Man: systematics and characteristic features in the structure of the body. The systematic position of man in the animal world The position of man in the organic world
What is the place of man in the system of the organic world? This question, it would seem, has been answered for a long time, which is increasingly disputed and subjected to revision.
The place of man in the system of the organic world
Briefly, we can say that the place of man is strictly defined in the classification of the organic world. He is a representative of the animal kingdom. The table shows its key ranks in the hierarchy of the biological world:
There are several groups of evidence that man is an animal and descended from them.
Animal origin of man
In favor of this they say:
Comparative anatomical evidence: a similar structure of cells, the location of organs, rudiments and atavisms in humans.
Embryological evidence: inside the womb at the initial stage of development, the baby is similar to the cubs of some animals. This is called Baer's law, and, in short, he postulates: the younger the embryo, the less specific features it has.
Physiological similarity (breathing, nutrition, etc.) of a person and an animal.
Similar chromosomal apparatus.
There are physiological features of the human species, which testify that the place of man in the system of the organic world among animals:
Upright posture, arched foot, developed muscles of the lower extremities.
The structure of the spine with 4 bends.
Movable hands.
The volume of the brain and, accordingly, the high organization of behavior.
binocular vision.
Fertility is limited: one female normally bears one fetus.
All these specific and physiological features brought man to a new stage of evolution.
Anthropogenesis and the formation of mankind
Anthropogenesis (part of the evolution that led to the emergence of man) began with hominins. Human society acquired the right to be called that and ceased to be a herd about 50 thousand years ago, when neoanthropes (Cro-Magnons) formed a new species of Homo sapiens.
The subsequent development of people began to determine the social, economic and religious laws. Progress began to go contrary to biological nature. To be a member of society, one cannot behave like a beast and obey instincts. The place and features of man in the system of the organic world turned out to be such that the very right to be called a biological species was called into question.
What distinguishes a person from the organic world
There are a number of highly developed organisms (for example, elephants or dolphins), what makes a person stand out from their background? High social component of people's life: their creative function, knowledge, work, consciousness, speech. All this makes the place of man in the system of the organic world beyond the usual limits available to other animals.
Fundamental differences between man and the organic world
The place of man in the system of the organic world and his biosocial nature sometimes contradict each other. A person does not behave like an animal in several cases:
- He has abstract thinking.
- Family planning, not uncontrolled reproduction, according to instinct.
- Consciousness (not just a highly developed brain, like dolphins, for example, not only a big brain in every sense of the word).
- Speech.
- Man is part of society. People coexist in their artificially created habitat.
These five points reflect the social nature of man.
Abstract thinking
Abstract thinking is a human ability. Thanks to him, the place of man in the system of the modern organic world is unique. After a series of repetitions of certain actions and their consequences, many animals (especially primates) demonstrate imaginative thinking. They are able to remember the image, especially if they are hungry, but you need to imagine food. But the next step, abstract thinking, is not available to them. They are not capable of imagining and remembering, drawing a conclusion and highlighting a generalizing sign of what does not exist, what cannot be touched or smelled.
Accumulation of experience, abstract conclusions, ability to find ways out of various situations, analyze and, based on this, make a decision and take actions, reason, generalize concepts - the privilege of people.
This article does not aim to analyze in detail the concept of abstract thinking, but it is worth giving an example of what abyss separates one of the closest relatives, chimpanzee monkeys, from people. They belong to the hominin family. A characteristic experiment on them was carried out in the laboratory. I.P. Pavlov in Koltushi near St. Petersburg.
The chimpanzee Rafael had to feast on the fire burning before eating on the ledge of the shelf. He quickly learned to use for this purpose a cup and water, which was offered to him in a tank and other containers. Then on the lake, on two rafts connected by a shaky crossing, they put food on one (as always behind the fire), and on the other a cup and a tank of water. From time to time, the chimpanzee preferred to make a difficult crossing to scoop up in a tank, but ignored a whole lake of water. It became clear that he could not generalize this concept. Water for him is tied to the image of the tank. In fairness to Raphael, it is worth adding that when the water was removed from the tank, in the end, albeit by accident, he scooped up water from the lake and, having put out the fire, got a treat.
creation
The place of man in the system of the organic world is already the whole planet. People do not live strictly within the boundaries of the place of birth, but adjust the chosen place of life to suit their needs. And it's not always the best. comfortable environment a habitat. But people are transforming it. This is the simplest creation, responsible for covering the urgent needs, but which arose as a result of a conscious choice of life in an unsuitable environment. People are literally going against biological selection. They do not look for the easiest habitats, but adapt very unsuitable ones.
There is creative creation. The desire to leave a mark in history, to influence the world and not just feed.
Speech
Another sign of abstract human thinking is speech. Even its very possibility. When certain natural phenomena are assigned a specific (and, by the way, abstract) concept - a word and its semantic meaning. It is not directly related to how and what the senses perceive in a particular period of time here and now. The image that each person forms about objects, of course, carries information-memories about weight, temperature and other associations. But with the help of words, non-existent objects are also described, those that cannot be touched with hands. Favorite examples of scientists are love or mathematical terms. How to describe the concept of seven?
Man is just a highly evolved animal
This problematic issue. Evidence of the animal nature and the origin of man is considered. According to biology, the place of man in the system of the organic world. There are anthropological factors that to some extent explain how physiological characteristics as a result could influence the formation of a highly developed individual and human society. But there is a long series of social factors that put a person on another level. Is it possible to speak of a separate fifth kingdom of the organic world? Or continue to put forward theories on the topic: where did our family come from? Is the soul a matter separate from the body, or are they physiological processes that mimic consciousness, but remain chemistry?
To reconcile opposites, it is customary to talk about the biosocial nature of man.
The school curriculum has not yet moved away from a strict focus on evolution. Teachers of biology and zoology do not always correctly emphasize that Darwin only put forward a theory. It is popular, but not supported by hard evidence. On the contrary, there are still many questions, white spots and arguments against it.
Although the basic postulates of this theory are an obligatory part school curriculum, and it is necessary to know them in order to be an educated person with a broad outlook. But what speaks against the theory of the origin of species, except that the social nature of man is pronounced, and thinking is unique?
Darwin's theory of the origin of species: the main arguments against
As Darwin himself and his contemporaries argued: the idea of evolution was in those days in the air. The genius of the most famous naturalist, the author of The Origin of Species, lies in the fact that he formulated how the big comes from the small in billions of years. It is not the strongest who survive, but the most adapted to the constant changes in the environment. This is the shorthand for natural selection.
Opponents of Darwinism turn to the concept of irreducible complexity. In the process of evolution, many organisms could not gradually form (due to mutations) the advantages that they possess at a given stage of development and thanks to which they survived in a certain habitat, in other words, they underwent natural selection.
Another main argument against the theory of evolution is the informational complexity of chromosomes and, as a consequence, of the DNA molecule. Such an ordered and long chain could not have been obtained by chance, even in billions of billions of years. In addition, given the enormous age of the Earth and the discovered fossils dating back to the most different periods, not found a sufficient number of missing links, transitional life forms, which the theory of evolution suggests in large quantities between all species.
The question of origin is most closely connected with the place of man in the system of the organic world and his role. Perhaps it is the social component of people's lives that determines. It imposes on humanity responsibility for the entire biosphere. The role, the place of a person in the system of the organic world is not given to him in vain - to protect and reasonably dispose of the planet, regardless of whether people are part of an ecosystem, or simply similar to other biological organisms, but have a higher origin and purpose of existence.
The appearance in the process of human embryonic development of a notochord, gill slits in the pharyngeal cavity, dorsal hollow neural tube, bilateral symmetry in the structure of the body determines whether a person belongs to the Chordata type. The development of the spinal column, the heart on the ventral side of the body, the presence of two pairs of limbs - to the Vertebrata subtype. Warm-bloodedness, the development of the mammary glands, the presence of hair on the surface of the body indicates that a person belongs to the class Mammalia (Mammalia). The development of the baby inside the mother's body and the nutrition of the fetus through the placenta determine the person's belonging to the subclass Placental (Eutheria). Many more specific signs clearly define the position of a person in the system of the order Primates (Primates).
So, from a biological point of view, a person is one of the types of mammals belonging to the order of primates, the suborder of the narrow-nosed.
The place of a reasonable person in modern classification appears as follows:
1. Subspecies Homo sapiens sapiens
2. Species of Homo sapiens
4. Tribe Homini
5. Subfamily Homininae
6. Family Hominidae
7. Superfamily Hominoidea
8. Section Catarrhini
9. Suborder Harlorhini (Antropoidea)
10. Squad Primates
Comparative anatomical evidence. The animal origin of man is evidenced by the presence of rudimentary organs and atavisms in him.
Rudiments are organs that have lost their original meaning in the process of evolution. There are only 90 rudiments in the human body:
1. coccygeal vertebrae (remainder of the caudal region);
2. poorly developed body hair;
3. subcutaneous muscle;
4. muscles that raise hair;
5. muscles that move the auricles;
7. brow ridges in the skull;
8. wisdom teeth;
9. appendix - caecum;
10. in the corner of the eye - the third eyelid;
11. in the circulatory system - the median sacral artery.
Atavisms are evidence of animal origin. These are deviations from the norm.
Atavisms - the appearance of signs characteristic of distant ancestors. These are signs that were laid down in embryonic development, but did not disappear, but remained for life in the human genotype:
o several pairs of nipples - multiple nipples;
o hairline - polymastia throughout the body;
o cervical fistula - as a result of non-closure of the gill slit;
o strong display of fangs;
o well-developed tubercle in the corner of the ear.
o Atavisms that disrupt normal life:
o a hole in the interventricular septum of the heart;
o the opening between the atria - the ductus botalis.
Comparative anatomical evidence includes: the same structure of the musculoskeletal, circulatory, respiratory, excretory and other organ systems in humans and monkeys. Embryological evidence of human animal origin.
Embryology is a science that studies the embryonic development of organisms.
In the early stages of development, the human embryo has signs of lower vertebrates:
ü cartilaginous skeleton - chord;
ü gill arches;
ü symmetrical discharge of blood vessels from the heart;
the smooth surface of the brain.
Later, features characteristic of mammals appear:
Ø thick hairline on the body of the fetus;
Ø several pairs of nipples;
Ø left aortic arch;
Ø constant body temperature;
Ø the body cavity is divided by the diaphragm: into the thoracic and abdominal sections;
Ø mature erythrocytes;
Ø teeth have two shifts (milk and permanent) and are divided into 3 groups;
Ø in the human skeleton there is not a single bone that mammals would not have;
Ø there are 3 auditory ossicles in the inner ear;
o A 6-month-old human fetus is covered with hair. similarities between man and great apes
o The same expression of feelings of joy, anger, sadness.
o Monkeys gently caress their cubs.
o Monkeys take care of children, but also punish them for disobedience.
o Monkeys have a well-developed memory.
o Monkeys are able to use natural objects as the simplest tools.
o Monkeys have concrete thinking.
o Monkeys can walk on their hind legs, leaning on their hands.
o On the fingers of monkeys, like humans, nails, not claws.
o Monkeys have 4 incisors and 8 molars - like humans.
o Humans and monkeys have common diseases (influenza, AIDS, smallpox, cholera, typhoid fever).
o In humans and great apes, the structure of all organ systems is similar.
o Biochemical evidence of human-monkey affinity:
o the degree of hybridization of human and chimpanzee DNA is 90-98%, human and gibbon - 76%, human and macaque - 66%;
o Cytological evidence of human-monkey affinity:
o humans have 46 chromosomes, chimpanzees and monkeys have 48 each, and gibbons have 44;
o in the chromosomes of the 5th pair of chimpanzee and human chromosomes there is an inverted pericentric region
All of the above facts indicate that man and great apes descended from a common ancestor and make it possible to determine the place of man in the system of the organic world.
The similarity between man and monkeys is evidence of their kinship, common origin, and the differences are the result of different directions in the evolution of monkeys and human ancestors, especially the influence of human labor (tool) activity. Labor is the leading factor in the process of turning a monkey into a man.
The most characteristic feature of man, which distinguishes him from anthropomorphic apes, is the exceptionally strong development of the large brain. In terms of body weight, a person occupies approximately the middle place between a gorilla and a chimpanzee. Data on the size of the brain in humans and other primates are given in Table. 11 and in fig. 13.9.
The large human brain differs from the large brain of anthropomorphic monkeys not only in its large mass, but also in other important features: the frontal lobe and parietal lobes are more developed, and the number of small furrows is increased. A significant part of the human cortex is associated with speech: the “motor center” of speech, the “auditory center”. There is a greater wealth of interneuronal contacts. A person has new qualities - sound and written language, abstract thinking. Many human anatomical features are associated with upright posture and labor activity, which required the restructuring of many organs. The human spinal column has characteristic bends in the sagittal plane (lordosis and kyphosis), the chest has a flattened shape, the pelvis is expanded, as it takes on the pressure of the internal organs (Fig. 13.10).
A person is characterized by a significant strengthening of the connection between the spinal column and the pelvis, more massive lower limbs: the femur is the most powerful in the skeleton, it can withstand loads up to 1650 kg. The muscles of the lower extremities are also strongly developed: the gluteal muscles, which provide abduction and extension of the hip, the large sciatic muscle (prevents the tendency of the body to tip forward), the gastrocnemius muscle and the calcaneal tendon (Fig. 13.11). The foot is a support organ, has a high arch, unlike the flat foot of monkeys.
The first finger of a person is less mobile. In monkeys, the upper limbs are adapted for hanging the body in an extended state and for moving through trees by "brachiation". The first toes of the hand and foot are short (Fig. 13.12), they play the role of a hook when suspended from a branch. When moving on the ground, long forelimbs act as an additional support. In humans, the upper limbs, which do not perform the function of support, are shortened and less massive (Fig. 13.13). For fast free movements excessively large limbs of the hands would be disadvantageous.
A person has increased mobility of the hand, which allows greater freedom of movement and ensures their diversity. The first finger is much better developed, its muscles are more differentiated.
Humans are characterized by the dominant development of the cerebral region of the skull, the absence of the sagittal and occipital crests, to which the chewing muscles are attached in monkeys, and the weaker development of the supraorbital relief (brow ridges). The facial section of the skull, unlike monkeys, is less developed (Fig. 13.14), which is associated with a decrease in the massiveness of the chewing apparatus, the mass of the lower jaw as a percentage of the mass of the skull in a gorilla is about 45%, and in humans only 15%.
The teeth are relatively small, a typical feature of a person is the absence of a conical shape of the fangs and their smaller size. The development of the chin protrusion is characteristic, which is not observed in any of the monkeys; this protrusion is absent in the ancient ancestors of man. The formation of the chin is associated with the reduction of the alveolar part, the straightening of the teeth, and the peculiarities of the growth of the bones of the facial skull. The human hairline is reduced. These features testify to the fundamental difference between man and animals, including monkeys.
All modern primates are not human ancestors; they separated from the common trunk of ancestral forms as early as the Tertiary period. There are two trends in the understanding of human nature; on the one hand, a misunderstanding of the qualitative specifics of a person and reducing his features only to quantitative ones (vulgar biologizing), on the other hand, an opposite nihilistic attitude towards the biological basis of a person, opposing him to other living organisms, separating him from the animal world and from nature, of which he is a part . Dialectical materialism will provide a basis for the scientific definition of the essence of man, which has a dual nature: biological and social
79. Paleontological data on the origin of primates and humans. Parapithecus, Driopithecus, Australopithecus, Archanthropes, Paleoanthropes, Neoanthropes. Scientists argue that modern man did not originate from modern anthropoid apes, which are characterized by a narrow specialization (adaptation to a strictly defined lifestyle in tropical forests), but from highly organized animals that died out several million years ago - driopithecus. The process of human evolution is very long, its main stages are presented in the diagram.
The main stages of anthropogenesis (the evolution of human ancestors)
According to paleontological finds (fossils), about 30 million years ago, ancient parapithecus primates appeared on Earth, living in open spaces and on trees. Their jaws and teeth were similar to those of great apes. Parapithecus gave rise to modern gibbons and orangutans, as well as an extinct branch of driopithecus. The latter in their development were divided into three lines: one of them led to the modern gorilla, the other to the chimpanzee, and the third to Australopithecus, and from it to man. The relationship of driopithecus with man was established on the basis of a study of the structure of his jaw and teeth, discovered in 1856 in France.
The most important step in the transformation of ape-like animals into the most ancient people was the appearance of bipedal locomotion. In connection with climate change and the thinning of forests, there has been a transition from an arboreal to a terrestrial way of life; in order to better view the area where the ancestors of man had many enemies, they had to stand on their hind limbs. Subsequently, natural selection developed and fixed upright posture, and, as a result of this, the hands were freed from the functions of support and movement. This is how australopithecines arose - the genus to which hominids belong (a family of people).
australopithecines
australopithecines- highly developed bipedal primates who used natural objects as tools (hence, Australopithecus cannot yet be considered people). Bony remains of Australopithecus were first discovered in 1924 in South Africa. They were as tall as chimpanzees and weighed about 50 kg, the brain volume reached 500 cm 3 - on this basis, Australopithecus is closer to humans than any of the fossil and modern monkeys.
The structure of the pelvic bones and the position of the head were similar to those of a person, which indicates a straightened position of the body. They lived about 9 million years ago in open steppes and fed on plant and animal food. The tools of their labor were stones, bones, sticks, jaws without traces of artificial processing.
skillful man
Not having a narrow specialization general structure, Australopithecus gave rise to a more progressive form, called Homo habilis - a skilled man. Its bone remains were discovered in 1959 in Tanzania. Their age is determined at about 2 million years. The growth of this creature reached 150 cm. The volume of the brain was 100 cm 3 larger than that of Australopithecus, the teeth of a human type, the phalanges of the fingers, like those of a person, are flattened.
Although it combined signs of both monkeys and humans, the transition of this creature to the manufacture of pebble tools (well-made stone ones) indicates the appearance of labor activity in it. They could catch animals, throw stones, and perform other activities. The heaps of bones found along with the fossils of Homo sapiens testify to the fact that meat has become a permanent part of their diet. These hominids used rough stone tools.
Homo erectus
Homo erectus - Homo erectus. the species from which modern man is believed to have descended. Its age is 1.5 million years. His jaws, teeth, and brow ridges were still massive, but the brain volume of some individuals was the same as that of modern man.
Some bones of Homo erectus have been found in caves, suggesting a permanent home. In addition to animal bones and rather well-made stone tools, heaps of charcoal and burnt bones were found in some caves, so that, apparently, at this time Australopithecus had already learned how to make fire.
This stage of hominin evolution coincides with the colonization of other colder regions by Africans. Endure cold winters without developing complex types behavior or technical skills would be impossible. Scientists suggest that the prehuman brain of Homo erectus was able to find social and technical solutions (fire, clothing, food supply and cohabitation in caves) to the problems associated with the need to survive in the cold of winter.
Thus, all fossil hominids, especially Australopithecus, are considered to be the precursors of humans.
Evolution physical features the first people, including modern man, covers three stages: ancient people, or archanthropes; ancient people, or paleoanthropes; modern people, or neoanthropes.
archanthropes
The first representative of the archanthropes - Pithecanthropus(Japanese man) - ape-man, upright. His bones were found on about. Java (Indonesia) in 1891. Initially, its age was determined to be 1 million years, but, according to a more accurate modern assessment, it is a little over 400 thousand years old. The height of Pithecanthropus was about 170 cm, the volume of the cranium was 900 cm 3 .
Somewhat later there was synanthropus(Chinese person). Numerous remains of it were found in the period 1927 to 1963. in a cave near Beijing. This creature used fire and made stone tools. This group of ancient people also includes the Heidelberg man.
Paleoanthropes
Paleoanthropes - Neanderthals appeared to replace the archanthropes. 250-100 thousand years ago they were widely settled in Europe. Africa. Front and South Asia. Neanderthals made a variety of stone tools: hand axes, side-scrapers, sharp-pointed ones; used fire, coarse clothing. The volume of their brain grew 1400 cm 3 .
Features of the structure of the lower jaw show that they had rudimentary speech. They lived in groups of 50-100 individuals and during the onset of glaciers they used caves, driving wild animals out of them.
The emergence of man as a biological species is the result of a long evolutionary process and is associated with historical development animal world. Man in himself combines the fundamental features of the structure and life that animals are characterized by. But unlike them, he has significant features, including highly developed thinking, consciousness, creative activity, articulate speech, which arose as a result of a person’s labor activity and his social relations. The anatomical and physiological features of modern man distinguish him into a special biological species - Homo sapiens (homo sapiens).
In addition to the signs in common with animals, a person has structural features inherent only to him:
- upright posture;
- spine with four curves;
- arched foot with strongly developed first toe;
- very mobile skeleton of the hand, and especially the hand;
- very mobile shoulder joint, allowing rotational movements with a swing of almost 1800;
- the location of the pelvis at an angle of 600 to the horizontal plane;
- strongly developed muscles of the lower extremities;
- a large volume of the brain skull in comparison with the facial part of the skull;
- powerfully developed cerebral hemispheres with a large area of the cortex (about 2400 cm2);
- binocular vision;
- limited fertility;
44. The ratio of biological and social factors in the development of man at various stages of anthropogenesis. The value of human biological heritage for social development and definitions of human health.
Usually, the following stages of human evolution are distinguished:
1. The oldest stages of hominization - the origin of the genus Homo.
2. The evolution of the genus Homo before the emergence of modern man.
3. The evolution of modern man.
The first stage of anthropogenesis is purely biological evolution. At the second stage, the action of the social factor, which is dominant at the third stage, is connected to the elementary factors of biological evolution.
Stage of anthropogenesis
1. A skilled person - Homo habilis highly developed australopithecine or the first member of the genus Homo.
The first being who consciously made tools for labor and hunting: the first still roughly processed stone pebbles were repeatedly found along with the remains of this creature. It was the Skillful Man who stepped over the invisible boundary separating the genus Homo from all other biological beings - he took the first step towards subordinating the surrounding nature to himself. The tools that the Handy Man made were almost all quartz, and quartz was not found in the parking lots of these people. They brought it from a distance of 3 to 15 km. This proved that the Handy Man really was a man. He preselected the stone for his tools. None of the animals not only does not select raw materials for their tools, but does not even think of splitting a stone in order to make it sharp, to turn it into a tool. However, unlike the later species of Homo, they were careless with the tools they made themselves, and after use they simply threw them away. Scientists conducted a series of studies and came to the conclusion that the Handyman's hand was capable of work. She possessed a force grip of greater power. None of the monkeys have such abilities. At the same time, the oldest of the representatives of the new genus, Australopithecus anamensis, descended directly from Ardipithecus ramidus 4.4-4.1 million years ago, and 3.6 million years ago gave rise to Australopithecus afarensis, to which the famous Lucy belongs.
2. Archanthropes (earliest people): Homo erectus - Homo erectus(Pithecanthropus, Sinanthropus), Homo erectus differed from its predecessors in height, straight posture, human gait. The average height of synanthropes was about 150 cm for women and 160 cm for men. The hand was more developed, and the foot acquired a small arch. The bones of the legs changed, the femoral joint moved to the center of the pelvis, the spine received a certain bend, which balanced the vertical position of the torso. Proceeding from these progressive changes in physique and growth, the most ancient man got his name - Homo erectus.
3. Heidelberg man (lat. Homo heidelbergensis)- a fossil species of people, a European variety of Homo erectus and the immediate predecessor of the Neanderthal. Representative of archanthropes. Found below. jaw (massive, without a chin protrusion, generally similar to a monkey) with a full set of teeth, to-rye, both in size and in shape and structure, are close to human. Usually, H. h. is combined with Pithecanthropes, Sinanthropes, and other ancient people into one species - Homo erectus (Homo erectus).
Speech (primitive, consisting of separate cries). The presence of speech centers, which appeared for the first time in H. habilis, also suggests the development of a second signaling system. in these adaptations, along with the factors of biological evolution, social factors also played a significant role: the joint production of shelters, tools and the use of fire.
4. Paleoanthropes (ancient people) Neanderthal man - Homo neanderthalensis
Considered as a subspecies of Homo sapiens neanderthalensis
Speech (advanced forms such as babble). Complex forms of collective activity (driven hunting), caring for others. Getting fire. They were characterized by a dense muscular build with a small stature (160-163 cm in men), a massive skeleton, a voluminous chest, an extremely high ratio of body mass to its surface, which reduced the relative heat transfer surface. These signs could be the result of selection acting in the direction of an energetically more favorable heat exchange and an increase in physical strength. Neanderthals had a large, although still primitive brain (1400-1600 cm3 and above), a long massive skull with a developed supraocular ridge, a sloping forehead and an elongated "chignon-like" occiput; very peculiar "Neanderthal face" - with sloping cheekbones, a strongly protruding nose and a cut chin.
5. Neoanthropes (new people) Homo sapiens (Cro-Magnon)
Real speech, thinking, art. Development of agriculture, crafts, religion. Fossil humans had a somewhat more massive skeleton than modern humans. Ancient people created a rich culture (a variety of tools made of stone, bone and horn, dwellings, sewn clothes, polychrome painting on cave walls, sculpture, engraving on bone and horn). The unusually fast process of the settlement of modern man, which can be evidence of the "explosive", spasmodic nature of anthropogenesis during this period, both in the biological and social sense. With the advent of man of the modern physical type, the role of biological factors in his evolution was reduced to a minimum, giving way to social evolution.
Homo sapiens is a unique life form that combines biological and social essence. The life of the human body is based on fundamental biological mechanisms, patterns of metabolism and energy, due to the morphological and functional characteristics of the body, which provide adaptation to the environment.
At the same time, the biological essence is manifested under the conditions of the operation of the laws of the highest, social form of the movement of matter. In the process of anthropogenesis, a social entity of a person as a system of material and spiritual factors, interpersonal and psycho-emotional relations that arise in joint labor activity. The social factor has a significant impact on the life of a person, on his health.
The process of individual human development is based on two types of information:
First view represents biologically expedient information that was selected and stored in the process of evolution of ancestral forms and recorded in the form of genetic information in DNA (universal for all living organisms, the mechanism for encoding, storing, implementing and transmitting information from generation to generation). Thanks to this, in the individual development of a person, a unique complex of structural and functional features distinguishing it from other living organisms.
Second view information is represented by the sum of knowledge, skills that are acquired, stored and used by generations of people in the course of the development of human society. The assimilation of this information by an individual occurs in the process of his upbringing, education and life in society. This feature of a person is determined by the concept of social heredity, inherent exclusively in human society.
Distinguish individual health(person) and collective health(family, professional group, social stratum, population). Human health has long been not only a personal problem, but also a criterion of life in various countries of the world.
The main indicators of the convenience and prosperity of human life are:
♦ the state of the healthcare system;
♦ sanitary conditions and environment;
♦ percentage of malnourished young children;
♦ attitude towards women in society;
♦ the level of literacy of the population;
♦ organization of obstetric care.
The health of the population is also determined by social factors:
♦ protection of the population (political, legal, legal);
♦ realization of the rights to work, education, healthcare, recreation, information, etc.;
♦ the nature of nutrition (its sufficiency and usefulness);
♦ real wages and working conditions;
♦ living conditions, etc.
Man has a very ancient evolutionary lineage. Among the more and more ancient ancestors are: lower ape, semi-monkey, lower placental mammal, primitive marsupial mammal, monotreme mammal, reptile, amphibian, lungfish, ganoid fish, primitive chordate animal of the lancelet type, common ancestor of the lancelet and ascidians in the form of an invertebrate . At the very beginning of the animal world are the first living beings, which are thus the starting point of development for man. The human egg is in some way reminiscent of this initial stage of phylogenetic evolution.
According to the structure and arrangement of its organs, a person belongs to the class of mammals. The most significant features inherent in both humans and mammals are the mammary, sebaceous and sweat glands, body hair, specialized teeth (incisors, canines, premolars and molars), a four-chambered heart and the left aortic arch, pulmonary respiration, the presence of a diaphragm, highly developed brain, intrauterine development of the embryo, feeding the baby with milk. Both in humans and animals, there are single links of tissue metabolism; growth and development are carried out in a similar way. individual development, the principle of storage and implementation of the genetic code that is common for the entire organic world, etc. The maximum similarity of a person is found with representatives of the family of anthropoid apes, or anthropoids: gorilla, chimpanzee, orangutan, gibbon.
It is almost impossible to distinguish between human embryos, primates and other vertebrates in the early stages of development. In the human embryo, a notochord, gill grooves, gill arches and a corresponding network of blood vessels are formed, just as is the case with the most ancient shark fish. Some features of the "fish stage" of development can manifest themselves in a person in the form of atavisms. An example is cervical fistulas communicating with the pharynx. In the process of embryonic development in humans, a number of other similar signs appear and then disappear, but some of them remain in the form of rudiments, indicating a clear connection with the animal world. These include: the coccyx - the remainder of the tail, expressed in the spine of the embryo at the age of 1.5-3 months of intrauterine development, the outer hairline, the appendix of the caecum, subcutaneous muscles, which are developed in humans only on the face and in the form of a rudiment there is subcutaneous ear muscle, etc. In total, a person has more than 90 rudiments.
From reptiles, a person inherited a number of features that are found mainly in the fetal period, for example, in the development of the brain, the structure and nature of the articulation of the limbs in a fetus of several months.
The nature of the distribution of hair on the body of the fetus in groups - three and five pieces, to a certain extent, corresponds to the way the scales are located on the skin of the ancient reptiles that served as the ancestors of mammals. Among the later ancestors of man were ancient mammals, as evidenced by even more facts. Thus, the brain of a human fetus at the early stages of development, with its smooth surface and primitive structure, strongly resembles the brain of modern lower mammals (these features are inherited by humans, probably from their Mesozoic forms).
The kinship of man with the lower mammals is also evidenced by other primitive traits found in his ontogeny. For example, in a human six-week-old fetus, the rudiments of several pairs of mammary glands are formed along the lactiferous lines. Throughout the body (except for the palms and soles) a rather thick, albeit small, hair fluff develops. In the oral cavity, noticeable ridges form on the soft palate, in a pronounced form so characteristic of monkeys, carnivores and other mammals.
A similar shape of the external ear is characteristic of human fetuses at the age of 5-6 months and is obviously inherited from a fossil lower monkey, in some respects similar to macaques and constituting one of the links in our family tree. In the case of incomplete wrapping of the shell helix, a small skin growth in the form of a tubercle, called "Darwin's", is formed on its upper lateral section.
The number of atavisms from the stage of mammals also includes: an unusually strong development of the ear muscles, which allows a person to move the auricle; development of the morgan's ventricles of the larynx to a depth of more than 1 cm; extra mammary glands, or nipples; the rudiments of some extra teeth; excessive hairiness on the body and face; tail. Every man has a appendix of the caecum, or appendix: this vestigial organ is indisputable evidence that our ancestors at the stage of lower mammals possessed a fairly long caecum. In some modern mammals, such as rodents, ungulates, an energetic process of digestion of food masses takes place in the caecum.
The appendix is one of the many vestiges of the human body. An extremely characteristic feature of rudiments as residual organs is the strong variability of their shape, size, and structure. So, with an average length of 8-9 cm, the human appendix sometimes reaches 20-25 cm, as in great apes; it can also be greatly shortened, up to 1-2 cm, and in very rare cases it is completely absent. Being rich in lymphoid tissue, especially at a young age, the appendix seems to correspond to some part of the caecum of other mammals that do not have an appendix.
At one time, Charles Darwin provided convincing evidence of the phylogenetic commonality of emotions and ways of expressing them, devoting a separate essay to them, closely related to The Descent of Man. In The Expression of the Emotions in Man and Animals, published in 1872, Darwin successfully showed that, according to the features of the elementary mental activity and ways of expressing feelings, man is undoubtedly genetically related to monkeys. Another important conclusion is that there are no psychic differences among the human races.
C. Darwin at one time concluded that none of the modern great apes is the direct ancestor of humans. The genealogy of man is a long chain of his predecessors, it goes back into the depths of time for tens of millions of years, and the last link before the first people was the fossil anthropoid ape. Unknown during the life of Darwin, the fossil precursor of man was subsequently discovered, confirming the scientific prediction of the scientist.
Remember!
What are the common features of representatives of the type Chordates; class Mammals.
The data of comparative embryology and anatomy of humans and other animals make it possible to clearly determine that, according to the criteria of zoological systematics, the species Homo sapiens (Homo sapiens) belongs to the kingdom Animals, subkingdom Metazoans, type Chordates, subtype Vertebrates, class Mammals, order Primates, family Hominidae (Fig. 144).
Rice. 144. The systematic position of man in the order of primates
Let us consider those properties and signs on the basis of which we occupy this position in the system of the organic world.
Comparative anatomy data. It is unlikely that anyone will dispute our belonging to a certain kingdom and sub-kingdom. We are bilaterally symmetrical multicellular animals and in these features are similar to all worms, arthropods and chordates.
For man, as for all representatives type chordates, characterized by common features of the organization that are not found in other types.
The human embryo has an internal axial skeleton that is not divided into segments - a chord. Our nervous and digestive systems are laid down in the form of two tubes lying on opposite sides of the notochord. At an early embryonic stage of development, the anterior part of the human digestive system - the pharynx - is riddled with gill slits, which later disappear, and one of them gives rise to the auditory meatus and the Eustachian tube. The human circulatory system is closed, and the heart is located on the ventral side of the body.
The chordate type is divided into three subtypes, and the vertebrate subtype, in turn, unites six classes. We list the signs that make us related to other representatives class Mammals: bone spine, replacing the chord; seven cervical vertebrae; two pairs of lever-type limbs; the presence of bone marrow (in birds, the bones are hollow); hairline; sweat and sebaceous glands of the skin; milk glands; well developed lips and muscular cheeks; diaphragm; three auditory ossicles of the middle ear (in birds and reptiles - one); Auricle; four-chambered heart, two circles of blood circulation and one left aortic arch; non-nuclear erythrocytes (in all other classes of vertebrates - nuclear); alveolar lungs. In addition to these morphological features It should be noted that all mammals, including humans, are characterized by such progressive organizational features as high development central nervous system, especially the cerebral cortex; diverse adaptive reactions and complex behavior; intensive metabolism and perfect thermoregulation. Intrauterine development and nutrition of the embryo through the placenta characterizes us as representatives subclass Placental. It should be noted that all of the listed morphological features common to humans and other mammals are homologous, i.e., they have the same origin.
Common features of a person and other representatives detachment Primates are the following: a limb of a grasping type (the first finger of the hand is opposed to the rest); the presence of a collarbone, which provides high mobility of the hand; expanded terminal phalanges of fingers with nails; three types of teeth - incisors, canines, molars; high development of the cerebral hemispheres; breeding throughout the year; the presence of one pair of mammary glands; the birth of usually one cub and long-term care for him; complex organization of relations between individuals and a high level of development of higher nervous activity.
Numerous rudiments and atavisms, which are known for almost all organ systems, also testify to the relationship of man with animals. Rudiments are underdeveloped organs that have practically lost their functions in the process of evolution. Their presence indicates the kinship of man with lower organized vertebrates. Examples of such rudiments are the muscles of the auricle, the caudal vertebrae (coccyx), the remains of the nictitating membrane of the eye, and the appendix of the caecum. Atavisms are signs that once existed among our ancestors, were later lost, but the genes responsible for their development are still preserved and, under certain conditions, cause the formation of these ancient signs. Vivid examples atavisms are facial hair, external tail, extra pairs of mammary glands, membranes between fingers (Fig. 145).
Rice. 145. Human atavisms
Comparative embryology data. In addition to the data of comparative anatomy, the results of a comparative study of the ontogeny of humans and animals are weighty evidence of the origin of man from animals.
The individual development of a person, like other animals that reproduce sexually, begins with the formation of a zygote. At the age of two weeks, the human embryo shows signs of fish-like ancestors: a two-chambered heart, gill slits, and a tail artery. Later, in the structure of the embryo, one can observe features inherited from amphibians: a nictitating membrane in the inner corner of the eye, swimming membranes between the fingers. A six-week-old fetus has several pairs of mammary glands, the caudal spine is laid, which is then reduced and turns into a coccyx. The smooth surface of the cerebral hemispheres and the continuous hairline of the human fetus indicate a relationship with primitive mammals. Thus, the main features of human embryonic development clearly define its animal origin.
Rice. 146. Great apes
Similarities and differences between humans and apes. With great apes, people have many features in common, such as a large body size, the absence of a tail and cheek pouches, good development of facial muscles and a similar structure of the skull (Fig. 146). Chimpanzees, gorillas, orangutans have a well-developed brain, especially its frontal lobes, big number convolutions in the cerebral cortex. In addition to morphological features, other data testify to our close relationship: we are similar in Rh factor and blood groups (AB0), we suffer from the same “human” diseases. The gestation period for both a gorilla and a human is about 280 days.
The evolutionary relationship of organisms can be determined by comparing their chromosomes. The greater the similarity between DNA nucleotide sequences, the closer the relationship between species. Humans and chimpanzees share over 95% of their genes.
Great apes, like humans, have a high level of development of higher nervous activity, they are easy to learn, they have an excellent memory and a rich emotional life.
At the same time, there are fundamental differences between humans and higher primates. Only a person is characterized by true upright posture (Fig. 147). Thanks to this, a person has long and powerful legs, an arched foot, a wide pelvis, and an S-shaped spine. The flexible hand and movable fingers provide precise and varied movements.
Rice. 147. Monkey and human skeletons
A person has a very complex structure of the brain, the average volume of which is 1350 cm 3 (in a gorilla 400 cm 3). Thanks to the development of the structures of the larynx, a person is capable of articulate speech.
Man is bio social being, occupying a high stage of evolutionary development, possessing consciousness, speech, abstract thinking and capable of social work.
Review questions and assignments
1. Describe the systematic position of man in the animal world.
2. Indicate the signs of a person as a representative of the class of mammals.
3. What features are common to humans and great apes?
4. List the structural features that are unique to humans.
5. What was the significance of the increase in brain volume in anthropogenesis?
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Question 1. Describe the systematic position of man in the animal world.
Man belongs to the phylum Chordates, the subtype Vertebrates, the class Mammals, the subclass Placentals, the order Primates, the suborder Humanoid (anthropoids-Higher apes) primates, the superfamily of the Greater narrow-nosed monkeys, the family Hominid (People), the only genus Homo (Homo) with the only species Homo sapiens (Homo sapiens).
In addition to the suborder of anthropoids, lemurs and tarsiers are also classified as primates.
Question 2. Indicate the signs of a person as a representative of the class of mammals.
Humans can be classified as Mammals on the following grounds:
seven cervical vertebrae;
hairline, sweat and sebaceous glands of the skin;
well developed lips and muscular cheeks;
diaphragm and alveolar lungs;
auricle and three auditory ossicles of the middle ear;
one aortic arch (left) and non-nuclear erythrocytes;
warm-bloodedness;
mammary glands, care for offspring;
similarities in embryonic development.
Question 3. What features are common to humans and great apes?
Man and apes (pongid) are related by the large size of the body, the absence of a tail and cheek pouches, the good development of mimic muscles, and the similar structure of the skull and skeleton in general. In addition, blood groups and the Rh factor, the similarity of chromosomes (out of 23 chromosomes, 13 are similar to chimpanzees), various diseases, a long gestation period, and a long prepubertal (pre-reproductive) period are common to humans and great apes. They are also united by a high level of development of higher nervous activity, the ability to learn quickly, the ability to use tools, good memory, rich emotions. As an example, we can cite experiments on teaching deaf-mutes to great apes, during which gorillas and chimpanzees learned up to 200-300 sign words. The human and chimpanzee genomes are 98.5% identical.
Question 4. List the structural features that are unique to humans.
There are differences between humans and animals.
Man is a social being that produces tools and uses them to influence nature. A person has a highly developed brain, has consciousness, thinking, articulate speech and a number of anatomical features that have arisen in connection with labor activity that is characteristic only of a person. The differences are related to the direction of evolution. Man and great apes are two branches of the order of primates, which in relatively recent times have separated from the common pedigree trunk.
It is typical for a person:
1. Adaptation to upright posture. The spine acquired an S-shaped curvature, the foot has a domed shape. These are the main devices that provide shock absorption and shock absorption of the body when walking, jumping, which is important for protecting the brain. The big toe acts as a support. The pelvis is wider, it takes on the pressure of the organs in an upright position. The chest is flat, compressed from the sides, due to the pressure that the internal organs exert on the ribs, due to the horizontal position of the torso when walking. The brain part of the skull has increased and prevails over the front. There are no superciliary ridges. The jaws and chewing muscles are less developed. In the lower part of the body, the gluteal, quadriceps, gastrocnemius, soleus muscles are especially developed. The consequences of upright walking are associated with a limitation in the speed of movement, hypertension, an immobile sacrum, dilated veins in the legs, and osteochondrosis.
2. The presence of a flexible hand - an organ of labor adapted to complex movements. The human hand is specialized as a grasping organ, the thumb is well movable. The human arms are shorter than the legs.
3. Well developed brain. A person has highly developed temporal, frontal and parietal lobes, where the main centers of higher nervous activity are located. The surface of the brain is 1250 cm2. The surface of the cortex in the frontal region is twice that of higher monkeys. Characterized by the appearance of speech, abstract thinking, consciousness.
4. Hairless skin has become a gigantic receptor field capable of bringing additional information to the brain. This was a factor in the intensive development of the brain. The "baldness" of the skin is the last biological prerequisite for the formation of man as a creative social being.
Question 5. What
An increase in the size and complexity of the structure of the brain provided a person with the opportunity to develop many functions, such as highly organized nervous activity, the ability to learn, the presence of a large amount of memory and complex emotions, speech. They also contributed to the emergence of abstract thinking and the ability to work. The centers associated with the sense organs provide the finest analysis visual and auditory information, which allows us to perceive and understand facial expressions and speech. The motor centers of the brain carry out extremely precise and efficient control of the muscles of the fingers, vocal cords, etc. In many respects, it was the development of the brain that allowed a person to reach the high stage of evolutionary development that he now occupies.
In accordance with modern scientific concepts, anatomically modern man is the result of the development of matter over 13.7 billion years and is the most complexly organized variety of it from all observed.
It is well known that man belongs to the world of multicellular beings. Among the colossal number of multicellular forms, a person belongs to the group of bilaterally symmetrical: the right and left halves of our body relate to each other like an object and its image in a mirror. Among bilaterally symmetrical organisms, man occupies a corresponding place in the animal kingdom.
The human body has many features in common with mammals: the spine, 7 cervical vertebrae, two pairs of lever-type limbs, a closed circulatory system, a four-chambered heart, non-nuclear erythrocytes, hairline, constant body temperature, pulmonary respiration, well developed nervous system and sense organs. The most similarity between humans and primates.
According to the criteria of zoological taxonomy, the species of Homo sapiens (Homo sapiens) as part of a special family of hominids belongs to the order of primates, the class of mammals, the subtype of vertebrates, the type of chordates (Table No. 1).
Table #1
The place of modern man in the animal kingdom
Taxon | Latin Name | Russian name | The composition of this group of Animals |
Kingdom | Animals | All animals | |
Type of | Chordata | chordates | All animals that have a notochord |
Subtype | Vertebrata | Vertebrates | All animals that have a spine and 2 pairs of limbs |
Class | mammalia | mammals | All warm-blooded, furry animals that give birth to live young |
Detachment | Primates | Primates | Prosimians, apes, apes and humans |
Suborder | Haplorhini | Gaplorin- new | Tarsiers, monkeys, apes and humans |
infraorder | catarrhini | narrow-nosed monkeys | Old World Monkeys, Great Apes and Man |
Superfamily | Hominoidea | Hominoids | Great apes and man |
Family | Hominidae | hominids | Man and his ancestors |
Genus | Homo | Actually people | Human |
View | H. sapiens | - | Neoanthrope |
Subspecies | H. sapiens sapiens | - | Anatomically modern human(s) |
Systematics of representatives of the order Primates.
About 200 species of modern primates are known, united in 61 genera, 12 families (Table No. 2). Currently, the number of primates is rapidly declining. More than 60 of their species and subspecies are listed in the Red Book.
Living primates are divided into two main groups - strepsirin and haplorin. The first group - strepsirin primates - is the most ancient group of primates, which include semi-monkeys - the most primitive representatives of primates.
Rice. 1.1. Common tupaya Fig. 1.2. mongoose lemur
This group includes 6 families: tupai (Fig. 1.1), lemurs (Fig. 1.2), loris (Fig. 1.3), indri, etc.
Strepsirin primates have nostrils in the form of commas that open onto the bare part of the tip of the nose, the upper lip of these primates is smooth, motionless and without hair. In addition to a more primitive morphology, semi-monkeys are small in size, differ from real monkeys in behavior. They are almost exclusively nocturnal, insectivorous and herbivores living in groups, but some species are solitary.
The second group - haplorin primates (they have more rounded nostrils, bordered by the walls of the nose and opening onto a mobile, with a developed muscular layer, and a hairy upper lip), - consists of three main taxa - tarsiers, broad-nosed and narrow-nosed monkeys.
Tarsiers are a relict group living in Southeast Asia, similar to prosimians (Fig. 1.4). This group includes only one family, which unites animals the size of a rat; in a number of systematization schemes, they are classified as higher primates. Tarsiers appeared in the Eocene, fossil groups were found on the territory of Europe and Northern
America.
Rice. 1.3. Slow loris Fig. 1.4. Philippine tarsier
Now preserved only in the Indonesian and Philippine islands. Modern tarsiers are exclusively nocturnal animals. A bright specialization for the nocturnal and twilight lifestyle is the huge eyes and ears of tarsiers. They live alone or in pairs, in bamboo thickets, in small trees or in light forests. Due to hopping, the hind legs are very long, with a specialized foot (the calcaneus and navicular bones are greatly elongated, the tibia and fibula are partially fused, and the big toe is enlarged for grasping). They feed on insects, spiders, small lizards.
Broad-nosed and narrow-nosed monkeys are a group of humanoid higher primates. They are also called monkeys of the New and Old Worlds. Approximately 35 million years ago, both Americas separated from Eurasia and Africa, so broad-nosed monkeys developed there in isolation. In most New World monkeys, the cartilaginous nasal septum is wide and the nostrils are widely separated and point outwards. Modern broad-nosed monkeys are represented by tree monkeys of two families - gamers and cebids, living in the tropical rainforests of Central and South America, they are almost completely arboreal, herd animals, they almost never descend to the ground, they eat mainly plants and insects. Outwardly very diverse, the behavior is sometimes very complex. The morphology is characterized by a combination of some primitive features in the structure of the skull and very specialized features in the structure of the body, for example, a prehensile tail. For broad-nosed, the formation of "mixed flocks" is characteristic, which includes representatives of different species of monkeys, and sometimes even raccoons and birds.
The size of broad-nosed monkeys ranges from a mouse to a dog. Broad-nosed are diurnal animals, except for a few nocturnal species.
In the Old World, primates developed more intensively and adapted to a terrestrial lifestyle. The monkeys of Eurasia and Africa have a narrower nasal septum and the nostrils, like those of humans, are turned downwards. The narrow-nosed monkeys are divided into two groups: the lower narrow-nosed monkeys and the great apes - hominoids.
Among modern lower narrow-nosed monkeys, only one family is distinguished - monkeys, this family includes monkeys, macaques, mandrills, baboons, thin-bodied monkeys, colobuses, proboscis, langurs - living in Africa, Asia and Europe (Gibraltar).
Rice. 1.5. Nosach Fig. 1.6. Japanese macaque
Morphologically, they differ from pongids in having a simpler brain and the presence of a tail (Fig. 1.5, Fig. 1.6). Monkeys are one of the most evolutionarily successful groups of monkeys. All species are diurnal. There are both terrestrial and arboreal monkeys. They took
a fairly wide range of ecological niches, all representatives are gregarious and herbivorous.
Rice. 1.7. Chimpanzee Fig. 1.8. Gorilla
Hominoids include modern humans and their closest relatives - pongids - great apes. Modern great apes (chimpanzee, gorilla, orangutan, gibbon) represent forms that deviated from the line of development common with humans about 10-15 million years ago (Fig. 1.7, Fig. 1.8). These are large-sized monkeys that lead a diurnal, herd lifestyle and are herbivorous. Large pongids - orangutans, gorillas and chimpanzees - lead a terrestrial lifestyle, while smaller ones - gibbons - are completely arboreal animals. Gibbons and orangutans inhabit Southeast Asia, gorillas, chimpanzees - equatorial Africa.
Therefore, they are divided into two groups: Asian forms, which include the orangutan and gibbon, and African forms, which include chimpanzees and gorillas - this is the largest living primate. Humans are more closely related to the African great apes. Of these, chimpanzees are the closest anatomically and behaviorally to humans.
The genus Chimpanzee includes two modern species: the common chimpanzee and the bonobo, or pygmy chimpanzee.
The common chimpanzee is common in Equatorial Africa, where it lives in tropical rain and mountain forests. These are large monkeys with a total body length of up to 1.5 m, body weight of 45-50 kg, sometimes up to 80 kg. Chimpanzees mainly eat plant food, occasionally termites and ants. With some regularity, chimpanzees prey on small animals. It is characteristic that at the same time their behavior changes dramatically. For example, altruism appears - they share meat, and the established hierarchy ceases to operate in the group - even a dominant individual cannot take away meat from a subordinate individual.
The pygmy chimpanzee lives in a small area between the Congo and Luabala rivers. It is much smaller than the common chimpanzee, slender, with black facial skin and longer hair on the sides of the forehead. It is characteristic that the pygmy chimpanzee often moves on its hind legs, carrying various objects in its hands, for example, nuts. Chimpanzees have a highly developed use of tools, for example, they crack nuts with stones.
Modern man stands out quite sharply from other hominoids in some features and is extremely similar to them in a number of others. Modern man inhabits the entire planet, is adapted to a daily lifestyle and is omnivorous.
In this lesson, you will learn about the relationship of man with other animal species. Find out the systematic position of the species Homo sapiens in the modern classification of living beings, get acquainted with the features that unite us with other mammals. We will also consider the features of the structure of our body, which distinguish a person from other animals and make our biological species unique and inimitable among other unique species.
Man, as a living being, is part of the animal world. Our species belongs to the phylum Chordates, the subtype Vertebrates, the class Mammals, the subclass Placental mammals, the order Primates, the family Hominids, the genus Man, and the species Homo sapiens (Scheme 1).
Scheme 1. The place of man in the system of living organisms
The fact that our species belongs to the Animal kingdom is convincingly proved by our morphology, cytology and physiology.
Belonging to the type of Chordata is visible at the stage of intrauterine development. The human embryo has a notochord, a neural tube located above the notochord, a heart located on the ventral side under the digestive tract.
The belonging of a person to the Vertebrate subtype is determined by the replacement of the notochord by the spine, the developed skull and jaw apparatus, as well as two pairs of limbs (Fig. 1) and the brain, consisting of five sections.
Rice. 1. Human and frog skeletons have similar features that are characteristic of all vertebrates
The presence of hair on the surface of the body, five sections of the spine, a four-chambered heart, a highly developed brain, sweat, sebaceous, and mammary glands, as well as warm-bloodedness, make it possible to attribute a person to the class of Mammals.
The development of the fetus inside the mother's body in the uterus and its nutrition through the placenta - to the subclass of placental mammals.
The presence of grasping forelimbs, in which the first finger is opposite to the rest of the fingers, nails, well-developed clavicles, as well as the change of milk teeth in the process of ontogenesis and the bearing of, mainly, one cub, makes it possible to classify a person as a Primate. At the order level, the resemblance between humans and other animals ends.
The features that distinguish the Human family from other primates are unique to humans. In the family People there is only one genus Man, in which there is only one modern species Homo sapiens.
Consider the features that distinguish humans from other animals.
First of all, it is a higher nervous activity. A person has a developed second signaling system (see lesson 8 of grade Higher nervous activity), which is responsible for the perception of speech, and are also well developed logical thinking, memory, abstract thinking. These abilities arise due to the developed cerebral cortex. Humans have the largest ratio of brain mass to body mass among all animals.
The second difference is the features of the skeleton responsible for true upright posture. Our spine has 4 curves that optimally transfer the weight of our upright body to the legs (Fig. 2).
Rice. 2. The human spine is adapted to true upright posture
And the legs have arched feet that withstand the load when running and jumping (see video).
A flexible hand, in principle, is characteristic of many primates, but only in humans has it reached such flexibility that it makes it easy to manipulate both small and heavy objects.
Moreover, the movements can be both powerful and very subtle, allowing, for example, to embroider or write (see video).
Upright posture, developed hands and a powerful brain allowed man to produce tools - from a pointed stick to a space satellite (Fig. 3).
Rice. 3. Artifacts of ancient (spears - on the left) and modern (space satellite - on the right) man
Some birds and other primates are able to use found tools, such as stones and sticks. But none of them is able to make a special tool for themselves.
The second signaling system made it possible to create a very highly organized society. No flock of animals is capable of such subtle and effective interaction as human society (see video).
Thus, from the biological standpoint of taxonomy, a person is an animal from the order Primates. It has all the tissues and organ systems characteristic of other primates.
The human genotype differs from the genotype of the closest great apes, such as bonobo pygmy chimpanzees, by one percent. At the same time, a person, unlike animals, has a developed abstract thinking, is able to produce and use tools. He exists in a society in which there is a division of labor and which is governed by speech.
Bibliography
- A.A. Kamensky, E.A. Kriksunov, V.V. Beekeeper. General biology, 10-11 class. - M.: Bustard, 2005. Download the textbook from the link: ()
- D.K. Belyaev. Biology 10-11 class. General biology. A basic level of. - 11th edition, stereotypical. - M.: Education, 2012. - 304 p. (