Traits that differentiate humans from apes. Similarities and differences between humans and apes

Humans and apes are approximately 98 percent genetically similar, but even the external differences between them are more than obvious. Monkeys hear, see differently and physically develop faster.

Many features that distinguish humans from apes are immediately noticeable. For example, upright walking. Despite the fact that gorillas are quite capable of moving on their hind legs, this is an unnatural process for them. It is convenient for humans to move in vertical position provide a flexible lumbar deflection, arched foot and long straight legs, which monkeys lack.

But between man and monkey there are distinctive features, which only zoologists can tell about. For example, experts note that some of the signs make a person closer to marine mammals than primates - this is a thick layer of fat and skin, rigidly attached to the muscular frame.
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 resulting common “tube” provides a person with exceptional speech resonator capabilities.

Brain

The volume of the human brain is almost three times larger than the brain of a monkey - 1600 and 600 cm3, which gives us an advantage in the development of mental abilities. The monkey brain lacks the speech centers and association areas that humans have. This gave rise not only to our first signal system (conditional and unconditioned reflexes), but also the second, responsible for speech forms of communication.
But more recently, British scientists discovered in human brain A much more prominent feature that the monkey brain lacks is the lateral frontal pole of the prefrontal cortex. He 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 some monkeys have a greater ability to distinguish between frequencies than humans. For example, Philippine tarsiers can hear sounds with frequencies up to 90,000 Hz.

True, the selective ability of human auditory neurons, which allow us to perceive differences 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 several tones (change the tonality), then the melodic pattern will be unrecognizable to the animals. It is not difficult for a person to guess the same sequence of sounds in different keys.

Childhood

Newborn children are absolutely helpless and completely dependent on their parents, while baby monkeys can already hang and move from place to place. Unlike apes, humans need a much longer time to mature. So, for example, a female gorilla reaches sexual maturity by the age of 8, given that her gestation period is almost the same as that of a woman.

Newborn children, unlike baby monkeys, have much less developed instincts - a person acquires most life skills during 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

Due to innate instincts, a male monkey is always able to recognize when a female is ovulating. Humans lack this ability. But there is a more significant difference between people and monkeys: this is the occurrence of menopause in humans. The only exception in the animal world is the black dolphin.
Humans and apes also differ in the structure of their genital organs. Thus, not a single ape has a hymen. On the other hand, the male genital organ of any primate contains a grooved bone (cartilage), which is absent in humans. There's another one characteristic feature concerning sexual behavior. Face-to-face sexual contact, so popular among humans, is unnatural for monkeys.

Genetics

Geneticist Steve Jones once noted that “50% of human DNA is similar to bananas, but that doesn’t mean we’re half bananas, either from head to waist or from waist to toe.” The same can be said when comparing a person with a monkey. The minimal difference in the genotype of humans and monkeys - approximately 2% - nevertheless creates 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 origins from higher primates.

There are significant differences between humans and apes in the set of chromosomes: if we have 46 of them, then gorillas and chimpanzees have 48. Moreover, human chromosomes contain genes that are absent in chimpanzees, which reflects the difference between immune system human and animal. Another interesting statement by geneticists is that the human Y chromosome differs from a similar chimpanzee chromosome as much as it differs from the chicken Y chromosome.

There is also a difference in the size of the genes. When comparing the DNA of humans and chimpanzees, 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 17.4%.
A genetic study by scientists from London revealed possible reason, according to which monkeys are not able to speak. So they determined that the FOXP2 gene plays a role in humans important role in the formation of the speech apparatus. Geneticists decided on a desperate experiment and introduced the FOXP2 gene into chimpanzees, in the hope that the monkey would speak. But nothing like this happened - the area responsible for speech functions in humans regulates the vestibular apparatus in chimpanzees. The ability to climb trees during evolution turned out to be much more important for the monkey than the development of verbal communication skills.

The fact that the monkey is a close relative of humans has been known for a long time; the chimpanzee, among all monkeys, is our closest relative. When studying DNA, the origin of humans from ape-like ancestors is fully confirmed. Genetic differences at the DNA level, between humans there is an average of 1 nucleotide out of 1000 (i.e. 0.1%), between humans and chimpanzees - 1 nucleotide out of 100 (i.e. 1%).

In terms of genome size, humans and higher primates do not differ from each other, but they differ in the number of chromosomes - humans have one less pair. As was discussed in previous lectures, a person has 23 pairs of chromosomes, i.e. a total of 46. Chimpanzees have 48 chromosomes, one pair more. During the process of evolution, in human ancestors, two different chromosomes of primates were combined into one. Similar changes in the number of chromosomes occur in the evolution of other species. They may be important for the genetic isolation of a group during the process of speciation, since in most cases individuals with different numbers of chromosomes do not produce offspring.

The time of divergence of species, or in other words, the time of existence of the last common ancestor for two species, can be determined in several ways. The first is this: they date the bone remains and determine who these remains could belong to, when the common ancestor of certain species could have lived. But there are not so many bone remains of supposed human ancestors that it is possible to confidently restore and date the complete sequence of forms in the process of anthropogenesis. Now they use another method of dating the time of divergence between humans and other primates. To do this, count the number of mutations that have accumulated in the same genes in each of the branches during their separate evolution. The rate at which these mutations accumulate is more or less known. The rate of accumulation of mutations is determined by the number of differences in the DNA of those species for which paleontological dating of the divergence of species based on bone remains is known. The time of divergence between humans and chimpanzees, according to various estimates, varies from 5.4 to 7 million years ago.

You already know that the human genome has been completely read (sequenced). Last year it was reported that the chimpanzee genome had also been read. By comparing the genomes of humans and chimpanzees, scientists are trying to identify the genes that “make us human.” This would be easy to do if, after the separation of the branches, only human genes evolved, but this is not so, chimpanzees also evolved, and mutations also accumulated in their genes. Therefore, in order to understand in which branch the mutation occurred - in humans or in chimpanzees - we also have to compare them with the DNA of other species, gorilla, orangutan, mouse. That is, what only chimpanzees have and, for example, orangutans do not, are purely “chimpanzine” nucleotide substitutions. Thus, comparing nucleotide sequences different types primates, we can identify those mutations that occurred only in the line of our ancestors. There are now about a dozen genes known that “make us human.”

Differences have been discovered between humans and other animals in the genes of olfactory receptors. In humans, many olfactory receptor genes are inactivated. The DNA fragment itself is present, but mutations appear in it that inactivate this gene: either it is not transcribed, or it is transcribed, but a non-functional product is formed from it. As soon as selection to maintain the functionality of a gene ceases, mutations begin to accumulate in it, disrupting the reading frame, inserting stop codons, etc. That is, mutations appear in all genes, and the mutation rate is approximately constant. It is possible to maintain a gene functioning only due to the fact that mutations that disrupt important functions, are rejected by selection. Such genes inactivated by mutations, which can be recognized by their nucleotide sequence, but have accumulated mutations that make it inactive, are called pseudogenes. In total, the mammalian genome contains about 1000 sequences corresponding to olfactory receptor genes. Of these, 20% of pseudogenes are in mice, a third (28-26%) are inactivated in chimpanzees and macaques, and more than half (54%) are pseudogenes in humans.

Pseudogenes are also found in humans among the genes that encode the family of keratin proteins that make up hair. Because hairline we have less than chimpanzees, it is clear that some of these genes could be inactivated.

When they talk about the difference between a person and a monkey, they primarily highlight the development of mental abilities and the ability to speak. A gene associated with the ability to speak has been found. This gene was identified by studying a family with a hereditary speech disorder: an inability to learn to form phrases in accordance with the rules of grammar, combined with a mild degree of mental retardation. The slide shows the pedigree of this family: circles are women, squares are men, filled figures are sick family members. The mutation associated with the disease is in the gene FOXP2(forkhead box P2). It is quite difficult to study gene functions in humans; it is easier to do this in mice. They use the so-called knockout technique. The gene is specifically inactivated, if you know the specific nucleotide sequence, then this is possible, after which this gene does not work in the mouse. In mice in which the gene is turned off FOXP2, the formation of one of the brain zones during the embryonic period was disrupted. Apparently, in humans this zone is associated with the development of speech. This gene encodes a transcription factor. Recall that at the embryonic stage of development, transcription factors turn on a group of genes at certain stages that control the transformation of cells into what they should turn into.

To see how this gene evolved, it was sequenced in different species: mouse, macaque, orangutan, gorilla and chimpanzee, and then compared these nucleotide sequences with human ones.

It turned out that this gene is very conserved. Among all primates, only the orangutan had one amino acid substitution, and the mouse had one substitution. On the slide, two numbers are visible for each line, the first shows the number of amino acid substitutions, the second - the number of so-called silent (synonymous) nucleotide substitutions, most often these are substitutions in the third position of the codon that do not affect the encoded amino acid. It can be seen that silent substitutions accumulate in all lines, that is, mutations in a given locus are not prohibited if they do not lead to amino acid substitutions. This does not mean that mutations in the protein-coding part did not appear; they most likely appeared, but were eliminated by selection, so we cannot detect them. At the bottom of the figure, the amino acid sequence of the protein is schematically depicted; the places where two human amino acid substitutions occurred, which apparently affected functional features squirrel FOXP2.

If a protein evolves at a constant rate (the number of nucleotide substitutions per unit time is constant), then the number of substitutions in the branches will be proportional to the time during which the substitutions accumulated. The time of separation of the line of rodents (mice) and primates is assumed to be 90 million years, the time of separation of humans and chimpanzees is 5.5 million years. Then the number of substitutions m accumulated in total in the mouse line and in the primate line between the point of separation with the mouse and the point of separation between humans and chimpanzees (see figure), compared with the number of substitutions h in the human line, should be 31.7 times greater. If more substitutions have accumulated in a person’s line than expected constant speed evolution of a gene, then they talk about accelerating evolution. How many times evolution is accelerated is calculated using a simple formula:

A. I.= ( h/5.5) / [ m/(2 x 90 - 5.5)]= 31.7 h/ m

Where is A.I. (Acceleration Index) – acceleration index.

Now we need to evaluate whether the deviation of the number of substitutions in a person’s line from is within the limits of chance, or whether the deviation is significantly higher than expected. The probability that 2 amino acid substitutions will appear in the human line within 5.5 million years, given that the probability of the occurrence of substitutions is estimated for the mouse line as 1/(90+84.6)=1/174.6. In this case, the binomial distribution is used B(h + m, Th/(Th+Tm)), where h is the number of substitutions in the human line, m is the number of substitutions in the mouse line: Th=5.5, Tm=174.5.

Based on Darwin's theory, the ancestor of man is the monkey. Man and ape have a common origin, but as a result various directions developments today differ so significantly.

Monkey- a representative of the order of anthropoid primates. Its main habitat is the crowns of trees.

Human is a subject capable of influencing environment. He is active, independent, his decisions are strong-willed and deliberate.

Let's look at the main differences between humans and monkeys:

Physical structure

The human spine is characterized by forward bending and backward bending. Humans, unlike apes, have wider pelvic bones and a more voluminous chest. He has an arched foot, which prevents shaking of internal organs when moving. All limbs are harmoniously related to the body.

Due to the fact that the thumb on the hand is opposed to the rest, a person is able to perform more operations with his hands than a monkey.

The spine of monkeys has the shape of an arc. Almost all species of monkeys, even from a distance, do not resemble humans in their structure, with the only exception being chimpanzees. The monkey's body is covered with fur, its arms are excessively long, and its legs lack calves. The front of the skull protrudes strongly forward.

Structure of teeth

Adapting to the peculiarities of the outside world, the way people eat changed significantly . The need to use fangs disappeared, and they gradually began to decrease in size and volume, and the spaces intended for closing the fangs in primates disappeared.

The shape, inclination and surface of other teeth have changed. The front teeth in humans are somewhat rounded, the lateral ones expand outward. Since the teeth have changed, general form The skull also underwent some transformations.

The ape's jaw is similar to a human's, but is easily identified by the presence of fangs and a U-shaped dental arch.

Brain state

The human brain is larger in volume than the brain of a monkey, which puts it in a special position relative to other primates. In addition, the number of nerve cells and their location are also different.

A person has two signaling systems, with the help of which he can create images, make plans for the future and subsequently implement them.

Way to travel

In the course of evolution, man acquired the ability to move on lower limbs, straightening your back. This made it possible to free my hands. Now they were involved in the labor process, during which dexterity and skill developed.

The main method of movement of primates is walking on all fours and climbing. There are some species of monkeys that partially practice upright walking, such as gorillas. However, their stay in a horizontal position is not long; from time to time, when moving, they rest on the backs of their hands.

Conclusions website

1. The human brain is larger in size and more developed.
2. Man has the ability to walk upright.
3. There is no hair on the human body, and the arms are shorter than the legs.
4. In addition to the first signal system, a person has a second one.
5. Man has consciousness.

Although chimpanzees are our closest relatives, they were still unknown in most parts of the world until Charles Darwin wrote about them in 1859 and they became popular. Only recently has a lot of hitherto unknown information been discovered, allowing us to take a different look at the misconceptions and exaggerations that are used in abundance in the works fiction. However, our similarities and differences are not what many imagine. By studying our immediate family, we can better understand ourselves.

1. Number of types

Chimpanzees are often incorrectly called apes, but they are actually just part of the extended family of apes, just like us. Other prominent representatives of primates are orangutans and gorillas. There is only one species of man at present: homo sapiens. In the past, many scientists have tried to prove that there are several species of humans, and often hasten to add that they belonged to the “higher” species. However, all humans can produce offspring from their own kind, and therefore we are all one species. When it comes to chimpanzees, there are actually two species: pan troglodytes, which is the common chimpanzee, and pan paniscus, the slender chimpanzee or bonobo. These two types of chimpanzees are completely separate species. Humans and chimpanzees as species evolved from a common ancestor, possibly sahelanthropus tchadensis, about five or seven million years ago. Only fossils remain of this ancestor.

2. DNA

It is often said that human and chimpanzee DNA are 99% identical. Genetic comparison is not an easy task due to the nature of the gene mutation, so a more accurate estimate is somewhere between 85% and 95%. And while this number may sound impressive, it has already been proven that DNA is used by all living things for basic cellular functions. For example, we have about half the same DNA as a banana, and yet no one emphasizes this fact to show how similar a person can be to a banana! Thus, 95% do not say as much as it seems at first glance. Chimpanzees have 48 chromosomes, two more than humans. Believed to be an inheritance from a human ancestor, two pairs of chromosomes merge into one pair. Interestingly, humans have the least genetic variation of any animal, so inbreeding can cause genetic problems. Even two completely unrelated humans are typically more genetically similar than two chimpanzee brothers.

3. Brain size

The average chimpanzee brain has a volume of 370 cc. On the other hand, humans have an average brain size of about 1350 cc. see However, the brain and its size are not in themselves absolute indicator intelligence. Some Nobel Prize winners had brain volumes below 900 cc. cm, and some - more than 2000 cubic meters. see The structure and organization of the various parts of the brain is the best way definitions of intelligence. The human brain has large area surface, so it has many more convolutions than the chimpanzee brain, which means the human brain has more connections between parts of the brain. And also the relatively large frontal lobe allows us to have much more developed abstract and logical thinking.

4. Social communication skills

Chimpanzees spend a lot of time communicating. Much of their communication involves grooming each other. Juvenile and young chimpanzees often play, chase each other, and tickle each other. Adult chimpanzees also often play with their offspring. Shows of affection include hugging and kissing and occur between chimpanzees of all ages and genders. Bonobos are especially outspoken, and almost every display of attention has a sexual connotation, regardless of gender. Chimpanzees form friendships and spend a lot of time together grooming each other. Humans also spend about the same amount of time communicating, but we do it more verbally than physically. However, much of the vast amount of meaningless chatter is simply a more complex version of chimpanzee behavior - and it serves a slightly different purpose than strengthening our bonds. People also demonstrate closer relationships through physical contact - friendly pats on the back or hugs. Dimensions social group primates are accurately reflected in the size of their brains. Chimpanzees have about 50 close friends and acquaintances, while humans have between 150 and 200.

5. Language and facial expressions

Chimpanzees have complex systems greetings and messages that depend on the social status of the communicating chimpanzees. They communicate verbally using a variety of calls, grunts and other vocalizations. Most of their communication, however, is done through gestures and facial expressions. Many of their facial expressions - surprise, smiles, pleading facial expressions and consoling facial expressions - are the same as those of humans. However, humans smile by showing their teeth, which for chimpanzees and many other animals is a sign of aggression or danger. Most human communication is carried out through vocalizations. Humans clearly have more complex vocal cords, which allows them to produce a greater range of sounds, but also makes it difficult for them to drink and breathe at the same time, as chimpanzees do. In addition, humans have very muscular tongues and lips, which allows them to perform precise manipulations of their voices. This is why humans have a pointed chin while chimpanzees have a sloping chin - humans have most of the labial muscles in the lower jaw in the chin area, but chimpanzees do not have many of these muscles and therefore do not need a prominent chin.

6. Food

Chimpanzees and humans are omnivores (eating plants and meat). Humans are more carnivorous than chimpanzees and have smaller intestines for digesting meat. Chimpanzees sometimes hunt and kill other mammals, often other monkeys, but otherwise chimpanzees are content with fruit and sometimes insects. People are much more dependent on meat - people can only get vitamin B12 naturally from animal products. Based on our digestive system and the lifestyle of surviving tribes, it is believed that humans evolved to eat meat at least once every few days. People also tend to eat on a schedule rather than eating continuously throughout the day, which is characteristic feature other carnivores. This may be because the meat could only be available after a successful hunt, and was therefore eaten in large quantities but infrequently. Chimpanzees will eat fruit throughout the day, while most humans will eat no more than three times a day.

7. Sex

Bonobos are known for their sexual appetite. The common chimpanzee may become angry or aggressive, but bonobos relieve tension through sexual pleasure. They also greet each other and show their affection for each other through sexual arousal. The common chimpanzee does not use sex recreationally, and mating takes only ten or fifteen seconds, often while eating or during other activities. Friendships and emotional attachments have no bearing on who the common chimpanzee associates with, and females in heat usually mate with several males, who sometimes wait patiently for each other's turn. Humans experience sexual pleasure like bonobos, but reproductive sex takes much longer and requires more effort, resulting in long-term partnerships. Unlike humans, chimpanzees have no concept of sexual jealousy or competition, as they do not have long-term partners.

8. Upright walking

Both humans and chimpanzees are bipedal creatures and can walk on two legs. Chimpanzees often do this to see further, but prefer to walk on all fours. Humans have been walking upright since childhood and have developed a cup-shaped pelvis to support them internal organs. Chimpanzees walk by leaning forward while moving, so that the pelvis does not support their organs, and they have more wide hips. This makes childbirth much easier for chimpanzees than for humans, whose cup-shaped pelvis is in the path of the large birth canal. Humans have straight legs with their toes pointed forward for ease of walking, while chimpanzees have protruding big toes and their feet look more like hands. They use their legs to climb and crawl sideways, diagonally, or in rotational movements.

9. Eyes

In humans, the iris of the eye is white, while the iris of the chimpanzee eye is typically dark brown. This makes it easier to see where a person is looking, and there are several theories as to why this is so. This may be an adaptation to a more complex social situation where it is advantageous to see who others are looking at and what they think. This can help when hunting in complete silence, where eye direction is very important for communication. Or it could simply be a genetic mutation with no purpose - some chimpanzees also have white irises. Both humans and chimpanzees can see in color, which helps them choose ripe fruits and plants for food, and have binocular vision, their eyes look in the same direction. This helps you see in depth and is more important during hunting than your eyes. different sides heads like rabbits, which helps them avoid being caught.

10. Tools

For many years, it was believed that among animals only humans use tools. Observations of chimpanzees dating back to 1960 showed the use of pointed branches to catch termites, but much has changed since then. Both humans and chimpanzees are capable of changing their environment by creating tools to solve everyday problems. Chimpanzees make spears, use rocks as hammers and anvils, and crush leaves to use as temporary sponges. It is believed that as a result of walking upright, our forelimbs are much more free to use tools, and we have elevated tool use to an art. We live constantly surrounded by the products of our abilities, and much of what people think makes us “successful” has its roots in our instrumental production.

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Man has his own characteristics that qualitatively distinguish him from animals, including our closest relatives - great apes.

• 1. Upright posture, due to which the spine is straightened, the cranium can develop in all directions, which creates the possibility of a significant increase in brain volume; hands are freed, which allows you to make and use tools.
• 2. The human hand differs from the forelimb of primates in greater mobility, better opposability of the thumb; strengthening the palmar region.
• 3. There is a difference in the structure of the brain, which consists mainly in a lower packing density of neurons in the cortex, in more dendrites, in a larger number of cortical neurons with short axons and more(per unit volume of cortex) neuroglial cells. Ratio absolute number neurons of the human cerebral cortex and the cerebral cortex of monkeys is 1.4: 1.0.
• 4. Although the structure of genes, as already mentioned, is the same for us and for monkeys, there is a difference in a characteristic called “gene expression”, in other words, this is their activity, the speed with which new proteins are born through them . It turned out that in the human brain this expression is 5 times higher than in monkeys.

There is an opinion that at some ancient stage in the evolution of primates, the human ancestor received an unexpected advantage in the form of “fast” brain genes. In other words, his brain began to evolve 5 times faster. Why none of the other animals received such a gift is anyone's guess, since it is impossible to answer this question. How we are so different is already more or less clear, but it is not at all clear why such a difference arose.

5. Only a person has speech and is capable of transmitting information not related to the present moment. There is an area in the human brain that controls the conceptual side of speech. And man is the only primate that, due to the low position of the larynx, is capable of articulate speech.

Meanwhile, judging by modern data, the closest relatives of humans - chimpanzees, bonobos and gorilla - understand symbols, operate with them, combine signs, creating new meanings. Pygmy chimpanzees are especially successful in this. For example, a bonobo named Kenzi learned to communicate using symbols, perceives words by ear without special training, quickly establishes a connection between a drawn symbol and its verbal expression, and understands the meaning simple sentences. Perhaps in natural conditions Bonobos are capable of transmitting information using symbols. A group of American and Japanese primatologists recently discovered that members of the same community, breaking into groups, leave each other real messages in the form of symbols: sticks stuck in the ground, branches laid on a path, plant leaves oriented in the right direction. Thanks to such marks, relatives can determine the direction of movement of the group ahead. These marks are more often found at forks or in places where it is impossible to leave marks on the ground - when crossing a stream, in a wetland, etc. This is what people would do in similar situations.

• 6. There are significant differences between the psyche of animals and the human psyche:
  • * a person operates with images and concepts, the content of which is free from the limitations of space and time and can relate to imaginary events that never exist anywhere, i.e. his thinking is abstract-logical, in contrast to the concrete-figurative thinking of animals;
  • * a person has a cognitive ability based on penetration into the structure of the world and the construction of models of the world;
  • * a person can both comply with existing moral standards of behavior and destroy and self-destruct;
  • * only man has self-awareness and self-reflection, manifested in the ability to contemplate one’s own existence and be aware of death.
• 7. Man, unlike animals, does not inherit forms of activity along with the structural and anatomical organization of the body. Forms of activity are transmitted to him indirectly, through the forms of objects created by human labor. In addition, as we have already said, a person knows how to make tools and is capable of long-term concentration of attention, which is necessary for work activity.