Savelyev morphology of the brain. Sergei Savelyev: biography and work
Sergei Savelyev is a famous domestic scientist. He is the head of a large laboratory for studying the characteristics of the nervous system, which works at the Research Institute of Human Morphology. Works under the Federal Agency for Scientific Organizations.
Biography of the scientist
Sergei Savelyev was born in Moscow. He was born in 1959. He developed an interest in natural sciences while still in school. Therefore, he entered the capital's State Pedagogical Institute. Graduated from the Faculty of Chemistry and Biology.
He began his working career at the Brain Institute of the Soviet Union. In 1984 he moved to a research institute engaged in the study of human morphology.
He is interested in photography, and is even a member of the Russian Union of Photographers.
Scientific activity
Sergei Savelyev became famous for the fact that for the past three decades he has been studying the morphology and evolution of the human brain. During this time, he wrote more than a dozen monographs and about a hundred scientific articles. Compiled the world's first stereoscopic atlas of the human brain. For him he received an award from the Russian Academy of Medical Sciences.
Professor Sergei Savelyev is famous for his research in the field of embryonic pathologies of the nervous system. He is developing methods for their diagnosis.
He was the first in the world to photograph a human embryo that was only 11 days old. Also among his achievements is the creation of a theory of control over early embryonic brain development in vertebrates. With its help, he proves that the future of a cell is determined not by genetics, but by biomechanical interactions. Thus, he questioned the existence of many genetic diseases.
Sergei Savelyev also studies theories of the origin of the human nervous system. And also its modern evolution. Develops the fundamental principles of the adaptive evolution of behavior and the nervous system itself.
Brain Study
Thanks to his research, he was able to develop a technique with which today the hidden signs of schizophrenia are determined. This is done based on the presence or absence of certain cavities in the pineal gland.
Since 2013, he has led a group of scientists who carefully study the mammoth brain. It includes not only employees of the Russian Academy of Medical Sciences, but also representatives of the Yakut Academy of Sciences and the Museum of Paleontology of the Russian Academy of Sciences. The results of this work were the world's first three-dimensional model of the mammoth brain, which was made in 2014.
Sergei Savelyev is a Doctor of Biological Sciences who led the Gecko experiment in 2014. His goal is to establish a connection between microgravity and sexual behavior. The subject of the study are geckos that were sent in an embryonic state for two months to a research satellite in orbit.
Recently he has been actively promoting the idea of cerebral sorting. This is a special method of analyzing a person’s unique abilities, which is done by assessing the structure of the brain using a tomograph.
Teaching work
The biography of Sergei Savelyev is closely connected with teaching. He lectures to students at Moscow State University. Works at the Department of Animal Psychology of Vertebrates.
In particular, he teaches a course on the comparative anatomy of the nervous system in vertebrates.
Scientist's views
Sergei Savelyev, whose photo is in this article, believes that in the future man will develop along the path of inevitable primitivization. His level of intelligence will decrease and his physical characteristics will deteriorate.
He considers the statements of a number of scientists about the functioning of the human body aimed at reproduction to be misconceptions. He calls the theory of the conditioned reflex, cloning, scientific-religious fanaticism. Justifies them only by the existence of social instincts.
Criticism of Savelyev's works
Many experts criticize the work of the hero of our article. In particular, they believe that in his articles he often makes factual errors and incorrectly interprets specialized terms. And in his judgments he often uses not scientific evidence, but mockery. At the same time, he is suspected of having a superficial knowledge of many basic sciences. For example, paleontology, archeology, anthropology, to which he constantly turns.
In this regard, many doubt his hypothesis about the reasons for the transition of human ancestors to upright walking. Savelyev himself believes that all this is connected with the denial of the scientific works of his colleague Stanislav Drobyshevsky, with whom they collaborate on the scientific portal Anthropogenesis.ru. For example, Savelyev gives elementary examples of how the brains of microcephalians and orangutans are structured, thus casting serious doubt on the entire evidence base, as well as the scientific meaning and significance of craniometry - a special technique for studying the skull, which assumes that its structure changes significantly over time.
Savelyev entered into a tense debate with Doctor of Biological Sciences Svetlana Borinskaya, who is a leading researcher at the genome analysis laboratory of the Vavilov Institute of General Genetics of the Russian Academy of Sciences. She directly pointed out the dangers of unproven faith in scientific theories, citing his Human Genome program as an example. She also recommended not to take Savelyev’s statements on genetics seriously.
Modern man in his development is not far from the monkey, his life is determined by the same laws as tens of millions of years ago, and the future does not promise anything good for humanity. Evolutionist, paleoneurologist, Doctor of Biological Sciences, Professor, Head of the Laboratory of Nervous System Development at the Institute of Human Morphology of the Russian Academy of Medical Sciences Sergey Vyacheslavovich Savelyev talks about the evolution and degradation of the brain and shares his predictions for the development of humanity.
How and why did the human brain develop?
The brain did not evolve so that we could think well, create immortal works, solve mathematical problems, or send people into space. It has evolved to solve biological problems quickly and efficiently. We have bad nails, slow legs, no wings, disgusting anatomy - we walk on two legs, like dinosaurs. And our only advantage over other species is brain size.
The brain was formed under the influence of biological laws for a very long time. Our distant ancestors, like all primates, lived in trees for 50 million years. Then, 15 million years ago, they descended from these trees. According to the official version, for no reason at all, they abandoned beautiful forests full of food and went to eat roots in open fields - where they could easily be torn to pieces by predators. Of course, this is nonsense. It is not so easy to drive monkeys out of the jungle; they can only be lured with food. This means that they went to the shores of lakes, of which there were a lot in Africa at that time, for fish, caviar and eggs of birds nesting there. An overabundance of protein-rich food and a lack of competition for it are the basis of the happiness of our ancestors. This paradise period lasted about 10 million years. What did primates do when they solved the food problem? Issues of reproduction and dominance. Fierce sexual competition began, and our ancestors began to sort things out among themselves. Excess food gives rise to social problems - this biological law is still in effect today. As long as everyone goes to work and earns money, everything is fine for everyone. As soon as one goes to work, the others begin to sort things out among themselves.
Was the speech that emerged at that time an instrument of sexual competition? And did it cause brain growth?
Speech and communication emerged as the basis for joint actions when hunting in water. But very quickly they began to be used in a different way - for deception. In any world, demonstrating the ability to act is much easier and more profitable than doing something. Just imagine: a male comes to a female and says that he caught a huge fish, but suddenly evil animals appeared, took it away and ate it. You already have an image - but there were no events. He came up with all this in order to achieve a result: to conquer the female and produce a descendant for himself. Speech began to evolve because it does not imply any activity. It is energetically more favorable. Lying is profitable everywhere, and everyone does it. Speech helped in the competitive struggle for food, for a female, for a dominant position in the pack. However, speech is not an acquisition that restructures or enlarges the brain. Microcephalians, for example, have smaller brains than chimpanzees, but they speak well.
When did the brain start to grow?
Ten million years ago, at the time of the transition from ape to man, a system of socialization arose and social selection began to operate. Since a group of primates could solve their problems only in a stable situation, when no one was squabbling among themselves, the most aggressive and the smartest were either destroyed or expelled from the pack. As a result of this hidden form of selection, evolution took place. On the one hand, this was preservative, or stabilizing, selection: thanks to the rejection of biological individuality, a group with certain averaged properties was created. On the other hand, the expelled individuals migrated, adapted to the new environment, multiplied and again expelled the asocial and the most intelligent. Thus a new migration route appeared. And if we trace the history of the movement of mankind, we will find out that at each new place the brain increased slightly and over several million years reached its maximum size - 1650 g, which is almost 300 g more than that of modern humans.
How did social selection within a group shape the brain?
A little over a million years ago, the social structure of society, thanks to the most severe internal selection, developed the frontal region of the brain. In humans, this area is huge: in other mammals it is much smaller relative to the entire brain. The frontal region was formed not to think, but to force an individual to share food with a neighbor. No animal is capable of sharing food because food is a source of energy. And people who did not share food were simply destroyed in the social group. By the way, we all know an example of the work of the frontal region - this is anorexia. A person who stops eating in order to lose weight cannot be forced to do so - and in the end he dies. But it turns out that he can be cured: if you trim his frontal areas, he will start eating. This method was practiced until the 1960s, when psychosurgery was banned.
When and why did the human brain begin to shrink?
The brain grew while there was somewhere to migrate and while people had to solve only biological problems. When humanity faced social problems, the brain began to lose weight. This process began approximately 100 thousand years ago. About 30 thousand years ago this led to the destruction of the Neanderthals. They were smarter, stronger than our Cro-Magnon ancestors; they creatively solved all problems, came up with tools, means of making fire, etc. But because they lived in small populations, their social selection was less pronounced. And the Cro-Magnons took advantage of large populations. As a result of long-term negative social selection, their groups were well integrated. Thanks to population unity, the Cro-Magnons destroyed the Neanderthals. Even the strongest geniuses can do nothing against the mass of mediocrity. In the end, we were left alone on this planet.
As this story shows, you don't need a big brain to socialize. A perfectly socialized dumb individual integrates into any community much better than an individualist. During evolution, personal talents and characteristics were sacrificed for biological advantages: food, reproduction, dominance. This is the price humanity has paid!
So the weight of the brain tells about a person’s abilities?
Yes, about its potential. 75% of the time, a person with a big brain is four times more likely to be a genius or talented than a person with a small brain. This is a fact, a statistic.
Why is mental work difficult for us? Is this also a result of brain shrinkage?
The brain is a strange structure.
On the one hand, it allows us to think, on the other hand, it does not allow us. After all, how does it work? In a relaxed state, when you are resting, say, watching TV, the brain consumes 9% of the body's total energy. And if you start to think, then the consumption increases to 25%. But we have 65 million years of struggle for food and energy behind us. The brain is used to this and does not believe that tomorrow it will have something to eat. Therefore, he categorically does not want to think. (For the same reason, by the way, people tend to overeat.) In the course of evolution, special protective mechanisms even arose: when you start working intensively, thinking, you immediately produce special compounds that cause irritation: you want to eat, go to the toilet, you a million things arise - anything, just not to think. And if you lie down on the sofa with delicious food, your body is delighted. Serotonin immediately begins to be produced - it differs by only one molecule position from LSD. Or dopamine, or endorphins - hormones of happiness. Intellectual expenditures are so unsupported and the body resists them. The brain is big not to work all the time, but to solve the energy problem. A biological task arose for you, you turned on and worked hard. And as soon as we solved the problem, we immediately switched off and went to the sofa. It’s more profitable to have a huge, powerful computer, run it for three minutes, solve the problem, and then turn it off.
Is the brain always working as a whole?
No, he is not suited for this. When you watch a movie, the occipital areas work, when you listen to music, the temporal areas work. And even the blood supply changes - now to the auditory area, now to the visual area, then to the motor area. Therefore, if you want to keep your brain intact, you cannot do, for example, physical education alone. If you do not give yourself intellectual loads, and varied ones at that, then the blood supply will take place mainly in the motor areas, and not in the intellectual, that is, associative areas, and sclerosis will begin there earlier. The old woman will be active, slender, but completely senile.
Does this feature of the brain make it difficult for us to do several things at the same time?
Yes, of course, many things require increased concentration, and energy costs increase sharply. The blood flow goes to several areas at once, the resistance of the brain increases: the more neurons you turn on, the more the brain does not want to work.
How to make a lazy brain work?
This is very difficult to do. Of course, the brain can be promised some delayed results, but biological organisms require only immediate results: after all, you may not live to see tomorrow. So this method is suitable for only a few. But you can deceive the brain. There are two methods for this. The first is through deceptive promises, the second is through the so-called displaced activity. Let me give you an example. The dog is sitting near the table, you are at the table, there is a sandwich on the table. The dog wants to steal the sandwich and understands that he will be punished. And so she sits and sits between two fires and suddenly begins to frantically scratch behind her ear. She can neither remain indifferent nor react - and chooses the third path. This is displaced activity - doing something that is not directly related to what you really need. This is what is driven into the gap between biological (“I want”) and social (“I need”) motivation. Writers, for example, begin to write something completely different from what they should, photographers begin to shoot something not related to the order - and the results are often brilliant. Some call it insight, others call it inspiration. It is very difficult to achieve this state.
Can we say that a person's abilities are embedded in his brain?
Yes, and they cannot be expanded or increased - only implemented. For example, an artist has huge occipital fields - five to six times larger (in weight, size, number of neurons) than an ordinary person. This determines his abilities. He has more processing resources, he will see more colors of the items, so you will never be able to agree with him regarding the visual assessment. People with different abilities find it difficult to understand each other. And the more pronounced their abilities are, the worse it is.
How to identify a person's abilities?
Psychology, unfortunately, cannot do this. And the technical means are not very developed yet. However, I am sure that in five to ten years the technology will be improved, high-resolution tomographs will appear (currently their resolution is 25 microns, but 4-5 microns are needed), and then, using a special algorithm, it will be possible to sort people by abilities and select geniuses in different fields .
Sounds scary. Where it leads?
To the point that the world will change forever. The best part is that thanks to this sorting, people will be able to do what they are really inclined to do. And this will bring happiness to many. There will be no need to poison anyone with RH gas, as in the film “Dead Season”, so that everyone is stupid and happy. Another consequence is that individual differences will overshadow ethnic ones, and racial problems will disappear. But new ones will appear - ones that humanity has never encountered before. Because the geniuses who are selected artificially will radically and, most importantly, unnoticed by others, change the world. In the near future, humanity faces a very short but very fierce race. Whoever first creates a sorting system will rule the world. You understand that this technology is primarily used not for the benefit of society, but for military purposes. It will be monstrous. Compared to this, World War II will seem like a game of toy soldiers.
In what direction is the natural evolutionary process going today?
Negative social selection, which began 10 million years ago, is still in effect today. Not only asocial elements are still expelled from society, but also the smartest ones. Look at the fates of great scientists, thinkers, philosophers - few of them had a good life. This is because we, like monkeys, continue to compete. If a dominant individual appears among us, it must be eliminated immediately; it threatens everyone personally. And since there are more mediocrities, any talent must either be expelled or simply destroyed. That is why at school excellent students are persecuted, offended, bullied - and so on all their lives. And who remains? Mediocre. But she is perfectly socialized.
That is, we still live according to the same laws as tens of millions of years ago?
Yes, we are the same monkeys as before, and we live according to the same monkey laws as 20 million years ago. Basically everyone eats, drinks, reproduces and dominates. This is the basis of the structure of humanity. All other laws and systems only mask this phenomenon. A society in which gifted people appear has come up with such a way to disguise our monkey roots and desires in order to protect biological principles from social ones. But even today all processes - in the sphere of politics, business, etc. - are built according to biological laws. Entrepreneurs, for example, strive to save on everything in order to gain competitive advantages and thus increase their dominance. Social laws, moral and ethical guidelines instilled by parents, on the contrary, interfere with business, and everyone tries to circumvent them in order to earn more.
Since everything is built on instincts, does it mean that in order to manage people, you need to appeal to these instincts?
And that's what everyone does. After all, what do politicians promise? For every man a woman, for every woman a man, for every man a bottle of vodka. We will change your social system - you will live better. We will provide you with affordable medical care - you will save money and preserve your health. We will reduce your taxes - you will have more food. These are all biological propositions related to energy and longevity. Where are the social offers? Almost none of the politicians talk about changing the social structure of society or values. Instead, they say: we will give you money - and you multiply. Or here’s another example of an instinctive form of behavior to establish dominance taken to the point of absurdity - Bill Gates’ smart home. There is an owner in this house - he comes in, and the air conditioning is adjusted for him, the humidity and light change. He leaves - and everything is adjusted to the needs of the less important boss. That is, in the house, in fact, there is a herd of baboons, who, by their appearance in each room, prove to each other who is more important. And this is called a smart home? Yes, this is schizophrenia in a monkey house. Apotheosis of the biological principle. And all this is presented as a device for the world of the future. What is the structure of the world of the future?! Just look, the tail will grow to the knee in such a future. All innovations are aimed at the same thing.
It seems that the prospects for our civilization, when it comes to intelligence, cannot be called rosy.
If civilization continues in its current form, which I doubt, then our intellectual level will drop significantly. It's unavoidable. Already now, the educational qualification is being significantly reduced, because a great thing has arisen - an information environment that allows people to imitate knowledge and education. For primates, this is a very big temptation - such imitation allows you to do nothing and be successful. While intellectual development will decline, the requirements for the level of social adaptation will increase.
For example, they united Europe. Who was the most successful? Smart? No. The most mobile and socialized are those who are ready to move to other cities and countries and settle down well there. Now these people are coming into power, into the management structure. Europe, having united, accelerated the degradation of intelligence. The first value level is a person’s ability to maintain relationships, the second is everything else: professionalism, abilities, skills. So what awaits us is intellectual degradation, a decrease in brain size, and partly, perhaps, physical restoration - a healthy lifestyle is now being promoted.
A person cannot have both high mental abilities and developed social skills?
Very rarely. If a person thinks about something of his own, looks for solutions that did not exist before in nature and in society, this excludes a high level of adaptation. And even if society recognizes him as a genius, he will not fit into it. High socialization, in turn, leaves no time for anything. Mass entertainers are not suitable for forced labor. Because they gain dominance and increase their rating with the help of language, not deeds.
Is a woman's brain different from a man's brain?
Women's brains are smaller than men's. The minimum difference in the average population is 30 g - maximum 250 g. Why is it less? Due to the associative centers responsible for abstract thinking, a woman does not really need them, since her biological task is related to reproduction. Therefore, women are especially successful in areas related to upbringing, education, and cultural identification - they well support, preserve, and transmit successive cultural systems - museums, libraries. In addition, they achieve excellent results in stabilized communities, where all the rules are already defined and well known. And, of course, women can be geniuses - the brain is a very changeable structure.
The nervous system of living beings in the process of evolution has come a long way from a set of primitive reflexes in the simplest to a complex system of analysis and synthesis of information in higher primates. What was the stimulus for the formation and development of the brain? An article by the famous scientist and popularizer of science Sergei Vyacheslavovich Savelyev, author of the book “The Origin of the Brain” (M.: VEDI, 2005), presents an original theory of the adaptive evolution of the nervous system.
From a single cell reaction to a multicellular organism
The most ancient property of the nervous system of the simplest living creatures is the ability to distribute information about contact with the outside world from one cell to the entire multicellular organism. The very first advantage that such a primitive nervous system gave to multicellular organisms was the ability to respond to external influences as quickly as the simplest unicellular organisms.
Animals attached to a specific place - sea anemones, ascidians, sedentary mollusks with large shells, coral polyps - have simple tasks: filtering water and capturing food floating by. Therefore, the nervous system of such sedentary organisms, compared to the nervous system of active animals, is structured very simply. It is basically a small peripharyngeal nerve ring with a set of primitive reflexes. However, even these simple reactions proceed several orders of magnitude faster than in plants of the same size.
Free-living coelenterates require a more extensive nervous network. Their nervous system is distributed almost evenly throughout the body or over most of it (with the exception of clusters of nerve cells at the sole and in the region of the peripharyngeal ring), which ensures a quick coordinated response of the whole organism to stimuli. A uniformly distributed nervous system is usually called diffuse. The body of such living creatures responds to various influences quickly, but nonspecifically, that is, in the same way. For example, a freshwater hydra reacts in the same way to any information signals - if you shake the leaf on which it sits, touch it with a bristle, or cause the movement of water - to shrink.
Emergence of sense organs
The next stage in the evolution of the nervous system was the emergence of a new quality - proactive adaptation. This means that the body has time to prepare for changes in the environment in advance, before direct contact with the irritant. To achieve this, nature has created a huge variety of sense organs, the operation of which is based on three mechanisms: chemical, physical and electromagnetic sensitivity of the nerve cell membrane. Chemical sensitivity can be represented by the sense of smell and taste contact organ, osmoreceptor and oxygen partial pressure receptor. Mechanical sensitivity is realized in the form of hearing, lateral line organs, gravitational and thermoreceptors. Sensitivity to electromagnetic waves is due to the presence of receptors for external or intrinsic fields, photosensitivity, or the ability to perceive the magnetic fields of the planet and the Sun.
 The main centers of the vertebrate nervous system using the example of a frog. The brain is colored red and the spinal cord is colored blue. Together they make up the central nervous system. The peripheral ganglia are green, the cephalic ganglia are orange, and the spinal ganglia are blue. There is a constant exchange of information between the centers. Generalization and comparison of information, control of effector organs occur in the brain (drawing by the author) |
Three types of sensitivity in the process of evolution were separated into specialized organs, which inevitably led to an increase in the directional sensitivity of the body. The receptors of the sensory organs have acquired the ability to perceive various influences at a distance. In the process of evolution, sensory organs arose in nematodes, free-living flat and roundworms, coelenterates, echinoderms and many other primitive living creatures. Such an organization of the nervous system in a stable environment is fully justified. The animal acquires high adaptive capabilities at an inexpensive price. As long as there is no external stimulus, the nervous system is “silent” and does not require special expenses for its maintenance. As soon as the situation changes, it perceives it with its senses and responds with directed activity of its effector organs.
 Basic structural levels of organization of the nervous system. The simplest level is a single cell that perceives and generates signals. A more complex option are clusters of nerve cell bodies - ganglia. The formation of nuclei or layered cellular structures is the highest level of cellular organization of the nervous system (drawing by the author) |
However, with the advent of anticipatory adaptation, living things encountered problems.
Firstly, some signals come from photoreceptors, others from chemoreceptors, and still others from electromagnetic radiation receptors. How to compare such disparate information? Signals can only be compared if they are encoded of the same type. An electrochemical impulse generated in neurons in response to information received from the senses has become a universal code that allows us to compare signals from different sense organs. It is transmitted from one nerve cell to another by changing the concentration of charged ions on both sides of the cell membrane. Such an electrical impulse is characterized by frequency, amplitude, modulation, intensity, repeatability and some other parameters.
Secondly, signals from different senses should arrive at the same place, where they could be compared, and not just compared, but the most important one at the moment should be selected, which will become the impetus for action. This can be realistically accomplished in a device where all the senses would be represented. To compare signals from different sense organs, an accumulation of nerve cell bodies is necessary, which are responsible for the perception of information of various natures. Such clusters, called ganglia or nodes, appear in invertebrates. Sensory neurons or their processes are located in the nodes, which allows cells to receive information from the periphery of the body.
But this entire system is useless without controlling responses to signals - muscle contraction or relaxation, the release of various physiologically active substances. To carry out the functions of both comparison and control, chordates develop a brain and spinal cord.
Formation of memory
In constantly changing environmental conditions, simple adaptive reactions are no longer enough. Fortunately, changes in the environment are subject to certain physical and planetary laws. It is possible to make an adequate behavioral choice in an unstable environment only by comparing heterogeneous signals with similar signals received earlier. Therefore, in the process of evolution, the organism was forced to acquire another important advantage - the ability to compare information over time, as if assessing the experience of a previous life. This new property of the nervous system is called memory.
In the nervous system, memory capacity is determined by the number of nerve cells involved in the memory process. To remember anything, you need to have about 100 compactly located neurons, like sea anemones. Their memory is short-term, unstable, but effective. If you collect sea anemones and place them in an aquarium, they will all reproduce their previous natural orientation. Consequently, each individual remembers in which direction its mouth opening “looked.” Even more complex behavior of sea anemones was discovered in learning experiments. Inedible pieces of paper were applied to the same tentacles of these animals for 5 days. The anemones first put them in their mouths, swallowed them, and then threw them away. After 5 days they stopped eating paper. Then the researchers began to apply pieces of paper to other tentacles. This time the animals stopped eating the paper much faster than in the first experiment. This skill lasted for 6–10 days. Such experiments demonstrate the fundamental differences between animals that have memory and creatures that do not have any means of storing information about the outside world and about themselves.
The nervous system after vertebrates reached land
The role of the nervous system became especially significant after the emergence of vertebrates on land, which put the former proto-aquatic animals in an extremely difficult situation. They perfectly adapted to life in an aquatic environment, which bore little resemblance to terrestrial habitats. New requirements for the nervous system were dictated by low environmental resistance, an increase in body weight, and good distribution of odors, sounds and electromagnetic waves in the air. The gravitational field placed extremely stringent demands on the system of somatic receptors and the vestibular apparatus. If it is impossible to fall in water, then on the surface of the Earth such troubles are inevitable. At the boundary of the environments, specific organs of movement - limbs - were formed. A sharp increase in the requirements for coordination of the body muscles led to intensive development of the sensorimotor parts of the spinal, hindbrain and medulla oblongata. Breathing in the air, changes in water-salt balance and digestive mechanisms led to the development of specific systems for controlling these functions in the brain and peripheral nervous system.
 Important evolutionary events leading to a change in habitat required qualitative changes in the nervous system. The first event of this kind was the emergence of chordates, the second was the emergence of vertebrates onto land, and the third was the formation of the associative part of the brain in archaic reptiles. The emergence of the bird brain cannot be considered a fundamental evolutionary event, but mammals went much further than reptiles - the associative center began to perform the functions of controlling the functioning of sensory systems. The ability to predict events has become a tool for mammals to dominate the planet. A–G- the origin of chordates in muddy shallow waters; |
As a result, the total mass of the peripheral nervous system increased due to the innervation of the limbs, the formation of skin sensitivity and cranial nerves, and control over the respiratory system. In addition, there was an increase in the size of the control center of the peripheral nervous system - the spinal cord. Special spinal thickenings and specialized centers for controlling limb movements were formed in the hindbrain and medulla oblongata. In large dinosaurs, these sections exceeded the size of the brain. It is also important that the brain itself has become larger. The increase in its size is caused by an increase in the representation of various types of analyzers in the brain. First of all, these are motor, sensorimotor, visual, auditory and olfactory centers. The system of connections between different parts of the brain was further developed. They have become the basis for quickly comparing information coming from specialized analyzers. In parallel, an internal receptor complex and a complex effector apparatus developed. To synchronize the control of receptors, complex muscles and internal organs, association centers arose in the process of evolution on the basis of various parts of the brain.
Energy consumption of the nervous system
To what extent do the new functions of the nervous system justify the costs of its maintenance? This question is key to understanding the direction and main pathways of evolution of the animal nervous system.
Those with a developed nervous system are faced with unexpected problems. Memory is burdensome. It must be maintained by “uselessly” wasting the body’s energy. After all, the memory of some phenomenon may be useful, or it may never be needed. Consequently, the luxurious ability to remember something is the lot of energetically wealthy animals, animals with a high metabolic rate. But it is impossible to do without it - it is needed by creatures that actively adapt to the external environment, use different senses, store and compare their individual experiences.
With the advent of warm-bloodedness, the demands on the nervous system increased even more. Any increase in metabolic rate leads to an increase in food consumption. Improving food acquisition techniques and constant energy savings are current conditions for the survival of an animal with a high metabolism. This requires a brain with developed memory and mechanisms for making quick and adequate decisions. An active life must be regulated by an even more active brain. The brain needs to work noticeably ahead of the developing situation; the survival and success of a particular species depend on this. However, an increase in brain metabolism leads to an inevitable increase in the cost of its maintenance. A vicious circle arises: warm-bloodedness requires increased metabolism, which can only be achieved by increasing the metabolism of the nervous system.
Energy costs of the big brain
According to an established but inexplicable tradition, the size of the nervous system is understood as the mass of the brain. Its relative mass is calculated as the ratio of brain mass to body mass. The hummingbird is considered the “record holder” for the largest relative brain size. The mass of her brain is 1/12 of her body mass. This is a record ratio for birds and mammals. It is higher only in a newborn child – 1/7. The relative masses of the cephalic ganglia of a bee and an ant are comparable to the relative sizes of the brain of a deer, and of a single wasp to the brain of a lion... Therefore, despite generally accepted beliefs, the relative mass of the brain cannot be considered as a parameter for assessing intelligence.
Based on the relative mass of the brain, the share of energy costs attributable to the “maintenance” of the nervous system is usually determined. However, in these calculations, as a rule, the mass of the spinal cord, peripheral ganglia and nerves remains unaccounted for. However, all of these components of the nervous system, like the brain, consume oxygen and nutrients, and the total mass of the spinal cord and peripheral nervous system can significantly exceed the mass of the brain.
In fact, the overall balance of energy costs for the functioning of the nervous system consists of several components. In addition to the brain, all peripheral parts that maintain muscle tone, control breathing, digestion, blood circulation, etc. are constantly in an active state. It is clear that turning off one of these systems will lead to the death of the body. The load on these systems is constant, but unstable. It changes depending on behavior. If an animal consumes food, the activity of the digestive system increases and the costs of maintaining its nervous system increase. Similarly, the costs of innervation and control of skeletal muscles increase if the animal is in active movement. However, the difference between these energy expenditures in an active state and a resting state is relatively small, since the body is forced to constantly maintain muscle tone or intestinal activity.
The brain is also always active. Memory is a dynamic process of transmitting a nerve impulse from one neuron to another. Maintaining both inherited (species-specific) and acquired memory is extremely energy-consuming. Many sense organs work by constantly perceiving and processing passing signals from the external environment, which also requires continuous expenditure of energy. However, energy consumption by the brain varies greatly in different physiological states. If the animal is in a state of relative rest, then the brain consumes a minimal amount of energy. If an animal is actively foraging for food, trying to avoid danger, or is in mating season, the body's expenditure on brain maintenance increases significantly. A well-fed and sleepy lioness spends much less energy on maintaining her brain than a hungry one during a hunt.
 In animals of different groups, the comparative sizes of the spinal cord and brain vary greatly. In a frog (A) both the brain and spinal cord are almost equal, in the green monkey (B) and marmoset (C) the mass of the brain is much greater than the mass of the spinal cord, and the spinal cord of a snake (D) is many times larger in size and weight than the head (photo : "Science and life") |
The energy costs for maintaining the brain vary among animals of different systematic groups. For example, proto-aquatic vertebrates are characterized by a relatively small brain, but a highly developed spinal cord and peripheral nervous system. In the lancelet, the brain does not have a clear anatomical boundary with the spinal cord and is identified only by its topological position and cytological structural features. In cyclostomes, cartilaginous fishes, lobe-finned fishes, ray-finned fishes and bony fishes, the brain is small compared to the size of the body. In these groups, the peripheral nervous system dominates. As a rule, it is several tens or even hundreds of times larger than the brain and spinal cord combined. For example, in nurse sharks with a body weight of about 20 kg, the brain weighs only 7–9 g, the dorsal brain weighs 15–20 g, and the entire peripheral nervous system, according to rough estimates, weighs about 250–300 g, that is, the brain is only 3% of the mass of the entire nervous system. Such a small brain, even in a state of high activity, cannot significantly affect changes in energy expenditure. Consequently, most of the energy expenditure in the nervous system of fish can be considered constant. Due to this, they easily mobilize the body when changing forms of behavior. Avoidance of danger, search for prey, pursuit of a competing individual occur in any sequence, stop and begin almost instantly. All Those who kept aquarium fish have observed similar situations many times.
For warm-blooded animals with relatively large brains, body size becomes critical. Little “tadpoles” simply cannot do without high-calorie intensive nutrition. Small insectivores eat huge amounts of food every day. The shrew consumes several times its own body weight every day. Abundant food for small bats and birds. In larger mammals the ratio nervous system mass/body mass increases in favor of the body. Along with a decrease in the relative size of the nervous system, the proportion of energy it consumes also decreases. In this regard, a large animal with a large brain is in a more favorable position than a small one.
The energy costs of maintaining the brain become a limiter of intellectual activity for small animals. Let's say that the American scalepus mole decided to use his brain as intensively as primates or humans. A mole weighing 40 g has a brain weighing 1.2 g and a spinal cord, together with a peripheral nervous system weighing approximately 0.9 g. Having a nervous system that makes up more than 5% of its body weight, the mole spends about 30% of the body’s total energy resources on its maintenance . If he thinks about solving a chess problem, then his body’s expenses for maintaining the brain will double, and the mole himself will instantly die of starvation. The mole's brain will require so much energy that insoluble problems will arise with the rate of oxygen production and the delivery of metabolic components from the gastrointestinal tract. There will be difficulties in removing metabolic products from the nervous system and cooling it. Thus, small insectivores and rodents are not destined to become chess players.
However, even with a slight increase in body size, a qualitatively different situation arises. Gray rat ( Rattus rattus) has a nervous system weighing approximately 1/60 of its body weight. This is already enough to achieve a noticeable decrease in the relative metabolism of the brain. And the activity based on animal experience for rats is not comparable to that of moles and shrews.
Many small animals with relatively large brains have developed a mechanism to protect the body from excessive energy consumption - torpidity, or hibernation for several hours. Small warm-blooded animals can generally be in two main states: hyperactivity and hibernation. The intermediate state is ineffective, since energy costs are not compensated by incoming food.
In the physiology of large mammals, torpidity is impossible, but still large warm-blooded animals also protect themselves from increased energy costs in various ways. Everyone knows the long winter pseudohibernation of bears, which allows them not to waste energy during a period unfavorable for food production. In terms of energy conservation, the behavior of cats is even more indicative. Lions, cheetahs, tigers and panthers, like domestic cats, spend most of their time half asleep. It is estimated that cats are inactive about 80% of the time, and spend 20% searching for prey, reproducing, and clarifying intraspecific relationships. But for them, even hibernation does not mean an almost complete stop of life processes, as in small mammals, amphibians and reptiles.
Nutrition and brain development
 Three dynamic processes can be distinguished in brain metabolism: exchange of oxygen and carbon dioxide, consumption of organic substances and exchange of solutions. The lower part of the figure shows the proportion of consumption of these components in the primate brain: the top line is in a passive state, the bottom line is during intense work. Consumption of aqueous solutions is calculated as the time it takes for all the body’s water to pass through the brain (drawing by the author) |
From what sources does the brain get energy? If any mammal's brain oxygen consumption drops below 12.6 L/(kg·h), death occurs. When the amount of oxygen decreases, the brain can only remain active for 10–15 seconds. After 30–120 seconds, reflex activity fades away, and after 5–6 minutes the death of neurons begins. Nervous tissue has practically no oxygen resources of its own. However, it is completely wrong to relate brain metabolic rate to total oxygen consumption. Energy costs for maintaining the brain also consist of nutrient consumption, as well as maintaining water-salt balance. The brain receives oxygen, water with electrolyte solutions and nutrients according to laws that have nothing to do with the metabolic rate of other organs. For example, a shrew's oxygen consumption is 7.4 l/h, and an elephant's is 0.07 l/h per 1 kg of body weight. Nevertheless, the consumption values of all “consumable” components cannot be below a certain level, which ensures the functional activity of the brain.
A stable supply of oxygen to the brain is achieved in different systematic groups due to differences in the speed of blood flow. The speed of blood flow depends on heart rate, breathing rate and food intake. The lower the density of the capillary network in the tissue, the higher the blood flow speed must be to ensure the necessary flow of oxygen and nutrients into the brain.
Information about the density of capillaries in the brain of animals is very fragmentary. However, there is a general trend showing the evolutionary development of the capillary network of the brain. In a pond frog, the length of capillaries in 1 mm3 of brain tissue is about 160 mm, in a whole-headed cartilaginous fish - 500, in a shark - 100, in an ambystoma - 90, in a turtle - 350, in a hatteria - 100, in a shrew - 400, in a mouse – 700, in a rat – 900, in a rabbit – 600, in a cat and dog – 900, and in primates – 1200–1400 mm. It should be taken into account that as the length of the capillaries decreases, the area of their contact with the nervous tissue decreases exponentially. Therefore, to maintain a minimum level of oxygen supply to the brain, the shrew’s heart must contract several times more often than that of primates: in humans this value is 60–90, and in the shrew it is 130–450 beats per minute. In addition, the mass of the human heart is about 4%, and of shrews – 14% of the mass of the entire body.
So, the nervous system of mammals in the process of evolution has become an extremely “expensive” organ. The cost of maintaining the mammalian brain is comparable to the cost of maintaining the human brain, which in its inactive state accounts for approximately 8–10% of the energy expenditure of the entire organism. The human brain makes up 1/50 of the body's weight, and consumes 1/10 of all energy - 5 times more than any other organ. Let's add the costs of maintaining the spinal cord and peripheral system and we get: about 15% of the energy of the entire body at rest is spent on maintaining the activity of the nervous system. According to the most conservative estimates, the energy expenditure of the brain alone in an active state increases by more than 2 times. Taking into account the general increase in the activity of the peripheral nervous system and the spinal cord, we can confidently say that about 25–30% of all expenses of the human body are accounted for by the maintenance of the nervous system.
The less time the brain works intensively, the cheaper its maintenance is. Minimizing the time of intensive work of the nervous system is mainly achieved by a large set of innate, instinctive behavior programs that are stored in the brain as a set of instructions. In order to save energy, the brain is almost not used to make decisions based on the animal's personal experience. The paradox is that as a result of evolution, a tool was created to implement the most complex mechanisms of behavior, but the energy intensity of such a super-perfect nervous system turned out to be very high, so all mammals instinctively try to use the brain as little as possible.
Visitors to the site (www.nkj.ru) and readers of the journal “Science and Life” sent Professor S. V. Savelyev many questions regarding the evolution of the brain. We publish answers to some of them.
- How will the structure of the human brain change in the future, for example in 500 years?
I think that in the next 500 years the brain will not change structurally, because there are no prerequisites for its improvement. The computer and the Internet give a person the illusion of technical equipment with the deepest misunderstanding of where everything comes from. A child will not multiply by column when he has a calculator under his desk. All this leads to the fact that the load on the brain is continuously decreasing.
When computers were created, everyone said that people were getting smarter. Because programmers really spent enormous intellectual effort on creating new software products. But now programs write how to add cubes. The basics of programming seem to have been forgotten. Today, even programmers are not required to have the intellectual level that was necessary 10-15 years ago. And what can we say about other areas!
Previously, in the era of socialism, C grade students became excellent students in the West. Soviet people lived in a system of double standards that forced their brains to work. And this led to the fact that the brain was always tense, mobilized, and expended more energy. This means that more connections were formed between neurons per unit time, and therefore, more information could be “downloaded” into long-term memory into such a brain.
What were the positive and negative structural changes in the human brain from an evolutionary point of view?
It depends on what is considered positive and what is negative changes. The fact that a person has lost the ability to detect high-frequency signals above 20,000 Hz is probably a negative change. Although even now children under one year old can perceive them using a special brain structure that was once responsible for the perception of high-frequency signals in those days when a person was like a rat. Compared to other animals, humans have a very poorly developed sense of smell. Is this change negative or not? Very difficult to evaluate.
Negative and positive changes in the brain are dictated by the history of our species. At first, the sense of smell, and therefore the forebrain, played a fundamental role in it. Then there was a change of habitats. Our ancestors switched to living in trees. The sense of smell lost its functions, and vision became the leading sense organ. And it’s impossible to say whether it’s good or bad. Another thing is that the design of the brain could be more intelligent. After all, the olfactory forebrain, with which we think, essentially grew out of the reproductive system. Hence this endless human problem of sexual relations, which runs like a red thread through all human life. Sexual motivations have become the basic principles of thinking. This makes us aggressive and very unreasonable.
But our brain is what it is.
- Is it true that a person uses only 10% of his brain capacity?
If the brain works at 10%, the person will die instantly. The brain always works entirely - during sleep and wakefulness, thanks to which a person breathes in a dream, the heart beats, and the muscles are in good shape. Another thing is that when we sleep, the brain spends 9% of the body’s total energy, and in an active state - 25%.
Is the origin of such a complex object as the human brain explainable from the perspective of Darwin’s theory of evolution, according to which the evolutionary process is based on random variability (mutations) and natural selection?
Darwinian theory is constructed as a negative process in which the strongest do not survive, but the weakest perish. The basis of brain evolution is not Darwinian selection, not mutations, but individual intraspecific variability, which constantly exists in all populations. The direction of evolution is determined by whose genome is introduced into the next generation, not by whose genome disappeared in the previous one. It is individual variability that provides the basis for the preservation of certain functions in the population. It’s as if aliens arrived and started beating us with a huge colander, into the holes of which the smartest ones would slip through. Then those who think worse would simply disappear.
Is it true that the volume of a person’s brain determines his intelligence?
In the latest edition of the "Atlas of the Human Brain" I provide data on the size of the brains of talented and brilliant people. There are very few people on this list with a brain mass similar to that of the average person - about 1300 g. Mostly it is 1700-1800 g, that is, much more. And I have to admit that brain size matters a lot. After all, if you have several tens of billions more neurons than another person, this is about the same as arming yourself with a laptop instead of a regular calculator.
Sergey Savelyev,
Doctor of Biological Sciences
“Science and Life” No. 11, 2006
The road to recognition has always been and remains difficult. To get results while doing fundamental research, a true scientist neglects the usual earthly joys. And it’s good when the experiment ends positively. But if the result is negative, then the failed scientist evokes a feeling of pity among those around him. The biography of Sergei Savelyev can be assessed in different ways. On the one hand, he is known as a successful specialist. An authoritative expert in the scientific world. His works are referred to, his conclusions are quoted.
People who do not have the opportunity to “leave” Russia are pleased to know that a famous scientist is among their compatriots. A specialist who knows, if not everything, then a lot about the human brain. Sergei Savelyev was born on March 7, 1959 in Moscow. The only child in the family. At the same time, he had to communicate with “a whole lot” of cousins. From an early age, observing the behavior of his relatives and how each of them lived, he began to think about the reasons that prompt a person to certain actions.
At secondary school, Sergei studied well. Without thinking at all about his future career, the boy made a very specific conclusion - the stronger the student was physically, the worse he studied. It was much easier for such a representative of the human race to take money from the weak than to earn it. Observations of this kind did not particularly upset Savelyev, but they did not bring joy either. Later, he realized that a scientist should behave impartially when studying processes occurring in nature and society. Friends on the street considered him an eccentric, but did not offend him.
Scientific career
After graduating from school, Savelyev decided to get a higher education at the Moscow Pedagogical Institute at the Faculty of Biology and Chemistry. In 1983, having received his diploma, a qualified specialist began working at the Brain Institute at the Academy of Medical Sciences. The young specialist is not satisfied with research work at this institution. Literally a year later he was invited to the Research Institute of Human Morphology. Within the walls of this institute, Sergei Vyacheslavovich made all his discoveries and wrote a sufficient number of monographs.
If we talk about the personal life of a scientist, the conversation will be difficult. When Sergei turned 25, following the accepted rules, he started a family. The husband and wife lived under the same roof for almost five years and decided to separate. The details of the procedure are carefully hidden from public discussion. What is known is that a daughter was born in the marriage and today she is already a mature person. When asked how the divorce affected his scientific activity, Savelyev prefers not to answer. At the same time, he claims that love is nothing more than the sum of chemical reactions and smells.
In recent years, Professor and Doctor of Biological Sciences Savelyev has devoted a lot of time to popularizing scientific research. He willingly shares his results and never tires of retelling complex biological processes in simple and even primitive language. On television, the professor is a welcome guest. Popular science films that are posted on the Internet attract an audience of thousands.
Sources:
- Sergey Savelyev
Professor Savelyev is a fairly well-known personality in scientific circles. Works as the head of a laboratory engaged in medical research of the nervous system. Sergei Savelyev is the first scientist to photograph a human embryo at the age of 11 days. His scientific works include studies of genetic diseases and the evolution of the theory of the nervous system.
Biography
The future scientist was born in the Russian capital in 1959. From his school days, he showed a keen interest in exact sciences. That’s why he chose the biology department at the Moscow State Pedagogical Institute for further studies.
After graduation, he went to work at the Brain Institute at the USSR Academy of Sciences. Later I worked at a research institute studying human morphology.
His main hobby was photography, he even joined the Union of Russian Artists and Photographers.
Who is this scientist
- evolutionist,
- paleoneurologist,
- author of scientific works,
- Professor,
- Doctor of Biological Sciences
Scientific works
Professor Savelyev devoted three decades of his life to questions of morphology and stages of evolution of the human brain. His personal library contains over ten of his own monographs and about a hundred research articles.
His world-class invention is a stereoscopic atlas of the human brain, for which he was awarded a prize named after him. V. Shevkunenko from the Russian Academy of Sciences. His scientific work was recognized as the best.
The professor's works in the medical field of embryonic pathologies are widely known. He developed a scientific method for diagnosing the nervous system. During this period, Sergei Vyacheslavovich made his next discovery - he photographed a living, developing human embryo at 11 days of age. He described moments of crisis that occur during disruptions in the formation of the human nervous system during embryonic development (strictly by day). Their manifestations provoke the development of brain pathologies already in adulthood.
He did not stop there and continued research into the early, prenatal embryonic development of the brain in many vertebrates. He brilliantly proved the theory that the further development of a cell does not depend at all on the genetically embedded code, but solely on biomechanical influence. Simply put, he found a refutation of the fact of the manifestation and inheritance of genetic diseases.
The nervous system of a reasonable person and the theory of its origin are also of keen interest to Sergei Savelyev. Just like its current stage of evolution. Thanks to these studies, the professor deduced the features of the evolution of the reaction of the nervous system itself. He proved a theory about the influence of the environment, which is called transitional. It affects the proper development of the neurobiological state of chordates, as well as birds, mammals, reptiles and other living beings. In his writings, he described real-life examples to which the laws of neurobiology can be applied. All this expanded the boundaries of the scientific community’s vision of the stages of development of animals (vertebrates and invertebrates).
Mammoth brain
An interesting area of Savelyev’s activity is the study of the brain of a mammoth that died and froze in the ice. Since 2013, he personally led a team of scientists who worked on this issue. The group of researchers included representatives of the Russian Academy of Medical Sciences, as well as specialists from the Yakut Scientific Academy and the Museum of Paleontology of the Russian Academy of Sciences.
Thus, for the first time in history, scientists were able to create a 3D model of the brain of this ancient animal. This happened in 2014.
Sexual Behavior Research
Doctor of Biological Sciences Sergei Vyacheslavovich in 2014 headed a research experiment called “Gecko”. It explored the relationship between microgravity and sexual behavior. The test subjects were ordinary geckos; they were sent in the embryonic stage to an active Earth satellite, which is in orbit. The sexual activity of geckos in a state of weightlessness was studied for two months.
Schizophrenia and giftedness
One of Savelyev's latest studies was the assessment of cerebral sorting. A unique methodology for analyzing the superpowers and talents of gifted people by assessing the structure of the brain using a high-precision medical tomograph. The purpose of creating a sorting is to provide every person with the opportunity to reach their maximum potential. Thanks to this practical study of brain tissue on a tomograph, now all people can find their place and their calling, including those who are not so successful in the race for survival. That is, Savelyev essentially, with his discovery, refuted the offensive theory of natural selection, equalizing all people in the search for their hidden capabilities.
Pedagogy
Of course, the professor combines scientific work with teaching. He gives lectures to audiences of students at Moscow State University. He also conducts teaching activities on a permanent basis at the Department of Zoopsychology of Vertebrates, where he teaches students the comparative anatomy of the nervous system of vertebrate creatures.
Books by Savelyev
- "Brain Poverty"
- "Cerebral sorting"
- "Stereoscopic atlas of the human brain"
- "Mirizzi syndrome (diagnosis and treatment)"
- "Atlas of the Human Brain"
- "Variability and Genius"
- "The Origin of the Brain"
- "The Emergence of the Human Brain"
- "Stages of embryonic development of the human brain"
- "Hernia and its secrets"
- “Aplanat. The Art of Photography"
And others.
"Brain Poverty"
The author of the book, according to his life observations, concluded that a person living today will have to develop through banal primitivization. That is, he will begin to become poor intellectually and physically weaken.
According to Savelyev, scientists are deeply mistaken that human individuals have the main function aimed at reproduction. However, he also called the theory of the conditioned reflex the fanaticism of religious and scientific fans; he treated such inventions as cloning and stem cells without respect and with criticism. In his opinion, today’s people with their similar research can only be justified by their inherent social instincts.
This is exactly what Sergei Savelyev writes about in one of his sensational books called “Poverty of the Brain.” The book blew up the Russian scientific world. After all, it revealed the peculiarities of human behavior that arose not as a result of natural selection, but due to the special structure of the human brain.
He covered no less paradoxical topics, such as individualism, non-standard development of thinking, sexual differences, duality of thinking, etc. In the same book, he analyzed the stages of the formation of people's instincts, the features of the development of community.
Non-standard assessments and conclusions of a modern scientist cause not only inspiration and delight, but also sharp criticism.
Some opponents look for scientific errors in his books and point out the incorrect use of terms. According to critics, Savelyev turns to rhetoric, rather than scientific justification, to convince a wide range of readers that he is right, turning his works from monographs into tabloid journalism. A number of well-known scientists insist that readers should not take the professor's conclusions at his word, especially in the field of genetics. Thus, according to Doctor of Biological Sciences Svetlana Borinskaya, who condemned the professor’s works, unsubstantiated and blind faith in scientific statements and theories is very dangerous, and this is exactly what Savelyev’s “Human Genome” program is.
And yet, books and articles by Sergei Vyacheslavovich, thanks to the original scientific approach and the novelty of proven theories, are incredibly popular both among the scientific community and among ordinary readers.
The monograph is devoted to the nature of the human brain and the morphofunctional foundations of giftedness and genius.
The basic principles of the individual structure of the brain, which underlie the uniqueness of each person, are described. The fundamental reasons for the hidden contradictions of consciousness and biological motivations in decision making are shown.
The section of the book devoted to giftedness reveals the fundamental features of the brain structure of geniuses and the nature of the non-standard nature of their thinking and behavior.
Stages of embryonic human brain development
The original material describes human development, from blastocyst implantation to the end of the 2nd month of embryonic development. A comparison of various methods of periodization of human ontogenesis is carried out.
The period of formation of the primitive streak and neurulation is described using embryonic material from human development. More than 10 developmental substages have been introduced, making it possible to more accurately identify the age of human embryos than before. The described stages of development are illustrated with graphic reconstructions, macroscopic and histological photographs.
Reader comments
Alexander 12/ 07/18/2019 Great scientist! Buy real books on the publisher's website, comrades!
Alexei/ 07/05/2019 Some specialists (cardiologists) believe that the presence of carbon dioxide in the blood improves oxygen exchange in tissues, including the brain. The Frolov Trainer device has been developed, which allows you to increase the percentage of carbon dioxide in the blood. Is it true? Help me understand.
Vladimir/ 03/21/2019 Sergey! “Let the Chinese launch their project, they will still take brains from Russia.” But the Chinese “Absolutely” do not need illiterate people.
Sergey/ 03/05/2019 From my youth I was singled out as a special person, all my bosses tried to make me their person. But I wanted to lay my own ladder. but it turned out to be not easy. But everything turned out to be simpler, there was no need to try to teach fools anything, but you had to look with a big brain. It’s a pity that only five years ago I learned from Savelyev the difference between us. And he is absolutely right. Many thanks to Sergey Vyacheslavovich Savelyev. And let the Chinese launch their project, they will still take brains from Russia.
Vladimir/ 01/18/2018 It presents an interesting analysis of cause-and-effect relationships in life that people prefer not to notice, not talk about, and immediately forget about.
Konstantin/ 10/13/2017 Another expert on all issues. With a self-confident air he speaks about politics, history, economics and a bunch of other areas in which he doesn’t really understand anything. Google “Savelyev criticism”, you will find a lot of interesting things.
guest/ 04/11/2017 guest, knigi na flibusta.is naslazhdaites" :)
Eugene/ 03/31/2017 I hope for sanity, what is the harmony of people selected by sorting in the future with brain variability or is it also sorted?
Sergey/ 01/21/2017 Hello Sergey. I watched your videos about the brain and death, everything is very convincing, and how do you feel about extrasensory perception and clairvoyance (Vanga), Natalya Bekhtereva at the end of her life said that there is something there. If you can comment in more detail. Thank you, best regards Sergey. I apologize for the mistakes.
Roxanne Meadows/ 10/24/2016 I am for Jacques Fresco. He has extensive knowledge.
Andrey/ 10/5/2016 I began to be interested in the work of the brain in the 80s. I became interested in psychology, almost professionally, with experiments, but I could not understand much. Only after listening to S. Savelyev’s speeches did much become clear and explainable.
Thank you very much Sergey Vyacheslavovich!
Stanislav/ 08/20/2016 Evgeniy, I absolutely agree! With Buddhism, etc. To understand the ultimate world order, it is useful to familiarize yourself with it, but in everyday life it is useless, and the brain uses it to save resources.
Eugene/ 04/05/2016 Thanks to Savelyev: He straightened my brain after Advaita, Buddhism, and other linguistic structures from all kinds of gurus - my applause.