The qualitative originality of human evolution lies in the fact that its driving forces were not only biological, but also social factors, and it was the latter that were of decisive importance in the process of the formation of man and continue to play a leading role in the development of modern human society.
Biological factors of human evolution. Man, like any other biological species, appeared on Earth as a result of the interconnected action of factors in the evolution of the living world. How, then, did natural selection contribute to the consolidation of those morphological features of man, in which he differs from his closest relatives among animals?
The main reasons that once forced arboreal animals to move to life on earth were the reduction in the area of tropical forests, the corresponding decrease in the food supply and, as a result, the enlargement of body size. The fact is that an increase in body size is accompanied by an increase in absolute, but a decrease in relative (i.e., per unit body weight) food needs. Large animals can afford to eat less high-calorie food. The reduction in the area of tropical forests has increased competition between monkeys. Different species approached the solution of the problems that confronted them in different ways. Some have learned to run fast on four limbs and have mastered open terrain (savannah). Baboons are an example. Gorillas, their enormous physical strength allowed them to stay in the forest, while being out of competition. Chimpanzees were the least specialized of all great apes. They can deftly climb trees and run quite quickly on the ground. And only hominids solved their problems in a unique way: they mastered the movement on two legs. Why was this mode of transportation beneficial for them?
One of the consequences of an increase in body size is a lengthening of life expectancy, which is accompanied by a lengthening of the gestation period and a slowdown in the rate of reproduction. In great apes, one cub is born every 5-6 years. His death as a result of an accident turns out to be a very expensive loss for the population. Bipedal great apes managed to avoid such a critical situation. Hominids have learned to take care of two, three, four cubs at the same time. But this required more time, effort and attention, which the female had to devote to her offspring. She was forced to give up many other forms of activity, including the search for food. This was done by males and childless females. The release of the forelimbs from participating in movement made it possible to bring more food for females and cubs. In the current situation, movement on four limbs became unnecessary. On the contrary, upright walking gave hominids a number of advantages, the most valuable of which turned out to be the possibility of making tools after 2 million years.
Social factors of human evolution. The creation and use of tools increased the adaptability of ancient man. From that moment on, any hereditary changes in his body that turned out to be useful in instrumental activity were fixed by natural selection. The forelimbs underwent an evolutionary transformation. Judging by the fossils and tools, the working position of the hand, the way of gripping, the position of the fingers, and the force tension gradually changed. In the technology of making tools, the number of strong blows was reduced, the number of small and precise movements of the hand and fingers increased, the factor of force began to give way to the factor of accuracy and dexterity.
A consequence of the use of tools for cutting carcasses and cooking on fire was a decrease in the load on the chewing apparatus. On the human skull, those bony protrusions to which powerful chewing muscles are attached gradually disappeared. The skull became more rounded, the jaws - less massive, the facial section - straightened (Fig. 101).
Rice. 101. Change in the proportions of the skull during the evolution of hominoids
An instrument of labor can be made only if a mental image and a conscious purpose of labor are formed in the imagination of its creator. Human labor activity helped to develop the ability to reproduce in the mind coherent ideas about objects and manipulations with them.
The prerequisite for the development of speech was to be sufficient developed brain, which allowed a person to associate a variety of sounds and ideas. Speech owes its origin to the imitation and modification of various natural sounds (voices of animals, instinctive cries of the person himself). The benefits of community rallying through speech cues were becoming apparent. Training and imitation made speech more and more articulate and perfect.
Thus, distinctive features human - thinking, speech, ability to tool activity - arose in the course and on the basis of its biological development. Thanks to these features, a person has learned to withstand the adverse effects of the environment to such an extent that his further development began to be determined not so much by biological factors as by the ability to create perfect tools, arrange dwellings, get food, raise livestock and grow edible plants. The formation of these skills occurs through training and is possible only in the conditions of human society, i.e. in the social environment. Therefore, tool activity, along with the social way of life, speech and thinking, is called the social factors of human evolution. Children who grew up isolated from people do not know how to speak, are not capable of mental activity, to communicate with other people. Their behavior is more reminiscent of the behavior of animals, among which they found themselves shortly after birth.
The formation of a person is inextricably linked with the formation of human society. In other words, anthropogenesis is inseparable from sociogenesis. Together they constitute a single process of the formation of mankind - anthroposociogenesis.
Correlation of biological and social factors in human evolution. Biological factors played a decisive role in the early stages of hominin evolution. Almost all of them are still active today. Mutational and combinative variability support the genetic heterogeneity of humanity. Fluctuations in the number of people during epidemics, wars randomly change the frequency of genes in human populations. These factors together provide material for natural selection, which acts at all stages of human development (culling of gametes with chromosomal rearrangements, stillbirths, infertile marriages, death from diseases, etc.).
The only biological factor that has lost its significance in evolution modern man, is isolation. In the era of perfect technical means of transportation, the constant migration of people has led to the fact that there are almost no genetically isolated population groups left.
Over the past 40 thousand years, the physical appearance of people has not changed much. But this does not mean the end of the evolution of man as a biological species. It should be noted that 40 thousand years is only 2% of the time of the existence of the human race. It is extremely difficult to catch the morphological changes of a person in such a short period of time on a geological scale.
With the formation of human society, a special form of communication between generations arose in the form of the continuity of material and spiritual culture. By analogy with the system of inheritance of genetic information, we can talk about the system of inheritance of cultural information. Their differences are as follows. Genetic information is passed from parents to offspring. Cultural information is available to anyone. The death of a person leads to the irrevocable disappearance of a unique combination of his genes. On the contrary, the experience accumulated by a person flows into the universal culture. Finally, the rate of dissemination of cultural information is much greater than the rate of transmission of genetic information. The consequence of these differences is that modern man as a social being develops much faster than as a biological being.
In the course of evolution, man has acquired the greatest advantage. He learned to maintain harmony between his unchanging body and changing nature. This is the qualitative originality of human evolution.
human races. In modern humanity, there are three main races: Caucasoid, Mongoloid and Equatorial (Negro-Australoid). Races are large groups of people that differ in some outward signs, such as skin color, eyes and hair, hair shape, facial features. The formation of racial characteristics was facilitated by the fact that human settlement on Earth 100-10 thousand years ago took place in small groups that made up a small part of the original population. This led to the fact that the newly formed isolated populations differed from each other in the concentrations of certain genes. Since the population of the Earth during this period was very small (no more than 3 million people 15 thousand years ago), newly formed populations in different parts of the world developed in isolation from each other.
In different climatic conditions, under the influence of natural selection, on the basis of differing gene pools, the characteristic external features of human races were formed. However, this did not lead to the formation different types, and representatives of all races belong to the same biological species - Homo sapiens. According to the ability to know, to labor activity, creativity all races are the same. At present, racial traits are not adaptive. The increase in population, a sharp decrease in the level of isolation of populations, the gradual disappearance of racial, ethnic and religious prejudices lead to the blurring of interracial differences. Apparently, in the future these differences should disappear.- What is meant by the biological and social factors of human evolution?
- Anthropogenesis is inseparable from sociogenesis. Justify this statement.
- Using specific examples, show that unique biological forms (which, no doubt, is a person) can be formed as a result of the action of ordinary biological factors.
- Summing up the discussion of possible ways of human development from some lower form, C. Darwin in his book "The Origin of Man and Sexual Selection" concluded that "the physical characteristics that a person has are acquired as a result of the action of natural selection, and some of them - sexual selection." The Duke of Argyll remarked that, on the whole, "the organization of man has deviated from that of animals in the direction of greater physical helplessness and weakness—an evasion which, of all others, can least be ascribed to natural selection." Darwin came out brilliantly from this situation. And what would you answer from the standpoint of modern knowledge about human evolution?
- Does the evolution of man as a biological species continue? Do you think that Homo sapiens will remain a single species?
- Give examples proving that the cultural development of mankind is much faster than biological. Why?
Biological factors influence human evolution.
Human development historically could not take place in isolation from the surrounding reality. This process was influenced by the biological factors of human evolution, the same as they influenced the rest wildlife. However, studies show that only biological factors are clearly not enough for anthropogenesis, social factors were also required.
The early stages of human evolution are characterized by the predominance of biological factors. Of decisive importance was the natural selection of individuals with better adaptability to constantly changing environmental conditions.
There was a selection and individuals who showed the ability to produce primitive tools, without which the extraction of food and protection from enemies became problematic.
At later stages, selection was already carried out on the basis of herding and related forms of communication. IN environment only groups of individuals capable of resisting surprises and unfavorable factors by common efforts could continue to exist.
At certain stages, the biological factors of human evolution included individual selection, which was based on the selective death of individual individuals and contributed to the formation of human morphophysiological features, such as upright posture, a large brain, and a developed hand.
Man already had a difference from the surrounding animal world in that he could speak, developed thinking and the ability to work. Thus, in the process of anthropogenesis, modern man was formed.
The biological factors of the historical-revolutionary process of the formation of man were exactly the same for all living nature. They became especially important in the early stages of human development. Charles Darwin wrote a lot about the role of biological factors for human evolution.
The biological factors of human evolution have created the prerequisites for the occurrence of hereditary changes in him, which determine, for example, eye and hair color, height, and also the body's resistance to environmental influences.
Man's dependence on nature was especially felt in the early stages of his evolution. Only individuals who were characterized by endurance could survive and leave offspring for procreation. physical strength, dexterity, ingenuity and other useful qualities.
The beginning of the improvement of labor tools significantly reduced the role biological evolution. Technogenic evolution has forced a person not to wait, as they say, for alms from nature. He no longer adapted painfully and slowly, but he himself consciously changed himself. surrounding nature and forced her to satisfy her needs. To do this, people used powerful tools.
However, the biological factors of human evolution have not completely lost their influence on animal world in general, and per person in particular. Nature is still the cause of the ongoing evolution of man.
The evolutionary doctrine is theoretical basis biology. It studies the causes and mechanisms historical development all living organisms. Human evolution has its own characteristics and factors.
What is anthropology
According to evolutionary doctrine, man has been formed over a long period of time. The processes of its historical development are studied by the science of anthropology.
The emergence of man has its own characteristics. They lie in the fact that the process of formation is influenced by both social and biological. The first group includes the ability to work, speech. The biological factor in human evolution is, in particular, the struggle for existence. as well as natural selection and hereditary variability.
The main provisions of evolutionary theory
According to Charles Darwin's theory, environmental conditions can cause changes in the structure of living organisms. If they are not inherited, then their role in the process of evolution is insignificant. In some individuals, changes occur in the germ cells. In this case, the trait is inherited. If it turns out to be useful in certain conditions, then organisms have a better chance of surviving. They successfully adapt and produce fertile offspring.
Struggle for existence
The main biological factor in human evolution is its essence lies in the emergence of competition between organisms. The reason for its appearance is the discrepancy between the ability of different species to feed and reproduce. As a result, the species that can best adapt to specific conditions survives.
Despite the fact that the process of the emergence of modern man was subject to general patterns, there are some differences. Natural selection occurred not only in strength, agility and endurance. In addition to these physical signs, the level of mental development also played a special role. Individuals who learned to make the most primitive tools and use them, communicate with fellow tribesmen, and act together had a greater chance of surviving.
Natural selection
In the course of the struggle for existence, natural selection occurs - a biological process during which adapted individuals survive and actively reproduce. Those who can't adapt die.
Thus, natural selection is also a biological factor in human evolution. Its peculiarity was that individuals with pronounced social traits survived. The most viable were the people who invented new tools, acquired new skills and socialized. Over time, the importance of natural selection in the process of anthropogenesis decreased. This is due to the fact that ancient people gradually learned to build, ennoble and heat dwellings, make clothes, grow plants, and tame animals. As a result, the importance of natural selection gradually decreased.
hereditary variability
The biological factor of human evolution is also hereditary variability. This property of living organisms lies in the ability to acquire new features in the process of their development and pass them on to offspring. Naturally, only useful signs had evolutionary significance in the process of anthropogenesis.
Humans are related to mammals by a number of similar biological traits. This is the presence of mammary and sweat glands, hairline, live birth. The body cavity is divided by a muscular septum into the thoracic and abdominal parts. Similar features are the absence of nuclei in red blood cells, erythrocytes, the presence of alveoli in the lungs, the general plan of the structure of the skeleton, differentiated teeth. Both humans and animals have rudimentary (underdeveloped) organs. These include the appendix, the third eyelid, the rudiments of the second row of teeth, and others. Scientists are aware of cases of the birth of people with the characteristic features of animals - a developed tail, a continuous hairline, an additional number of nipples. This is additional evidence from animals. But in the process of anthropogenesis, only the most useful features have been preserved.
The following biological traits are specific only to humans:
bipedalism;
Enlargement of the brain and reduction of the facial part of the skull;
Arched foot with strongly developed big toe;
Movable hand, opposition of the thumb to the rest;
An increase in the volume of the brain, the development of its cortex.
The biological evolution of man is closely connected with the social one. For example, the ability to make a fire and cook food led to a decrease in the size of the teeth and the length of the intestines.
The biological factors of human evolution are a necessary condition for the formation of social factors, which together led to the appearance of Homo sapiens on Earth.
Human evolution began over 10 million years ago and continues to this day. Social and biological factors of anthropogenesis acted on the formation of the modern human species.
Factors
Man is a biological species that emerged from the biosphere and created an artificial environment, which was called the noosphere. That's why human development depends on two factors:
- biological - natural and identical for all kinds of living beings;
- social - due to society, norms of behavior, labor, culture.
Initially, only biological factors acted on human evolution. However, with the evolutionary complication of both a separate type of person and society (tribe) as a whole, social factors began to play a significant role.
Anthropogenesis is sometimes called anthroposociogenesis, emphasizing the importance of social life in human evolution.
Biological
Mankind, like any other species, was formed under the influence of the driving forces of evolution, which include:
- variability;
- natural selection;
- mutations;
- isolation;
- struggle for existence.
In the early stages of anthropogenesis, natural selection played a decisive role. Thanks to the forces of natural selection, mankind has acquired character traits distinguishing it from other great apes. Evolution was largely facilitated by a change in lifestyle due to climate change and terrain.
Thanks to natural selection, mankind has acquired:
- developed brain;
- grasping brush;
- upright posture;
- bare skin (the hair is preserved only on the head).
Rice. 1. Differences between humans and chimpanzees.
It is believed that the ancestors of man were driopithecus living on trees. With the disappearance of forests, they had to gradually go out into the savannas and adapt to new conditions, which contributed to further evolution.
Rice. 2. Dryopithecus.
Social
The development of human abilities was influenced by the social factors of anthropogenesis. First of all, collective labor is distinguished, namely hunting. Man is a rather weak creature to hunt large and dangerous prey alone. Therefore, the rallying of the tribe, the distribution of tasks, the establishment of relations contributed to a successful hunt.
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Rice. 3. Collective hunting.
Also social factors are:
- speech - ability to communicate;
- thinking - development logical thinking, application of experience, training;
- creation - the ability to create objects, works of art, solve non-standard tasks;
- public lifestyle - manifestation of altruism, care, respect for socially significant individuals.
The main advantage of mankind over other animals is the presence of speech. With the help of a system of words, people can communicate, solve complex problems, explain feelings, emotions, their physical state. This increases the speed of information exchange and decision making.
Social factors are characteristic only of human evolution, despite the fact that many animals lead a social lifestyle.
What have we learned?
Considered the main factors of anthropogenesis. Human evolution is influenced by biological and social factors. The leading biological factors of human evolution include variability and natural selection. The social factors inherent only in the evolution of man are labor, thinking, creativity, speech, and the social way of life.
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Topic: Factors of human evolution. Human races Tasks: To characterize the factors of human evolution, to consider the question of the origin of human races Chapter XIV. The origin of man Pimenov A.V. On house: §§
Biological Factors The biological factors of evolution—hereditary variation, natural selection, population waves, isolation, and genetic drift—have led, as a result of tree life, to the emergence of primates with their binocular color vision and long fingers.
Adaptation of some primates to life on open spaces led to movement on two legs, natural selection fixed mutations useful for new conditions. Those who were most adapted to walking upright survived, the freed hands were used to collect and carry food and objects. Larger ones survived - it is easier for them to defend themselves from predators and they dominate the group. Among the Australopithecus, those who learned how to make tools began to survive, selection fixed the increase in the brain, changed the hand. Biological factors
Then, as a result of natural selection, a skilled man appeared, a man erect, from which a reasonable man originated - subspecies of a reasonable Neanderthal man and a reasonable man. The modern man supplanted the Neanderthals and became the dominant species on Earth. With the advent of the modern type of man, the biological factors of evolution lose their leading significance. Biological factors
The leading role of natural selection is decreasing, life in society ensures the upbringing and transfer of accumulated experience, protection from animals and bad weather, and food security. Behind recent years The physical appearance of a person has not changed much. But biological factors continue to operate in modern world. Biological factors
In the first place are the social factors, the social way of life, labor activity, speech, thinking. If earlier the strongest survived, then in the conditions of collective life, altruism, concern for one's neighbor, becomes an important factor in evolution. Social factors
Human races, their origin and unity The settlement of neoanthrope populations in Europe, Asia and Australia, along the Beringian bridge to the American continent, their further isolation, led to morphological adaptations, adaptations to various climatic conditions. Large and small human races have formed, systematic divisions within the species Homo sapiens, to which the entire population of the Earth belongs.
Human races, their origin and unity Three large races are distinguished: the Eurasian Caucasoid, the Asian-American Mongoloid and the Equatorial Australo-Negroid. Within each race, small races and racial groups are distinguished. All races belong to the same species, as evidenced by the fecundity of interracial marriages. In addition, all races are equal biologically and psychologically.
Human races, their origin and unity In every race there are people who consider their race to be special, superior. Racists claim that different races have different origins, are biologically unequal, that there are "superior" and "inferior" races. They explain the economic and cultural backwardness of some peoples by racial inequality, and not by socio-economic factors. There is no scientific evidence for racial disparity. Morphological features of races are the result of adaptations to specific living conditions.
Human races, their origins and unity The dark skin of the Negroid race, due to the pigment melanin, protects the body from excess ultraviolet rays and excessive formation of vitamin D. Anti-rachitis vitamin D is formed in the skin under the influence of ultraviolet rays and is necessary to maintain calcium balance in the body. If there is too much vitamin D, calcium in the bones is more than normal, they become brittle.
Human races, their origin and unity The Mongoloid race is characterized by a skin with a yellowish tinge, a flat face with wide cheekbones, straight black hair, a slit in the eyes and a developed epicanthus with a swollen upper eyelid. These features are adaptations to life in certain light conditions in open spaces.
Human races, their origin and unity Europeans, living in latitudes with less solar radiation, have lighter skin, less melanin, and, accordingly, a sufficient amount of vitamin D is formed. Beard and mustache - protection from the cold in winter.
Recap: Why does hereditary variation remain an important factor in human evolution? The mutational process continues to operate, combinative variability spreads mutations and creates a variety of combinations of gene alleles that are unique in each organism. Give an example of the action of natural selection in the evolution of modern man? The high mortality of children with hereditary diseases is the result of natural selection.
