The structure of human populations. Human population: definition and properties

Humanity can be viewed as a single global population, divided into subordinate populations, the main of which are races. Human race- this is a part of the species Homo sapiens, uniting a historically formed large group of people, characterized by some common inherited morphological and physiological features related to the unity of origin and a certain area of \u200b\u200bhabitat. There are 3 large races (Mongoloid, Caucasoid and Equatorial), which are divided into small races (Asian, American, Eurasian, Negroid and Australoid). In races, smaller populations are distinguished, based on a common language, territory, nationality and religion. Races break up into small races, sub-races, ethnic groups that live in a separate territory and speak the same language. These include clans, tribes, nations.

In the biological (genetic) sense, the boundaries of a population, i.e. the commonality of a group of people determines not spatial proximity, but family ties between members of the population. Large populations are usually subdivided into subpopulations. There are temporary, relatively isolated groups of people called demes(from Greek Demos - people). Demas are characterized by a small percentage of persons originating from other groups (1-2%), a high frequency of intra-group marriages (80-90%), their number is usually 1.5 - 4.0 thousand people.

Smaller groups of people (no more than 1.5 thousand people), in which representatives of other groups make up no more than 1%, are called isolates. The isolating factors can be geographical (impediments to movement), but more often they are social factors (ethnic, religious). Therefore, the inhabitants of even one small area can form a number of completely isolated groups.

The frequency of intragroup marriages in isolates is over 90%. Calculations show that if an isolate exists for at least 4 generations (100 years), then all its members become no less than second cousins.

Human populations are characterized by demographic and genetic characteristics. Demographic characteristics include population size, population density, birth and death rates, age and sex structure, occupation, economic status, etc. The genetic structure of populations is determined by the system of marriages and gene frequencies. The calculation uses the inbreeding coefficient and the Hardy-Weinberg equation.

In human populations there are systems of marriages:

non-inbred,

inbred,

Incest.

Inbreeding coefficient- the probability that any individual in a given locus will have two allelic genes that were in one of the progenitors of this individual in one of the previous generations. The inbreeding coefficient is calculated by the formula:

F=(1/2) n+ n +1 (1+Fz), where

F is the coefficient of inbreeding;

n and n- the number of generations, from a common ancestor to the parents of an individual;

Fz is the inbreeding coefficient for a common ancestor.

If the parents of this ancestor were not relatives, then F z = 0. Then:

F=(1/2) n+ n +1 .

Incest (forbidden) marriages are marriages between relatives of the first degree of kinship: father-daughter, brother-sister, mother-son. Nowadays, such marriages are extremely rare and condemned in all cultures.

The consequences of consanguineous marriages are an increase in the degree of homozygosity of traits and the phenotypic manifestation of pathological recessive genes, which leads to an increase in general and hereditary morbidity.

Action of elementary evolutionary factors in human populations.

mutation process.

Human populations, just like natural ones, are under the pressure of mutations. Mutations cover all the signs and properties of a person. The totality of all mutations in a human population is called genetic cargo human populations. The genetic load is:

The segregation load is recessive mutations that are passed from parents to children from generation to generation;

Mutation load - mutations that arise anew in each generation in germ cells.

The share of segregated cargo, as a rule, does not exceed 20%. The bulk of the load is made up of mutations that occur de novo in each generation. Spontaneous occurrence of mutations can be caused by replication errors, or exposure to exogenous and endogenous mutagenic factors, or repair defects. The frequency of mutations is influenced to a greater extent by the age of the mother. Thus, the frequency of occurrence of chromosomal mutations in children born to mothers over 35 years of age increases 10 times. In some cases, the dependence of the occurrence of mutations on the age of the father is also noted. For example, the probability of having a child with achondroplasia (dwarfism) from a 50-year-old man increases by 2 times compared to the general population.

Migration. Migration of people in recent decades has increased dramatically in all countries. From a genetic point of view, migration breaks down marriage boundaries and promotes gene flow. The destruction of marriage boundaries, in turn, leads to heterozygotization of the population and an increase in its stability.

Insulation. Isolation is the opposite of migration. In small isolated populations, the degree of kinship of marriage partners increases and the homozygotization of the population increases. This leads to an increase in the number of homozygotes for recessive pathological genes and reduces the stability of the population, leading to gradual extinction.

Drift of genes. Genetic drift is more pronounced in small isolated populations. In parallel with the decrease in the population size, the role of random fluctuations in the concentration of individual alleles increases. So in a series of generations, some alleles may be completely lost, while others will become more frequent.

Natural selection. In modern human society, selection acts weakly due to the improvement of living conditions, the development of medicine, etc. This contributes to the accumulation of recessive mutations in the population. The intensity of selection is higher in the embryonic period. Chromosomal and genomic mutations are subjected to rigorous selection.

Races and racegenesis.

The first attempt to identify and describe the main human races belongs to Francois Bernier (1684), who distinguished four races: the first - living in Europe, North Africa, Asia Minor, India; the second - in the rest of Africa; the third - in East and Southeast Asia; the fourth - in Lapland.

As a result of the accumulation by the beginning of the XVIII century. large factual material, collected mainly by travelers and doctors in previous periods, there was a need to systematize it. Not only biologists (Linnaeus, Buffon) and anatomists were engaged in the systematics of races, but also representatives of other branches of knowledge, such as philosophers, astronomers, etc.

Linnaeus distinguished four forms within the species Homo sapiens - American, European, Asian and African. The advantage of the Linnean classification is that it singles out the main racial types of humanity that are associated with a certain area and that the geographical distribution of each race is reflected in its name. His idea of human races as subdivisions of one species of Homo sapiens was correct.

The teachings of Ch. Darwin had a strong influence on racial classifications. This influence had both positive and negative aspects. The triumph of the evolutionary principle allowed the authors of classifications to rely on a deeper and more thoughtful knowledge of the patterns of development and transformation of forms. Darwin's argument for the monophyletic origin of races, based on an analysis of the similarities between them, at the same time allowed us to get closer to understanding how their differences could have arisen, despite the common origin.

However, this approach led to the consideration of races as different stages of human evolutionary development. Certain racial types were declared to be closer or further away from the fossil extinct forms of human ancestors, and hence often involuntarily, without the special desire of the authors of such classifications, the idea of higher and lower races in the evolutionary aspect arose.

When constructing the classification, the following were taken into account: the degree of morphological similarity of the races, their geographical distribution, and, if possible, the antiquity of their formation.

All modern humanity belongs to a single polymorphic species - Homo sapiens. The unity of mankind is based on a common origin, socio-psychological development, on the unlimited ability to interbreed people of even very different races, as well as on an almost identical level of general physical and mental development of representatives of all races. Racial characteristics are nothing more than individual manifestations of a common genetic polymorphism, expressed in complex morphological characters. Some of them are adaptive, others were formed on the basis of correlative variability, but all of them concern only a number of minor features (skin color, hair, eyes, etc.) and do not affect such universal human characteristics as the structure of the brain, hands as a labor organ.

Based on the determination of the number of alleles characteristic of any group of organisms, it is possible to determine the genetic distance between them. This value for large human races is 0.03. It is less than that of the true subspecies of animals (0.17 - 0.22), and even less than the interspecific distances (0.5 - 0.6 or more). In the animal kingdom, a genetic distance of 0.03 usually corresponds to the genetic differences between local populations from each other. All these data indicate that the concept of race is conditional, secondary and does not allow us to talk about deep biological differences between races.

The morphophysiological polymorphism of mankind is based on polymorphism of hereditary material at the genome level and modification variability. These factors provide not only individual morphophysiological diversity, but also intraspecific group differentiation of mankind into races and adaptive ecological types. Race factors also include drift of genes, isolation and mixing of populations.

The new concept of understanding the biological composition of mankind has received the name of population. The population concept explains the group differentiation of the human species. The whole species of H. sapiens is divided into 3 large races - equatorial (Australian-Negroid), Eurasian (Caucasoid) and Mongoloid (Asiatic-American).

Race is not the sum of individuals, but the totality of populations. This means that morphologically and genetically similar populations that form one or another racial community are interconnected not by chance, but by virtue of origin or some other historical reasons. Race, any racial community consists of separate historically organized elements - populations. The mosaic of racial variability is made up of the mosaic population variability. Together they create all the richness of the variability of the human species.

Within each large race, separate anthropological types are distinguished with stable complexes of features, called small races. First of all, the three large races are subdivided into five small races: Caucasoid, American, Asian, Negroid and Australoid, which, in turn, are divided into even smaller sub-races. In total, they are distinguished by 22 subraces (subpopulations). Even smaller populations are local natural communities of people - specific ethnic formations - nations, nationalities.

The classification of human races reflects the family ties between them. The degree of kinship is established on the basis of a study of the morphological features of the living races and the location of the geographical areas in which they were formed. The method of DNA hybridization between large samples of representatives of small races within one large one showed a high degree of homology of nucleotide sequences. DNA hybridization of representatives of pairs of different large races reveals their significant distance from each other. DNA hybridization of representatives of transitional small races showed intermediate values, which indicates their hybridogenic origin.

In the course of race formation, along with the processes of divergence of signs and their convergence under the influence of the external environment, a huge role was played by mixing processes, which were often accompanied by migrations of newly emerging mixed racial types. Subsequently, these mixed types could be in isolation and be exposed to a new environment. In order to reflect the relationship between races, it is necessary to clearly represent the history of these races.

V.V. Bunak tried to correlate the history of race formation with the main periods of the world historical process. There are four stages in total.

The first stage of race formation: the allocation of primary foci and the formation of the main racial trunks - the western (uniting Caucasoids, Negroids and Australoids) and the eastern (uniting Asian Mongoloids and Americanoids). Primary foci arose in the era of the lower and middle Pleolithic. It was then that the formation of a modern type of man was going on, which ended by the end of the Upper Paleolithic. This stage lasted, apparently, about 200 thousand years.

The second stage of racial formation: the allocation of secondary foci and the formation of racial branches within the main racial trunks. It covers the Upper Paleolithic and partly the Mesolithic and is associated with a significant expansion of the ecumene (Australia, North and South America). During this period, new ecological niches were mastered, man penetrated into new areas, and adaptive processes took place in completely new conditions. The duration of this stage is approximately 15 - 20 thousand years.

The third stage of race formation: formation of tertiary foci of race formation. Within their limits, local races are formed, hierarchically subordinated to racial branches and trunks. In their appearance, adaptive processes to the conditions of new ecological niches are of great importance. By this period, the entire ecumene was inhabited, with the exception of some hard-to-reach inland areas. There was an increase in the population and intensive economic exploitation of the populated areas.

The third stage of race formation covers the end of the Mesolithic and the Neolithic era, which is approximately 10 - 12 thousand years. It was during the third and subsequent stages that mixing between already differentiated racial variants acquired a significant role in the processes of racial formation.

The fourth stage of race formation: the formation of Quaternary foci and the emergence of groups of populations - carriers of stable racial combinations within local races. There is a further differentiation of races, the picture of the racial composition of mankind is finally formed. Its duration is approximately from the turn of the IV - III millennium BC. e. and before the beginning of a new era, i.e. 3 - 3.5 thousand years. Mixing intensifies and races of mixed origin arise, formed during the contact of local races.

Lecture 10

Section 2. Anthropogenic impact on the biosphere

Chapter 6

It is necessary to note the inseparability of man from the biosphere. From the standpoint of ecology, humanity is a global population of a biological species, an integral part of the Earth's ecosystem. Being one of the 3 million currently known biological species, man has received his place in the system of the animal kingdom: the class of mammals, the order of primates, the family of hominids, the genus - man.

A person enters the biotic component of the biosphere, where he is connected by food chains with producers, is a consumer of the first and second (sometimes third) order, a heterotroph, uses ready-made organic matter and biogenic elements, is included in the cycle of substances in the biosphere and obeys the law of physicochemical unity of matter B .AND. Vernadsky - living matter is physically and chemically uniform.

In its relationship with the environment, the human population purely biologically exhibits a certain reaction rate, i.e. predictable change in the state of the organism at a certain level of external influence. The rate of human reaction, in turn, is determined by genotype, which is a hereditary development program. The diverse interactions of the individual's genotype with the environment forms it. phenotype- a set of signs (including external) and properties of the organism, which are the result of these interactions.

All the diversity of people on Earth is a direct consequence of their inherent genetic and environmental differences. An example of this would be the races of people: Caucasoid, Negroid, Australoid and Mongoloid.

The above example of the influence of environmental conditions on the human body can be supplemented with more recent examples, for example acceleration- a massive increase in the average height of people that arose after the end of the Second World War, and in various regions of the planet. According to scientists, this phenomenon is primarily due to the improvement in the quality of nutrition as a result of increased trade exchange, the transport of food from one area to another. In addition to acceleration, the adaptation of the human body to changes in the pace and nature of the development of social processes is confirmed in retardation(slowing down the aging process) and prolongation(extension of the reproductive period of human development).

Thus, the ecological similarity of the human population with the populations of all other biological species lies in the fact that humanity has the same genetic goal (procreation) and the whole range of ecological relationships that have been identified in natural populations. Consequently, man as a species is inseparable from the biosphere.

Analyzing the differences between the human population and populations of other species, even the closest ones, for example, great apes, we note only the inherent fundamentally new form of intrapopulation communication links inherent in humanity - articulate speech and its accompanying figurative, abstract (conceptual) thinking. The main advantage of speech over other signals is its almost limitless "information capacity".

Obeying, like all living things, general ecological laws, humanity also follows specific ones, i.e. species laws. Among them, the main one is sociality, which affects all manifestations of people's life: from their individuality in the morphological aspect to family relations, types and forms of development of society, inclusive.

It is important and should be emphasized at the same time that the well-being of physical existence in the collective of each person is largely determined by the degree of his usefulness for other people. Surprisingly, the constant harm to others contributes to the inclusion of the mechanism of self-destruction of the pest organism, which is due to the evolutionary development of the population. This phenomenon is a particular manifestation of the general biological law, according to which natural selection destroys individuals that harm their species.

According to many scientists, a huge positive role in the development of mankind was played by the development of a purely human quality - altruism, i.e. the ability to selflessly care for others.

Animals of all kinds receive energy to sustain life in two main ways: by eating food and by warming under the rays of the sun. Accordingly, the work performed by them is carried out only as a result of muscular strength. Man, being a representative of the animal kingdom, is the only exception: at first he mastered the reserves of canned solar energy in the form of fossil fuels (wood, coal, oil and gas), and now he has begun to use atomic and other energy. According to the figurative comparison of V. Nebel, the existence of modern man, when transferring the energy expended by him to muscular strength, is ensured by the labor of 80 ... 100 conditional slaves.

All types of living organisms living on Earth are forced to adapt (adapt) to the environment, to changing living conditions. And only man, using the additional energy mastered by him, adapts the entire environment of his habitat to his own needs, essentially and in a relatively short time transforms nature on a planetary scale. This is another fundamental ecological difference of human civilization.

Like any population, the human population in a certain way affects the environment of its habitat, changes it, and, in turn, experiences reciprocal resistance. However, the pressure of mankind on the natural environment now exceeds the resistance of the environment in its scale and often suppresses it. The growing imbalance between anthropogenic pressure on nature and its reciprocal resistance is one of the main ecological features of the human population. It is in it that the threat of complete destruction of natural ecosystems, including the global one - the Earth, lurks.

The principle of territoriality, which, as is well known, is an important factor in regulating the size of any population, practically does not work in relation to humanity, since natural resources move relatively easily across different territories.

Unlike biological populations, such as animals, if there is a regulation of the number (China, India), it occurs due to a conscious impact on the birth rate, and not as a reaction to the existing number.

The ability to produce food is a fundamental ecological difference between man and all biological species, one of the main manifestations of his social characteristics.

The climate in all its diversity has a huge impact on the life of any living organisms. Nevertheless, now man has no equal among biological species in terms of his ability to populate any climatic zones.

Finally, let us point out one more ecological difference between man and other types of living beings inhabiting the Earth. This is a conscious desire for the development of new habitats, inherent in his genetic program, initially alien and even deadly for him in a number of their indicators.

Hypereurybionty, i.e. the extremely wide ecological valence of man, as well as the practically unlimited ecological niche, contributed to the formation of an essentially superspecies capable of subordinating other species to its interests and even destroying them (intentionally or without intent). This is absolutely alien to species that exist within the boundaries of ecosystems and occupy certain places in food chains, since the destruction of other species is adequate to self-destruction. According to N.A. Voronkov, this is one of the most important paradoxes in the development of man as a biosocial being. Therefore, no matter how paradoxical and tragic it may seem, but man - this unique creation of nature - is one of the first candidates to leave the arena of life as a result of the changes in the environment he himself causes. This conclusion is consistent with the rule of socio-ecological balance: "Society develops as long as and insofar as it maintains a balance between its pressure on the environment and the restoration of this environment - natural and artificial."

Human reproduction is carried out sexually, and reproductive areas are more or less limited to a certain group of the population. This makes it possible to identify communities in humanity that are similar to populations in the biological sense of the term. In anthropogenetics, a population is a group of people occupying a common territory and freely marrying. Isolating barriers that prevent marriages are often of a pronounced social nature (for example, differences in religion). Due to this, in the formation of human populations, the main role is played not by the common territory, but by social factors.

Size, birth and death rates, age composition, economic status, lifestyle are demographic indicators of human populations. Genetically, they are characterized by gene pools (allele pools). Demographic indicators have a serious impact on the state of the gene pools of human populations, mainly through the structure of marriages. Of great importance in determining the structure of marriages is the size of the group.

Populations from 1500-4000 people called demes, population size up to 1500 people- isolates.

Relatively low natural population growth is typical for demes and isolates - respectively, about 20% and no more than 25% per generation. The frequency of intra-group marriages in them is 80-90% and over 90%, and the influx of people from other groups remains at the level of 1-2% and less than 1%. Due to the high frequency of intra-group marriages, members of isolates that have existed for four generations (approximately 100 years) or more are no less than second cousins (siblings).

Any population is characterized by certain indicators or properties. And since a population is a supraorganismal structure, it is characterized by indicators that are characteristic both for individual organisms (for example, growth, development) and that characterize it as a group of individuals (birth rate, mortality, density). The most significant characteristics are the number, density, birth rate, mortality, growth, growth, structure.

Population size- this is the total number of individuals (or their biomass, or energy bound in biomass) in a given area or in a given volume. This indicator varies and fluctuates widely. It depends on the living conditions, the availability of food, enemies, the sex ratio in the population, the size of its constituent individuals.

Density- this is the number of individuals in a population (or biomass) per unit of occupied space or volume (the number of trees per 1 ha, the mass of cyclops in 1 m 3 of water). This indicator indicates differences in the living conditions of organisms: the more favorable they are, the higher the density. Fertility - the number of new individuals born in a certain period of time, related to a certain number of individuals in a population (in humans, per 1000 population). Fertility characterizes the ability of a population to increase in numbers.

Mortality characterizes the death of individuals in a population and shows the number of deaths per unit of time, calculated for a certain number of living individuals (the opposite of fertility). Minimal mortality is observed in ideal conditions, ecological - in specific ones.

Population Growth is the difference between births and deaths. It is considered an indicator of the vitality of the population. With a high birth rate, high mortality is not always a negative phenomenon for the population. The growth indicates the prospects for the development of the population, the ability of a person to exploit such a population without the risk of its destruction.

population growth means an increase in its population. This indicator is influenced by numerous external and internal factors, and above all - the ratio of births and deaths. Population growth is constrained by unfavorable conditions, lack of food, predators

Effect of evolutionary factors on human populations: mutation process, population waves, isolation, genetic drift, natural selection.

In the synthetic theory of evolution, 4 basic elementary factors of evolution are considered that can affect the genotypic composition of populations: the mutation process, population waves, isolation and natural selection.

mutation process

1. A variety of emerging mutants are carriers of elementary units of hereditary variability - mutations; in sum they are elementary evolutionary material. But, the very process of their occurrence in quantitative and qualitative terms is characterized by quite definite features. It exerts a certain pressure (quantitative impact) on the populations of all living organisms. Therefore, the mutation process is considered an elementary evolutionary factor - a "supplier" of new elementary material in the population.

The mutation process is of evolutionary importance, primarily from the quantitative point of view. This is how the degree of possible pressure exerted by this factor on the population is determined.

2. It should be especially emphasized that the effect of a significant part of mutations on the vital activity of individuals is, as a rule, negative. There is a fairly high percentage of newly emerging mutations, which are sharply pathogenic and even lethal in the homozygous state.

3. The mutation process as an evolutionary factor maintains a high degree of heterogeneity in natural populations. However, mutations occur "accidentally"; and different directions, and their action is indefinite. Therefore, this process does not have a directing influence on the course of evolutionary changes.

4. There are also limiting conditions for the course of the mutation process. Therefore, their diversity is not an infinite number.

5. Thus, the mutation process is only a factor-supplier of elementary evolutionary material.

population waves

1. The next elementary evolutionary factor, which can be called "population waves", has a completely different nature. At the same time, like the mutation process, it also has a statistical significance.

2. The action of population waves occurring in all populations of any living organisms have different meanings. First of all, the waves of life are completely random (statistically) and dramatically change the concentration of all rare mutations and genotypes in populations. When the population is in a small state, processes work drift of genes. At the same time, naturally, a number of mutations present in low concentrations by chance (regardless of their selective value) will disappear from the population, while others, which were also in the previous peak in very low concentrations and also accidentally remained in a much higher concentration by the time of the decline, sharply increase their concentration.

The composition of the gene pool of a population recovering from a decline in population includes only those mutations and genotypes that, in certain quantitative ratios, have been preserved in the reproductive population, creating ratios of alleles and gene complexes that are somewhat different from those created in previous population peaks. Although these processes occur within the limits of genetic homeostasis, population waves, quite randomly, but dramatically change the set of mutations and especially affect their concentration in populations.

3. Population waves are the supplier of evolutionary material under the influence of relatively intensive selection.

4. These populations are, as it were, "forward detachments" of a species expanding the boundaries of its range. They form new relationships with the environment, with previously unseen complexes of biocenoses and physical and geographical conditions5. Population waves operate in a completely different way than the mutation process. However, their action is similar. The evolutionary significance of population waves is estimated as a factor - a supplier of evolutionary material. The pressure of this factor can be very different even in different populations of the same species and probably exceeds that of a spontaneous mutation process.

Gene drift is a random change in gene frequencies in a small, completely isolated population. Genetic drift occurs randomly, while the frequency of alleles in a population varies somewhat from generation to generation.

Insulation- restriction or violation of free interbreeding of individuals and mixing of different forms of organisms. Isolation is one of the elementary factors of evolution.

In macroevolutionary terms, isolation is due to the non-crossing of different species. In microevolutionary terms, at the intraspecific level, there are 2 main groups of isolation:

geographical, which includes the occurrence of barriers between different parts of a population or different populations (water barriers for land and land for aquatic organisms, mountains for valleys and valleys for mountain species, etc.),

biological (ecological, anatomical-morphological-physiological and genetic).

The end result of isolation is the formation of new subspecies, and then species.

Natural selection- the main evolutionary process, as a result of which the number of individuals with maximum fitness (the most favorable traits) increases in the population, while the number of individuals with unfavorable traits decreases. In the light of the modern synthetic theory of evolution, natural selection is considered as the main reason for the development of adaptations, speciation, and the origin of supraspecific taxa. Natural selection is the only known cause of adaptations, but not the only cause of evolution. Non-adaptive causes include genetic drift, gene flow, and mutations.

based on the occurrence of relevant biological differences.

human population - a group of people occupying a common territory and freely entering into marriage.

Populations have certain specific genetic and ecological signs , reflecting the ability of systems to maintain existence in constantly changing conditions: growth, development, sustainability.

Populations can vary in size area and living conditions may also be different.

On this basis, distinguish 3 types of populations:

Elementary (local ) A group of individuals of the same species occupying a small area of a homogeneous area. There is a constant exchange of genetic information between them. (One of several schools of fish of the same species in the lake)

Ecological – set of elementary populations; intraspecific groups confined to specific biocenoses. The exchange of genetic information occurs between them quite often. (Populations of squirrels in pine, spruce-fir and deciduous forests of one region)

Geographic – the totality of ecological populations inhabiting geographically similar areas; exist autonomously, their ranges are relatively isolated, the exchange of genetic information is rare. At this level, the formation of races, varieties. (The species "common squirrel" has about 20 geographical populations, or subspecies)

Genetic characteristics of human populations:

gene pool - a set of alleles that form the genotypes of organisms of a given population. Gene pools of natural populations are distinguished by hereditary diversity (genetic heterogeneity or polymorphism), genetic unity, dynamic balance of the proportions of individuals with different genotypes

Genetic heterogeneity – the presence of different alleles of genes in a population .

Intrapopulation polymorphism : within a single population, there are sharply distinguishable, hereditarily determined phenotypes.

Inherited diversity (heterogeneity or polymorphism) associated with the presence in the gene pool of simultaneously different alleles of individual genes. It is created by the mutation process. Mutations, being usually recessive and not affecting the phenotypes of heterozygous organisms, are stored in the gene pools of populations in a state hidden from natural selection. Accumulating, they form a "reserve of hereditary variability". Due to combinative variability, this reserve is used to create new combinations of alleles in each generation.

Types of polymorphism :

a) sexual - the difference between the sexes according to external characteristics, due to genetic factors

b) adaptive

c) heterozygous Pr: sickle cell anemia

genetic unity due to a sufficient level of panmixia.

Within the gene pool of a population proportion of genotypes containing different alleles one gene, subject to certain conditions from generation to generation does not change.

Migration is the gene flow of a population within populations. They are creating genetic cargo - part of the hereditary variability of the population, which determines the appearance of less adapted individuals, subject to selective death in the process of natural selection depending on origin :

Mutational - newly emerged mutations

Segregational - mutations that are transmitted from generation to generation for a long time, hidden in the heterozygous state

Recombination - mutations based on gene recombination

Migratory - mutations transmitted by the migration of individuals in a population.

In relations with the environment, the human population purely biologically exhibits a certain rate of reaction, i.e. predictable change in the state of the organism at a certain level of external influence. The norm of a person's reaction, in turn, is determined by the genotype, which is a hereditary development program. The diverse interactions of an individual's genotype with the environment form its phenotype - a set of signs (including external ones) and properties of the organism, which are a consequence of these interactions.

The above example of the influence of environmental conditions on the human body can be supplemented with more recent examples, for example, acceleration - a massive increase in the average height of people that arose after the end of the Second World War, and in various regions of the planet. According to scientists, this phenomenon is primarily due to the improvement in the quality of nutrition as a result of increased trade exchange, the transport of food from one area to another. In addition to acceleration, the adaptation of the human body to changes in the pace and nature of the development of social processes is confirmed in retardation (slowing down the aging process) and prolongation (extension of the reproductive period of human development).

Analyzing the differences between the human population and populations of other species, even the closest ones, for example, great apes, we note only a fundamentally new form of intrapopulation communication links inherent in humanity - articulate speech and its accompanying figurative, abstract (conceptual) thinking. The main advantage of speech over other signals is its almost limitless "information capacity".

Obeying, like all living things, general ecological laws, humanity also follows specific ones, i.e. species laws. Among them, the main one is sociality, which affects all manifestations of people's life: from their individuality in the morphological aspect to family relations, types and forms of development of society, inclusive.

According to many scientists, a huge positive role in the development of mankind was played by the development of a purely human quality - altruism, i.e. the ability to selflessly care for others.

The ability to produce food is a fundamental ecological difference between man and all biological species, one of the main manifestations of his social characteristics.

Hypereurybionty, i.e. the extremely wide ecological valence of man, as well as the practically unlimited ecological niche, contributed to the formation of an essentially superspecies capable of subordinating other species to its interests and even destroying them (intentionally or without intent). This is absolutely alien to species that exist within the boundaries of ecosystems and occupy certain places in food chains, since the destruction of other species is adequate to self-destruction. According to N.A. Voronkov, this is one of the most important paradoxes in the development of man as a biosocial being. Therefore, however paradoxical and tragic it may seem, man, a unique creation of nature, is one of the first candidates to leave the arena of life as a result of the changes in the environment he causes. This conclusion is consistent with the rule of socio-ecological balance: "Society develops as long as and insofar as it maintains a balance between its pressure on the environment and the restoration of this environment - natural and artificial."

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