The similarity of many anatomical and physiological features testifies to the relationship between great apes (anthropoids) and humans. This was first established by Charles Darwin’s colleague, Thomas Huxley. After conducting comparative anatomical studies, he proved that the anatomical differences between humans and higher apes are less significant than between higher and lower apes.

There is much in common in the appearance of humans and apes: large body sizes, long limbs in relation to the body, long neck, broad shoulders, absence of a tail and ischial calluses, a nose protruding from the plane of the face, a similar shape of the auricle. The body of anthropoids is covered with sparse hair without undercoat, through which the skin is visible. Their facial expressions are very similar to human ones. In the internal structure, one should note a similar number of lobes in the lungs, the number of papillae in the kidney, the presence of a vermiform appendix of the cecum, an almost identical pattern of tubercles on the molars, a similar structure of the larynx, etc. The timing of puberty and duration of pregnancy in apes is almost the same as in humans.

An exceptionally close similarity is noted in biochemical parameters: four blood groups, similar reactions of protein metabolism, diseases. Apes in the wild easily become infected by humans. Thus, the reduction in the range of the orangutan in Sumatra and Borneo (Kalimantan) is largely due to the mortality of monkeys from tuberculosis and hepatitis B acquired from humans. It is no coincidence that great apes are indispensable experimental animals for the study of many human diseases. Humans and anthropoids are also close in the number of chromosomes (46 chromosomes in humans. 48 in chimpanzees, gorilla, orangutan), their shape and size. There is much in common in the primary structure of such important proteins as hemoglobin, myoglobin, etc.

However, there are also significant differences between humans and anthropoids, largely due to human adaptation to walking upright. The human spine is S-shaped, the foot has an arch, which softens shaking when walking and running (Fig. 45). When the body is in a vertical position, the human pelvis takes on the pressure of the internal organs. As a result, its structure differs significantly from the pelvis of anthropoids: it is low and wide, firmly articulated with the sacrum. There are significant differences in the structure of the hand. The human thumb is well developed, opposed to the rest and very mobile. Thanks to this structure of the hand, the hand is capable of varied and subtle movements. Anthropoids, due to their arboreal lifestyle, have hook-shaped hands and a grasping type of foot. When forced to move on the ground, apes rely on the outer edge of the foot, maintaining balance with the help of the forelimbs. Even a gorilla that walks on its entire foot is never in a fully erect position.

Differences between anthropoids and humans are observed in the structure of the skull and brain. The human skull does not have bone ridges and continuous brow ridges, the brain part predominates over the facial part, the forehead is high, the jaws are weak, the fangs are small, and there is a chin protrusion on the lower jaw. The development of this protrusion is associated with speech. Monkeys, on the contrary, have a highly developed facial part, especially the jaws. The human brain is 2-2.5 times larger than the brain of apes. The parietal, temporal and frontal lobes, in which the most important centers of mental functions and speech are located, are highly developed in humans.

Significant differences lead to the idea that modern apes could not be the direct ancestors of humans.

Introduction

In 1739, the Swedish naturalist Carl Linnaeus, in his System of Nature (Systema Naturae), classified humans - Homo sapiens - as one of the primates. In this system, primates are an order in the class mammals. Linnaeus divided this order into two suborders: prosimians (including lemurs and tarsiers) and higher primates. The latter include apes, gibbons, orangutans, gorillas, chimpanzees and humans. Primates share many common characteristics that distinguish them from other mammals.
It is generally accepted that Man as a species separated from the animal world within the framework of geological time quite recently - approximately 1.8-2 million years ago at the beginning of the Quaternary period. This is evidenced by the finds of bones in the Olduvai Gorge in western Africa.
Charles Darwin argued that the ancestral species of Man was one of the ancient species of apes that lived in trees and were most similar to modern chimpanzees.
F. Engels formulated the thesis that the ancient ape turned into Homo sapiens thanks to work - “labor created Man.”

Similarities between humans and monkeys

The relationship between humans and animals is especially convincing when comparing their embryonic development. In its early stages, the human embryo is difficult to distinguish from the embryos of other vertebrates. At the age of 1.5 - 3 months, it has gill slits, and the spine ends in a tail. The similarity between human and monkey embryos remains for a very long time. Specific (species) human characteristics arise only at the very latest stages of development. Rudiments and atavisms serve as important evidence of the kinship between humans and animals. There are about 90 rudiments in the human body: the coccygeal bone (the remnant of a reduced tail); fold in the corner of the eye (remnant of the nictitating membrane); fine body hair (fur residue); a process of the cecum - appendix, etc. Atavisms (unusually highly developed rudiments) include the external tail, with which people are very rarely born; abundant hair on the face and body; multiple nipples, highly developed fangs, etc.

A striking similarity of the chromosomal apparatus was discovered. The diploid number of chromosomes (2n) in all apes is 48, in humans - 46. The difference in chromosome numbers is due to the fact that one human chromosome is formed by the fusion of two chromosomes, homologous to those of chimpanzees. A comparison of human and chimpanzee proteins showed that in 44 proteins the amino acid sequences differed by only 1%. Many human and chimpanzee proteins, such as growth hormone, are interchangeable.
The DNA of humans and chimpanzees contains at least 90% of similar genes.

Differences between humans and monkeys

True upright walking and associated structural features of the body;
- S-shaped spine with distinct cervical and lumbar curves;
- low widened pelvis;
- chest flattened in the anteroposterior direction;
- legs elongated compared to the arms;
- arched foot with massive and adducted big toe;
- many features of the muscles and location of internal organs;
- the hand is capable of performing a wide variety of high-precision movements;
- the skull is higher and rounded, does not have continuous brow ridges;
- the cerebral part of the skull dominates to a large extent over the facial part (high forehead, weak jaws);
- small fangs;
- the chin protuberance is clearly defined;
- the human brain is approximately 2.5 times larger than the brain of apes in volume and 3-4 times larger in mass;
- a person has a highly developed cerebral cortex, in which the most important centers of the psyche and speech are located;
- only humans have articulate speech, and therefore they are characterized by the development of the frontal, parietal and temporal lobes of the brain;
- the presence of a special head muscle in the larynx.

Walking on two legs

Upright walking is the most important sign of a person. The rest of the primates, with a few exceptions, live primarily in trees and are quadrupeds, or, as they sometimes say, “four-armed.”
Some apes (baboons) have adapted to a terrestrial existence, but they walk on all fours like the vast majority of mammal species.
Great apes (gorillas) are primarily terrestrial dwellers, walking in a partially upright position, but often supported by the backs of their hands.
The vertical position of the human body is associated with many secondary adaptive changes: the arms are shorter relative to the legs, wide flat feet and short toes, the originality of the sacroiliac joint, the S-shaped curve of the spine that shock-absorbs when walking, a special shock-absorbing connection between the head and the spinal column.

Brain enlargement

An enlarged brain puts Man in a special position in relation to other primates. Compared to the average chimpanzee brain size, the modern human brain is three times larger. In Homo habilis, the first of the hominids, it was twice as large as in chimpanzees. Humans have significantly more nerve cells and their arrangement has changed. Unfortunately, fossil skulls do not provide sufficient comparative material to evaluate many of these structural changes. It is likely that there is an indirect relationship between brain enlargement and its development and upright posture.

Structure of teeth

The transformations that have occurred in the structure of teeth are usually associated with changes in the way of eating of ancient man. These include: reduction in the volume and length of the fangs; closure of the diastema, i.e. the gap that includes the protruding canines in primates; changes in the shape, inclination and chewing surface of different teeth; development of a parabolic dental arch, in which the anterior section has a rounded shape, and the lateral sections expand outward, in contrast to the U-shaped dental arch of monkeys.
During the evolution of hominids, brain enlargement, changes in cranial joints and transformation of teeth were accompanied by significant changes in the structure of various elements of the skull and face and their proportions.

Differences at the biomolecular level

The use of molecular biological methods has made it possible to take a new approach to determining both the time of the appearance of hominids and their relationships with other primate families. The methods used include: immunological analysis, i.e. comparison of the immune response of different species of primates to the introduction of the same protein (albumin) - the more similar the reaction, the closer the relationship; DNA hybridization, which allows one to estimate the degree of relatedness by the degree of matching of paired bases in double strands of DNA taken from different species;
electrophoretic analysis, in which the degree of similarity of proteins of different animal species and, therefore, the proximity of these species is assessed by the mobility of the isolated proteins in an electric field;
Protein sequencing, namely the comparison of the amino acid sequences of a protein in different animal species, which makes it possible to determine the number of changes in the coding DNA responsible for the identified differences in the structure of a given protein. The listed methods showed a very close relationship between species such as gorilla, chimpanzee and man. For example, one protein sequencing study found that the differences in DNA structure between chimpanzees and humans were only 1%.

Traditional explanation of anthropogenesis

The common ancestors of apes and humans - gregarious monkeys - lived in trees in tropical forests. Their transition to a terrestrial lifestyle, caused by climate cooling and the displacement of forests by steppes, led to upright walking. The straightened position of the body and the transfer of the center of gravity caused a restructuring of the skeleton and the formation of an arched S-shaped spinal column, which gave it flexibility and the ability to absorb shock. An arched springy foot was formed, which was also a method of shock absorption during upright walking. The pelvis expanded, which provided greater stability to the body when walking upright (lowering the center of gravity). The chest has become wider and shorter. The jaw apparatus became lighter from the use of food processed over fire. The forelimbs were freed from the need to support the body, their movements became more free and varied, and their functions became more complex.

The transition from using objects to making tools is the boundary between ape and man. The evolution of the hand proceeded through the natural selection of mutations useful for work activity. The first tools were hunting and fishing tools. Along with plant foods, higher calorie meat foods began to be used more widely. Food cooked over fire reduced the load on the chewing and digestive apparatus, and therefore the parietal crest, to which the chewing muscles are attached in monkeys, lost its importance and gradually disappeared during the selection process. The intestines became shorter.

The herd lifestyle, as labor activity developed and the need to exchange signals, led to the development of articulate speech. Slow selection of mutations transformed the undeveloped larynx and oral apparatus of monkeys into human speech organs. The root cause of the emergence of language was the social and labor process. Work, and then articulate speech, are the factors that controlled the genetically determined evolution of the human brain and sense organs. Concrete ideas about surrounding objects and phenomena were generalized into abstract concepts, and mental and speech abilities developed. Higher nervous activity was formed, and articulate speech developed.
The transition to upright walking, a herd lifestyle, a high level of development of the brain and psyche, the use of objects as tools for hunting and protection - these are the prerequisites for humanization, on the basis of which work activity, speech and thinking developed and improved.

Australopithecus afarensis - probably evolved from some late Dryopithecus about 4 million years ago. Fossils of Australopithecus afarensis have been discovered in Omo (Ethiopia) and Laetoli (Tanzania). This creature looked like a small but erect chimpanzee weighing 30 kg. Their brains were slightly larger than those of chimpanzees. The face was similar to that of apes: with a low forehead, a supraorbital ridge, a flat nose, a cut off chin, but protruding jaws with massive molars. The front teeth had gaps, apparently because they were used as tools for grasping.

Australopithecus africanus settled on Earth approximately 3 million years ago and ceased to exist about a million years ago. It probably descended from Australopithecus afarensis, and some authors have suggested that it was the ancestor of the chimpanzee. Height 1 - 1.3 m. Weight 20-40 kg. The lower part of the face protruded forward, but not as much as in apes. Some skulls show traces of the occipital crest, to which strong neck muscles were attached. The brain was no larger than that of a gorilla, but casts indicate that the structure of the brain was somewhat different from that of apes. In terms of the relative size of the brain and body, Africanus occupies an intermediate position between modern apes and ancient people. The structure of the teeth and jaws suggests that this ape-man chewed plant food, but perhaps also gnawed the meat of animals killed by predators. Experts dispute its ability to make tools. The oldest record of Africanus is a 5.5-million-year-old jaw fragment from Lotegama in Kenya, while the youngest specimen is 700,000 years old. Findings indicate that Africanus also lived in Ethiopia, Kenya and Tanzania.

Australopithecus gobustus (Mighty Australopithecus) had a height of 1.5-1.7 m and a weight of about 50 kg. It was larger and better physically developed than Australopithecus africanus. As we have already said, some authors believe that both of these "southern monkeys" are males and females respectively of the same species, but most experts do not support this assumption. Compared to Africanus, it had a larger and flatter skull, which accommodated a larger brain - about 550 cc. cm, and a wider face. Powerful muscles were attached to the high cranial crest, which moved the massive jaws. The front teeth were the same as those of Africanus, and the molars were larger. At the same time, the molars of most specimens known to us are usually very worn, despite the fact that they were covered with a thick layer of durable enamel. This may indicate that the animals ate solid, tough food, in particular cereal grains.
Apparently, the mighty Australopithecus appeared about 2.5 million years ago. All the remains of representatives of this species were found in South Africa, in caves where they were probably dragged by predatory animals. This species became extinct about 1.5 million years ago. Beuys's Australopithecus may have originated from him. The structure of the skull of the mighty Australopithecus suggests that it was the ancestor of the gorilla.

Australopithecus boisei had a height of 1.6-1.78 m and a weight of 60-80 kg, small incisors designed for biting and huge molars capable of grinding food. The time of its existence is from 2.5 to 1 million years ago.
Their brain was the same size as that of the mighty Australopithecus, that is, about three times smaller than our brain. These creatures walked upright. With their powerful physique they resembled a gorilla. As with gorillas, males were apparently significantly larger than females. Like the gorilla, Beuys's Australopithecus had a large skull with supraorbital ridges and a central bony ridge that served to attach powerful jaw muscles. But compared to the gorilla, Beuys's crest was smaller and more forward, his face was flatter, and his fangs were less developed. Because of its huge molars and premolars, this animal received the nickname “nutcracker.” But these teeth could not exert strong pressure on food and were adapted for chewing not very hard material, such as leaves. Since broken pebbles were found along with the bones of Australopithecus Beuys, which is 1.8 million years old, it can be assumed that these creatures could have used the stone for practical purposes. However, it is possible that representatives of this species of monkeys fell victim to their contemporary - a person who succeeded in using stone tools.

A little criticism of classical ideas about the origin of Man

If man's ancestors were hunters and ate meat, then why are his jaws and teeth weak for raw meat, and his intestines relative to the body are almost twice as long as those of carnivores? The jaws of prezinjanthropes were already significantly reduced, although they did not use fire and could not soften food on it. What did human ancestors eat?

When there is danger, birds fly into the air, ungulates run away, monkeys take refuge in trees or rocks. How did the animal ancestors of people, with slow movement and the absence of tools other than pathetic sticks and stones, escape from predators?

M.F. Nesturkh and B.F. Porshnev openly include the mysterious reasons for the loss of hair in people as unresolved problems of anthropogenesis. After all, even in the tropics it is cold at night and all monkeys retain their fur. Why did our ancestors lose it?

Why did a cap of hair remain on a person’s head while it was being reduced on most of the body?

Why does a person’s chin and nose protrude forward with the nostrils turned down for some reason?

The speed of transformation of Pithecanthropus into modern man (Homo sapiens), as is usually believed, in 4-5 millennia, is incredible for evolution. Biologically this is inexplicable.

A number of anthropological researchers believe that our distant ancestors were australopithecines who lived on the planet 1.5-3 million years ago, but australopithecines were land monkeys, and like modern chimpanzees they lived in savannas. They could not be the ancestors of Man, since they lived at the same time as him. There is evidence that Australopithecines, who lived in West Africa 2 million years ago, were hunted by ancient people.

The human genetic code differs from the genetic code of monkeys by less than 1%! The remaining 99% endowed monkeys with almost all human emotions: joy and sadness, enthusiasm and despondency, pride and uncertainty.

Sense of humor

Monkeys have an amazing sense of humor, love to play pranks on their comrades and simply show off their wide smile to the whole world! However, a monkey's wide smile does not always mean that it is happy to see you. On the contrary, most likely, she is wildly irritated and warns you that you should not joke with her. But if you happen to communicate with a monkey in person, and it gently grabs your neck and asks to be held in your arms, then you can count on friendship. It’s the same in our lives: the sincerity of intentions is not always hidden behind a sweet smile.

Passion

Those who are even slightly familiar with monkeys and men are not surprised by their striking similarities during the courtship period. So, trying to impress on the first date, the male performs a mating song and presents his chosen one with a small gift in the form of a twig or fruit. To show the seriousness of their intentions, men, like monkeys, give gifts and are distinguished by special eloquence. Of course, you won’t be interested in your chosen one, but a bouquet of pretty flowers, a box of delicious chocolates or a cute trinket will help you win favor on the first date.

If the female’s position is threatened and a rival appears, the primate begins to growl loudly, break branches and generally behave, like men in a similar situation, quite aggressively.

Care

Monkeys are not inferior to women in love for their offspring. And not only to one’s own, but also to someone else’s. There is a wonderful story about a wild macaque who once adopted a kitten and has not left the adult cat to this day!

thoughtfulness

Every person needs peace and quiet from time to time - for many of us this is the only way to relax and think about the eternal. Monkeys sometimes stop smiling, stop and seem to be seriously thinking about something personal.

The chimpanzee Caesar, the hero of the film “Rise of the Planet of the Apes,” is prone to reflection, just like a person: just one glance from under his brows is worth something! By the way, the filmmakers were able to achieve this “humanizing” effect using digital technology, in which the movements and voice of actor Andy Serkis (“King Kong”, “The Lord of the Rings”) were used to create a computer character.

Taxonomy conclusions about the closeness of humans to these monkeys are based on solid comparative morphological and comparative physiological material.

The latter serves as the basis for the theory of the pithecoid (monkey) origin of man, in view of which we will briefly dwell on it. A comparative morpho-physiological analysis of the characteristics of humans and anthropomorphic monkeys makes it possible, in particular, to outline the formulation of the question of the phylogenetic relationships between them. Indeed, it seems important to find out which of the three great apes is closer to humans.

The table compares, first of all, the main dimensional characteristics of all four forms.

The table shows that according to most of the listed dimensional characteristics, chimpanzees and gorilla are closest to humans. It is striking that in terms of brain weight the chimpanzee is closest to a human.

Hairline. The body of anthropomorphic monkeys is covered with coarse hair. The back and shoulders are more heavily haired (especially in the orang). The chest is poorly covered. The face, part of the forehead, soles of the feet, palms of the hands are hairless. The backs of the hands are lightly covered with hair. There is no undercoat. Consequently, the hairline shows signs of rudimentation, however, not nearly as pronounced as in humans. Chimpanzees sometimes have armpits covered with hair (similar to humans). Orangs have a strong development of beard and mustache (resemblance to humans). As in humans, the hair of the shoulder and forearm of all anthropomorphic individuals is directed towards the elbow. Chimpanzees and orangs, like humans, experience baldness, especially in the hairless chimpanzee - A. calvus.

Dimensional signs	Orang	Chimpanzee	Gorilla	Human	Greatest closeness to a person in this characteristic
Body weight - kg	70-100	40-50	100-200	40-84	Chimpanzee
Height - m	Up to 1.5	Up to 1.5	Up to 2	1,40-1,80	Gorilla
Arm length to body length (100%)	223,6%	180,1%	188,5%	152,7%	Chimpanzee
Leg length to body length (100%)	111,2%	113,2%	113,0%	158,5%	Gorilla and chimpanzee
Length of the hand as a percentage of the length of the body (100%)	63,4%	57,5%	55,0%	36,8%	Gorilla
Foot length as a percentage of body length (100%)	62,87%	52-62%	58-59%	46-60%	Gorilla
Brain weight to body weight	1:200	1:90	1:220	1:45	Chimpanzee

Color of the skin. Chimpanzees have light skin except for their faces. The pigment is formed in the epidermis of the skin, like in humans.

Skull and jaw apparatus. The skull of an adult human is, in a number of ways, sharply different from the skull of great apes. However, here too there are some similarities: the table compares some elements of the characteristics of human and ape skulls.

Selected elements of the characteristics, as well as the data in the table, show that African anthropomorphic monkeys are closer to humans than the orangutan. If we calculate the volume of a chimpanzee's braincase in relation to its body weight, then this monkey will be closest to humans. The same conclusion follows from a comparison of the 5th, 6th, 10th and 12th indicators given in the table.

Spinal column. In humans, it forms an S-shaped profile line, that is, it functions like a spring, protecting the brain from a concussion. Cervical vertebrae with weak spinous processes. Anthropomorphic monkeys do not have an S-shaped curvature; the spinous processes are long, especially in the gorilla. They are most similar to human ones in chimpanzees, evenly lengthening from the first to the last cervical vertebrae, as in humans.

Rib cage. Its general shape in humans and anthropomorphic animals is barrel-shaped, somewhat compressed in the dorso-ventral direction. This configuration of the chest is characteristic only of humans and anthropomorphs. In terms of the number of ribs, the orang is the closest to humans, having, like the latter, 12 pairs of ribs. However, the same number is observed in the gorilla, although, like in the chimpanzee, there are 13 pairs. A human embryo normally has the same number of ribs that is sometimes found in an adult. Thus, anthropomorphic animals are very close in this characteristic to humans, especially the orangutan. However, the chimpanzee and gorilla are closer to humans in the shape of the sternum, which in them consists of a small number of elements, more numerous in the orang.

Limb skeleton. Anthropomorphic monkeys, like all monkeys, are characterized by a certain similarity in the functions of the fore and hind limbs, since both arms and legs are involved in climbing a tree, with the forelimbs having a significantly greater lifting force than those of Homo. Both anthropomorphic limbs are multifunctional, and the functions of the hand are wider and more diverse than the functions of the leg. A person's hand is completely freed from the function of movement, and other functions associated with his work activity have become unusually enriched. The human leg, having become the only support of the body, on the contrary, experienced a process of narrowing of functions and, in particular, an almost complete loss of the grasping function. These relationships caused the development of significant differences in the skeletal structure of anthropomorphic and human limbs, especially the legs. The human leg - thigh and lower leg - significantly exceeds the same anthropomorphic elements in length.

The powerful development of muscles in the human leg has determined a number of features in the structure of its bones. The femur is characterized by a strong development of the linea aspera, a long neck and an obtuse angle at which it deviates from the body of the bone itself. The human foot has a number of distinctive features. Whereas in anthropomorphic people, as a rule, the big toe is deviated at an angle to the rest, in humans it is located approximately parallel to the other toes. This increases the supporting force of the leg, i.e. is a sign associated with upright posture. This is also confirmed by the fact that in the mountain gorilla, which often assumes a vertical position, the big toe of the hind foot is similar in position to a human one. Another feature of humans is the dome-shaped, concave lower surface of the sole, which springs when walking. This feature is absent in the pes planus of monkeys. The latter have very long hands and feet. The gorilla's hand and foot are, in general, closer to those of humans, which is due to the more developed chthonobiontism of this monkey.

Pelvis. The human pelvis is wider than it is long. The sacrum fused with it includes 5 sacral vertebrae, which increases the supporting force of the pelvis. The gorilla's pelvis is most similar to that of humans, followed by chimpanzees and orangutans. And in this feature, the closeness of the gorilla to humans is a consequence of chthonobnoty.

Muscles. A person has highly developed leg muscles (upright posture), namely: gluteus, quadriceps, gastrocnemius, soleus, third peroneus, quadratus pedis. As in humans, the ear muscles of anthropomorphs are vestigial, especially in the orang, while the chimpanzee is able to move its ears. However, in general, the muscular system of African anthropomorphs is closer to that of the human than to that of the orangutan.

Human and chimpanzee brains. (12). Both brains are shown equal in size for ease of comparison (in reality, the chimpanzee brain (2) is much smaller). Brain regions: 1 - frontal, 2 - frontal granular, 3 - motor, 4 - parietal, 5 - striatal, 6 - temporal, 7 - preoccipital, 8 - insular, 9 - postcentral. (From Nesturkh)

Brain, sense organs. The volume of the cranium and the weight of the brain have already been indicated. The farthest from humans in terms of brain weight are orangs and gorillas, the closest are chimpanzees. The human brain is strikingly larger in volume and weight than the brains of anthropomorphic creatures. More. more important is the fact that it is richer in convolutions, although in this respect it is similar to the brain of anthropomorphs. However, the functional characteristics of the brain associated with its fine (cytological) architecture are of decisive importance. The figure shows that this latter is very similar in humans and chimpanzees. However, in anthropomorphic animals the motor and sensory “speech centers” are not developed, of which the first is responsible for the motor work of the human articulatory apparatus, and the second for the semantic perception of heard words. The cytological architecture of the human brain is much more complex and more developed, especially within the frontal lobe, which makes up 47% of the lateral surface of the brain in humans, 33% in chimpanzees, 32% in gorilla, and even less in orang.

Sense organs human and anthropomorphic are similar in many ways. In all these forms, some reduction of the olfactory organs is observed. Human hearing is close in its perceptive characteristics to the hearing of a gorilla; a chimpanzee has a greater ability to perceive high tones. The similarity between the auricle of African anthropomorphic animals and humans is very great. It is remarkable that the pinna exhibits variations remarkably similar to those of chimpanzees and other apes. Both humans and anthropomorphic species are characterized by greater visual acuity, both three-dimensional (stereometric) and color.

Ontogenesis. The embryogenesis of anthropomorphic animals is unusually similar to human embryogenesis. The early stages of development are generally little distinguishable in all monkeys. Differentiation by species (and generic) characters begins at later stages. The figure shows that the heads of human, chimpanzee and gorilla embryos on the eve of birth, as well as the skulls of newborn anthropomorphic humans, have many similarities - the roundness of the cranial vault, large, forward-directed rounded orbits, the dominance of the cranium over the jaw apparatus. There are also many similarities in the soft parts of the face. In chimpanzee and gorilla embryos, the eyeball protrudes noticeably from the eye orbit, due to the initial predominance of eyeball growth over orbital growth. In the human embryo, this discrepancy also occurs, but to a lesser extent. On the eyelids of human embryos and these monkeys, characteristic restrictive grooves are visible, weaker in humans. The ear of the gorilla embryo has a free lobe, like many people, etc. The general similarity of the mentioned embryos is therefore very great. In gorilla and chimpanzee embryos, distinct “mustaches” and “beards” are visible. In the human embryo they are less developed, but Darwin pointed out (“The Descent of Man and Sexual Selection”) that in the human embryo in the fifth month around the mouth the embryonic down is noticeably elongated, so in this character; there is a clear resemblance.

However, during postembryonic development, signs of similarity give way to increasing signs of differences, i.e., ontogenetic divergence occurs. In the skull, it is expressed in the progressive development of the dentition, jaws, chewing muscles and sagittal crest in anthropomorphic monkeys (in the gorilla and orang) and a lag, compared with humans, in the development of the cranium.

General conclusion. The above comparative review leads to the following general conclusions:

A. Humans and anthropomorphic monkeys have many similarities in morpho-physiological organization and in the patterns of embryogenesis.

b. African forms (gorilla, chimpanzee) are closer to humans than orangutans. The chimpanzee is closest to humans, but in a number of characteristics it is a gorilla, and in a few it is an orangutan.

V. If we take into account the phenomena of ontogenetic divergence noted above and the fact that signs of similarity with humans are scattered within all three genera of apes, then the final conclusion from the review will be the following: humans and anthropomorphic apes come from a common root, and later historically developed in divergent directions.

We see, therefore, that the theory of the pithecoid (monkey) origin of man corresponds to comparative morphological and comparative physiological data.

Question 1. Describe the systematic position of man in the animal world.
Man belongs to the phylum Chordata, subphylum Vertebrates, class Mammals, subclass Placentals, order Primates, suborder Anthropoid (anthropoid-Great apes) primates, superfamily Greater apes, family Hominids (Humans), the only genus Homo with the only species Homo sapiens (Homo Sapiens).
In addition to the anthropoid suborder, primates also include lemurs and tarsiers.

Question 2. Indicate the characteristics of humans as a representative of the class of mammals.
Humans can be classified as Mammals based on the following characteristics:
seven cervical vertebrae;
hair, sweat and sebaceous glands of the skin;
well developed lips and muscular cheeks;
diaphragm and alveolar lungs;
the auricle and three auditory ossicles of the middle ear;
one aortic arch (left) and anucleate red blood cells;
warm-blooded;
mammary glands, care of offspring;
similarities in embryo development.

Question 3. What characteristics are common to humans and apes?
Humans and apes (ponids) are similar in their large body size, the absence of a tail and cheek pouches, good development of facial muscles, and a similar structure of the skull and skeleton in general. In addition, what humans and apes have in common are blood types and the Rh factor, 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. 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, and rich emotions. An example is experiments on teaching apes the language of deaf-mutes, 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 inherent only to humans.
There are differences between humans and animals.
Man is a social being who produces tools and uses them to influence nature. A person has a highly developed brain, possesses consciousness, thinking, articulate speech and a number of anatomical features that have arisen in connection with labor activity, which is unique to humans. The differences are related to the direction of evolution. Man and apes are two branches of the order of primates, which in relatively recent times separated from the common genealogical trunk.
It is typical for a person to:
1. Adaptation to upright walking. The spine has acquired an S-shaped curvature, the foot has a dome shape. These are the main devices that provide shock absorption and shock absorption of the body when walking and jumping, which is important for protecting the brain. The big toe functions as a support. The pelvis is wider, it takes on the pressure of the organs in an upright position. The chest is flat, compressed laterally, due to the pressure that the internal organs exert on the ribs, due to the horizontal position of the body when walking. The brain part of the skull has increased and dominates the facial part. There are no brow ridges. The jaws and chewing muscles are less developed. In the lower part of the body, the gluteal, quadriceps, gastrocnemius, and soleus muscles are especially developed. The consequences of upright walking are associated with limited speed of movement, hypertension, 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 mobile. A person's arms are shorter than his legs.
3. The brain is well developed. In humans, the temporal, frontal and parietal lobes are highly developed, where the main centers of higher nervous activity are located. The surface of the brain is 1250 cm2. The surface area of ​​the cortex in the frontal region is twice that of great apes. The appearance of speech, abstract thinking, and consciousness is characteristic.
4. Hairless skin has become a giant receptor field capable of bringing additional information to the brain. This was a factor in the intensive development of the brain. "Balding" of the skin is the last biological prerequisite for the development of man as a creative social being.

Question 5. Which
The 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 senses provide the finest analysis of visual and auditory information, which allows us to perceive and understand facial expressions and speech. The motor centers of the brain exercise extremely precise and operational control of the muscles of the fingers, vocal cords, etc. In many ways, it was the development of the brain that allowed man to reach the high stage of evolutionary development that he now occupies.