Evidence of the origin of man from animals.

1. Scientific substantiation by Charles Darwin of the idea of ​​the origin of man from animals based on the establishment of the similarity of man with mammals, especially with apes. C. Darwin's statement that modern apes cannot be the ancestors of humans.
2. Evidence of the origin of man from animals: comparative anatomical, embryological, paleontological.
3. Comparative anatomical evidence of the origin of man from mammals: man has all the characteristics of the class of mammals and belongs to this class, has a similar structure of all organ systems, has a diaphragm, mammary glands, auricles, etc. The presence of rudiments in humans (developed in mammals, but atrophied organs in humans): the coccyx, the appendix, the remainder of the third eyelid (about 90 rudiments in total) - proof of the relationship between man and animals. Cases of the birth of children with characteristics of mammals - atavisms (return to ancestors): with thick body hair, with a large number of nipples, with an elongated caudal spine - evidence of human origin from animals.
4. Embryological evidence of the origin of humans from animals: similarities in the development of human and animal embryos, development begins with one fertilized cell, at a certain stage gill slits are formed in the human embryo, the caudal spine is developed, the brain of a one-month embryo is similar to the brain of a fish, and a seven-month embryo is similar to the brain of a fish. with a monkey brain, etc.
5. The similarity of the structure, life activity, behavior of humans and apes. Monkeys express feelings of joy, anger, sadness, care for young, good memory, developed higher nervous activity, use of objects as tools, diseases similar to humans.

6. Paleontological evidence - finds of fossil remains of human ancestors, the similarity of their structure with modern humans and apes - evidence of their relationship, as well as the development of human ancestors and modern apes in different directions: along the path of increasing formation of human traits in human ancestors and narrow specialization of great apes to live in certain conditions, to a certain way of life.

The influence of the environment on the emergence of man .

During the life of Dryopithecus, a significant part of the land was affected by climate change: tropical jungles disappeared and were replaced by spaces devoid of forests. This circumstance could not but affect the way of life of animals. Some retreated under the cover of the disappearing forest, others tried to adapt to life in the open area. This is how life forced Dryopithecus “to descend from the trees to the ground.”

It must be said that meat food played a very important role in the development of the human mind. The life of plant-eating apes (for example, gorillas) is an almost continuous process of obtaining food. To get enough, a gorilla needs to absorb a huge amount of food. Animals are busy with this from morning to evening. Meat food saves much more “free time” compared to vegetarian food.

One of the results (it must be said, rather sad) of human preference for meat food was cannibalism (cannibalism), which persisted throughout almost the entire history of mankind. At an ancient Homo sapiens site excavated by archaeologists on the island of Java, for example, 11 skulls with broken bases were found that belonged to representatives of the Homo erectus species. This is evidence of cannibalism. This is how it turns out that the relationships between representatives of various species of the genus Homo developed. (However, it should be noted that more often ancient people ate representatives of their own species, and not other species of the genus Homo.)

But Neanderthals, Pithecanthropus and representatives of other species and subspecies of this genus, too, apparently, were far from harmless. Perhaps the ideas of wild, shaggy cannibals living in the forest, living in the folklore of many peoples, are a faint echo of those distant battles.

Hominid evolution

One of the main problems that immediately confronted scientists was the identification of the line of primates that gave rise to hominids. Throughout the 19th century. Several hypotheses have been put forward in this regard. Some of them rejected the idea that humans are closely related to living apes and linked the origin of the hominid line with one or another more primitive primate. Others, on the contrary, suggested that humans, chimpanzees and gorilla are closely related, having descended from a common ancestor - a species that existed for a significant period of time before it split into three modern forms. These disagreements highlighted a fundamental problem: how to develop acceptable criteria for recognizing organisms that were a step or steps in the development of hominids, and how to identify such steps from the entire body of data on ancient primates.

Hominids have a number of differences at the anatomical and biomolecular level that allow them to be given a special place among primates. Some of these differences are primary, while others are secondary, i.e. arose as an adaptation to the conditions created as a result of the appearance of primary differences.

Locomotion 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.” Although some apes, such as baboons, have adapted to a terrestrial existence, they nevertheless move on all fours. And apes, particularly gorillas, which primarily live on the ground, walk in a characteristic partially straightened position, often leaning on their hands.

The vertical position of the human body, of course, turned out to be associated with many secondary adaptive changes. These include changes in the proportions of the arms and legs, modifications to the foot, sacroiliac joint and spinal curves, and the connection of the head to the spinal column.

Brain enlargement. The next primary difference that puts humans in a special position in relation to other primates is their extremely enlarged brain. Compared, for example, to the average size of a chimpanzee's brain, the modern human brain is three times larger; even Homo habilis, the first of the hominids, it was twice as large as that of chimpanzees. However, size is not the only feature of the human brain: its various areas have undergone specialized development, the number of nerve cells has increased and their arrangement has changed. These, as well as some other modifications, endowed the human brain with its increased capabilities. Unfortunately, fossil skulls do not provide sufficient comparative material to evaluate many of these structural changes. Unlike other traits noted above as adaptive to upright posture, brain enlargement does not have a direct connection with it, although an indirect relationship between upright posture and brain development is quite likely.

Structure of teeth. The third of the basic changes concerns the structure of teeth and their use. The transformations that have occurred are usually associated with changes in the way ancient humans fed. If their cause can still be discussed, then the nature of the changes is firmly established. 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 results are not yet indisputable. The methods used include the following: 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 assess the closeness of relationship by the degree of matching of paired bases in double strands formed by DNA strands 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, for example hemoglobin, 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, and, moreover, to calculate over what time such changes could occur, and thereby assess the degree of relatedness of the species being compared and how long ago they separated.

These methods have shown the very close relationship and, therefore, relatively recent separation in the course of evolution of such species 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%.

Biological, social and labor factors of human evolution

Anthropogenesis is the process of historical and evolutionary formation of man, which is carried out under the influence of biological and social factors.

Biological factors, or the driving forces of evolution, are common to all living nature, including humans. These include hereditary variability and natural selection.

The role of biological factors in human evolution was revealed by Charles Darwin. These factors played a big role in human evolution, especially in the early stages of its formation.

A person experiences hereditary changes that determine, for example, hair and eye color, height, and resistance to environmental factors. In the early stages of evolution, when man was heavily dependent on nature, individuals with hereditary changes that were useful in given environmental conditions (for example, individuals distinguished by endurance, physical strength, dexterity, and intelligence) predominantly survived and left offspring.

Social factors of anthropogenesis include labor, social lifestyle, developed consciousness and speech. The role of social factors in anthropogenesis was revealed by F. Engels in his work “The Role of Labor in the Process of Transformation of Ape into Man” (1896). These factors played a leading role in the later stages of human development.

The most important factor in human evolution is labor. The ability to make tools is unique to humans. Animals can only use individual objects to obtain food (for example, a monkey uses a stick to get a treat).

Labor activity contributed to the consolidation of morphological and physiological changes in human ancestors, which are called anthropomorphoses.

An important anthropomorphosis in human evolution was upright walking. Over many generations, as a result of natural selection, individuals with hereditary changes favoring upright walking were preserved. Adaptations for upright walking gradually developed: an S-shaped spine, an arched foot, a wide pelvis and chest, and massive bones of the lower extremities.

Walking upright resulted in the release of the arm. At first, the hand could only perform primitive movements. In the process of work, she improved and began to perform complex actions. Thus, the hand is not only an organ of labor, but also its product. The developed hand allowed man to make primitive tools. This gave him significant advantages in the struggle for existence.

Joint work activity contributed to the unity of team members and necessitated the exchange of sound signals. Communication contributed to the development of the second signaling system - communication using words. At first, our ancestors exchanged gestures and individual inarticulate sounds. As a result of mutations and natural selection, the oral apparatus and larynx were transformed, and speech was formed.

Work and speech influenced the development of the brain and thinking. Thus, over a long period of time, as a result of the interaction of biological and social factors, human evolution took place.

If the morphological and physiological characteristics of a person are inherited, then the ability to work, speech and thinking develop only in the process of upbringing and education. Therefore, with prolonged isolation of a child, his speech, thinking, and adaptability to life in society do not develop at all or develop very poorly.

Ancient and Ancient People

The most ancient people lived 2 million - 500 thousand years ago.

Pithecanthropus - "ape-man". The remains were discovered

first on o. Java in 1891 by E. Dubois, and then in a number of other places.

Pithecanthropus walked on two legs, their brain volume increased, they

used primitive tools in the form of clubs and lightly hewn

stones. Low forehead, powerful brow ridges, half-bent body with abundant

hair - all this pointed to their recent (monkey) past.

cave near Beijing, is in many ways similar to Pithecanthropus, it is geographical

variant of Homo erectus. Sinanthropus already knew how to maintain a fire. The main factor in the evolution of ancient people was natural selection.

Ancient people characterize the next stage of anthropogenesis,

when social factors begin to play a role in evolution: labor

activities in the groups in which they lived, a joint struggle for life and

development of intelligence. These include Neanderthals, whose remains were

found in Europe, Asia, Africa. They got their name from the place

the first find in the river valley. Neander (Germany). Neanderthals lived during the Ice Age

era 200 - 35 thousand years ago in caves where fire was constantly maintained,

dressed in skins. Neanderthal tools are much more advanced and have

some specialization: knives, scrapers, percussion tools. More artificial and have

some specialization: knives, scrapers, percussion tools. Real name

they received at the place of the first discovery in the river valley. Neander (Germany). jaws

evidenced articulate speech. Neanderthals lived in groups of 50

- 100 people. Men hunted collectively, women and children gathered

edible roots and fruits, old people made tools. Latest

Neanderthals lived among the first modern humans, and were then eventually

completely repressed. Some scientists consider Neanderthals a dead end

branch of hominid evolution that did not participate in the formation of modern

person.

The emergence of modern physical people

type happened relatively recently, about 50 thousand years ago. Their remains

found in Europe, Asia, Africa and Australia. In the Cro-Magnon Grotto (France)

several fossil skeletons of modern people were discovered

type, which were called Cro-Magnons. They had the whole package

physical features that characterize. They had everything

a complex of physical features that is characteristically articulate

speech, as indicated by the developed chin protuberance; housing construction,

the first beginnings of art (rock paintings), clothing decoration,

perfect bone and stone tools, the first domesticated animals -

everything indicates that this is a real person, definitively

separated from his beast-like ancestors. Neanderthals, Cro-Magnons and

modern people form one species - Homo sapiens - Homo sapiens; this

the species formed no later than 100–40 thousand years ago.

Social factors were of great importance in the evolution of Cro-Magnons.

factors, the role of education and the transfer of experience has grown immeasurably.

The position of man in the animal world

Anthropology is the science of human origins.

2. Fill out the table

Development of views on human origins

3. What is the main evidence for the origin of humans from animals?
Data from comparative anatomy and embryology show similarities in the body structure and development of humans and animals.
Traits inherent in chordates:
In humans, in the early stages of development, the internal skeleton is represented by a notochord, the neural tube is laid on the dorsal side, and the body has bilateral symmetry. Next, the notochord is replaced by the spinal column, the skull and five sections of the brain are formed. The heart is on the ventral side of the body, there is a skeleton of paired free limbs.
Traits inherent in the class Mammals:
There are five sections of the spine, the skin is covered with hair, there are sweat and sebaceous glands. Feeding children with milk, four-chambered heart, warm-bloodedness, diaphragm.
Traits inherent to Placentals:
Carrying a fetus inside the body, feeding the fetus through the placenta.
The main features of the order Primates:
The structure of the limbs, nails, eyes in one plane, replacement of milk teeth with permanent ones.
Similar features to great apes. The presence of atavisms (features of ancestral forms that appeared in individual individuals of a given species) - this is a tail, multiple nipples, abundant hair, etc. and rudiments (organs or parts of the body that have lost their original functions in the process of evolution and are present in all individuals of a given biological species) – this is the appendix, wisdom teeth, etc.

4. Describe the position of man in the system of the organic world.
Kingdom Animals, Subkingdom Multicellular, phylum Chordata, subtype Vertebrates, class Mammals, subclass Placentals, order Primates, suborder Apes, family People (Hominids), genus Homo, species Homo sapiens, Subspecies Homo sapiens sapiens.

5. Make a table.

Similarities and differences between humans and apes.

1. Define the concept.
Anthropogenesis- part of the biological evolution that led to the emergence of Homo sapiens, which separated from other hominids, apes and placental mammals; the process of historical and evolutionary formation of a person’s physical type, the initial development of his work activity, speech.

2. What concept underlies modern scientific ideas about human origins?
The basis of modern ideas about the origin of man is the concept according to which man emerged from the animal world, and the first scientific evidence in favor of this concept was presented by Charles Darwin in his work “The Descent of Man and Sexual Selection” (1871). Scientists believe that the evolutionary line of hominids begins from some group of Dryopithecus (an extinct group of great apes).

3. What paleontological finds allow us to identify the main stages and directions of the historical development of humans and apes?
Analysis of paleontological finds allows us to identify the main stages and directions of the historical development of humans and great apes. These include the remains of Australopithecus archanthropus (Pithecanthropus, Sinanthropus), paleoanthropus (Neanderthal), Cro-Magnon man, their tools and rock paintings. That is, humans and modern apes had a common ancestor. Further, their evolutionary development followed the path of divergence (divergence of characteristics, accumulation of differences) in connection with adaptation to specific and different conditions of existence.

4. Why can’t we say that man descended from the ape?
The development of humans and apes is not sequential steps, but parallel branches of evolution, the divergence between which in evolutionary terms is very deep. That is, humans and modern apes had a common ancestor. Further, their evolutionary development followed the path of divergence (divergence of characteristics, accumulation of differences) in connection with adaptation to specific and different conditions of existence.

5. Fill out the table.

Main stages of anthropogenesis

Driving forces of anthropogenesis

1. Define the concept.
Social evolution- a process of structural reorganization over time, as a result of which a social form or structure emerges that is qualitatively different from the previous form.

2. Make a diagram.

Factors of anthropogenesis.

3. What is the role of biological and social factors in anthropogenesis?
In anthropogenesis, an important role is played not only by biological factors (variability, heredity, selection), but also by social ones (speech, accumulated experience of work and social behavior). Human characteristics, determined by social factors, are not fixed genetically and are not inherited, but in the process of upbringing and training. In the first stages of evolution, selection for greater adaptability to rapidly changing circumstances was of decisive importance. However, subsequently, the ability to transmit genetic acquisitions from generation to generation in the form of various scientific, technical and cultural information began to play an increasingly important role, freeing humans from the strict control of natural selection. Social patterns have become of great importance in human evolution. The winners in the struggle for existence were not necessarily the strongest, but those who preserved the weak: children - the future of the population, old people - keepers of information about ways to survive. The victory of populations in the struggle for existence was ensured not only by strength and intelligence, but also by the ability to sacrifice themselves in the name of the tribe. Man is a social being, the distinctive feature of which is consciousness, formed on the basis of collective labor.
In the evolution of Homo sapiens, social relationships play an ever-increasing role. For modern people, social-labor relations have become leading and determining. This is the qualitative uniqueness of human evolution.

4. What modern problems of human society can you name?
People are increasingly using surrogates and imitations of natural biological activity, going so far as to “virtualize” life. The human population is characterized by phenomena that are impossible for animal populations. The human population accumulates the genetic load of hereditary diseases, predisposition to diseases, malignant neoplasms, infections, mental and allergic disorders, maladjustment phenomena, etc. Residents of large cities experience overcrowding stress phenomena. Many people maintain their existence and functionality only with the help of artificial devices and medications.
Rapid population growth creates economic problems and increases social inequality among people. There is a growing gap between the maximum opportunities for obtaining benefits and their accessibility for the majority of people. Different people have very unequal life chances.
Products are stimulated and produced that are not only unnecessary for human life, but also cause harm (alcohol, tobacco, drugs).
All these factors as a whole can ultimately lead to a crisis of modern human civilization, degradation and extinction of Homo sapiens as a species.

5. What factors contributed to the development of upright walking in humans?
There are a number of hypotheses regarding the development of upright walking in humans. The appearance of an S-shaped spine, an arched foot, an expanded pelvis, and a strong sacrum in human ancestors are hereditary changes that contributed to upright walking.
According to Jan Lindblad's hypothesis, the ape-like ancestors of humans were forced to rise on their hind limbs when searching for food in the water and when wading through water obstacles. Also, due to climate and flora changes, human ancestors were forced to get down from the trees to the ground. To search for food in the tall grass, they had to stand up from all fours onto their hind limbs.

6. What advantages and what problems, including health problems, have people experienced due to upright walking?
Individuals capable of walking on their hind limbs found themselves in a more advantageous position. The horizons expanded, hands were freed, with the help of which human ancestors were able to use improvised means - sticks and stones, and subsequently - to make the tools themselves.
The disadvantages of upright walking include loss of speed, greater load on the legs and spine. Also, there was an incorrect distribution of blood volume between the lower and upper halves of the body. In this case, the lower extremities are constantly in a state of hypertension, while the upper extremities are in hypotension.
The vertical position of the human body leads to indigestion and back pain, varicose veins and other disorders of its vital functions. The same reason makes pregnancy and childbirth extremely difficult and delays.

7. Is it possible to say that the biological evolution of modern man has completely stopped?
Evolution- a continuous process, therefore, even for the species Homo sapiens, it did not stop. Evolution has moved to another level. A person adapts to new living conditions, physical labor becomes less important and widespread. Due to the weakening of biological factors and the increase in social factors, a person will be subject to changes, both external and internal, what exactly is a matter of time, the answer to which scientists are already looking for today.

Origin of human races

1. Give definitions of concepts.
Human races– historically established groupings of people within the species Homo sapiens sapiens, characterized by similar morphological and physiological traits.
Racism– anti-scientific ideology about the inequality of human races.

2. Look at the drawing “Races of Man.” Label it with the names of the races you know.
Australian-Negroid, Caucasoid, Mongoloid.

3. What hypotheses of raceogenesis do you know?
Raceogenesis is the process of the emergence and formation of human races. There are several hypotheses of raceogenesis.
The first is monocentrism. Scientists recognize a common origin, socio-psychological development, and a single level of mental development. Evidence of the monocentric hypothesis transfers it to the category of theories (hypothesis + evidence):
differences in secondary characteristics;
there is no genetic isolation;
biological evolutionary changes (decrease in skeletal mass, increase in height, acceleration of development) appear in representatives of all races;
results obtained from studying human DNA: the first was the division of the African branch into Negroid and Mongoloid-Caucasian about 40-100 thousand years ago.
Polycentricists believe that races arose independently from different ancestors and in different places. Their hypothesis is less scientifically substantiated.

4. What are the main factors of raceogenesis?
Natural selection;
Mutations;
Insulation;
Mixing of populations.
As humans populated the globe, faced with new environmental conditions, adapted individuals survived and gave birth to offspring. The morphological characteristics formed during biological evolution are explained:
the nature of the environment;
climate;
food resources;
amount of sunlight.

5. Fill out the table.

Human races

6. What arguments can be made to criticize racist theories?
People of all races are characterized by specific characteristics:
similarity in body structure (structure of the skull, brain, internal organs);
physiological similarity (blood types, diseases, defense reactions);
the possibility of unlimited crossing, which results in fertile offspring;
all are of the same origin.
It is impossible to accurately determine a person’s race based on a person’s genes, therefore, in the genetic sense, races do not exist (only traits, dominant and recessive, different norms of behavior). Racial differences are the result of people's adaptation to certain conditions of existence, as well as the historical and socio-economic development of human society.

The evidence for the animal origin of man is based on evidence for the evolution of the organic world.

I. Paleontological evidence

1. Fossil forms.

2. Transitional forms.

3. Phylogenetic series.

Paleontological finds make it possible to restore the appearance of extinct animals, their structure, similarities and differences with modern species. This makes it possible to trace the development of the organic world over time. For example, in ancient geological strata the remains of only representatives of invertebrates were found, in later ones - chordates, and in young sediments - animals similar to modern ones.

Paleontological finds confirm the existence of continuity between various systematic groups. In some cases, it was possible to find fossil forms (for example, Sinanthropus), in others, transitional forms, combining the characteristics of ancient and historically younger representatives.

In anthropology, such forms are: dryopithecines, australopithecines, etc.

In the animal world, such forms are: Archeopteryx - a transitional form between reptiles and birds; inostracevia - a transitional form between reptiles and mammals; psilophytes - between algae and land plants.

Based on such finds, it is possible to establish phylogenetic (paleontological) series - forms that successively replace each other in the process of evolution.

Thus, paleontological finds clearly indicate that as we move from more ancient earth layers to modern ones, there is a gradual increase in the level of organization of animals and plants, bringing them closer to modern ones.

II. Biogeographical evidence

1. Comparison of species composition with the history of territories.

2. Island forms.

3. Relics.

Biogeography studies the patterns of distribution of plant (flora) and animal (fauna) worlds on Earth.

It has been established: the earlier the isolation of individual parts of the planet occurred, the greater the differences between the organisms inhabiting these territories - island forms.

Thus, the fauna of Australia is very peculiar: many Eurasid animal groups are absent here, but those that are not found in other regions of the Earth have been preserved, for example, oviparous marsupial mammals (platypus, kangaroo, etc.). At the same time, the fauna of some islands is similar to the mainland (for example, the British Isles, Sakhalin), which indicates their recent isolation from the continent. Consequently, the distribution of animal and plant species on the surface of the planet reflects the process of the historical development of the Earth and the evolution of living things.

Relics are living species with a complex of characteristics characteristic of long-extinct groups of past eras. Relict forms indicate the flora and fauna of the Earth's distant past.

Examples of relict forms are:

1. Hatteria is a reptile native to New Zealand. This species is the only living representative of the Proto-Lizard subclass in the Reptile class.

2. Coelacanth (coelocanthus) is a lobe-finned fish that lives in deep-sea areas off the coast of East Africa. The only representative of the lobe-finned fish order, closest to terrestrial vertebrates.

3. Ginkgo biloba is a relict plant. Currently common in China and Japan only as an ornamental plant. The appearance of ginkgo allows us to imagine tree forms that became extinct in the Jurassic period.

In anthropology, a relict hominid means the mythological “Bigfoot”.

III. Comparative embryological

1. K. Baer’s law of germinal similarity.

2. Haeckel-Müller biogenetic law.

3. The principle of recapitulation.

Embryology is a science that studies the embryonic development of organisms. Data from comparative embryology indicate similarities in the embryonic development of all vertebrates.

Karl Baer's law of germline similarity(1828) (Darwin gave this name to the law), indicates a common origin: embryos of different systematic groups are much more similar to each other than adult forms of the same species.

In the process of ontogenesis, the characteristics of the type appear first, then the class, the order, and the last to appear are the characteristics of the species.

Main provisions of the law:

1) In embryonic development, embryos of animals of the same type successively go through stages - zygote, blastula, hastrula, histogenesis, organogenesis;

2) embryos in their development move from

more general characteristics to more specific ones;

3) embryos of different species gradually separate from each other, acquiring individual characteristics.

German scientists F. Müller (1864) and E. Haeckel (1866) independently formulated a biogenetic law, which was called the Haeckel-Müller Law: the embryo in the process of individual development (ontogenesis) briefly repeats the history of the development of the species (phylogeny).

The repetition of structures characteristic of ancestors in the embryogenesis of descendants was called - recapitulations.

Examples of recapitulation are: notochord, five pairs of nipples, a large number of hair buds, cartilaginous spine, gill arches, 6-7 finger buds, general stages of intestinal development, the presence of a cloaca, the unity of the digestive and respiratory systems, phylogenetic development of the heart and main vessels, gill slits , all stages of development of the intestinal tube, recapitulation in the development of the kidney (prerenal, primary, secondary), undifferentiated gonads, gonads in the abdominal cavity, paired Müllerian canal from which the oviduct, uterus, vagina is formed; main stages of phylogenesis of the nervous system (three brain vesicles).

Not only morphological characteristics recapitulate, but also biochemical and physiological ones - the release of ammonia by the embryo, and in the later stages of development - uric acid.

According to comparative embryological data, in the early stages of embryonic development, the human embryo develops signs characteristic of the Chordata type, later the characters of the Vertebrates subtype are formed, then the Mammals class, the Placental subclass, and the Primates order.

IV. Comparative anatomical

1. General plan of the body structure.

2. Homologous organs.

3. Rudiments and atavisms.

Comparative anatomy studies the similarities and differences in the structure of organisms. The first convincing proof of the unity of the organic world was the creation of the cell theory.

Unified building plan: all chordates are characterized by the presence of an axial skeleton - the notochord; above the notochord there is a neural tube, under the notochord there is a digestive tube, and on the ventral side there is a central blood vessel.

Availability homologous organs - organs that have a common origin and a similar structure, but perform different functions.

Homologous are the forelimbs of a mole and a frog, the wings of birds, the flippers of seals, the forelegs of a horse and human hands.

In humans, like in all chordates, organs and organ systems have a similar structure and perform similar functions. Like all mammals, humans have a left aortic arch, a constant body temperature, a diaphragm, etc.

Organs that have different structures and origins, but perform the same functions are called similar(eg butterfly and bird wings). To establish the relationship between organisms and prove evolution, similar organs are not important.

Rudiments- undeveloped organs that, during the process of evolution, lost their significance, but were present in our ancestors. The presence of rudiments can only be explained

the fact that in our ancestors these organs functioned and were well developed, but during the process of evolution they lost their importance.

In humans, there are about 100 of them: wisdom teeth, poorly developed hair, muscles that move the auricle, tailbone, auricles, appendix, male uterus, muscles that raise the hair; rudiments of vocal sacs in the larynx; brow ridges; 12-pair of ribs; wisdom teeth, epicanthus, variable number of coccygeal vertebrae, brachiocephalic trunk.

Many rudiments exist only in the embryonic period and then disappear.

The rudiments are characterized by variability: from complete absence to significant development, which is of practical importance for the doctor, especially the surgeon.

Atavisms- manifestation in descendants of characteristics characteristic of distant ancestors. Unlike rudiments, they are deviations from the norm.

Possible reasons for the formation of atavisms: mutations of regulatory genes of morphogenesis.

There are three types of atavisms:

1) underdevelopment of organs when they were at the stage of recapitulation - three-chamber heart, “cleft palate”;

2) preservation and further development of recapitulation characteristic of ancestors - preservation of the right aortic arch;

3) violation of the movement of organs in ontogenesis - the heart in the cervical region, undescended testicles.

Atavisms can be neutral: strong protrusion of the fangs, strong development of the muscles that move the auricle; and can manifest themselves in the form of developmental anomalies or deformities: hypertrichosis (increased hairiness), cervical fistula, diaphragmatic hernia, patent ductus botallus, hole in the interventricular septum. Polynipple, polymastia - an increase in the number of mammary glands, non-fusion of the spinous processes of the vertebrae (spina bifida), caudal spine, polydactyly, flat feet, narrow chest, clubfoot, high scapula, non-fusion of the hard palate - “cleft palate”, atavisms of the dental system, bifurcated tongue, neck fistulas, shortening of the intestine, preservation of the cloaca (common opening for the rectum and genitourinary opening), fistulas between the esophagus and trachea, underdevelopment and even aplasia of the diaphragm, two-chambered heart, heart septal defects, preservation of both arches, preservation of the ductus bollus, transposition vessels (the left arch departs from the right ventricle, and the right aortic arch departs from the left ventricle), pelvic location of the kidney, hermaphroditism, cryptorchidism, bicornuate uterus, uterine duplication, undeveloped cerebral cortex (proencephaly), agyria (absence of brain convolutions).

Comparative anatomical study of organisms made it possible to identify modern transitional forms. For example, the first animals (echidna, platypus) have a cloaca, lay eggs like reptiles, but feed their young with milk like mammals. The study of transitional forms makes it possible to establish kinship between representatives of different systematic groups.

V. Molecular genetic evidence

1. The universality of the genetic code.

2. Similarity to proteins and nucleotide sequences.

Similarities between humans and apes (similarities between pongids and hominids) There is much evidence of the relationship between humans and modern apes. Humans are closest to gorilla and chimpanzee

I. General anatomical features

Humans and gorilla have 385 common anatomical features, humans and chimpanzees have 369, humans and orangutans have 359: - binocular vision, progressive development of vision and touch with weakening of the sense of smell, development of facial muscles, grasping type limbs, opposition of the thumb to the rest, reduction caudal spine, the presence of an appendix, a large number of convolutions in the cerebral hemispheres, the presence of papillary patterns on the fingers, palms and soles, fingernails, developed collarbones, a wide flat chest, nails instead of claws, a shoulder joint that allows movement with a range of up to 180° .

II Similarity of karyotypes

■ All great apes have a diploid chromosome number of 2/n = 48. In humans, 2n = 46.

It has now been established that the 2nd pair of human chromosomes is a product of the fusion of two monkey chromosomes (interchromosomal aberration - translocation).

■ Homology of 13 pairs of chromosomes between pongidae and humans has been revealed, which is manifested in the same pattern of chromosome striations (the same arrangement of genes).

■ The cross-striation of all chromosomes is very similar. The percentage of gene similarity in humans and chimpanzees reaches 91, and in humans and apes it reaches 66.

■ Analysis of the amino acid sequences in human and chimpanzee proteins shows that they are 99% identical.

III. Morphological similarities

The structure of proteins is similar: for example, hemoglobin. The blood groups of gorillas and chimpanzees are very close to the ABO system group of apes and humans, the blood of the pygmy chimpanzee Bonobos corresponding to humans.

The Rh factor antigen has been found in both humans and the lower ape, the rhesus macaque.

Similarities are observed in the course of various diseases, which is especially valuable in biological and medical research.

The similarity is based on Vavilov’s law of homologous series. In experiments, diseases such as syphilis, typhoid fever, cholera, tuberculosis, etc. were obtained in apes.

Apes are close to humans in terms of the duration of pregnancy, limited fertility, and timing of puberty.

Differences between humans and apes

1. The most characteristic feature that distinguishes humans from apes is the progressive development of the brain. In addition to its greater mass, the human brain has other important features:

The frontal and parietal lobes are more developed, where the most important centers of mental activity and speech are concentrated (the second signaling system);

The number of small furrows has significantly increased;

A significant part of the human cerebral cortex is associated with speech. New properties have emerged - sound and written language, abstract thinking.

2. Upright walking (bipedia) with a heel-to-toe position and work activity required the restructuring of many organs.

Humans are the only modern mammals that walk on two limbs. Some monkeys are also capable of walking upright, but only for a short time.

Adaptations to bipedal locomotion.

The more or less straightened position of the body and the transfer of the center also mainly to the hind limbs dramatically changed the relationship between all of us in the animal:

The chest became wider and shorter,

The spinal column gradually lost its arch shape, characteristic of all animals that move on four legs, and acquired a 3-shaped shape, which gave it flexibility (two lordosis and two kyphosis),

Displacement of the foramen magnum,

The pelvis is expanded, as it takes on the pressure of the internal organs, the chest is flattened, at more powerful lower limbs (bones and muscles of the lower limb (the femur can withstand a load of up to 1650 kg), arched foot (unlike the flat foot of monkeys),

Inactive first toe

The upper limbs, which ceased to function as supports when moving, became shorter and less massive. They began to make various movements. This turned out to be very useful, as it made it easier to get food.

3. Complex of the “labor hand” -

The muscles of the thumb are better developed,

Increased mobility and strength of the hand,

High degree of opposition of the thumb on the hand,

The parts of the brain that provide fine movements of the hand are well developed.

4. Changes in the structure of the skull are associated with the formation of consciousness and the development of the second signaling system.

In the skull, the brain section predominates over the facial section,

The brow ridges are less developed,

Reduced mass of the lower jaw,

The profile of the face is straightened,

Small size of teeth (especially canines compared to animals),

It is typical for humans to have a chin protuberance on the lower jaw.

5. Speech function

Development of cartilage and ligaments of the larynx,

The chin protrusion is pronounced. The formation of the chin is associated with the emergence of speech and concomitant changes in the bones of the facial skull.

The development of speech became possible thanks to the development of two parts of the nervous system: Broca's area, which made it possible to quickly and relatively accurately describe accumulated experience with ordered sets of words, and Wernicke's area, which allows us to just as quickly understand and adopt this experience conveyed by speech - the result of which was the acceleration of verbal exchange of information and simplifying the acquisition of new concepts.

6. A person has experienced hair reduction.

7. The fundamental difference between Homo sapiens and all animals is the ability to purposefully manufacture tools of labor (purposeful labor activity), which allows modern man to move from subjugating nature to intelligently managing it.

Signs such as:

1- upright posture (bipedia),

2- hand adapted to work and

3- highly developed brain - called the hominid triad. It was in the direction of its formation that the evolution of the human hominid line went.

All of the above examples indicate that, despite the presence of a number of similar characteristics, a person is significantly different from co temporary monkeys.

People have always been more interested in their own ancestry than the origin of plants and animals. Attempts to understand and explain how man arose are reflected in the beliefs, legends, and tales of various tribes and peoples. In solving this problem, the struggle between materialistic and idealistic views is especially acute. For a long time, scientific knowledge was too fragmentary and incomplete to solve the problem of human origins. Only in 1857 Charles Darwin expressed a hypothesis, and in 1871, in his work “The Descent of Man and Sexual Selection,” he convincingly proved that people descended from monkeys, and were not created by an act of divine creation, as the church teaches. “If we do not deliberately close our eyes, then with the modern level of knowledge we will be able to approximately recognize our ancestors, and we have no need to be ashamed of them,” wrote Charles Darwin. The role of social factors, which Charles Darwin also pointed out, was revealed by F. Engels in his work “The Role of Labor in the Process of Transformation of Ape into Man” (1896). By the 80s of our century, numerous fossil finds and the use of a wide variety of research methods made it possible to significantly clarify the questions of the evolution of apes, although even now it is impossible to say with complete certainty from which ape-like ancestors man descended.

The commonality of humans and vertebrates is confirmed by the commonality of their structure: skeleton, nervous system, circulatory, respiratory, and digestive systems. 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. All these rudiments are useless for humans and are the heritage of animal ancestors. 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.

The commonality of the structural plan, the similarity of embryonic development, rudiments, atavisms are indisputable evidence of the animal origin of man and evidence that man, like animals, is the result of a long historical development of the organic world.

A thorough study of the higher nervous activity of great apes has revealed the closeness of these animals to humans in a number of their behavioral reactions. In this regard, their ability to use various objects as simple tools is especially indicative. Man is closest to the African apes - the gorilla and especially the chimpanzee. The DNA of humans and chimpanzees contains at least 90% of similar genes. The study of all the structural and developmental features shows that man belongs to the Hominids family of the order Primates of the Mammals class. However, there are fundamental differences between humans and apes. Only humans have true upright walking and the associated structural features of an S-shaped spine with distinct cervical and lumbar curves, a low expanded pelvis, a chest flattened in the anteroposterior direction, proportions of the limbs (lengthening of the legs compared to the arms), an arched foot with a massive and adducted thumb, as well as features of the muscles and location of internal organs. The human hand is capable of performing a wide variety of highly precise movements. The human skull is higher and rounded, and does not have continuous brow ridges; the cerebral part of the skull predominates to a greater extent over the facial part, the forehead is high, the jaws are weak, with small fangs, the chin protrusion is clearly defined. The human brain is approximately 2.5 times larger than the brain of apes in volume and surface area, 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; therefore, they are characterized by the development of the frontal, parietal and temporal lobes of the brain, the presence of a special brain muscle in the larynx and other anatomical features.

Evidence of human origin from animals

Lesson-lecture (11th grade, 2 hours)

Lesson objectives: show the relationship between humans and animals based on comparison; explain the qualitative difference between humans and animals; bring to the conclusion that man was formed under the influence of biological and social factors of evolution; show how the theory of evolution explains the processes of formation of characteristics of the species Homo sapiens; develop the ability to critically examine facts and theories.

Equipment: figures, tables indicated in the lecture; models of the brain of different classes of chordates: fish, amphibians, reptiles, birds, mammals; human skeleton; table “Evolution of the circulatory system of chordates”; voluminous table “Development of vertebrate embryos”.

DURING THE CLASSES

I. Introduction

As we begin to study the extremely interesting section “The Origin of Man,” I would like to offer you a comparative assessment of the time during which man lives on Earth and the duration of some important periods in the history of the Earth. If we take the age of our planet to be equal to one year, then in such a calendar one day will be 12.3 million years, and one hour will be 525 thousand years. Then the history of the Earth and humanity can be presented in the form of the following table.

According to this scale, a person appeared less than 6 hours before the New Year, and the average life expectancy of a person in our time is half a second. As the Persian philosopher and poet O. Khayyam said:

I came - the sky did not add beauty,
I left - the skies will bloom the same way...

What is the origin of man, how did he appear on Earth? There are many opinions on this matter. The accumulation of scientific data, especially in recent years, when the genomes of humans and many other organisms have been deciphered, has made it possible to construct and substantiate the theory of the origin of humans from animals. Today we will look at the evidence for the origin of humans from animals that underlies this theory.

II. Learning new material

Lecture outline

1. Features of the human body.
2. Evidence of kinship with animals:

a) skull, jaws, teeth;
b) skin;
c) nerves and sensory organs;
d) brain;
e) lungs, blood circulation, kidneys;
f) reproduction and embryonic development.

3. Defects of the human body.
4. Similarities and differences between humans and apes.
5. Charles Darwin on the origin of man.

Based on morphophysiological characteristics, one can determine the position of a person in the system of living nature. These conclusions are supported by data from genetic studies.

Features of the human body

The body of Homo sapiens is built from the same basic chemical elements as the body of any other living creature, i.e. from carbon, hydrogen, oxygen, nitrogen and phosphorus. We differ from other mammals only in the structure and functioning of cells, tissues and organ systems.

The human body has four important features, the combination of which is unique to it: an erect skeleton, movable arms capable of manipulating objects, three-dimensional color vision and a uniquely complex brain.

The erect skeleton allows us, unlike other animals, to move on two legs. Without feeling the need to lean on our forelimbs, we use our flexible and sensitive fingers to explore the surface of objects (Fig. 1).

Forward-looking eyes provide binocular vision and allow us to accurately focus images, determine distance, and distinguish not only color, but also shape. We can follow the movement of an object without turning our heads - using only eye movements.

Compared to other animals, the human brain is very large relative to body size. Thanks to him, a person has excellent abilities for learning, logical thinking, and speech control; coordination of vision and hand movements.

(The teacher explains the drawings on the board. Some of their students transferred to notebook.)

Evidence of animal kinship

Comparative Anatomy Data

The similarity in the body structure of humans and some modern and extinct animals lies the key to resolving the question of their common ancestors.

The body of early worm-like human ancestors acquired bilateral symmetry: each side was a mirror image of the other. This made it easier to move forward, turn in one direction or another, and maintain the correct course of movement. The pairing of our limbs, ears and nostrils is a consequence of this body structure.

A. Skull, jaws and teeth

Our skull, jaws and teeth have different and complex origins.

B. Leather

Our skin is waterproof, like that of reptiles, but from the horny scales that covered the bodies of reptiles, we only have nails - flattened shields on the fingers and toes, developed from claws. The grip-promoting papillary lines on our fingers and toes are left over from the hard pads that helped our ancestors walk and climb.

B. Nerves and sense organs

In us, like in early vertebrates, the main sensory organs are concentrated in the head - the former anterior end of the body. In humans, as in fish, these organs provide the perception of signals from the external environment caused by chemical, mechanical or electromagnetic influence. Thus, the taste buds of the human tongue distinguish substances dissolved in water, and moist nasal membranes distinguish odors.

G. Brain

The brain, as a coordinating center, already appeared in such primitive animals as flatworms, and in early fish, the brain, like ours, consisted of three main parts: posterior, middle, anterior. In mammals, the brain becomes much larger and more complex. The function of coordinating the activity of the sense organs was transferred to the anterior part, from which a large, numerously convoluted part of the brain developed, which controls the processes of memorization and learning. The huge hemispheres of the human brain - the seat of the mind - are larger in size than the rest of the brain and have caused changes in the structure of the skull.

(Demonstration of brain models of animals of different classes.)

D. Lungs, circulation, kidneys

The lungs most likely originate from moist sacs in the throat of lobe-finned fish, which accumulated atmospheric air necessary for life in swamp puddles with a low oxygen content.
Only warm-blooded animals - birds and mammals - have a four-chambered heart.
The kidneys apparently originated from the Malpighian vessels present in invertebrates. In fish they are grouped in the form of two long stripes, in reptiles these are already two dense clusters, in mammals they are two buds.

Comparative embryology data

E. Embryonic development

The similarity of the human embryo to the embryos of other animals provides a compelling argument for evolutionary relatedness. The development of the human embryo, like that of any other animal, begins with the formation of two layers of cells: ectoderm (external) and endoderm (internal), similar to the two layers of cells of such primitive invertebrates as jellyfish. Then, as in all animals, except sponges and coelenterates, the third germinal layer is formed - the mesoderm. As a result, at the gastrulation stage, a three-layer (as in all higher vertebrates) embryo is formed. From these three layers of cells all the organs of the body develop. During the period between the fourth and sixth weeks of development, the human embryo transforms from a fish-like organism into an organism indistinguishable from a monkey embryo. At two months of age, the fetus is already, without any doubt, a tiny human being.

(Demonstration of the table “Animal Embryos”.)

The human body is adapted to its way of life, which has developed in the process of evolution. Any adaptation is accompanied by an improvement in some body functions and a weakening of others. As a result, the modern human body has several “weak points” or flaws. Most of them are associated with the vertical position of the skeleton.

Teeth. Too close arrangement of teeth is a consequence of a decrease in the size of the jaws, which occurred relatively recently in the process of evolution.

Disc loss. Diseases of the lower spine are usually the result of degenerative age-related changes associated with the transfer of load through the spine to two, rather than four, limbs, as was the case with our ancient mammalian ancestors.

Appendix. Appendicitis is a disease associated with infectious infection and inflammation of the appendix, a rudimentary vermiform appendix of the cecum.

Hernia – protrusion, for example, of a section of intestines from the abdominal cavity under the skin through natural or artificially formed openings in this cavity.

Varicose veins are a disease characterized by a loss of elasticity in the veins, causing them to stretch and even expand, forming “knots.” This leads to slow blood flow and often the formation of blood clots.

Flat feet. Weakening of the arch of the foot is widespread and is due to the fact that the weight of the human body is distributed only between the soles of the feet.

Similarities and differences between humans and apes

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 comrade, T. Huxley.

Already in appearance there is a lot in common: large body size, long neck, broad shoulders, absence of ischial calluses, protruding nose, similar shape of the auricle. Very similar to human facial expressions of apes. In the internal structure, one should note a similar number of lobes of the lungs, the number of papillae in the kidney, the presence of a vermiform appendix of the cecum, a similar structure of the larynx...

The timing of puberty and the duration of pregnancy in anthropoids is almost the same as in humans. Extremely close similarities are noted in biochemical parameters: four blood groups, similarities in protein metabolism, and diseases. The species are also close in the number of chromosomes (46 in humans, 48 ​​in chimpanzees, gorilla, orangutan).

Now about the differences. The human brain is 2–2.5 times larger, the cerebral part predominates over the facial part. These and other very significant differences lead to the idea that modern apes could not be the ancestors of humans. In this case, what were the ancestors of modern man?

Charles Darwin on the origin of man

The biological theory of human origin was developed by Charles Darwin. In the books “The Origin of Man and Sexual Selection”, “On the Expression of Emotions in Man and Animals” (1871–1872), he comes to the conclusion that man is part of living nature and that his emergence is no exception to the general patterns of development of the organic world .

First of all, he proved the origin of man from the “lower animal form.” Thus, man was included in the general chain of evolutionary changes in nature. On the basis of comparative anatomical and embryological data, he substantiated the idea of ​​kinship between humans and anthropoids.

This is how I was born simial– “monkey” theory of anthropogenesis. According to this theory, humans and modern anthropoids descended from a common ancestor who lived in the Neogene era and was, according to Charles Darwin, an ape-like creature. The German scientist E. Haeckel called the missing transitional form Pithecanthropus - the ape-man. In 1891, the Dutch anthropologist E. Dubois discovered parts of a creature on the island of Java, which he called Pithecanthropus erectus. Over the past century, remains of creatures intermediate between the ape ancestor and humans have been discovered.

So do you think the simial theory is confirmed?

III. Repetition of what has been learned

Frontal conversation

1. Name the characteristics of a person that allow him to be classified as a subtype of vertebrates.
2. Indicate the characteristics that determine the position of a person in the class of mammals.
3. What characteristics are common to humans and apes?
4. Why can’t modern apes be considered the ancestors of humans?
5. List the structural features inherent only to humans.

Discussion

Together with the whole class, the question is discussed: “Who has doubts about our origin from animals?”
Two groups of 3 people are formed and given 4 minutes to prepare to argue their position.
As experience shows, a lively discussion ensues. Its optimal time is about 10 minutes.