their overall stability, provided that they are differentiated into two conjugated subsystems, with conservative and operational specialization, which belong to female and male individuals, respectively. How does it happen?
Initially, the female organism has a wider reaction rate than the male. So, if a man in conflict behavior, for example, usually behaves in an explosive way, then it will hardly be possible to make him tolerant and peaceful. And a woman can combine several strategies in her behavior, using them flexibly depending on the situation. Due to this, the adaptive abilities of females are much higher, and learning is better. (Studies in educational psychology note that boys tend to have higher initial levels of ability, but plateau more quickly as they learn, while girls, starting from lower levels, pick up the pace and overtake boys.) If we If we come to a school class and look at the performance of children, it turns out that girls (like boys) are equally divided into excellent students, poor students and mediocre students. However, if we put the question differently: who is the most notorious loser and bully, who is the most talented student? - then it turns out that these groups are filled, as a rule, with boys. That is, the male subsample has more specialized behavior, which generally hinders adaptation at the individual level. All extremes are more pronounced in men, but women are more trainable.
Let us assume that the environment of existence of the species practically does not change (such an environment is called stabilizing). In this environment, natural selection leads to a simple increase in the number of individuals, without changing their genotype. For this purpose, it is not necessary to have a large number of males in the population, the main thing is that there should be a sufficient number of females. And indeed, in stable conditions, a little less boys are born (there is even a sign that many boys are born for war).
But if the environment abruptly changes its conditions (becomes driving), then the tasks of selection in adaptation change somewhat; it leads not only to an increase in the number of individuals, but also to a change in the genotype. In conditions of catastrophes (environmental, social, historical), elimination and exclusion from reproduction mainly affect the male sex, while modification affects the female. Due to the differentiation of the sexes, two main changes appeared in comparison with asexual reproduction - this is a wider cross-section of the information channel of interaction in the male and a wider reaction rate in the female. Thus, the male can fertilize more females, and the female can provide a range of phenotypes from one genotype.
After the disappearance of the catastrophic factor and the end of selection, the proportion of males decreases, and their genotypic variance narrows (those who did not survive leave no genetic traces). Thus, females provide permanent phylogenetic memory of the species, while males provide temporary, ontogenetic memory (3).
To illustrate this idea, Geodakyan gives the following poetic example. When there was a general cooling on the planet, then in women, as highly adapted creatures, the fat layer increased. And men, due to poor adaptability, were unable to do this and for the most part simply died out. But the rest - invented fire to warm the entire community, and from that moment it was his genotype that began to be fixed. So, men are searching, and women are perfecting. This is the mechanism of evolutionary biological (and psychological) progress.
Obviously, having a narrow reaction rate, men are more biologically (and psychologically) vulnerable. Therefore, their life expectancy is lower. Newborn boys are more likely to die than girls. However, most centenarians are still men.
Of course, not all anatomical, physiological and behavioral signs develop and change, but only some. The presence of differences in traits between males and females is called sexual dimorphism. those. the existence of two forms (and in psychology the expression sexual dipsychism has already begun to be used). In modern people, for example, there is sexual dimorphism in terms of height, weight, hairiness, but there is no dimorphism in terms of the number of fingers or ears, or eye color.
IN no sexual dimorphism in stabilizing environment(there is no need to adapt, and males and females have the same evolutionarily advantageous trait value). And in driving environment already in one generation genotypic sexual dimorphism appears, growing in the next generations. According to the variability of the trait, one can judge the phase of the evolutionary process according to the trait. So, if the variance in the male subsample is higher than in the female one, this indicates the beginning of the evolutionary process, and the selection phase is called divergent. Divergent evolution is a form of evolution in which distinctive traits develop in organisms that are descended from the same ancestor. Then comes the parallel phase, in which the variances in both groups are approximately equal. And finally, the convergent phase, in which the variability in women increases compared to men, indicates that the evolutionary process is close to completion.
Geodakyan formulated the phylogenetic rule of sexual dimorphism: if for any trait there is a population sexual dimorphism, then this trait evolves from the female form to the male. That is, the population is masculinized, and the trait values that exist in the male subsample are evolutionarily favorable. This applies to all species with dioecious reproduction. So, for example, if in mammals the female is smaller than the male, this means that in the course of the evolutionary process, the females will increase in size, because this is beneficial to the species. And in insects (for example, in spiders), females, on the contrary, are much larger than males; this suggests that it is easier for a light creature to survive in its environment. Consequently, the females will also become smaller.
Breeding also exploits this fact: since breeding traits are more advanced in sires, sire selection is a key issue for breeding new breeds, even if it involves latent traits such as milk production.
There is also an ontogenetic rule of sexual dimorphism: if there is a population sexual dimorphism for any trait, then in ontogenesis this trait changes, as a rule, from the female form to the male. The rule of the paternal effect in breeding is that according to the diverging traits of the parents (which are the subject of attention), the paternal form (breed) should dominate, and according to the convergent ones (not essential for breeding the breed), the female form should dominate.
It is interesting that in ontogeny, the female forms of the trait appear earlier, and the male forms later. So, small children of both sexes are more like girls, and in older people, again, regardless of gender, masculine features begin to appear (a rough voice, facial hair growth, etc.). According to the characterological features of a little girl, it is possible to predict with greater certainty the structure of the personality and behavior of an adult woman than in boys. Therefore, we can speak not only about dimorphism, but also about dichronomorphism (i.e., a temporary discrepancy between the manifestation of female and male characteristics) (3, 6).
It is noteworthy that congenital anomalies of an "atavistic" nature are more often manifested in women, and "futuristic" in men. So, among newborn girls, those with ponytails are more likely to come across. However, the longest ponytail, which is 13 cm, still belonged to the boy ..
© V.A. Geodakyan
EVOLUTIONARY THEORY OF SEX V.A. Geodakyan
Vigen Artavazdovich Geodakyan, Doctor of Biological Sciences, Senior Researcher, Institute of Evolutionary Morphology and Animal Ecology named after A.I. A.N. Severtsov Academy of Sciences of the USSR. Theoretical biologist. Scientific interests - sex-related problems of evolution, genetics, ecology, brain asymmetry and psychology, as well as issues of information and organization of systems.Unfortunately, for technical reasons, pictures are not provided - V.V.
NO ONE natural phenomenon aroused such interest and did not contain so many mysteries as gender. The largest biologists dealt with the problem of sex: C. Darwin, A. Wallace, A. Weisman, R. Goldschmidt, R. Fisher, G. Meller. But the mysteries remained, and modern authorities continued to talk about the crisis of evolutionary biology. "Sex is the main challenge of the modern theory of evolution... the queen of the problems of evolutionary biology",- considers G. Bell - "The intuitions of Darwin and Mendel, which illuminated so many mysteries, failed to solve the central mystery of sexual reproduction". Why are there two genders? What does it give?
The main advantages of sexual reproduction are usually associated with ensuring genetic diversity, suppression of harmful mutations, and an obstacle to closely related crossing - inbreeding. However, all this is the result of fertilization, which hermaphrodites also have, and not differentiation (separation) into two sexes. In addition, the combinatorial potential of hermaphroditic reproduction is twice as high as that of dioecious reproduction, and the quantitative efficiency of asexual methods is twice as high as that of sexual ones. It turns out that the separate-sex method is the worst? Why, then, are all evolutionarily progressive forms of animals (mammals, birds, insects) and plants (dioecious) dioecious?
Back in the early 60s, the author of these lines expressed the idea that gender differentiation is an economical form of informational contact with the environment, specialization in two main "aspects of evolution - conservative and operational". a theory that explains from a unified position a variety of facts and predicts new ones.The essence of the theory will be presented in the article.
TWO SEXES - TWO STREAMS OF INFORMATION
In principle, two solutions to this conflict are possible for the system: to be at some optimal "distance" from the environment or to be divided into two conjugated subsystems - conservative and operational, the first "remove away" from the environment in order to save the available information, and the second "bring it closer" to the environment to get a new one. The second solution increases the overall stability of the system, therefore it is often found among evolving, adaptive, tracking systems (regardless of their specific nature) - biological, social, technical, etc. This is the evolutionary logic of gender differentiation. Asexual forms "adhere" to the first decision, dioecious - to the second.
If we single out two flows of information: generative (the transfer of genetic information from generation to generation, from the past to the future) and ecological (information from the environment, from the present to the future), then it is easy to see that the two sexes participate in them differently. In the evolution of sex at different stages and levels of organization, a number of mechanisms appeared that consistently ensured a closer connection between the female sex and the generative (conservative) flow, and the male - with the ecological (operational) flow. Thus, in males, compared to females, the mutation rate is higher, the additivity of inheritance of parental traits is less, the reaction rate is already higher, aggressiveness and curiosity are higher, exploratory, risky behavior is more active, and other qualities "bringing them closer to the environment." All of them, purposefully bringing the male sex to the periphery of distribution, provide him with preferential receipt of environmental information. Another group of features is the huge redundancy of male gametes, their small size and high mobility, the great activity and mobility of males, their tendency to polygamy, and other ethological and psychological properties. Long periods of pregnancy, feeding and caring for offspring in females, in fact increasing the effective concentration of males, turn the male sex into "excessive", therefore, "cheap", and the female into scarce and more valuable.
This leads to the fact that selection operates mainly due to the removal of males, "redundancy" and "cheapness" allow it to work with large coefficients. As a result, the number of males decreases in the population, but their great potentialities allow them to fertilize all females. A small number of males transmit as much information to their offspring as a large number of females, in other words, the channel of communication with the offspring of the male is wider than that of the female. This means that the genetic information transmitted through the female line is more representative, but selective through the male line, i.e., the past diversity of genotypes is more fully preserved in the female line, and the average genotype changes more strongly in the male line.
Let's move on to the population - an elementary evolving unit.
Any segregated population is characterized by three main parameters: sex ratio (the ratio of the number of males to the number of females), sex dispersion (the ratio of the values of the variance of a trait, or its diversity, in males and females), sexual dimorphism (the ratio of the average values of a trait for male and female sexes). Attributing a conservative mission to the female sex, and an operational one to the male sex, the theory links these population parameters with environmental conditions and the evolutionary plasticity of the species.
In a stable (optimal) environment, when there is no need to change anything, conservative tendencies are strong and evolutionary plasticity is minimal. In a driving (extreme) environment, when it is required to increase plasticity, operational tendencies are intensified. In some species, say, lower crustaceans, these transitions are carried out by switching from one type of reproduction to another (for example, under optimal conditions - parthenogenetic, in extreme conditions - dioecious). In most dioecious species, this regulation is smooth: under optimal conditions, the main characteristics decrease (the birth rate of males decreases, their dispersion narrows, sexual dimorphism decreases), and in extreme conditions they increase (this is an ecological rule for sex differentiation).
Since environmental stress leads to their sharp growth, these population parameters can serve as an indicator of the state of the ecological niche. In this regard, it is indicative that the birth rate of boys in Karakalpakstan has increased by 5% over the past decade. According to the ecological rule, the main parameters should grow in case of any natural or social cataclysms (strong earthquakes, wars, famine, resettlement, etc.). Now about the elementary step of evolution.
TRANSFORMATION OF GENETIC INFORMATION IN ONE GENERATION
A genotype is a program that in different environments can be realized in one of a whole range of phenotypes (traits). Therefore, the genotype does not contain a specific value of a trait, but a range of possible values. In ontogeny, one phenotype, the most suitable for a particular environment, is realized. Consequently, the genotype sets the range of realizations, the environment "chooses" a point within this range, the width of which is the reaction norm, which characterizes the degree of participation of the environment in determining the trait
According to some signs, for example, blood type or eye color, the reaction rate is narrow, so the environment does not actually affect them;, according to others - psychological, intellectual abilities - it is very wide, so many associate them only with the influence of the environment, i.e. upbringing; third signs, say height, weight, occupy an intermediate position.
Taking into account two differences between the sexes - according to the reaction rate (which is wider in females) and the cross section of the communication channel (wider in males) - let's consider the transformation of genetic information in one generation, i.e. from zygotes to zygotes, in becoming a bilizing and driving environment . Let us assume that the initial distribution of genotypes in the population is the same for male and female zygotes, i.e., there is no sexual dimorphism for the trait under consideration. In order to obtain from the distribution of genotypes of zygotes the distribution of phenotypes (organisms before and after selection), from it, in turn, the distribution of genotypes of eggs and sperm, and, finally, the distribution of zygotes of the next generation, it is enough to trace the transformation of two extreme zygote genotypes into extreme phenotypes, extreme gametes and again into zygotes. The remaining genotypes are intermediate and will remain so in all distributions. The wider reaction rate of the female sex allows it, due to the modification plasticity, to leave the selection zones, preserve and pass on to the offspring the entire range of initial genotypes.
The narrow reaction rate of the male sex forces him to remain in the zones of elimination and undergo intense selection. Therefore, the male sex passes on to the next generation only a narrow part of the initial spectrum of genotypes, which maximally corresponds to the environmental conditions at the moment. In a stabilizing medium, this is the middle part of the spectrum; in a moving medium, it is the edge of the distribution. This means that the genetic information transmitted by the female sex to offspring is more representative, and that transmitted by the male is more selective. Intensive selection reduces the number of males, but since the formation of zygotes requires an equal number of male and female gametes, males have to fertilize more than one female. The wide section of the male canal allows this. Consequently, in each generation of a population, eggs of a wide variety, carrying information about the past richness of genotypes, fuse with sperm of a narrow variety, whose genotypes contain information only about the most suitable for the current environmental conditions. Thus, the next generation receives information about the past from the maternal side, about the present from the paternal side.
In a stabilizing environment, the average genotypes of male and female gametes are the same, only their variances differ, so the genotypic distribution of the next generation zygotes coincides with the initial one. The only result of the differentiation of the sexes in this case is reduced to the payment of the population for ecological information by the "cheaper" male sex. The picture is different in the driving environment, where changes affect not only dispersions, but also the average values of genotypes. There is a genotypic sexual dimorphism of gametes, which is nothing more than a record (fixation) of environmental information in the distribution of male gametes. What is his future fate?
If paternal genetic information is transmitted stochastically to sons and daughters, it will be completely mixed at fertilization and sexual dimorphism will disappear. But if there are any mechanisms that prevent complete mixing, some of this information will get from the fathers only to the sons, and, therefore, part of the sexual dimorphism will be preserved in the zygotes. And such mechanisms exist. For example, only the sons receive information from the genes of the Y chromosome; genes are manifested differently in offspring, depending on whether they are inherited from the father or mother. Without such barriers, it is also difficult to explain the dominance of the paternal genotype in the offspring from reciprocal crosses, known in animal husbandry, for example, the high milk yield of cows transmitted through a bull. All this allows us to consider that only the differences between the sexes in terms of the reaction rate and the cross section of the communication channel are sufficient for genotypic sexual dimorphism to arise in the driving environment already in one generation, which will accumulate and grow with the change of generations.
DIMORPHISM AND DICHRONISM IN PHYLOGENESIS
So, when the stabilizing environment becomes a driving force for a given trait, the evolution of the male trait begins. sex, but in the female it is preserved, i.e., a divergence of the trait occurs, from monomorphic it turns into dimorphic.
From several possible evolutionary scenarios, only two obvious facts allow one to choose: both sexes evolve; There are both mono- and dimorphic characters. This is possible only if the phases of the evolution of the trait in the sexes are shifted in time: in the male, the change in the trait begins and ends earlier than in the female. At the same time, according to the ecological rule, the minimum dispersion of a trait in a stabilizing environment expands with the beginning of evolution and narrows after its completion.
The evolutionary trajectory of a trait bifurcates into male and female branches, sexual dimorphism appears and grows. This is a divergent phase, in which the rate of evolution and dispersion of the male pain trait. After many generations, the variance of the female begins to expand and the sign changes. Sexual dimorphism, having reached the optimum, remains constant. This is a parallel phase: the rate of evolution of the trait and its dispersion in both sexes are constant and equal. When the trait reaches a new, stable value in the male, the dispersion narrows and evolution stops, but still continues in the female. This is the convergent phase, in which the rate of evolution and variance is greater in females. Sexual dimorphism gradually decreases and, when the trait in the sexes becomes the same, it disappears, and the dispersions level out and become minimal. This completes the dimorphic stage of trait evolution, followed again by the monomorphic or stability stage.
Thus, the entire phylogenetic trajectory of the evolution of a trait consists of alternating monomorphic and dimorphic stages, while the theory considers the presence of dimorphism itself as a criterion for the evolution of a trait.
So, sexual dimorphism in any trait is closely related to its evolution: it appears with its beginning, persists while it is going on, and disappears as soon as evolution ends. This means that sexual dimorphism is a consequence not only of sexual selection, as Darwin believed, but of any: natural, sexual, artificial. This is an indispensable stage, a mode of evolution of any trait in dioecious forms, associated with the formation of a "distance" between the sexes along the morphological and chronological axes. Sexual dimorphism and sexual dichronism are two dimensions of a common phenomenon - dichronomorphism.
The above can be formulated in the form of phylogenetic rules of sexual dimorphism and dispersion of sexes: if for any trait there is a population sexual dimorphism, then the trait evolves from the female form to the male; if the variance of the trait is greater in males - the phase is divergent, the variances are equal - parallel, the variance is greater in the female - the phase is convergent. According to the first rule, it is possible to determine the direction of evolution of a trait, according to the second - its phase, or the path traveled. Using the rule of sexual dimorphism, a number of easily verifiable predictions can be made. Thus, based on the fact that the evolution of most vertebrate species was accompanied by an increase in size, it is possible to establish the direction of sexual dimorphism - in large forms, males, as a rule, are larger than females. Conversely, since many insects and arachnids have evolved to become smaller, in smaller forms, males should be smaller than females.
The rule is easy to check on farm animals and plants, the artificial evolution (selection) of which was directed by man. Selection - economically valuable - traits should be more advanced in males. There are many such examples: in meat breeds of animals - pigs, sheep, cows, birds - males grow faster, gain weight and produce better quality meat; stallions are superior to mares in athletic and working qualities; rams of fine-wool breeds give 1.5-2 times more wool than sheep; male fur animals have better fur than females; silkworm males give 20% more silk, etc.,
Let us now pass from the phylogenetic time scale to the ontogenetic one.
DIMORPHISM AND DICHRONISM IN ONTOGENESIS
If each of the phases of the phylogenetic scenario is projected onto ontogenesis (according to the law of recapitulation, ontogenesis is a brief repetition of phylogenesis), we can get six corresponding to them (three phases in the evolutionary stage and three in the stable; pre-evolutionary, post-evolutionary and interevolutionary) different scenarios for the development of sexual dimorphism in the individual development. Dichronism will manifest itself in ontogeny as an age delay in the development of a female trait, i.e., the dominance of the female form of the dimorphic trait at the beginning of ontogenesis and the male form at the end. This is the ontogenetic rule of sexual dimorphism: if there is a population sexual dimorphism for any trait, in ontogenesis this trait changes, as a rule, from the female form to the male. In other words, the signs of the maternal breed should weaken with age, and the signs of the paternal breed should increase. Checking this rule for two dozen anthropometric features fully confirms the prediction of the theory. A striking example is the development of antlers in different species of deer and antelopes: the stronger the "hornness" of the species, the earlier in ontogenesis horns appear first in males and then in females. The same pattern - age-related developmental delay in the female sex according to the functional asymmetry of the brain - was revealed by S. Vitelson. She studied the ability of 200 right-handed children to recognize objects by touch with their left and right hands and found that boys at the age of 6 have a right hemisphere specialization, and girls up to 13 years old are "symmetrical".
The described patterns refer to dimorphic, evolving characters. But there are also monomorphic, stable ones, according to which there is no sexual dimorphism in the norm. These are fundamental features of species and higher ranks of community, such as multicellularity, warm-bloodedness, a common body plan for both sexes, the number of organs, etc. According to theory, if their dispersion is greater in the male, then the phase is pre-evolutionary, if in the female - post-evolutionary. In the last phase, the theory predicts the existence of "relics" of sexual dimorphism and gender dispersion in pathology. The "relic" of dispersion manifests itself as an increased frequency of congenital anomalies in the female, and the "relic" of sexual dimorphism - in their different directions. This is the teratological rule of sexual dimorphism: congenital anomalies of an atavistic nature should appear more often in the female sex, and those of a futuristic nature (search) in the male.For example, among newborns with an excess number of kidneys, ribs, vertebrae, teeth, etc. - of all organs , who have undergone a reduction in the number in the course of evolution, there should be more girls, and with their shortage - boys. ka confirms this: among 2 thousand children born with one kidney, there are about 2.5 times more boys, and among 4 thousand children with three kidneys there are almost twice as many girls. This distribution is not accidental, it reflects the evolution of the excretory system. Consequently, three kidneys in girls is a return to the ancestral type of development, an atavistic direction; one kidney in boys is futuristic, a continuation of the reduction trend. The statistics on the anomalous number of edges is similar. With hip dislocation, a congenital defect with which children run and climb trees better than healthy ones, five to six times more girls are born than boys.
A similar picture is in the distribution of congenital heart defects and major vessels. Of the 32 thousand verified diagnoses in all "female" defects, elements characteristic of the heart of the embryo or phylogenetic predecessors of a person prevailed: an open oval hole in the interatrial septum, a non-grown ductus botalis (a vessel connecting the pulmonary artery to the aorta in the fetus), etc. "Male" the defects were more often new (search): neither in phylogeny nor in embryos had analogies - various kinds of stenosis (narrowing) and transposition of the great vessels.
The listed rules cover the dimorphic characters inherent in both sexes. But what about the signs that are characteristic of only one sex, such as egg production, milk production? Phenotypic sexual dimorphism according to such traits is of an absolute, organismic nature, but hereditary information about them is recorded in the genotype of both sexes. Therefore, if they evolve, there must be genotypic sexual dimorphism in them, which can be found in reciprocal hybrids. According to such signs (among other evolving ones), the theory predicts the direction of reciprocal effects. In reciprocal hybrids, according to the diverging traits of the parents, the paternal form (breed) should dominate, and according to the convergent ones, the maternal form. This is the evolutionary rule of reciprocal effects. It provides an amazing opportunity to reveal the greater genotypic advancement of the male sex, even in terms of purely female characteristics. Such a seemingly paradoxical prediction of the theory is fully confirmed: in the same breed, bulls are genotypically "more milky" than cows, and roosters are more "egg-laying" than hens, i.e., these traits are transmitted mainly by males.
The problems of evolution are mainly related to "black boxes" without entry - direct experiment is impossible in them. The evolutionary doctrine drew the necessary information from three sources: paleontology, comparative anatomy and embryology. Each of them has significant limitations, since it covers only a part of the features. The formulated rules provide a new method for evolutionary research on absolutely all signs of dioecious forms. Therefore, the method is of particular value for studying human evolution, its features such as temperament, intelligence, functional asymmetry of the brain, verbal, spatial-visual, creative abilities, humor and other psychological properties to which traditional methods are not applicable.
FUNCTIONAL BRAIN ASYMMETRY AND PSYCHOLOGICAL PECULIARITIES
For a long time it was considered a privilege of a person, associated with speech, right-handedness, self-awareness, it was believed that asymmetry is secondary - a consequence of these unique features of a person. It has now been established that asymmetry is widespread in placental animals; most researchers also recognize the difference in its severity in men and women. J. Levy believes, for example, that the female brain is similar to the brain of a left-handed man, that is, less asymmetrical than that of a right-handed man.
From the point of view of sex theory, the more asymmetric brain in males (and males of some vertebrates) means that evolution is going from symmetry to asymmetry. Sexual dimorphism in the asymmetry of the brain gives hope to understand and explain the differences in the abilities and inclinations of men and women.
It is known that our distant phylogenetic ancestors had lateral eyes (they are located in the same way in early human embryos), the visual fields did not overlap, each eye was connected only with the opposite hemisphere (contralateral connections). In the process of evolution, the eyes moved to the front side, the visual fields overlapped, but in order for a stereoscopic picture to appear, visual information from both eyes had to be concentrated in one area of the brain.
Vision became stereoscopic only after additional - ipsilateral - fibers arose that connected the left eye with the left hemisphere, the right with the right. This means that the ipsilateral connections are evolutionarily younger than the contralateral ones, and therefore in men they should be more advanced, i.e., there are more ipsilateral fibers in the optic nerve.
Since three-dimensional imagination and spatial-visual abilities are associated with stereoscopy (and the number of ipsifibres), they should be better developed in men than in women. Indeed, psychologists are well aware that men are far superior to women in understanding geometric problems, as well as in reading geographical maps, orienting themselves in the area, etc.
How did psychological sexual dimorphism arise, from the point of view of sex theory? There is no fundamental difference in the evolution of morphophysiological and psychological or behavioral traits. The wide reaction rate of the female sex provides it with a higher plasticity (adaptability) in ontogeny than that of the male sex. This also applies to psychological signs. Selection in zones of discomfort for males and females goes in different directions: due to the wide norm of reaction, the female sex can “get out” of these zones due to education, learning, conformity, i.e., in general, adaptability. For the male sex, this path is closed because of the narrow rate of reaction; only resourcefulness, ingenuity, ingenuity can ensure his survival in uncomfortable conditions. In other words, women adapt to the situation, men get out of it by finding a new solution, discomfort stimulates the search.
Therefore, men are more willing to take on new, challenging, extraordinary tasks (often performing them in rough outline), and women are better at bringing the solution of familiar tasks to perfection. Isn't that why they excel in jobs that can get by with well-honed skills, such as assembly line work?
If the mastery of speech, writing, any craft is considered in an evolutionary aspect, we can single out the phase of search (finding new solutions), mastering and the phase of consolidation, improvement. The male advantage in the first phase and the female advantage in the second was revealed in special studies.
Innovation in any business is a male mission. Men were the first to master all professions, sports, even knitting, in which the monopoly of women is now undeniable, was invented by men (Italy, XIII century). The role of the avant-garde belongs to men in susceptibility to certain diseases and social vices. It is the male sex that is more often subject to "new" diseases, or, as they are called, diseases of the century; civilization, urbanization - atherosclerosis, cancer, schizophrenia, AIDS, as well as social vices - alcoholism, smoking, drug addiction, gambling, crime, etc.
According to theory, there should be two opposite types of mental illness associated with the vanguard role of the male and the rearguard role of the female.
Pathology, which is accompanied by insufficient asymmetry of the brain, small size of the corpus callosum and large anterior commissure, should be two to four times more common in women, anomalies with opposite characteristics - in men. Why?
If there are no differences between the sexes in terms of a quantitative trait, then the distribution of its values in the population is often described by a Gaussian curve. The two extreme areas of such a distribution are the zones of pathology - "plus" and "minus" deviations from the norm, into each of which male and female individuals fall with equal probability. But if sexual dimorphism exists, then for each sex the trait is distributed according to -in its own way, two curves are formed that are spaced apart by the amount of sexual dimorphism.Since they remain within the general population distribution, one zone of pathology will be enriched in males, the other in females.By the way, the "sex specialization" of many others, which is characteristic of the population of almost all countries of the world, is also explained diseases.
The above examples show how the theory of sex "works" only in some human problems, in fact, it covers a much larger array of phenomena, including the social aspect.
Since the dimorphic state of the trait indicates that it is on the "evolutionary march", the maximum differences should be in the most recent evolutionary acquisitions of a person - abstract thinking, creative abilities, spatial imagination, humor, they should prevail in men. Indeed, outstanding scientists, composers, artists, writers, directors are mostly men, and there are many women among the performers.
The problem of gender affects very important areas of human interest: demography and medicine, psychology and pedagogy, the study of alcoholism, drug addiction and crime, through genetics it is connected with the economy. A correct social concept of gender is needed to solve the problems of fertility and mortality, family and upbringing, and vocational guidance. Such a concept should be built on a natural biological basis, because without understanding the biological, evolutionary roles of male and female, it is impossible to correctly determine their social roles.
Only a few general biological conclusions of the theory of sex are given here, various previously incomprehensible phenomena and facts are explained from a unified position, and prognostic possibilities are mentioned. So let's recap. The evolutionary theory of sex allows:
- 1) predict the behavior of the main characteristics of a dioecious population in a stable (optimal) and driving (extreme) environment;
- 2) differentiate evolving and stable traits;
- 3) determine the direction of evolution of any feature;
- 4) establish the phase (traveled path) of the trait evolution;
- 5) determine the average rate of evolution of the trait: V= dimorphism / dichronism
- 6) to predict six different variants of the ontogenetic dynamics of sexual dimorphism corresponding to each phase of phylogenesis;
- 7) predict the direction of dominance of the trait of the paternal or maternal breed in reciprocal hybrids;
- 8) to predict and uncover "relicts" of gender dispersion and sexual dimorphism in the field of congenital pathologies;
- 9) to establish the relationship between age and gender epidemiology.
So, the specialization of the female sex in the preservation of genetic information, and the male - in its change is achieved by the heterochronous evolution of the sexes. Therefore, sex is not so much a way of reproduction, as is commonly believed, but a way of asynchronous evolution.
Since the work presented here is the fruit of theoretical reflections and generalizations, it is impossible not to say a few words about the role of theoretical research in biology. Natural science, according to the famous physicist, Nobel Prize winner R. Milliken, moves on two legs - theory and experiment. But this is how things stand - in physics, in biology, the cult of facts reigns, it still lives by observations and experiments, theoretical biology as such, an analogue of theoretical physics does not exist. Of course, this is due to the complexity of living systems, hence the skepticism of biologists, who are used to following the traditional path - from facts and experiments to generalizing conclusions and theory. But can the science of living things still remain purely empirical in the "age of biology", which, according to many contemporaries, is replacing the "age of physics"? It seems that it is time for biology to stand on both legs.
Literature
Bell G., The Masterprice of Nature. The Evolution and Genetics of Sexuality, London, 1982.
. Geodakyan V.A. // Probl. transmission of information 1965. V. 1. No. 1. S. 105-112.
. For details see; Geodakyan V.A. Evolutionary logic of sex differentiation // Priroda. 1983. No. 1. S. 70-80.
. Geodakyan V.A. // Dokl. Academy of Sciences of the USSR. 1983. V. 269. No. 12. S. 477-482.
. Vitelson S.F.// Science. 1976. V. 193. M 4251. P. 425-427.
. Geodakyan V. A., Sherman A. L. // Zhurn. total biology. 1971. V. 32. No. 4. S. 417-424.
. Geodakyan V. A. // System Research: Methodological Problems. Yearbook. 1986. M., 1987. S. 355-376.
. Geodakyan V. A. The theory of gender differentiation in human problems // Man in the system of sciences. M., 1989. S. 171-189.
“The main question is why the floor?”
Bell (1982)
T theory V. Geodakyan can be reduced to one phrase:
Men are nature's guinea pigs.
Sex is not so much a method of reproduction, as is commonly believed,
how much way asynchronous evolution.
V. Geodakyan (1991)
To understand the phenomenon of sex, knowledge of its reproductive and recombinative role is not enough. It is necessary to know its evolutionary role. Oncedelnocavity includes two fundamental phenomena: crossing(combination of parents' genetic information ) and differentiation( division into two sexes). The presence of crossing distinguishes sexual forms of reproduction from asexual ones, the presence of differentiation distinguishes dioecious forms from hermaphroditic ones. Classical genetics, however, considers only the results of crossing individuals, therefore some phenomena associated with differentiation itself cannot be explained..
The new theory considers sex differentiation as a form of informational contact with the environment that is beneficial for the population, as evolutionary specialization in two main alternative aspects of evolution: conservation(conservative) and changes(operational).
What qualities "bring" the male sex to the environment and provide him with environmental information? Compared to women, males have a higher mutation rate, less additivity of inheritance of parental traits, a narrower reaction rate, higher aggressiveness and curiosity, more active exploratory, risky behavior. Another group of features is the huge redundancy of male gametes, their small size and high mobility, the great activity and mobility of males, and their tendency to polygamy. Long periods of pregnancy, feeding and caring for offspring in females, in fact increasing the effective concentration of males, turn the male sex into "excessive", therefore, "cheap", and the female into scarce and more valuable.
This leads to the fact that selection acts mainly due to the exclusion of males, but their great potentialities allow them to fertilize all females (in a panmictic or polygamous population). As a result, a small number of males pass on as much information to their offspring as a large number of females. We can say that the channel of communication with the offspring of the male is wider than that of the female. The hereditary information received by offspring from mothers better reflects the distribution of genotypes in the population and in past generations. Information received from fathers is more selective, it reflects the genotypes most adapted to environmental conditions.
The wide reaction rate of female individuals provides them with higher ontogenetic plasticity (adaptation), allows them to leave the zones of elimination and discomfort and group around the population norm, that is, in a stable environment, reduce their phenotypic variance. The narrow male response rate preserves their wide phenotypic variance and makes them more selective. This means that the male sex is the first to undergo evolutionary changes.
In asexual and hermaphroditic populations, information from the environment reaches all individuals:
In the case of sexual differentiation, the sequence of appearance of control information from the environment is as follows:
Wednesday → male → female
Consequently, the male sex can be considered as the evolutionary “vanguard” of the population, and sexual dimorphism in terms of the trait as the evolutionary “distance” between the sexes and as a “compass” showing the direction of evolution of this trait. (“The phylogenetic rule of sexual dimorphism”). Therefore, the traits that are more common and more pronounced in females should be of an “atavistic” nature, while the traits that are more pronounced in males should be of a “futuristic” nature (search). Maximum sexual dimorphism should be observed for evolutionarily young (new) characters.
In reciprocal hybrids of divergent forms according to evolving (new) traits, reciprocal “paternal effect”(dominance of the paternal breed, lines). According to the divergent traits of the parents, the paternal form should dominate, according to the convergent traits, the maternal one. In particular, the theory successfully predicts the existence of a paternal effect for all economically valuable traits in farm animals and plants.
A new look at the evolutionary role of sex makes it possible to better understand many of the phenomena associated with sex: sexual dimorphism (PD), sex ratio (SP), the role of sex chromosomes (HR) and sex hormones (GH), psychological differences between men and women, etc.
Instead of the earlier view of the main characteristics of a dioecious population as species-specific constants, a new one is proposed: sex ratio, dispersion and sexual dimorphism are variables, adjustable quantities, closely related to environmental conditions. Under stable conditions (optimal environment), they should fall, and under changing conditions (extreme environment), they should rise. In the first case, the evolutionary plasticity of the species decreases, while in the second it increases.
Sexual dimorphism is the "distance" between the sexes in the evolution of any trait. This is genetic information, which, due to the specialization of the sexes at the population level, has already entered the male subsystem, but has not yet reached the female subsystem.
The informational contact of the body with the environment is determined and regulated by the ratio of male (androgens) and female (estrogens) hormones in it. Androgens “bring closer” (in the informational sense) the body to the environment, and estrogens, on the contrary, “remove” it from the environment.
The revealed phylogenetic and ontogenetic patterns of sex differentiation are formulated in the form of rules.
Until now, it was believed that the division into two sexes is necessary for self-reproduction, that sex is a way breeding. But it turns out that the floor is it's rather way of evolution .
The theory allows from a unified position to answer many questions that Darwin's theory of sexual selection cannot answer and predict new phenomena.
The medicineIt becomes possible to explain sexual dimorphism in many ways. diseases. The sex ratio of morbidity depends on the phase of interaction of the population with a harmful environmental factor.
Read more...
More about gender theory
First post:Boy or girl. Is the sex ratio a quantity regulated by nature? (V. A. Geodakyan). Science and life, 1965, No. 1, pp. 55–58.
Popular exposition: Evolutionary theory of sex . (A. Gordon). Program "00:30" NTV, 03/06/2002
A more complete scientific presentation:
Most recent post: Man and woman. Evolutionary biological purpose . Geodakyan V. A. Int. Conf.: Woman and freedom. Ways of choice in a world of tradition and change. Moscow, June 1–4, 1994, p. 8–17.
Copyright © 2005 -2012 S. Geodakyan. All rights reserved.
What can be the reason for individual differences between males and females? Obviously, to answer this question, it is necessary to go beyond psychology and turn to the theories and hypotheses that exist in ethology and biology.
The question of why gender exists at all has been around for a long time. The simplest answer - for reproduction - cannot be considered satisfactory. In the living world, in addition to dioecious, there is also asexual (vegetative) and hermaphroditic reproduction, and there are no obvious advantages over them in dioecious reproduction. On the contrary, the combinatorial potential (combination of genes) in hermaphrodites is twice as large, and the number of offspring (reproductive efficiency) is higher in asexual ones. However, all progressive forms reproduce sexually (3, 5).
To clarify the role of dioecious reproduction in 1965, the domestic biologist V.A. Geodakyan (under the obvious influence of cybernetics and systems theory) created the so-called evolutionary theory of sex. In which the author argued that the differentiation of the sexes is associated with specialization in two main aspects of the evolutionary process - preservation and change of genetic information as a form of informational contact with the environment that is beneficial for the population. Obviously, only male (or only female) individuals are not enough to ensure the continuity and development of the species. They must coexist.
Having based his theory on the principle of conjugated subsystems, Geodakyan noted that adaptive systems evolving in a moving environment significantly increase their overall stability, provided that they are differentiated into two conjugated subsystems, with conservative and operational specialization, which belong to female and male individuals, respectively. How does it happen?
Initially, the female organism has a wider reaction rate than the male. So, if a man in conflict behavior, for example, usually behaves in an explosive way, then it will hardly be possible to make him tolerant and peaceful. And a woman can combine several strategies in her behavior, using them flexibly depending on the situation. Due to this, the adaptive abilities of females are much higher, and learning is better. (Studies in educational psychology note that boys tend to have higher initial levels of ability, but plateau more quickly as they learn, while girls, starting from lower levels, pick up the pace and overtake boys.) If we If we come to a school class and look at the performance of children, it turns out that girls (like boys) are equally divided into excellent students, poor students and mediocre students. However, if we put the question differently: who is the most notorious loser and bully, who is the most talented student? - then it turns out that these groups are filled, as a rule, with boys. That is, the male subsample has more specialized behavior, which generally hinders adaptation at the individual level. All extremes are more pronounced in men, but women are more trainable.
Let us assume that the environment of existence of the species practically does not change (such an environment is called stabilizing). In this environment, natural selection leads to a simple increase in the number of individuals, without changing their genotype. For this purpose, it is not necessary to have a large number of males in the population, the main thing is that there should be a sufficient number of females. And indeed, in stable conditions, a little less boys are born (there is even a sign that many boys are born for war).
But if the environment abruptly changes its conditions (becomes driving), then the tasks of selection in adaptation change somewhat; it leads not only to an increase in the number of individuals, but also to a change in the genotype. In conditions of catastrophes (environmental, social, historical), elimination and exclusion from reproduction mainly affect the male sex, while modification affects the female. Due to the differentiation of the sexes, two main changes appeared in comparison with asexual reproduction - this is a wider cross-section of the information channel of interaction in the male and a wider reaction rate in the female. Thus, the male can fertilize more females, and the female can provide a range of phenotypes from one genotype.
After the disappearance of the catastrophic factor and the end of selection, the proportion of males decreases, and their genotypic variance narrows (those who did not survive leave no genetic traces). Thus, females provide permanent phylogenetic memory of the species, while males provide temporary, ontogenetic memory (3).
To illustrate this idea, Geodakyan gives the following poetic example. When there was a general cooling on the planet, then in women, as highly adapted creatures, the fat layer increased. And men, due to poor adaptability, were unable to do this and for the most part simply died out. But the rest - invented fire to warm the entire community, and from that moment it was his genotype that began to be fixed. So, men are searching, and women are perfecting. This is the mechanism of evolutionary biological (and psychological) progress.
Obviously, having a narrow reaction rate, men are more biologically (and psychologically) vulnerable. Therefore, their life expectancy is lower. Newborn boys are more likely to die than girls. However, most centenarians are still men.
Of course, not all anatomical, physiological and behavioral signs develop and change, but only some. The presence of differences in traits in males and females is called sexual dimorphism, i.e. the existence of two forms (and in psychology the expression sexual dipsychism has already begun to be used). In modern people, for example, there is sexual dimorphism in terms of height, weight, hairiness, but there is no dimorphism in terms of the number of fingers or ears, or eye color.
In a stabilizing environment, there is no sexual dimorphism (there is no need to adapt, and males and females have the same evolutionarily advantageous trait value). And in the driving environment, already in one generation, genotypic sexual dimorphism appears, which increases in subsequent generations. According to the variability of the trait, one can judge the phase of the evolutionary process according to the trait. So, if the variance in the male subsample is higher than in the female one, this indicates the beginning of the evolutionary process, and the selection phase is called divergent. Then comes the parallel phase, in which the variances in both groups are approximately equal. And finally, the convergent phase, in which the variability in women increases compared to men, indicates that the evolutionary process is close to completion.
Geodakyan formulated the phylogenetic rule of sexual dimorphism: if for any trait there is a population sexual dimorphism, then this trait evolves from the female form to the male. That is, the population is masculinized, and the trait values that exist in the male subsample are evolutionarily favorable. This applies to all species with dioecious reproduction. So, for example, if in mammals the female is smaller than the male, this means that in the course of the evolutionary process, the females will increase in size, because this is beneficial to the species. And in insects (for example, in spiders), females, on the contrary, are much larger than males; this suggests that it is easier for a light creature to survive in its environment. Consequently, the females will also become smaller.
Breeding also exploits this fact: since breeding traits are more advanced in sires, sire selection is a key issue for breeding new breeds, even if it involves latent traits such as milk production.
There is also an ontogenetic rule of sexual dimorphism: if there is a population sexual dimorphism for any trait, then in ontogenesis this trait changes, as a rule, from the female form to the male. The rule of the paternal effect in breeding is that according to the diverging traits of the parents (which are the subject of attention), the paternal form (breed) should dominate, and according to the convergent ones (not essential for breeding the breed), the female form should dominate.
It is interesting that in ontogeny, the female forms of the trait appear earlier, and the male forms later. So, small children of both sexes are more like girls, and in older people, again, regardless of gender, masculine features begin to appear (a rough voice, facial hair growth, etc.). According to the characterological features of a little girl, it is possible to predict with greater certainty the structure of the personality and behavior of an adult woman than in boys. Therefore, we can speak not only about dimorphism, but also about dichronomorphism (i.e., a temporary discrepancy between the manifestation of female and male characteristics) (3, 6).
It is noteworthy that congenital anomalies of an "atavistic" nature are more often manifested in women, and "futuristic" in men. So, among newborn girls, those with ponytails are more likely to come across. However, the longest tail, which is 13 cm, still belonged to the boy. Sexual dimorphism is observed both in the field of the appearance of diseases (all new diseases, such as cancer, AIDS, first appeared in men), and in the structure of the brain (in men, the asymmetry of the hemispheres and operational systems are more pronounced - the cortex and the left hemisphere, and in women - conservative systems - the subcortex and the right hemisphere, which determines the predominance of analytical thinking in men, and in women - intuitive, figurative and sensory cognition). Due to less asymmetry, women are also more trainable. In addition, the flagship role of men is also observed in the cultural and historical process: at first, each new profession was only male and only then became female, and the main scientific discoveries and cultural revolutions were also made by men.
