Some of the most important traits that distinguish humans from great apes and are not present at birth. The origin of man in the classical sense

great apes or hominoids is a superfamily that includes the most highly developed representatives of the order of primates. It also includes man and all his ancestors, but they are included in a separate family of hominids and will not be considered in detail in this article.

What distinguishes an ape from a human? First of all, some features of the body structure:

The human spine curves forward and backward.

The facial part of the skull of the great ape is larger than the brain.

The relative and even absolute volume of the brain is much smaller than that of a human.

The area of ​​the cerebral cortex is also smaller, in addition, the frontal and temporal lobes are less developed.

Great apes do not have a chin.

The chest is rounded, convex, and in humans it is flat.

The fangs of the monkey are enlarged and protrude forward.

The pelvis is narrower than in humans.

Since a person is erect, his sacrum is more powerful, since the center of gravity is transferred to it.

The monkey has a longer body and arms.

The legs, on the contrary, are shorter and weaker.

Monkeys have a flat prehensile foot with the thumb opposed to the rest. In humans, it is curved, and thumb located parallel to others.

A person has practically no wool cover.

In addition, there are a number of differences in thinking and activities. A person can think abstractly and communicate using speech. He has consciousness, is capable of generalizing information and compiling complex logical chains.

Signs of great apes:

large powerful body (much larger than other monkeys);

absence of a tail;

no cheek pouches

absence of ischial calluses.

Hominoids are also distinguished by their way of moving through trees. They do not run on them on all fours, like other representatives of the order of primates, but grab the branches with their hands.

Great ape skeleton also has a specific structure. The skull is located in front of the spine. At the same time, it has an elongated front part.

The jaws are strong, powerful, massive, adapted for chewing solid plant food. The arms are noticeably longer than the legs. The foot is grasping, with the thumb set aside (as on a human hand).

The great apes are, orangutans, gorillas and chimpanzees. The first are singled out in a separate family, and the remaining three are combined into one - pongids. Let's consider each of them in more detail.

The gibbon family consists of four genera. All of them live in Asia: India, China, Indonesia, on the islands of Java and Kalimantan. Their color is usually gray, brown or black.

Their sizes are relatively small for great apes: the body length of the largest representatives reaches ninety centimeters, weight - thirteen kilograms.

The lifestyle is daytime. They live mainly in trees. On the ground they move uncertainly, for the most part on hind legs, only occasionally leaning on the front. However, they rarely go down. The basis of nutrition is plant foods - the fruits and leaves of fruit trees. They may also eat insects and bird eggs.

Pictured is the great ape gibbon

Gorilla is very great great ape. This is the largest representative of the family. The growth of a male can reach two meters, and weight - two hundred and fifty kilograms.

These are massive, muscular, incredibly strong and hardy monkeys. The coat color is usually black; older males may have a silvery-gray back.

They live in African forests and mountains. They prefer to be on the ground, on which they walk mainly on four legs, only occasionally rising to their feet. The diet is vegetable, includes leaves, grass, fruits and nuts.

Fairly peaceful, they show aggression towards other animals only in self-defense. Intraspecific conflicts occur, for the most part, between adult males over females. However, they are usually resolved by demonstrating threatening behavior, rarely reaching even fights, and even more so to murders.

Pictured is a gorilla monkey

Orangutans are the rarest modern great apes . Currently, they live mainly in Sumatra, although they used to be distributed throughout almost all of Asia.

These are the largest of the monkeys, living mainly in trees. Their height can reach one and a half meters, and weight - one hundred kilograms. The coat is long, wavy, and can be of various shades of red.

They live almost entirely in the trees, not even going down to get drunk. For this purpose, they usually use rainwater, which accumulates in the leaves.

For spending the night, they build nests for themselves in the branches, and every day they build a new dwelling. They live alone, forming pairs only during the breeding season.

Both modern look, Sumatran and Klimantan, are on the verge of extinction.

Pictured is an orangutan monkey

Chimpanzees are the smartest primates, great apes. They are the closest relatives of man in the animal world. There are two types of them: ordinary and dwarf, also called. The dimensions of even the usual type are not too large. The coat color is usually black.

Unlike other hominoids, with the exception of humans, chimpanzees are omnivores. In addition to plant food, they also consume animal food, obtaining it by hunting. Quite aggressive. Often there are conflicts between individuals, leading to fights and death.

They live in groups, the number of which is, on average, ten to fifteen individuals. This is a real complex society with a clear structure and hierarchy. Common habitats are forests near water. The range is the western and central part of the African continent.

Pictured is a chimpanzee monkey

Ancestors of great apes very interesting and varied. In general, there are much more fossil species in this superfamily than living ones. The first of them appeared in Africa almost ten million years ago. Their further history is very closely connected with this continent.

It is believed that the line leading to humans separated from the rest of the hominoids about five million years ago. One of the likely contenders for the role of the first ancestor of the genus Homo is considered australopithecine - great ape that lived more than four million years ago.

These creatures contain both archaic signs and more progressive, already human ones. However, the former are much more numerous, which does not allow australopithecines to be attributed directly to humans. There is also an opinion that this is a side, dead-end branch of evolution that did not lead to the emergence of more developed forms of primates, including humans.

And here is the statement that another interesting human ancestor, Sinanthropus - ape, is fundamentally wrong. However, the statement that he is the ancestor of man is not entirely correct, since this species already unequivocally belongs to the genus of people.

They already had a developed speech, language and their own, albeit primitive, but culture. It is very likely that Sinanthropus was the last ancestor of modern Homo sapiens. However, the option is not excluded that he, like Australopithecus, is the crown of a side branch of development.

A person at birth goes through the transformations described above, associated with the change of the aquatic environment to the air; moreover, it exhibits all the traits that have arisen in the process of evolution, due to physiological changes similar to those that accompany the transition from an aquatic environment to an air environment in other animals.

Homo sapiens, chimpanzees, gorillas and orangutans share a common ancestor and are among the great primates. The two main features in which man differs from the great apes are absent at birth, although it is generally believed that he already has them. These signs - the large size of the brain and skeletal changes that make the vertical position of the body possible - arise as a result of physiological changes that occur during postnatal development. This is of great evolutionary importance, indicating that such characters are not innate species characteristics, but arise as a result of physiological changes that occur in the later stages of development. In humans, brain volume continues to increase long after birth, while in chimpanzees it increases only slightly. The same applies to walking on two legs.

Rice. 7. Change in the curvature of the human spine during growth. The newborn has only one bulge backwards, like a gorilla

In a newborn child, the spine is curved in the same way as in a gorilla moving on two limbs, i.e. has one curve convex back. At the age of three months, the first change appears - a bend in the cervical region, and by nine months - the second change, creating a compensatory bend in the lumbar region, which basically ensures the vertical position of the body. There are other changes, in particular in the structure of the pelvis, which forms the bottom abdominal cavity, i.e. occupies a completely different position in humans than in quadrupeds. Thus, it is not until the age of nine months that the body of a person is changed enough to assume an upright position. What kind of signals initiate such changes? At the present time this is not yet fully established. However, the skeletal and muscular differences between humans and great apes are only slightly more pronounced than those between males and females, whose pelvis has a different shape and different musculature. As you know, these differences are of a hormonal nature and depend on the activity of the parathyroid glands and adrenal glands, which send chemical signals that affect bone tissue and muscle contractions, respectively. Thus, the changes that result in a person becoming a quadruped to a biped can be caused mainly by chemical signals of the hormonal type. From an evolutionary point of view, this means that such a transformation does not require new structural genes that are characteristic of only one species. homo sapiens, and that it can easily be achieved as a result of changes at the level of regulatory DNA. In addition, this transformation occurs quickly - in one individual and in a few months.

Human evolution seems to have depended mainly on changes at the level of regulatory DNA rather than at the level of structural genes.

The above considerations are confirmed by the data collected over the past 10 years on the genetic similarity between humans and great apes. In contrast to expectations based on ideas about random mutations, the analysis of genomes showed the following.

1. A detailed study of the colored transverse discs that form permanent patterns in the chromosomes revealed their striking similarity in the orangutan, gorilla, chimpanzee and man.

2. About 400 genes have been localized in human chromosomes. Forty of them are found in great apes, and in most cases on the same chromosomes.

3. The DNA homology of higher primates is also confirmed by DNA/DNA hybridization experiments. The differences between the nucleotide sequences of human and chimpanzee DNA are approximately 1.1% and affect mainly non-transcribed regions in which regulatory DNA is localized.

4. These homologies are also found in proteins. The similarity between the amino acid sequences of 44 chimpanzee and human proteins exceeds 99%.

5. King and Wilson concluded from their research that the major morphological and physiological differences between humans and chimpanzees may be the result of regulatory changes at the level of gene expression rather than point mutations in structural genes.

Man and chimpanzee are not only different types but also to different genera and families. Man belongs to the family. Hominidae, chimpanzees - to the family. Pongidae. Therefore, there must be some kind of transformation leading to such a large modification that it can cause a difference that separates families without causing significant changes in structural genes.

The latest paleontological evidence supports the possibility of a sudden emergence of species.

Verba has done extensive research on the evolution of African mammals from the Miocene to the modern era. It determined the duration of the existence of species in antelopes and other groups. Vrba concluded that there were synchronous waves that led to the sudden appearance hallmarks then persisted for long periods of time. As she points out, these data do not favor sequential speciation based on the accumulation of small changes, but a sudden explosion of specific characters, which then became fixed.

Species, genera, and families can arise in many ways.

According to the generally accepted point of view, species arise mainly by: 1) mutations of structural genes, i.e. genes that determine protein synthesis; 2) chromosomal rearrangements; 3) random events; 4) numerous small and sequential genetic changes; 5) slow process of transformation. This further leads to the transformation of species into genera and genera into families.

The data currently available indicate that very different mechanisms may be involved in these evolutionary processes. In addition, not one, but several mechanisms can be used in speciation.

1. Each transformation was conditioned by the order given by the initial organization of the mineral components of the cell and the preservation of several nucleotide sequences of DNA from prokaryotes and eukaryotes to humans.

2. Modifications of mineral components, for example, as a result of changes in membrane permeability, may be involved in the transformation of species, since they affect the basic types of structures.

3. Changes in physical factors, such as gravity, which lead to changes in the layered distribution of macromolecular components in a fertilized egg, cannot be excluded from these processes. Modifications caused by chemical and physical factors can be passed on to offspring because the separation between somatic cells and germline cells is not as strict as previously thought.

4. The participation of changes in structural genes is not excluded, but they probably depend mainly on the physicochemical limitations inherent in the structure of the cell and DNA.

5. In addition, the evolution of DNA may depend on the internal and external environment. It is known that such a physical factor as temperature channels the nucleotide composition of DNA. It can be expected that in higher vertebrates, such as birds and mammals, thermoregulation, which ensures the constancy of cell temperature, channels changes in the nucleotide sequences of both structural and regulatory regions of DNA.

6. The significance of chromosomal rearrangements, which have so often been called the source of species transformation, is quite obvious. However, the impression is created that they arise and are maintained by ordered processes, due mainly to the initial structure of the chromosome. Ordering, which determines the optimal gene territories within the centromere-telomeric field, should have participated in their establishment.

7. Both internal and external factors are involved in the sudden formation of additional copies of specific DNA sequences. The number of copies can be regulated by the chromosome itself. Their sharp change can also be caused by environmental factors.

8. Along with the obvious slow changes, fast changes are also possible. This is explained by the fact that many abrupt structural and functional changes occur without the participation of structural genes; they are determined by changes in regulatory DNA and even external factors affecting hormone secretion. Structural genes seem to play a modest role in evolution compared to the role of regulatory DNA nucleotide sequences.

9. The initial processes leading to the transformation of species, genera and families do not always proceed slowly. Slow are, apparently, later events generated by various kinds of small adjustments. A major transformation does not require millions of years or thousands of random mutations. The results of the study of autoevolution make it possible to formulate a more versatile and coherent concept of species transformation.

To this we can add that the extinction of species as a result of catastrophes is not necessary: ​​perhaps they have some kind of clock that determines the duration of their existence. The presence in mammals of a clock that limits the number of somatic cell divisions is well known. It is possible that these cellular clocks also manifest themselves at the species level.

Differences in the structure and behavior of humans and animals

Along with similarities, humans have certain differences from monkeys.

In monkeys, the spine is arched, while in humans it has four bends, giving it an S-shape. The person has a wider pelvis, an arched foot that softens the concussion internal organs when walking, a wide chest, the ratio of the length of the limbs and the development of their individual parts, structural features of muscles and internal organs.

A number of structural features of a person are associated with his labor activity and the development of thinking. In humans, the thumb on the hand is opposed to other fingers, so that the hand can perform a variety of actions. The brain part of the skull in humans prevails over the front due to the large volume of the brain, reaching approximately 1200-1450 cm 3 (in monkeys - 600 cm 3), mandible well developed chin.

The big differences between monkeys and humans are due to the adaptation of the first to life on trees. This feature, in turn, leads to many others. The essential differences between man and animals lie in the fact that man has acquired qualitatively new features - the ability to walk upright, the release of hands and their use as labor organs for the manufacture of tools, articulate speech as a method of communication, consciousness, i.e. those properties that closely related to the development of human society. Man not only uses the surrounding nature, but subordinates, actively changes it according to his needs, creates the necessary things himself.

Similarities between humans and great apes

The same expression of feelings of joy, anger, sadness.

Monkeys gently caress their cubs.

Monkeys take care of children, but also punish them for disobedience.

Monkeys have a well-developed memory.

Monkeys are able to use natural objects as the simplest tools.

Monkeys have concrete thinking.

Monkeys can walk on their hind limbs, leaning on their hands.

On the fingers of monkeys, like humans, nails, not claws.

Monkeys have 4 incisors and 8 molars - like humans.

In humans and monkeys common diseases(influenza, AIDS, smallpox, cholera, typhoid fever).

In humans and great apes, the structure of all organ systems is similar.

Biochemical evidence for human-monkey affinity:

the degree of hybridization of human and chimpanzee DNA is 90-98%, human and gibbon - 76%, human and macaque - 66%;

Cytological evidence of the proximity of man and monkeys:

humans have 46 chromosomes, chimpanzees and monkeys have 48 each, and gibbons have 44;

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.

F. Engels drew attention to this feature of human evolution in his essay "The Role of Labor in the Process of the Transformation of Apes into Humans", which was written in 1876-1878. and published in 1896. He was the first to analyze the qualitative originality and significance of social factors in the historical development of man.

The decisive step for the transition from ape to man was taken in connection with the transition of our ancient ancestors from walking on all fours and climbing to a straight gait. AT labor activity developed articulate speech and public life man, with whom, as Engels said, we enter the realm of history. If the psyche of animals is conditioned only by biological laws, then human psyche is the result of social development and influence.

Humans and monkeys share about 98 percent genetic similarity, but even the external differences between them are more than obvious. Monkeys hear differently, see differently and physically develop faster.

Structure

Many of the features that distinguish humans from monkeys are immediately noticeable. For example, upright posture. Despite the fact that gorillas can move on their hind legs, this is not a natural process for them. A flexible lumbar arch, arched foot and long straight legs, which monkeys lack, provide the convenience of moving in an upright position for a person.

But between man and ape there are distinctive features that only zoologists can tell about. For example, experts note that some of the signs make a person closer to marine mammals than to primates - this is a thick body fat and skin rigidly attached to the muscular skeleton.
There are significant differences in the vocal capabilities of humans and monkeys. Thus, our larynx occupies a much lower position in relation to the mouth than that of any other primate species. The common “tube” formed as a result of this provides a person with exceptional opportunities for a speech resonator.

Brain

The volume of the human brain is almost three times that of the brain of a monkey - 1600 and 600 cm3, which gives us an advantage in the development of mental abilities. In the brain of a monkey, there are no speech centers and zones of association that a person has. This led to the emergence of not only the first signal system (conditioned and unconditioned reflexes), but also the second one, which is responsible for speech forms of communication.
But more recently, British scientists discovered in the human brain a much more noticeable detail that the monkey brain lacks - this is the lateral frontal pole of the prefrontal cortex. It is he who is responsible for strategic planning, task differentiation and decision making.

Hearing

Human hearing is particularly sensitive to the perception of sound frequencies - in the range of approximately 20 to 20,000 Hz. But in some monkeys, the ability to distinguish frequencies significantly exceeds that of a human. For example, Philippine tarsiers can hear sounds up to 90,000 Hz.

True, the selective ability of human auditory neurons, which allow us to perceive the difference in sounds that differ by 3-6 Hz, is higher than that of monkeys. Moreover, people have a unique ability to relate sounds to each other.

However, monkeys can also perceive a series of repeated sounds of different pitches, but if this series is shifted up or down a few tones (change the key), then the melodic pattern will be unrecognizable for animals. It is not difficult for a person to guess the same sequence of sounds in different keys.

Childhood

Newborn babies are completely helpless and completely dependent on their parents, while baby monkeys can already hang and move from place to place. Unlike a monkey, a person needs a much longer time to grow up. So, for example, a female gorilla reaches puberty by the age of 8, given that her gestation period is almost the same as that of a woman.

In newborn children, unlike monkey cubs, instincts are much less developed - a person receives most of the life skills in the learning process. It is important to note that a person is formed in the process of direct communication with his own kind, while a monkey is born with an already established form of its existence.

Sexuality

By virtue of innate instincts, the male monkey is always able to recognize when the female is ovulating. Humans don't have this ability. But there is a more significant difference between humans and monkeys: this is the occurrence of menopause in humans. The only exception in the animal world is the black dolphin.
Man and monkey differ in the structure of the genital organs. So, not a single great ape has a hymen. On the other hand, the male genital organ of any primate contains gutter bone (cartilage), which is absent in humans. There is one more characteristic feature concerning sexual behavior. Face-to-face sexual intercourse, so popular with humans, is unnatural for monkeys.

Genetics

Geneticist Steve Jones once observed that "50% of human DNA is similar to that of bananas, but this does not mean at all that we are half bananas, either from head to waist or from waist to toe." The same can be said when comparing man with a monkey. The minimal difference in the genotype of humans and monkeys - about 2% - nevertheless forms a huge gap between the species.
The difference includes about 150 million unique nucleotides, which contain about 50 million individual mutation events. Such changes, according to scientists, cannot be achieved even on an evolutionary time scale of 250 thousand generations, which once again refutes the theory of human origin from higher primates.

There are significant differences between humans and monkeys in the set of chromosomes: if we have 46 of them, then gorillas and chimpanzees have 48. Moreover, there are genes in human chromosomes that are absent in chimpanzees, which reflects the difference between immune system man and animal. Another interesting genetic claim is that the human Y chromosome is as different from the similar chimpanzee chromosome as it is from the chicken Y chromosome.

There is also a difference in the size of the genes. When comparing human and chimpanzee DNA, it was found that the monkey genome is 12% larger than the human genome. And the difference in the expression of human and monkey genes in the cerebral cortex was expressed in 17.4%.
A genetic study by scientists from London has revealed possible cause which monkeys are unable to speak. So they determined that the FOXP2 gene plays an important role in the formation of the speech apparatus in humans. Geneticists decided on a desperate experiment and introduced the FOXP2 gene to a chimpanzee, in the hope that the monkey would speak. But nothing of the kind happened - the zone responsible for the functions of speech in humans, in chimpanzees, regulates the vestibular apparatus. The ability to climb trees in the course of evolution for a monkey turned out to be much more important than the development of verbal communication skills.

The relationship of great apes (anthropoids) and humans is evidenced by the similarity of many anatomical and physiological features. This was first established by Charles Darwin's colleague - Thomas Huxley. Having carried out 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 external appearance of humans and great 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 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 internal structure it should be noted a similar number of lobes in the lungs, the number of papillae in the kidney, the presence of a vermiform appendix of the caecum, an almost identical pattern of tubercles on the molars, a similar structure of the larynx, etc. The timing of puberty and the duration of pregnancy in great apes are almost the same as in humans.

An exceptionally close similarity is noted in terms of biochemical parameters: four blood groups, similar reactions of protein metabolism, and diseases. Great apes in nature are easily infected with infections from 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 obtained from humans. It is no coincidence that great apes are indispensable experimental animals for studying many human diseases. Humans and anthropoids are also close in the number of chromosomes (46 chromosomes in humans, 48 ​​in chimpanzees, gorillas, orangutans), in their shape and size. There is much in common in the primary structure of such important proteins as hemoglobin, myoglobin, etc.

However, there are significant differences between humans and anthropoids, to a greater extent due to the adaptability of humans to walking upright. The human spine is S-shaped, the foot has an arch, which softens the concussion when walking and running (Fig. 45). With the vertical position of the body, the human pelvis takes on the pressure of the internal organs. As a result, its structure differs significantly from the anthropoid pelvis: it is low and wide, firmly articulated with the sacrum. There are significant differences in the structure of the brush. The thumb of the human hand is well developed, opposed to the rest and very mobile. Thanks to this structure of the hand, the hand is capable of various and subtle movements. In anthropoids, in connection with the arboreal way of life, the hands are hook-shaped, and the type of foot is prehensile. When forced to move on the ground, great apes lean 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 extended position.

Differences between anthropoids and humans are observed in the structure of the skull and brain. The human skull does not have bony ridges and continuous superciliary arches, the brain part prevails over the front, 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. In monkeys, on the contrary, the facial part, especially the jaws, is highly developed. The human brain is 2-2.5 times larger than the brain of great 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 signs of difference lead to the idea that modern great apes could not be the direct ancestors of man.