The last common ancestors of chimpanzees and humans lived. Summary of a lesson in biology on the topic "Directions of human evolution, common ancestors of humans and great apes (Grade 11). Neoanthropes and Homo sapiens

Common ancestors of humans and great apes

Among the first small mammals - insectivores - in the Mesozoic era, a group of such animals stood out that did not have sharp teeth and claws, wings, or hooves. They lived both on the ground and on trees, eating fruits and insects. From this group originated branches that led to semi-monkeys, monkeys and man.

The most ancient higher apes, from which the ancestors of man originate, are considered parapithecus. These ancient, unspecialized apes diverged into two branches: one led to modern gibbons and orangutans, the other to dryopithecus, extinct arboreal apes. Dryopithecus has undergone divergence in three directions: one branch led to the chimpanzee, another to the gorilla, and the third to man. Man and apes are closely related. But these are different branches of a common pedigree trunk.

Scientists suggest that the ancestral home of mankind was somewhere in the territory, including the northeastern part of Africa, South Asia, southeastern Europe, from where people settled throughout the Earth.

What were the initial forms from which the most ancient people originated? To date, such forms have not been found, but a well-studied group of South African monkeys - Australopithecus ("Australus" - southern) gives an idea of ​​​​them. This group lived on Earth at the same time as the most ancient people, therefore it cannot be considered the direct ancestors of people.

Australopithecus lived among the rocks on flat treeless spaces, were bipedal, walked slightly bending over, knew meat food; their skull had a volume of approximately 650 cm 3.

In the early 60s of our century, the English scientist Louis Leakey in the Oldowai Gorge on the territory of modern Tanzania (East Africa) found fragments of skulls, bones of the hand, foot, lower leg, and collarbone. The fossil creatures to which they belonged were somewhat closer to humans than Australopithecus in the structure of the foot and hand, but their brain volume did not exceed 650 cm3. Pebbles of a pointed shape and stones that left the impression of artificially processed were also found there. According to most Soviet anthropologists, these creatures should also be considered Australopithecus. Morphologically, they differed little from the great apes. The difference consisted in the appearance of the first flashes of consciousness associated with the use of natural objects as tools, which prepared the transition to their manufacture.

It is assumed that the ancestors of the most ancient people were a species of bipedal apes close to African Australopithecus, which, on the basis of hereditary variability, in the process of natural selection, developed the ability to often and variously use sticks and stones as tools.

In the process of becoming a person, three stages or phases should be distinguished: 1) the most ancient people, 2) ancient people and 3) the first modern people.

The oldest people

The transition from fossil anthropoid apes to man took place through a series of intermediate creatures that combined the features of monkeys and humans - ape people. It is believed that they appeared at the beginning of the Anthropogen, that is, about a million years ago.

Pithecanthropus means "monkey-man" in translation. His remains were first discovered by the Dutch doctor Dubois in 1891 on about. Java. Pithecanthropus walked on two legs, leaning slightly forward and possibly leaning on a club. Had a height of about 170 cm, his cranium was the same length and width as that of modern man, but lower and consisted of thick bones. The volume of the brain reached 900 see 3: The forehead is very sloping, above the eyes there is a solid bony roller. The jaws strongly protruded forward, there was no chin protrusion.

Pithecanthropes created the first tools from stone, which they found in the same layers as the bones. These are primitive scrapers, drills. There is no doubt that the Pithecanthropes used sticks and branches as tools. Ancient people thought, invented,

The emergence of labor proved to be a powerful impetus to the development of the brain. Darwin attached exceptional importance to the high mental development of our ancestors, even the most ancient ones. The development of the mind took a great step forward with the advent of speech. According to F. Engels, the rudiments of speech arose among the most ancient people in the form of inarticulate sounds that had the meaning of various signals.

Interesting finds Sinanthropus- "Chinese man", who lived somewhat later than Pithecanthropus. His remains were found in 1927-1937. near Beijing.

Outwardly, Sinanthropus in many ways resembled Pithecanthropus: a low forehead, with a developed superciliary ridge, a massive lower jaw, large teeth, and no chin protrusion.

However, the synanthropes were more developed creatures. Their brain volume ranged from 850 to 1220 cm 3; the left lobe of the brain, where the motor centers of the right side of the body are located, was somewhat larger than the right lobe. Consequently, the right hand of Sinanthropes was more developed than the left. Sinanthropes mined and knew how to maintain fire, dressed, apparently, in skins. The excavations revealed a thick layer of ash, charred branches, tubular bones and skulls of large animals, tools made of stones, bones, and horns.

In 1907, near the city of Heidelberg in Germany (on the modern territory of the Federal Republic of Germany), a very massive lower jaw was found, without a chin protrusion, but with teeth like a person's. The owner of this jaw was named Heidelberg man. Pithecanthropus and Sinanthropus are considered two species of the first subgenus - ape-men (genus of people): Pithecanthropus erectus and Beijing Sinanthropus. They are representatives of the first initial stage of the transformation of a monkey into a man; in the words of F. Engels, these are "formed" people. From them descended representatives of the second stage of humanization - Neanderthals. The Heidelberg man, on the other hand, is considered by some researchers to be among the most ancient people, while others are considered ancient.

Ancient people

Entire skeletons of adults and children have been found in the lowest layers of cave deposits in Europe, Asia and Africa. Neanderthals(named after the place of discovery in 1856 - the valley of the Neander River in Germany on the modern territory of Germany). In the USSR, the remains of Neanderthals were found in the south of Uzbekistan and in the Crimea. The first Neanderthal settlements date back to 400-550 thousand years ago.

Neanderthals were shorter than us, stocky (men average 155-158 cm), walked a little bent over. They also had a low, sloping forehead; strongly developed brow ridges hung at its base, the lower jaw without a chin protrusion or with its weak development. The volume of the brain approached the human brain - about 1400 cm 3, but there were fewer convolutions of the brain. The curvature of the spine in the lumbar region was less than that of a modern person. They lived in the difficult conditions of the onset of glaciers, in caves, where they constantly maintained fire. They ate vegetable and meat food. Neanderthals owned stone and bone tools. Apparently, they also had wooden tools.

Judging by the structure of the skull and facial bones, scientists believe that when communicating with each other, Neanderthals used gestures, inarticulate sounds, and rudimentary articulate speech. They lived in groups of 50-100 people together. The men hunted the animals; women and children gathered edible roots and fruits; older, more experienced, made tools. Neanderthals dressed in skins and used fire. Neanderthals are considered species belonging to the second subgenus - ancient people (kind of people). They are the ancestors of the first modern people - the Cro-Magnons.

The first modern humans

A large number of finds of skeletons, skulls and tools of the first modern people are known - Cro-Magnons(the name of the town of Cro-Magnon in the south of France), who lived 100-150 thousand years ago. The remains of the Cro-Magnons were also found in Russia (south of Voronezh, on the right bank of the Don). Cro-Magnons were up to 180 cm, with a high straight forehead and cranial volume up to 1600 cm 3; a continuous supraorbital ridge was absent. A developed chin protrusion indicated a good development of articulate speech. The Cro-Magnons lived in dugouts, caves with painted walls. Tools made of horn, bone, flint are very diverse and decorated with carvings. Hunting episodes, sacred dances, people and deities were depicted on the walls of dwellings. The drawings are made with ocher and other mineral paints or scratched. Cro-Magnons dressed in clothes made of skins sewn with bone and flint needles. The technique of making tools and household items is much more perfect than that of the Neanderthals. The man knew how to grind, drill, knew pottery. He tamed animals and took the first steps in agriculture. The Cro-Magnons lived in a tribal society.

Cro-Magnons and modern humans form the species Homo sapiens - reasonable man, relating to the third subgenus - new people (kind of people).

So, having risen from the animal world, our ancestors, as a result of a complex and lengthy process of becoming a person, turned into people of a modern look. Social factors and laws have become leading and determining factors. This is the qualitative originality of human evolution in comparison with the evolution of animals.

Hereditary variability and natural selection among people still take place, but on the basis of developing knowledge and social reorganization, a person learns to control biological laws, prevent harmful manifestations and enhance useful ones.

Scientists argue that modern man did not originate from modern anthropoid apes, which are characterized by a narrow specialization (adaptation to a strictly defined lifestyle in tropical forests), but from highly organized animals that died out several million years ago - driopithecus. The process of human evolution is very long, its main stages are presented in the diagram.

The main stages of anthropogenesis (the evolution of human ancestors)

According to paleontological finds (fossils), about 30 million years ago, ancient parapithecus primates appeared on Earth, living in open spaces and on trees. Their jaws and teeth were similar to those of great apes. Parapithecus gave rise to modern gibbons and orangutans, as well as an extinct branch of driopithecus. The latter in their development were divided into three lines: one of them led to the modern gorilla, the other to the chimpanzee, and the third to Australopithecus, and from it to man. The relationship of driopithecus with man was established on the basis of a study of the structure of his jaw and teeth, discovered in 1856 in France.

The most important step in the transformation of ape-like animals into the most ancient people was the appearance of bipedal locomotion. In connection with climate change and the thinning of forests, there has been a transition from an arboreal to a terrestrial way of life; in order to better view the area where the ancestors of man had many enemies, they had to stand on their hind limbs. Subsequently, natural selection developed and fixed upright posture, and, as a result of this, the hands were freed from the functions of support and movement. This is how australopithecines arose - the genus to which hominids belong (a family of people).

australopithecines

Australopithecus - highly developed bipedal primates that used natural objects as tools (hence, australopithecines cannot yet be considered people). Bony remains of Australopithecus were first discovered in 1924 in South Africa. They were as tall as chimpanzees and weighed about 50 kg, the brain volume reached 500 cm 3 - on this basis, Australopithecus is closer to humans than any of the fossil and modern monkeys.

The structure of the pelvic bones and the position of the head were similar to those of a person, which indicates a straightened position of the body. They lived about 9 million years ago in open steppes and fed on plant and animal food. The tools of their labor were stones, bones, sticks, jaws without traces of artificial processing.

skillful man

Not possessing a narrow specialization of the general structure, Australopithecus gave rise to a more progressive form, called Homo habilis - a skilled man. Its bone remains were discovered in 1959 in Tanzania. Their age is determined at about 2 million years. The growth of this creature reached 150 cm. The volume of the brain was 100 cm 3 larger than that of Australopithecus, the teeth of a human type, the phalanxes of the fingers, like those of a person, are flattened.

Although it combined signs of both monkeys and humans, the transition of this creature to the manufacture of pebble tools (well-made stone ones) indicates the appearance of labor activity in it. They could catch animals, throw stones, and perform other activities. The heaps of bones found along with the fossils of Homo sapiens testify to the fact that meat has become a permanent part of their diet. These hominids used rough stone tools.

Homo erectus

Homo erectus - Homo erectus. the species from which modern man is believed to have descended. Its age is 1.5 million years. His jaws, teeth, and brow ridges were still massive, but the brain volume of some individuals was the same as that of modern man.

Some bones of Homo erectus have been found in caves, suggesting a permanent home. In addition to animal bones and rather well-made stone tools, heaps of charcoal and burnt bones were found in some caves, so that, apparently, at this time Australopithecus had already learned how to make fire.

This stage of hominin evolution coincides with the colonization of other colder regions by Africans. It would be impossible to survive the cold winters without developing complex behaviors or technical skills. Scientists suggest that the prehuman brain of Homo erectus was able to find social and technical solutions (fire, clothing, food supply and cohabitation in caves) to the problems associated with the need to survive in the cold of winter.

Thus, all fossil hominids, especially Australopithecus, are considered to be the precursors of humans.

The evolution of the physical features of the first humans, including modern humans, spans three stages: ancient people, or archanthropes; ancient people, or paleoanthropes; modern people, or neoanthropes.

archanthropes

The first representative of the archanthropes is Pithecanthropus (Japanese man) - an ape-man, upright. His bones were found on about. Java (Indonesia) in 1891. Initially, its age was determined to be 1 million years, but, according to a more accurate modern estimate, it is a little over 400 thousand years old. The height of Pithecanthropus was about 170 cm, the volume of the cranium was 900 cm 3 .

Somewhat later, there was Sinanthropus (Chinese people). Numerous remains of it were found in the period 1927 to 1963. in a cave near Beijing. This creature used fire and made stone tools. This group of ancient people also includes the Heidelberg man.

Paleoanthropes

Paleoanthropes - Neanderthals appeared to replace the archanthropes. 250-100 thousand years ago they were widely settled in Europe. Africa. Front and South Asia. Neanderthals made a variety of stone tools: hand axes, side-scrapers, sharp-pointed ones; used fire, coarse clothing. The volume of their brain grew 1400 cm 3 .

Features of the structure of the lower jaw show that they had rudimentary speech. They lived in groups of 50-100 individuals and during the onset of glaciers they used caves, driving wild animals out of them.

Neoanthropes and Homo sapiens

Neanderthals were replaced by people of the modern type - Cro-Magnons - or neoanthropes. They appeared about 50 thousand years ago (their bone remains were found in 1868 in France). Cro-Magnons form the only genus and species of Homo Sapiens - Homo sapiens. Their monkey features were completely smoothed out, there was a characteristic chin protrusion on the lower jaw, indicating their ability to articulate speech, and in the art of making various tools from stone, bone and horn, the Cro-Magnons had gone far ahead compared to the Neanderthals.

They tamed animals and began to master agriculture, which made it possible to get rid of hunger and get a variety of food. Unlike their predecessors, the evolution of the Cro-Magnon people took place under the great influence of social factors (team building, mutual support, improvement of work activity, a higher level of thinking).

The emergence of Cro-Magnons is the final stage in the formation of a modern type of person. The primitive human herd was replaced by the first tribal system, which completed the formation of human society, the further progress of which began to be determined by socio-economic laws.

human races

Humanity living today is divided into a number of groups called races.
human races
- these are historically established territorial communities of people that have a unity of origin and similarity of morphological features, as well as hereditary physical features: facial structure, body proportions, skin color, hair shape and color.

According to these features, modern humanity is divided into three main races: Caucasoid, Negroid and Mongoloid. Each of them has its own morphological features, but all these are external, secondary features.

The features that make up the human essence, such as consciousness, labor activity, speech, the ability to cognize and subdue nature, are the same for all races, which refutes the assertions of racist ideologues about "higher" nations and races.

The children of the Negroes, brought up together with the Europeans, were not inferior to them in intelligence and talent. It is known that the centers of civilization 3-2 thousand years BC were in Asia and Africa, and Europe at that time was in a state of barbarism. Consequently, the level of culture does not depend on biological characteristics, but on the socio-economic conditions in which peoples live.

Thus, the statements of reactionary scientists about the superiority of some races and the inferiority of others are groundless and pseudoscientific. They were created to justify wars of conquest, plunder of colonies and racial discrimination.

Human races must not be confused with such social associations as nationality and nation, which were formed not according to a biological principle, but on the basis of the stability of a common speech, territory, economic and cultural life, formed historically.

Man in the history of his development has come out of submission to the biological laws of natural selection, his adaptation to life in different conditions occurs through their active alteration. However, these conditions to some extent still have a certain effect on the human body.

The results of such an influence can be seen in a number of examples: in the peculiarities of the digestive processes of reindeer herders in the Arctic, who consume a lot of meat, in residents of Southeast Asia, whose diet consists mainly of rice; in the increased number of erythrocytes in the blood of the highlanders compared with the blood of the inhabitants of the plains; in the pigmentation of the skin of the inhabitants of the tropics, which distinguishes them from the whiteness of the integument of the northerners, etc.

After the completion of the formation of modern man, the action of natural selection did not stop completely. As a result, in a number of regions of the globe, humans have developed resistance to certain diseases. Thus, measles among Europeans is much easier than among the peoples of Polynesia, who encountered this infection only after the colonization of their islands by immigrants from Europe.

In Central Asia, blood group 0 is rare in humans, but the frequency of group B is higher. It turned out that this is due to the plague epidemic that took place in the past. All these facts prove that in human society there is biological selection, on the basis of which human races, nationalities, nations were formed. But the ever-increasing independence of man from the environment has almost suspended biological evolution.

We talk about this with paleoanthropologist Alexander Belov.

Alexander Ivanovich, will a new candidate for the role of our ancestor be suitable?

Alexander Belov: - It will depend on how his foot looks. For a century and a half, science has been under the spell of the theory (it would be more correct to call it a hypothesis) of Charles Darwin that the great ape was the ancestor of man. Followers of Darwin still share this opinion.

However, this hypothesis has obvious weaknesses. Here is one of them: in the human foot, the main supporting function is performed by the big toe, which accounts for 30-40% of the weight. The structure of the foot of a gorilla, an orangutan, a chimpanzee - the most seemingly "smart" and human-like monkeys - is different: their thumb is at an angle from the foot. This difference is key, it proves that even the great ape is incapable of prolonged upright posture, but only of moving on all fours.

But does this argument really contradict Darwin? The monkey developed - and its foot improved.

AB: - According to this logic, the more ancient ancestors of apes and humans should have a foot even less similar to ours.

But it is precisely this logic that has cracked at the seams after the high-profile discoveries of recent decades. At the end of the 70s. In the 20th century, a fossilized Australopithecus foot was found that lived about 4 million years ago. And then it became clear that he did not “fall off the tree” at all, as the evolutionary hypothesis would require. This primate had a foot much more human-like than that of the great apes.

In 2000, the bones of the Sahelanthropus Chadian, who lived 7 million years ago, were found. According to the peculiarities of the attachment of the occipital muscles to the base of the skull, it turned out that he was upright. The conclusion is striking: Sahelanthropus is even more human-like than Australopithecus, and even more so than monkeys.

Apparently, under the pressure of facts, Darwin's concept had to be "corrected": is it not a man - from a monkey, but both of them - from some common ancestor?

A.B.: - Darwinists would like to cling to this idea, but it doesn’t work out: why then did man improve the forms of his ancestor, and the monkey lost all its advantages and climbed back into the tree? It turns out that the monkey showed the opposite direction of development - involution?

Your books are devoted to the hypothesis of involution. According to it, it turns out that the forms of living matter develop from more complex to simpler ones. That is, the living world is degrading. Let's assume it is. But then where did complex shapes come from? Who created man?

A. B.: - Scientists are not yet ready to answer this most important question. Homo sapiens is a relatively young species, it has about 60 thousand years. Against several million years separating us from the found anthropoids, this is a trifle. It turns out that homo sapiens is located outside the line of development of primates - at least evolutionary, at least involutionary. Therefore, it is more honest, in my opinion, to call our species homo incognitos - an unknown person, than to make him related to monkeys and their more perfect ancestors.

Maybe a new Ethiopian find will put everything in its place?

A.B.: - Doubtful. After all, we talked only about the inconsistency "monkey - man." But even more eloquent are the inconsistencies between any two rungs on the ladder of evolution. For example, a pig and even a bat are in some ways closer to humans than a monkey.

But you reject the assumption that a more ancient human ancestor has been found?

A. B.: - I am ready to argue that the dog and the bear are the descendants of man. For example, the bear does not come from small tree-climbing animals such as raccoons (as paleontologists believe). And he is not related to monkeys, although outwardly he looks a bit like them. The bear's foot resembles a human one and is much more perfect than a monkey's: in it and for us there is no yok on the thumb that is set aside. Obviously, some degrading human being never climbed trees, but gained fat, staggering between trees, first on two legs, then on four. The legs of the bear's ancestor were shortened to make it more convenient to step on the entire foot. It turns out that the bear descended from man? ..Dossier

Alexander Belov, born in 1963. An animal biologist by training. Author of the book "The Mystery of the Origin of Man Revealed."

Natural selection. Criteria for evaluation of works. Human life. Chronology of life on earth. Plaster reconstructions. Biological equivalence of human races. What types of tools did archanthropes use? embryological evidence. Evidence for evolution. Nutrition method. Heredity. Features of modern man. Evidence of human kinship with apes. Characters of the chordate type. Interrelation of biological and social factors.

"The Theory of Human Evolution" - At 22, Darwin goes on a five-year voyage on the Beagle as a naturalist without salary. Comparative anatomy. Biogeography. The principle of divergence from a common ancestor. Sources of Darwin's ideas. Insulation. New equilibrium state. The process of sympatric speciation by food specialization in the fly Rhagoletis pomonella. If a population is an elementary evolving unit, then a species is a qualitative stage of evolution.

"The position of man in nature" - Tolstoy. Man as a representative of primates. Organs that were once active. Rudiments and atavisms. The development of the fetus in the mother's body. Anaximander. Man belongs to the class Mammals. Human belonging to the suborder of the great apes. The evolution of the animal world. Human belonging to the Vertebrate subtype. Weak thermoregulation. Ch. Darwin. embryological evidence.

"The process of human evolution" - Homo erectus. Human evolution. The common ancestor of man and great apes is driopithecus. The tools of labor of a skilled man. Neanderthal. Cro-Magnon. A reasonable person. Australopithecus.

"Stages of human evolution" - Tools of the Eneolithic. Lesson goals. Neoanthropes. What we already know. Neanderthals Homo neandertalensis. Ancient people Archanthropes. Afar Australopithecus "Lucy". Brain volume. Fossil humans of the modern type. Dryopithecus. The drawing was cut into the wall and filled with mineral pigments. Cro-Magnons. Neoanthropes. The evolution of hominids. Synanthropes. Bone objects of the Mesolithic people. What do we want to know. Homo ergaster "working man".

"Anthropogenesis, human evolution" - Anthropogenesis. Complex options for TVV. Pithecanthropus. Ancient people. The process of separating a person from the animal world. Ancient people. Bipedal gait. Social and labor relations. Advantages. Much of this evidence can be interpreted ambiguously. One of the branches of anthropology. Neanderthals. Neoanthropes were tall people. Neoanthropes. Shifts in morphology. The main stages of human evolution. Theory of spatial anomalies.

Did Charles Darwin at the end of his life renounce his theory of human evolution? Did ancient people find dinosaurs? Is it true that Russia is the cradle of mankind, and who is the Yeti - is it not one of our ancestors who got lost in the centuries? Although paleoanthropology - the science of human evolution - is experiencing a rapid flowering, the origin of man is still surrounded by many myths. These are anti-evolutionary theories, and legends generated by mass culture, and pseudo-scientific ideas that exist among educated and well-read people. Do you want to know how it was "really"? Alexander Sokolov, editor-in-chief of the portal ANTROPOGENESIS.RU, has collected a whole collection of such myths and checked how well they are.

Book:

Man did not come from a monkey; Humans and apes share a common ancestor!

"Yes Yes! Oh, you learn materiel! Not from a monkey, but from a common ancestor with a monkey!” For greater effect, the phrase may be accompanied by a meaningful gesture. Now less knowledgeable debaters should tremble: a savvy fighter for science demonstrates to opponents a deep insight into the subject. However, before repeating the mantra about the “common ancestor”, it is worth considering: who was this “common ancestor”? A shrew? An animal-toothed reptile? A brush-finned fish?

Of course, humans and modern great apes had a common ancestor - a creature that gave rise to both us and them (in science, the abbreviation LCA is used - Last Common Ancestor - the last common ancestor). And, of course, he was none other than an ape, moreover, a humanoid ape. Only not modern - not a chimpanzee or a gorilla, of course - but an ancient, fossil one; but the meaning does not change. The evolutionary paths of humans and chimpanzees diverged no more than 7 million years ago - both paleontology and genetics speak about this. In 2007, Nakalipithecus was described - a common ancestor of humans, chimpanzees and gorillas, 10 million years old, and this creature was 100% ape. Little of. The ancestor of all anthropoids - rukvapitek (25 million years), and the common ancestor of anthropoids and monkeys - saadania (29 million years), and the common ancestor of all monkeys in general - archicebus (55 million years) were apes. Now, if we move even further into the past, to the root of the order of primates, then exemplary monkeys end and “almost monkeys”, “not quite monkeys”, creatures remotely resembling monkeys begin ... (For more details, see myth No. 23 about the origin of monkeys.)

So the appearance of a person was preceded by a long string of cute, but quite monkey muzzles.

Thus, the phrase about a common ancestor is nothing more than a rhetorical device, an attempt to sweeten the pill for those who are jarred at the thought of four-legged hairy ancestors. Great-great-grandfather-monkey - it's a shame; monkey second cousin - tolerable. Well, if such a politically correct wording reconciles someone with reality, I'm all for it. But we, dear readers, will calmly face the facts.