History of development of biology. Development of modern biology. Biology in the first half of the 19th century
Lecture Search
| 1) | Open diaphragm. |
| 2) | Determine the magnification of the eyepiece and microscope objective. |
| 3) | Set the microscope in a comfortable position in front of you at a palm-width distance from the edge of the desk. |
| 4) | By turning the macroscrew, set the tube in such a position that the distance from the lens to the stage is no more than 1 cm. |
| 5) | Wipe all the lenses with a clean cloth, put the microscope in a special case. |
| 6) | Place the preparation on the microscope stage and, looking from the side, lower the objective with the screw until the distance is 4-5 mm. |
| 7) | Slowly turn the macro screw to achieve a sharp image of the subject |
| 8) | While looking into the eyepiece, rotate the mirror to achieve uniform maximum illumination of the field of view. |
What concept should be entered in place of the gap in this table?
19. A microbiologist wanted to know how fast one type of bacteria multiplies in different nutrient media. He took two flasks, filled them halfway with different nutrient media, and placed approximately the same number of bacteria in them. Every 20 minutes, he took samples and counted the number of bacteria in them. The data of his research are reflected in the table.
Study the table "Change in the rate of reproduction of bacteria over a certain time" and answer the questions.
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Biology
1868 - discovery of the pattern of hereditary traits
Gregor Johann Mendel (1822-1884). Austrian naturalist. Engaged in experiments on hybridization of peas, he traced the inheritance of parental traits in the offspring of the first and second generations and came to the conclusion that heredity is determined by constancy, independence and free combination of traits.
1892 - the theory of heredity
August Weisman (1834-1914).
German biologist. Observations of the developmental cycle of protozoa led Weisman to the hypothesis of the continuity of the "germ plasm", and he saw in this cytological arguments about the impossibility of inheriting acquired traits - a conclusion that is important for the development of the theory of evolution and Darwinism.
Weisman emphasized the sharp difference between inherited traits and acquired traits, which, as Weisman argued, are not inherited.
He was the first to understand the fundamental role of the chromosome apparatus in cell division, although at that time he could not prove his assumptions due to the lack of experimental scientific data.
1865-1880s - biochemical theory of fermentation. Pasteurization. Research in the field of immunology
Louis Pasteur (1822-1895). French scientist, whose works laid the foundation for the development of microbiology as an independent scientific discipline.
Pasteur developed the biochemical theory of fermentation; he showed that microorganisms play an active role in this process. As a result of these studies, a method was developed to protect wine, beer, milk, fruit juices and other food products from spoilage, a process later called pasteurization.
From the study of fermentation processes, Pasteur moved on to the study of pathogens of infectious diseases in animals and humans and the search for methods to combat these diseases. Pasteur's outstanding achievement was the discovery of the principle of protective vaccinations against chicken cholera, anthrax in cattle, and rabies.
The method of preventive vaccination developed by him, in which active immunity is developed in relation to the causative agent of the disease, has become widespread throughout the world. His studies of pathogenic microbes served as the basis for the development of medical microbiology and the study of immunity.
1846 - discovery of ether anesthesia. U.
Morton, American physician.
1847 - the first use of ether anesthesia and plaster casts in the field
19th century medicine
Nikolai Ivanovich Pirogov (1810-1881).
Russian surgeon and anatomist, whose research laid the foundation for the anatomical and experimental direction in surgery; founder of the military field surgery.
The rich personal experience of a military surgeon allowed Pirogov to develop for the first time a clear system for organizing surgical care for the wounded in the war. He proposed and put into practice a fixed plaster cast for gunshot wounds (during the Crimean War of 1853-1856). The resection operation developed by Pirogov elbow joint contributed to the limitation of amputations. Pirogov's practical experience in the use of various antiseptic substances in the treatment of wounds (iodine tincture, bleach solution, silver nitrate) anticipated the work of the English surgeon J.
Lister on the creation of antiseptics. In 1847, Pirogov published a study on the effect of ether on the animal organism. He proposed a number of new methods of ether anesthesia (intravenous, intratracheal, rectal), created devices for the introduction of anesthesia. Pirogov investigated the essence of anesthesia; he pointed out that the narcotic substance has an effect on the central nervous system through the blood, regardless of the route of its introduction into the body.
At the same time, Pirogov paid special attention to the presence of sulfur impurities in the ether, which can be dangerous for humans, and developed methods for cleaning the ether from these impurities. In 1847, Pirogov was the first to use ether anesthesia in the field.
1863 - research by I. M. Sechenov "Reflexes of the brain"
Ivan Mikhailovich Sechenov (1829-1905).
Russian naturalist, materialist thinker, founder of the Russian physiological school, founder of the natural science trend in psychology.
Sechenov dealt with many problems of physiology and psychology. However, his "Reflexes of the Brain" are of the greatest importance, where for the first time the problems of psychology were solved from the standpoint of physiology, from the standpoint of natural science.
1867-1880s
Discovery of antiseptics
Joseph Lister (1827-1912). English surgeon, famous for introducing antiseptics into medical practice. Based on the works and clinical data of N. I. Pirogov, L. Pasteur and others, Lister, as a result of many years of research, developed methods for disinfecting wounds with a solution of carbolic acid.
He was also offered an antiseptic dressing impregnated with carbolic acid. Lister also developed new methods of surgical technique, in particular, he introduced antiseptic absorbable catgut as a material for surgical sutures.
1895 - discovery of conditioned reflexes. Research in the field of higher nervous activity.
Ivan Petrovich Pavlov (1849-1936). Russian physiologist, creator of the doctrine of the higher nervous activity of animals and humans.
They have done exceptional research on the work of cardio-vascular system of a person, according to the physiology of digestion, according to the functions of the cerebral hemispheres, the principle of reflex self-regulation of all body systems has been proved, conditioned reflexes have been discovered.
Development of biology in the 19th century
The most significant events of the first half of the 19th century were the formation of paleontology and the biological foundations of stratigraphy, the emergence of cell theory, the formation of comparative anatomy and comparative embryology. The central events of the second half of the 19th century were the publication of Charles Darwin's On the Origin of Species and the spread of the evolutionary approach to many biological disciplines.
cell theory
The cell theory was formulated in 1839.
German zoologist and physiologist T. Schwann. According to this theory, all organisms have a cellular structure. The cell theory asserted the unity of the animal and plant world, the presence of a single element of the body of a living organism - the cell. Like any major scientific generalization, the cell theory did not emerge suddenly: it was preceded by separate discoveries by various researchers.
IN early XIX V. attempts were made to study the internal contents of the cell.
In 1825, the Czech scientist J. Purkynė discovered the nucleus in the egg of birds. In 1831, the English botanist R. Brown first described the nucleus in plant cells, and in 1833 he came to the conclusion that the nucleus is an essential part of the plant cell.
Thus, at this time, the idea of the structure of the cell changes: the main thing in its organization was considered not the cell wall, but the contents.
The German botanist M.
Schleiden, who established that the body of plants consists of cells.
Numerous observations regarding the structure of the cell, generalization of the accumulated data allowed T.
Schwann in 1839 to draw a number of conclusions, which were later called the cell theory. The scientist showed that all living organisms consist of cells, that the cells of plants and animals are fundamentally similar to each other.
Cell theory includes the following main provisions:
1) A cell is an elementary unit of the living, capable of self-renewal, self-regulation and self-reproduction, and is a unit of structure, functioning and development of all living organisms.
2) The cells of all living organisms are similar in structure, chemical composition and the main manifestations of life.
3) Cell reproduction occurs by dividing the original mother cell.
4) In a multicellular organism, cells specialize in functions and form tissues from which organs and their systems are built, interconnected by intercellular, humoral and nervous forms of regulation.
The creation of cell theory has become major event in biology, one of the decisive proofs of the unity of living nature.
The cell theory had a significant impact on the development of biology as a science, served as the foundation for the development of such disciplines as embryology, histology and physiology.
It made it possible to create the foundations for understanding life, individual development organisms to explain the evolutionary relationship between them. The main provisions of the cell theory have retained their significance even today, although for more than one hundred and fifty years new information has been obtained on the structure, vital activity and development of the cell.
The evolutionary theory
A revolution in science was made by the book of the great English natural scientist Charles Darwin, "The Origin of Species", written in 1859. Summarizing the empirical material of contemporary biology and breeding practice, using the results of his own observations during his travels, he revealed the main factors in the evolution of the organic world.
In the book "Changing Domestic Animals and Cultivated Plants" (1868), he presented additional factual material to the main work. In the book "The Origin of Man and Sexual Selection" (1871), he put forward the hypothesis of the origin of man from an ape-like ancestor.
The essence of the Darwinian concept of evolution is reduced to a number of logical, experimentally verified and confirmed by a huge amount of factual data provisions:
1) Within each species of living organisms, there is a huge range of individual hereditary variability in morphological, physiological, behavioral and any other characteristics.
This variability may be continuous, quantitative, or discontinuous qualitative, but it always exists.
2) All living organisms reproduce exponentially.
3) Life resources for any kind of living organisms are limited, and therefore there must be a struggle for existence, either between individuals of the same species, or between individuals different types, or with natural conditions. In the concept of "struggle for existence" Darwin included not only the actual struggle of an individual for life, but also the struggle for success in reproduction.
4) In the conditions of the struggle for existence, the most adapted individuals survive and give offspring, having those deviations that accidentally turned out to be adaptive to given environmental conditions.
This is a fundamentally important point in Darwin's argument. Deviations do not occur in a directed way - in response to the action of the environment, but by chance. Few of them are useful in specific conditions. The descendants of a surviving individual who inherit a beneficial variation that allowed their ancestor to survive are better adapted to the environment than other members of the population.
5) The survival and preferential reproduction of adapted individuals Darwin called natural selection.
6) The natural selection of individual isolated varieties under different conditions of existence gradually leads to divergence (divergence) of the characteristics of these varieties and, ultimately, to speciation.
At the heart of Darwin's theory is the property of organisms to repeat in a number of generations similar types of metabolism and individual development in general - the property of heredity.
Heredity, together with variability, ensures the constancy and diversity of life forms and underlies the evolution of living nature. One of the basic concepts of his theory of evolution - the concept of "struggle for existence" - Darwin used to denote the relationship between organisms, as well as the relationship between organisms and abiotic conditions, leading to the death of the less adapted and the survival of the more adapted individuals.
Darwin identified two main forms of variability:
A certain variability - the ability of all individuals of the same species in certain environmental conditions to respond in the same way to these conditions (climate, soil);
Uncertain variability, the nature of which does not correspond to changes in external conditions.
In modern terminology, indefinite variability is called a mutation.
Mutation - indefinite variability, in contrast to a definite one, is hereditary in nature. According to Darwin, minor changes in the first generation are amplified in subsequent ones. Darwin emphasized that it is precisely indefinite variability that plays a decisive role in evolution. It is usually associated with deleterious and neutral mutations, but mutations that turn out to be promising are also possible. The inevitable result of the struggle for existence and the hereditary variability of organisms, according to Darwin, is the process of survival and reproduction of organisms that are most adapted to environmental conditions, and death in the course of evolution of the unadapted - natural selection.
The mechanism of natural selection in nature operates similarly to breeders, i.e.
adds up minor and indefinite individual differences and forms from them the necessary adaptations in organisms, as well as interspecies differences. This mechanism discards unnecessary forms and forms new species.
The thesis of natural selection, along with the principles of the struggle for existence, heredity and variability, is the basis of Darwin's theory of evolution.
Cell theory and Darwin's theory of evolution are the most significant achievements of biology in the 19th century.
But I think that other rather important discoveries should also be mentioned.
With the development of physics and chemistry, there are also changes in medicine. Over time, the areas of application of electricity are becoming more and more. Its use in medicine marked the beginning of electro- and iontophoresis. The discovery of X-rays by Roentgen aroused particular interest among physicians. The physics laboratories where the equipment used by Roentgen to produce X-rays were created were attacked by doctors and their patients, who suspected that they contained needles, buttons, etc., once swallowed.
The history of medicine has never known such a rapid implementation of discoveries in the field of electricity, as happened with a new diagnostic tool - x-rays.
WITH late XIX century, experiments on animals begin to determine the threshold - dangerous - values of current and voltage. The determination of these values was caused by the need to create protective measures.
A significant discovery in the field of medicine and biology was the discovery of vitamins.
Back in 1820, our compatriot P. Vishnevsky for the first time suggested the existence of a certain substance in antiscorbutic products that contributes to the proper functioning of the body.
The actual discovery of vitamins belongs to N. Lunin, who proved in 1880 that food contains certain vital important elements. The term "vitamins" is derived from the Latin roots: "vita" - life and "amine" - nitrogen compound.
In the 19th century, the fight against infectious diseases began.
The English doctor Jenner invented the vaccine, Robert Koch discovered the causative agent of tuberculosis - Koch's bacillus, and also developed preventive measures against epidemics and created medicines.
Development of microbiology in the 19th century
Louis Pasteur gave the world new science- microbiology.
This man, who made a number of the brightest discoveries, had to defend his truths in useless disputes all his life. Natural scientists all over the world have been debating whether or not there is a "self-generation" of living organisms.
Pasteur did not argue, Pasteur worked. Why does wine ferment? Why does milk sour? Pasteur established that the process of fermentation is a biological process caused by microbes.
In Pasteur's laboratory, there is still an amazingly shaped flask - a fragile structure with a bizarrely curved spout.
More than 100 years ago, young wine was poured into it. It has not turned sour to this day - the secret of the form protects it from fermentation microbes.
Pasteur's experiments were great importance to create sterilization and pasteurization methods (heating a liquid to 80°C to kill microorganisms and then rapidly cooling it) of various products.
He developed methods of protective vaccinations against contagious diseases. His research served as the basis for the teachings on immunity.
Genetics
The author of these works, the Czech researcher Gregor Mendel, showed that the characteristics of organisms are determined by discrete hereditary factors. However, these works remained practically unknown for almost 35 years - from 1865 to 1900.
Galen (129 or 131 - about 200 or 217) - Roman physician, surgeon and philosopher. Galen made significant contributions to the understanding of many scientific disciplines, including anatomy, physiology, pathology, pharmacology, and neurology, as well as philosophy and logic. His anatomy based on the dissection of monkeys and pigs. His theory that the brain controls movement through the nervous system is still relevant today. Andreas Vesalius (1514-1564) - physician and anatomist, life physician of Charles V, then Philip II.
A younger contemporary of Paracelsus, the founder of scientific anatomy. The main work "On the structure human body". Vesalius dissected human corpses to illustrate his words. The book contains a thorough study of the organs and the entire structure of the human body.
William Harvey (1578-1657) - English physician, anatomist, physiologist, embryologist of the first half of XVII century, known for discovering the large and small circles of blood circulation.
The founder of modern physiology and embryology .. In the works "Anatomical Study of the Movement of the Heart and Blood in Animals" (1628), he outlined the doctrine of blood circulation, which refuted the ideas that had prevailed since the time of Galen. For the first time he expressed the idea that "every living thing comes from an egg." Francesco Redi (1626-1698), Italian naturalist, physician and writer.
To prove the impossibility of spontaneous generation of flies from rotten meat, in his experiment he isolated meat from flies
10350506477000-10350516764000 Robert Hooke (1635 - 1703) - English naturalist, scientist-encyclopedist. He was the first to use a microscope to study plant and animal tissues. Studying the cut of the cork and the core of the elderberry, I noticed that many cells are introduced into their composition.
He gave them the name cage. Introduced the term "cell" into biology, although R. Hooke did not see the actual cells, but the shells of plant cells. Anthony van Leeuwenhoek (1632-1723) - Dutch naturalist, member of the Royal Society of London, discovered protozoa (microbes). One of the founders of scientific microscopy.
Having made lenses with 150-300-fold magnification, for the first time he observed and sketched (publications since 1673) a number of protozoa, spermatozoa, bacteria, erythrocytes and their movement in capillaries.
Carl Linnaeus (1707 - 1778) - Swedish naturalist, naturalist, botanist, zoologist, mineralogist, doctor, XVIII century.
The founder of the biological taxonomy of the plant and animal world, Linnaeus was the first to use the binary nomenclature of the species name and built the most successful artificial classification of plants and animals, described about 1500 plant species. Karl advocated the permanence of species and creationism. The author of "The System of Nature" (1735), "Philosophy of Botany" (1751) and others. Spallanzani (Spallanzani) Lazzaro (1729-1799), Italian naturalist. For the first time he proved the impossibility of spontaneous generation of microorganisms (experiments with broth), carried out artificial insemination in amphibians and mammals.
Preformist
Edward Anthony Jenner (1749-1823) was an English physician who developed the world's first vaccine against smallpox by inoculating the cowpox virus, which is harmless to humans.
"No doctor has saved the lives of such a significant number of people as this man" J.-B. Lamarck (1744-1829) the great French naturalist and biologist of the late 18th and early 19th centuries, known for having created the first scientific theory of the evolution of the living world. Introduced the terms "biology" (1802), "zoology of invertebrates" (1794) and determined their content. Laid the foundations of taxonomy of invertebrates. He developed the basic principles for the classification of plants and animals in the form of a family tree from protozoa to humans.
Created the first evolutionary theory.
His main scientific work is the two-volume "Philosophy of Zoology" (1809)
1905-44450012649205715000 Charles Robert Darwin (1809-1882) - the great English naturalist and biologist of the mid-19th century, naturalist, traveler, creator of Darwinism, foreign corresponding member.
Known for creating the theory of evolution based on the struggle for existence and natural selection. He singled out three forms of the struggle for existence: intraspecific, interspecific and with adverse conditions.
Wallace Alfred Russell (1823–1913), English naturalist and writer
who simultaneously created the theory of natural selection with Charles Darwin
Matthias Jakob Schleiden (1804-1881) German botanist.
made his discoveries in the field of cytology, one of the authors of the cell theory.
1838, M. Schleiden proved that the nucleus is an essential component of all plant cells Theodor Schwann (1810 - 1882)
German cytologist, histologist and physiologist, author of the cell theory.
He made his discoveries in the field of cytology.
Nikolai Ivanovich Pirogov (1810-1881) - Russian surgeon and anatomist, naturalist and teacher, public figure, founder of military field surgery and anatomical and experimental direction in surgery (gr.
from cheir - hand and ergon - work). Known in science for being the first to use anesthesia in surgery. Gregor Johann Mendel (1822-1884) - Austrian naturalist, botanist and religious figure, Augustinian monk, abbot.
Founder of the doctrine of heredity (Mendelism).
Using statistical methods to analyze the results of hybridization of pea varieties, the scientist formulated the patterns of heredity (Mendel's laws), which was the first step towards modern genetics.
147828017907000 Louis Pasteur (1822 - 1895) - French scientist, one of the founders of stereochemistry, microbiology and immunology.
First time vaccinated against rabies. In 1864, he proposed a method of disinfecting wine by heating it for a long time to 50-60 ° C, which bears the name "Pasteurization" in his honor. In 1860-1862, the scientist experimentally refuted the hypothesis of spontaneous generation of microorganisms (experiments with broth and a flask with an S-shaped neck).
1060453048000 Sechenov Ivan Mikhailovich (1829-1905)
Founder of the Russian school of physiologists. Proved that mental life is the result of the activity of human brain cells
established the nature of mental phenomena, which are based on physiological processes - reflexes
Botkin Sergei Petrovich (1832 -1889)
Russian therapist.
He created a doctrine according to which the body is a single whole, and the nervous system plays a leading role in its life and communication with the external environment.
Pavlov Ivan Petrovich (1849-1936) - Russian scientist, physiologist, creator of the doctrine of higher nervous activity. Classical works on the physiology of blood circulation and digestion (Nobel Prize, 1904).
He studied the physiology of digestion, the higher nervous activity of animals and humans.
Revealed the mechanisms of occurrence of conditioned reflexes
Timiryazev Kliment Arkadievich (1843-1920) an outstanding Russian botanist and physiologist, researcher of the process of photosynthesis, supporter and popularizer of Darwinism.
Ilya Ilyich Mechnikov (1845-1916) made his discoveries in the field of botany Ilya Ilyich Mechnikov (1845-1916) was a Russian biologist and pathologist, one of the founders of comparative pathology, evolutionary embryology and Russian microbiology and immunology.
Nobel laureate, creator of the theory of phagocytosis and the cellular theory of immunity
Paul Ehrlich (1854-1915). - German physician, immunologist, bacteriologist, chemist, founder of chemotherapy. Winner of the Nobel Prize (1908) for the discovery of humoral immunity. Ukhtomsky Alexey Alekseevich (1875 - 1942)
Renowned physiologist. Created the doctrine of the dominant (principle of the dominant)
Burdenko Nikolai Nilovich (1876-1946) Russian surgeon. Creator of the experimental surgical school.
Developed operations on the spinal cord.
Vladimir Ivanovich Vernadsky (1863 - 1945) - Russian and Soviet naturalist, thinker and public figure of the late 19th century and the first half of the 20th century, known for creating the doctrine of the biosphere and noosphere. One of the representatives of Russian cosmism; creator of the science of biogeochemistry.
Oparin Alexander Ivanovich (1894 - 1980), biochemist, founder of technical biochemistry.
In 1922, he put forward a biochemical theory of the origin of life. According to Oparin's theory, all life on Earth arose from coacervates - self-organizing high-molecular structures that spontaneously formed in the "primary ocean". Oparin's theory became the foundation of evolutionary biochemistry.
John Haldane (1860-1936). - An English scientist in 1929, independently of Oparin A.I., put forward a biochemical hypothesis of the origin of life.
Watson and Crick developed the DNA model in 1953. Nobel Prize in Physiology or Medicine, 1962 James Watson with Francis Crick and Maurice G.F. Wilkins
As scientific research unfolded in the 19th and early 20th centuries, a system of special institutions, institutions and societies, including international ones, was created. For example, in 1875 the International Bureau of Weights and Measures was founded, in 1912 the Bureau of Time. It has become common practice to hold national and international scientific conferences, congresses, symposiums; scientists different countries constantly exchanged experience. Throughout the 19th century a system educational institutions for the training of various kinds of specialists, the professions of a technician, engineer, and many others appeared.
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| L. Pasteur demonstrates a scientific experiment. Photo from the end of the 19th century. |
Geography
Throughout the 19th century extensive geographical discoveries. At the beginning of the century, the last continent, Antarctica, was discovered; Pacific Ocean, interior regions of Africa, Australia, South America, Central Asia. By the end of the century, there were no unknown countries and peoples left on the planet. Geological research led to the discovery of new mineral deposits and contributed to the development of the mining industry. As independent areas of scientific research appeared oceanography, meteorology and many other scientific disciplines.
On this page, material on the topics:
The development of science in the 19th and early 20th centuries
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In the 18th century the fundamental "System of Nature" (1735 and later), based on the recognition of the immutability of the originally created world, was given by K. Linnaeus, using binary nomenclature.
A supporter of limited transformism, J. Buffon, built a bold hypothesis about the past history of the Earth, dividing it into a number of periods, and, unlike creationists, attributed the appearance of plants, animals, and humans to the last periods.
With experiments on hybridization, J. Kölreuter finally proved the existence of sexes in plants and showed participation in the fertilization and development of both eggs and pollen of plants (1761 and later). J. Senebier (1782) and N. Saussure (1804) established the role of sunlight in the ability green leaves give off oxygen and use carbon dioxide in the air to do this. In con. 18th century L. Spallanzani carried out experiments that refuted the idea that until then dominated biology in the possibility of spontaneous generation of organisms.
Already from the 2nd floor. 18th century and at the beginning of the 19th century. more and more insistently, in one form or another, ideas of the historical development of living nature arise. C. Bonnet developed (1745, 1764) the idea of the "ladder of beings", which was interpreted by J. B. Lamarck (1809) in evolutionary terms. The evolutionary ideas of Lamarck at that time were not successful and were criticized by many scientists, among whom was J. Cuvier, the founder of comparative anatomy and paleontology of animals, who put forward (1812) the doctrine of catastrophes , a doctrine that considers the geological history of the Earth as an alternation of long epochs of relative rest and relatively short catastrophic events that dramatically transformed the face of the planet.
The theory of catastrophes was brought to its logical conclusion by Cuvier's student A. D'Orbigny, who counted 27 catastrophes in the history of the Earth, after which living organisms allegedly arose as a result of new divine "acts of creation".
Anti-evolutionary concepts of Cuvier were established in 1830. as a result of a discussion with E. Geoffroy Saint-Hilaire, who tried to substantiate the natural-philosophical doctrine of the "unity of the structural plan" of animals and allowed the possibility of evolutionary changes under the direct influence of the external environment.
The idea of the development of organisms found convincing confirmation in the embryological studies of K. F. Wolf (1759, 1768), H. Pander (1817) and K. M. Baer (1827), in the establishment by Baer of the principles of comparative embryology of vertebrates (1828-37). Justified by T. Schwann (1839), the cellular theory played a huge role in understanding the unity of the organic world and in the development of cytology and histology.
In the middle of the 19th century the features of plant nutrition and its difference from animal nutrition were established, and the principle of the circulation of substances in nature was formulated (Yu. Liebig, J. B. Boussengo).
In animal physiology, major successes were achieved by the works of E. Dubois-Reymond, who laid the foundations of electrophysiology, C. Bernard, who elucidated the role of a number of secretory organs in digestion (1845, 1847) and proved the synthesis of glycogen in the liver (1848), H. Helmholtz and K. Ludwig who developed methods for studying the neuromuscular system and sensory organs. I. M. Sechenov laid the foundations for a materialistic understanding of higher nervous activity (“Reflexes of the Brain”, 1863). L. Pasteur finally refuted the possibility of spontaneous generation of organisms (1860-1864). S. N. Vinogradsky discovered (1887-91) bacteria capable of forming organic substances from inorganic substances by chemosynthesis. D. I. Ivanovsky discovered (1892) viruses.
The largest conquest of the 19th century. was the evolutionary teaching of Charles Darwin, set forth by him in his work "The Origin of Species ..." (1859), in which he revealed the mechanism of the evolutionary process by means of natural selection. The affirmation of Darwinism in biology contributed to the development of a number of new areas: evolutionary comparative anatomy (K. Gegenbaur), evolutionary embryology (A. O. Kovalevsky, I. I. Mechnikov), evolutionary paleontology (V. O. Kovalevsky).
Great strides were made in the 1970s and 1980s. 19th century in the study of complex processes of cell division (E. Strasburger, 1875; W. Flemming, 1882, etc.), maturation of germ cells and fertilization (O. Hertwig, 1875 and later; G. Fol, 1877; E. van Beneden, 1884 ; T. Boveri, 1887, 1888) and the patterns of distribution of chromosomes associated with them in mitosis and meiosis, gave rise to many theories that looked for carriers of heredity in the nucleus of germ cells (F. Galton, 1875; K. Negeli, 1884; E. Strasburger, 1884 ; A. Weisman, 1885-1892; X. De Vries, 1889).
The Austrian naturalist Gregor Mendel in 1868 discovered the patterns of hereditary traits. However, they remained unnoticed until 1900, when they were confirmed and formed the basis of genetics.
Thus, in the XVII - XIX centuries. in the field of natural science, the science of biology was created and developed - as a set of sciences about wildlife.
1.2 Development of evolutionary ideas
Evolution means a gradual, regular transition from one state to another. Biological evolution is understood as the change in populations of plants and animals in a number of generations, directed by natural selection. Over the course of many millions of years, beginning with the emergence of life on Earth, as a result of a continuous, irreversible, natural process of replacing some species by others, the animal and plant forms that exist today have been formed.
The idea that organisms evolve over generations has intrigued many naturalists. The idea that modern living organisms evolved from simpler, primitive ones has long lived in the minds of people.
The first systematization of material on plants and animals was made by the famous Swedish scientist Carl Linnaeus in 1735. On the basis of one or two features (mainly morphological), he classified plants and animals into species, genera, and classes. He took the form as the unit of classification.
The contribution of K. Linnaeus to the progressive development of natural science is enormous: he proposed a system of animals and plants; introduced a binary system of double names; described about 1,200 genera and more than 8,000 plant species; reformed the botanical language and established up to 1,000 terms, many of which he introduced for the first time.
The works of K. Linnaeus helped his followers to systematize the disparate factual material and improve it.
At the beginning of the XVIII century. French scientist Jeannot-Baptiste Lamarck created the first evolutionary theory, which he outlined in his work “Philosophy of Zoology” (1809). According to Lamarck, some organisms evolved from others in the process of long evolution, gradually changing and improving under the influence of the external environment. Changes were fixed and inherited, which was the main factor that determined evolution.
J.-B. Lamarck was the first to set forth the ideas of the evolution of living nature, which affirmed the historical development from the simple to the complex. Evidence for evolutionary theory put forward by J.-B. Lamarck, turned out to be insufficient for their complete acceptance, since no answers were given to the questions: how to explain the great diversity of species in nature; what is the reason for the improvement of the organization of living beings; how to explain the adaptability of organisms to environmental conditions?
in Russia in the 18th century. notable for the emergence of new scientific ideas. The brilliant Russian scientist M.V. Lomonosov, the materialist philosopher A.N. Radishchev, academician K.F. Wolf and other prominent scientists expressed ideas about the evolutionary development and changeability of nature.
M. V. Lomonosov argued that changes in the landscape of the Earth caused climate changes, in connection with which the animals and plants that inhabited it changed.
K. F. Wolf argued that during the development of the chicken embryo, all organs appear as a result of development, and are not predetermined (the theory of epigenesis), and all changes are associated with nutrition and climate. Not yet having sufficient scientific material at his disposal, K. F. Wolf made an assumption that brilliantly anticipated the full scientific evolutionary teaching of the future.
In the 19th century metaphysical ideas about the immutability of living beings are being criticized more and more. In Russia, evolutionary ideas were constantly expressed.
For example, Afanasy Kaverznev ( late 18th- the beginning of the 19th century) in his work “On the Rebirth of Animals” argued that species do exist in nature, but they are changeable. Variability factors are changes environment: food, climate, temperature, humidity, relief, etc. He raised the question of the origin of species from one another and their relationship. A. Kaverznev confirmed his reasoning with examples from human practice in breeding animal breeds.
K. F. Roulier (1814-1858), 10-15 years before the publication of Charles Darwin’s work “The Origin of Species”, wrote about the historical development of nature, sharply criticizing metaphysical views on the immutability and constancy of species and the descriptive direction in science . He linked the origin of species with their struggle for existence.
Progressive evolutionary ideas were expressed by K. M. Baer (1792-1876), doing research in the field of embryology.
And another scientist - A.I. Herzen (1812-1870) in his works “Amateurism in Science” and “Letters on the Study of Nature” wrote about the need to study the origin of organisms, their family ties, to consider the structure of animals in unity with physiological characteristics and that mental activity should also be studied in development - from the lowest to the highest, including man. He saw the main task in revealing the reasons for the unity of the organic world with all its diversity and explaining the origin of animals.
N.G. Chernyshevsky (1828-1889) in his works dwelled on the causes of variability and the question of the unity of the origin of man and animals.
The greatest English naturalist C. Darwin (1809-1882) initiated a new era in the development of natural science with his evolutionary theory.
The emergence of the evolutionary teachings of Charles Darwin was facilitated by socio-economic prerequisites - the intensive development of capitalism, which gave impetus to the development of science, industry, technology, and agriculture.
After a five-year journey as a naturalist on the ship "Beagle" around the world and almost 20 years of summarizing and comprehending a large amount of factual data, he wrote the book "The Origin of Species by Means of Natural Selection, or the Preservation of Favored Breeds in the Struggle for Life", published in 1859. , exactly 50 years after Lamarck's book.
During this journey, Darwin had the idea of evolution - his own fresh concept, correcting or improving the views and arguments of his predecessors. Darwin's idea explained the laws of development of life better than any other theory.
Charles Darwin in this book outlined the evolutionary theory, which revolutionized biological thinking and became a historical method of research in biology.
The main merit of Darwin is that he explained the mechanism of the evolutionary process, created the theory of natural selection. Darwin connected numerous separate phenomena of organic life into a logical whole, thanks to which the kingdom of living nature appeared before people as something constantly changing, striving for constant improvement.
Darwin's theory of natural selection was so reasonable and so well founded that most biologists soon accepted it. Darwin connected numerous separate phenomena of organic life into a logical whole, thanks to which the kingdom of living nature appeared before people as something constantly changing, striving for constant improvement.
Russian evolutionists paved the way for the adoption of Darwin's theory, so in Russia she found her followers. However, in Darwin's time, many areas of biological science were not well developed and had little to offer him in developing his theory.
The main discoveries of Gregor Mendel in the theory of heredity (in genetics) were not known to either Darwin (although they worked at the same time), or most scientists of his time. Cytology, which studies cells, did not yet know how cells divide. Paleontology, the science of fossils, was a young science, and the beautiful specimens of fossil animals and plants that appeared later had not yet been discovered.
The discreteness of the factual material and the lack of scientific achievements at that time, which appeared later, allowed Darwin's opponents to express an opinion about the lack of evidence for the correctness of the provisions of the theory of evolution.
Due to the lack of these and some other data, the development of the theory of evolution by natural selection in the 19th century. was an even more remarkable achievement than if it had taken place in the middle of the 20th century.
Thus, existed in the XVII-XVIII centuries. metaphysical ideas in science and philosophy left a deep imprint on the study of physiological problems: all phenomena in nature were considered as permanent and unchanging. The evolutionary teaching of Charles Darwin dealt a severe blow to the metaphysical view of nature.
Within zoology, narrower disciplines have developed, for example, protozoology, entomology, ornithology, theriology and etc.; in botany - algology, bryology, dendrology and others. microbiology, mycology, lichenology, virology.
The beginning of the development of microbiology and the doctrine of immunity as an independent scientific discipline was laid by the works of the French scientist L. Pasteur in 1865-1869.
At the beginning of the XIX century. is formalized as an independent science of plant morphology. German scientists M. Schleiden (1838) and T. Schwann (1839) created a cellular theory that proves the unity of the origin of all organisms.
By the end of the XIX century. new branches of biology have been developed: phylogenetic systematics, evolutionary morphology, biogeography and others. During this period, phylogenetic systems of various plant groups were developed.
Zoological classification began to proceed from the data comparative anatomy, and taxonomy began to express family ties of animal classes in the exact meaning of the word. Particularly developed, in particular, comparative anatomy, including histology(tissue science) and cytology(the science of the cell).
Scientists began to note that the anatomical similarities and differences of living organisms are the result of a common origin or adaptability of the organism of various animals and plants to environmental conditions. It became clear why some organs are similar in structure to each other, why the main structural features of these organs are common among the observed classes of animals or plants, why living conditions cause changes in organs when they adapt to new conditions, while maintaining a common structure, and why, finally, there are residual organs and what is their significance.
The formation of physiology as a science is associated with the name of the English physician William Harvey (1578-1657), who discovered blood circulation. In 1628 Harvey published On the Movement of the Heart and Blood. In it, he summed up the results of many years of observations and put forward a theory about the circulation of blood in the human body.
The further development of anatomy and physiology was determined by new methods of scientific research and the general development of science.
The creator of the general theory of anatomy is Bisha (1771-1802), who in the book "General Anatomy" combined, according to functional features, previously disparate ideas about tissues, organs and organ systems. Very important for the development of physiology was the discovery of the reflex in the first half of the 17th century by the French philosopher Descartes.
The same significant development comparative embryology. Such basic biological problems as the heredity of forms have come to the fore. The study of the process of fertilization, division of the germ cell, the phenomenon of parthenogenesis, crossing, mutation, which zoologists and botanists have been intensively engaged in, is nothing more than a continuation of the search for laws arising from Darwin's theory.
Creator of the first theories of heredity who showed biologists the way to solving a number of issues in this area was the German zoologist August Weismann. It was his theory of the continuity of the germ plasm, published in 1855, that attracted the attention of many scientists to a large extent to the experimental and theoretical study of the germ cell, the carrier of heredity.
Weismann's hypothesis has become a major conquest of biology. Outstanding researchers in Germany, the USA, Russia, England, Sweden and in many other countries, developing this hypothesis, made many important discoveries that substantiated the phenomenon of heredity.
Darwin's theory significantly influenced the development of all fields of science, even those that, at first glance, were not connected with it in any way. This theory had a considerable influence on the methodology used in various humanities and, above all, on research methods. sociology and general history.
In these branches of science, not only were the exact methods of research used by biology after Darwin, but, most importantly, methods of determining the causal dependence of facts from the history of mankind began to be applied, just as biologists consider the phenomena of the development of living organisms.
The biological approach had a strong impact on philosophical and cosmogonic views, concerning the beginning of the origin of the universe, is reflected in psychology, biogeography, linguistics and in other scientific fields. As a result of studying the past history of the organic world, the science of paleontology and its sections - paleozoology, paleobotany, paleoecology, etc., were developed.
The creativity contained in Darwin's main work, The Origin of Species by Means of Natural Selection, slowly but decisively influenced religion and anthropology.
True, Darwin believed that religion is such a direction of human activity, which should be touched with caution, but he believed that his theory would be an incentive for a new approach to religious beliefs, to the idea of the existence of the soul and other similar concepts.
The influence of Darwinism manifested itself with particular force in anthropology, a branch of biology that became an independent science in the middle of the 18th century.
Human origin, education human races, the search for human connection with other mammals, in particular, with their highly developed forms, the solution of the problems of natural selection are the main issues that scientists have been keenly interested in since the second half of the last century. Over time, the natural history of man has been transformed into a science that studies the biological foundations of social phenomena in the life of mankind. This humanitarian-biological approach to sociology brought about the unification of anthropology in the exact sense of the word with ethnography and prehistoric archaeology.
Thus, biology is characterized by the interpenetration of ideas and methods of various biological disciplines, as well as other sciences - chemistry, mathematics, physics.
2.2 The contribution of Russian scientists to the development of biological sciences
Systematic research on plants began in Russia in the 18th century. Initially, this was associated with the opening in 1725 of the Academy of Sciences in St. Petersburg. The floristic direction developed - studied species composition plants throughout the vast territory of Russia. Important scientific works, I.G. Gmelin “Flora of Siberia” (1747-1759), P.S. Pallas “Flora of Russia” (1784-1788), K.F. Ledebour “Flora of Altai” and “Flora of Russia” ( 1841-1853), he also made the first attempt to divide the map of Russia into floristic regions.
Among the friends and followers of M. V. Lomonosov, who worked on the study of nature, and in particular the fauna of Russia, first of all it is necessary to note Academician Stepan Petrovich Krasheninnikov. The main work of the scientist "Description of the Land of Kamchatka" (1755) was later translated into many European languages. The book is a comprehensive description of the region, in which natural phenomena and people's lives are considered in mutual connection.
This is the first experience in domestic and world science of a comprehensive geographical description of a certain territory. The book had a great influence on the further development of zoogeographical and faunal studies in Russia.
In the 19th century Russian scientists began to study the plant world of other countries - China, Mongolia, Asia Minor, etc. M.A. Maksimovich in the “Systematics of Plants” (1831) made the first attempt to consider evolution as a process of speciation. By the second half of the XIX century. - the beginning of the XX century. the relative activity of such prominent Russian scientists as the botanists L.S. Tsenkovsky, A.N. Beketov, D.I. Ivanovsky; plant physiologists A.S. Faminiin, K.A. Timiryazev; plant morphologist I.I. Gorozhankin; plant cytologists I.I. Gerasimov and S.G. Navashin and others. G.V. Morozov studied the dynamics of forest communities.
The works of Russian scientists were widely used by scientists all over the world. The study of the flora of Russia contributed to the deepening and refinement of plant classifications, provided material for conclusions related to the geographical distribution of plants and ecology, made it possible to identify the centers of origin of cultivated plants and establish geographical patterns in the distribution of their hereditary traits, and made it possible to achieve significant success in plant breeding.
Academician of the Russian Academy of Sciences K. F. Wolf (1734-1794) is known in world science as one of the founders of embryology and the defender of the doctrine he developed about epigenesis, that is, the gradual development of organisms through neoplasms. His works shattered the reformist, metaphysical ideas that prevailed at that time, which reinforced the dogma of the immutability of species, affirmed the idea of development from simple to complex, and thereby prepared the ground for the evolutionary idea.
By the beginning of the 60s of the XIX century. the embryology of vertebrates was developed in sufficient detail, while that of invertebrates was presented in the form of disparate facts not connected by a common guiding idea. By this time, the process of crushing the eggs of some intestinal cavities, worms, molluscs and echinoderms, the structure and transformation of the larvae of many invertebrates were described in detail, but almost nothing was known about the internal processes of their development, about the methods of laying and differentiation of organs, and most importantly , it was not possible to reliably find common features in embryonic processes in animals belonging to different types.
Evolutionary embryology as a science based on a historical principle has not yet emerged. The date of its occurrence is considered to be the mid-60s - the beginning of research by the founders of evolutionary comparative embryology A.O. Kovalevsky and I.I. Mechnikov. The statement of the Darwinian theory of the origin of the entire animal world on the basis of embryological material, verified in numerous experimental studies, was the basis for the creation of comparative embryology by Kovalevsky.
One of the outstanding zoologists of the first half of the XIX century. is Academician Karl Maksimovich Baer. Baer's most valuable research is related to embryology. However, he is known not only as an embryologist, but also as an outstanding ichthyologist, geographer-traveler, anthropologist and ethnographer, a thoughtful and energetic researcher of Russia's natural resources. Darwin held Baer in high esteem as a scientist, and in On the Origin of Species names him among his predecessors. This outstanding biologist became famous as the creator of modern comparative embryology.
Vladimir Onufrievich Kovalevsky (1842-1883) - an outstanding paleontologist, founder evolutionary paleontology. He was the successor of the best materialistic traditions of Russian biological science, developed under the influence of the great Russian materialist philosophers. The studies of V. O. Kovalevsky, his ideas and conclusions concerning the general laws of evolution, were the initial data for the successful development of the problems of evolutionary paleontology and, in particular, issues directly related to the phylogeny of the animal world.
In the 19th century In Russia, science has made great strides in medicine as well. Physiology has also made significant progress. Since the 18th century (under Peter I) systematic training of medical workers began in Russia. In the 19th century many Russian scientists worked in the field of anatomy and physiology.
The works of P. A. Zagorsky, I. V. Builsky, N. I. Pirogov had a great influence on the development of Russian anatomy. The brilliant Russian scientist N. I. Pirogov (1810-1881) worked in the field of surgery, anatomy and other branches of medicine. He developed the basics of topographic (interposition) anatomy, is the founder of military field surgery, developed a clear system for organizing surgical care for the wounded in the war, proposed a number of new methods of ether anesthesia.
A great contribution to the development was made by P. F. Lesgaft (1837-1909), V. P. Vorobiev (1876-1937), V. N. Tonkov (1872-1954) and many others, and physiology - V. A. Basov, N. A. Mislavsky, V. F. Ovsyannikov, A. Ya. Kulyabko, S. P. Botkin and others.
A special role in the development of physiology was played by I.M. Sechenov and I.P. Pavlov. Of exceptional importance was the book by I. M. Sechenov "Reflexes of the brain" (1863), in which for the first time the position was expressed that all brain activity is reflex in nature.
IP Pavlov (1849-1936), for more than 60 years of scientific activity, developed a number of different problems of physiology, which had a great influence on the development of not only medicine, but biology as a whole. He did greatest discoveries in various sections of physiology - blood circulation, digestion and the study of the work of the cerebral hemispheres.
In the works of I. P. Pavlov, the idea expressed by I. M. Sechenov about the reflex nature of the activity of organs was brilliantly confirmed. Of particular importance are the studies of IP Pavlov devoted to the study of the cerebral cortex. He found that the basis of the activity of the cerebral cortex is the process of formation of conditioned reflexes (1895).
Thus, outstanding Russian scientists have made a great contribution to the formation and development of the system of biological sciences.
Generally, in the 19th century the heyday of the taxonomy of the animal and plant kingdoms began. Systematics has ceased to be a descriptive science, dealing with a simple enumeration of forms on the basis of an artificial classification, has become an exact part of research, in which the search for causes and natural relationships has come to the fore.
Conclusion
As a result of the study
Education At the beginning of the XIX century. in Russia there was a system of higher, secondary and primary education reform in the field of education (under Alexander I).
Under Nicholas I, all types of schools were preserved, but each of them became isolated by class. Law of God, literacy and arithmetic. Representatives of the "lower classes" studied. Parish one-class schools Russian language, arithmetic, geometry, history and geography. Children of merchants, artisans, philistines. County three-year schools All sciences. Children of nobles, officials, merchants of the first guild. Seventh grade gymnasiums
Working with a document. Read the document and answer the question. In the rescript of Nicholas I of August 19, 1827, it is said that "the subjects of learning and the very methods of teaching" should be "consistent with the future purpose of students." It is necessary that in the future the student “does not strive to exalt himself beyond measure on the state in which he is destined to remain.” - How do you understand the words of the document?
Biology. In 1806, he argued that the earth's surface and the creatures inhabiting it undergo fundamental changes over time. Ivan Alekseevich Dvigubsky In 1816, he put forward and proved the idea that all phenomena in nature are due to natural causes and are subject to general laws of development. Justin Evdokimovich Dyadkovsky His work "The Universal Law of the Development of Nature" (1834) substantiated ideas about the development of living organisms. (Charles Darwin's predecessor and his teachings. Karl Maksimovich Baer
In the 19th century Russian scientists began to study the flora of other countries - China, Mongolia, Asia Minor, etc. M.A. Maksimovich in the Systematics of Plants (1831) made the first attempt to consider evolution as a process of speciation. By the second half of the XIX century. - the beginning of the XX century. the relative activity of such prominent Russian scientists as the botanists L.S. Tsenkovsky, A.N. Beketov, D.I. Ivanovsky; plant physiologists A.S. Faminiin, K.A. Timiryazev; plant morphologist I.I. Gorozhankin; plant cytologists I.I. Gerasimov and S.G. Navashin and others. G.V. Morozov studied the dynamics of forest communities. Maksimovich, Mikhail Alexandrovich
The works of Russian scientists were widely used by scientists all over the world. The study of the flora of Russia contributed to the deepening and refinement of plant classifications, provided material for conclusions related to the geographical distribution of plants and ecology, made it possible to identify the centers of origin of cultivated plants and establish geographical patterns in the distribution of their hereditary traits, and made it possible to achieve significant success in plant breeding.
Wolf, Kaspar Friedrich Academician of the Russian Academy of Sciences KF Wolf (gg.) is known in world science as one of the founders of embryology and a defender of the doctrine he developed about epigenesis, that is, the gradual development of organisms through neoplasms. His works shattered the reformist, metaphysical ideas that prevailed at that time, which reinforced the dogma of the immutability of species, affirmed the idea of development from simple to complex, and thereby prepared the ground for the evolutionary idea.
By the beginning of the 60s of the XIX century. the embryology of vertebrates was developed in sufficient detail, while that of invertebrates was presented in the form of disparate facts not connected by a common guiding idea. By this time, the process of crushing the eggs of some intestinal cavities, worms, molluscs and echinoderms, the structure and transformation of the larvae of many invertebrates were described in detail, but almost nothing was known about the internal processes of their development, about the methods of laying and differentiation of organs, and most importantly , it was not possible to reliably find common features in embryonic processes in animals belonging to different types. Evolutionary embryology as a science based on a historical principle has not yet emerged. The date of its occurrence is considered to be the mid-60s - the beginning of research by the founders of evolutionary comparative embryology A.O. Kovalevsky and I.I. Mechnikov. The statement of the Darwinian theory of the origin of the entire animal world on the basis of embryological material, verified in numerous experimental studies, was the basis for the creation of comparative embryology by Kovalevsky.
Karl Ernst von Baer, or, as he was called in Russia, Karl Maksimovich Baer One of the outstanding zoologists of the first half of the 19th century. is Academician Karl Maksimovich Baer. Baer's most valuable research is related to embryology. However, he is known not only as an embryologist, but also as an outstanding ichthyologist, geographer-traveler, anthropologist and ethnographer, a thoughtful and energetic researcher of Russia's natural resources. Darwin held Baer in high esteem as a scientist, and in On the Origin of Species names him among his predecessors. This outstanding biologist gained fame as the creator of modern comparative embryology.
Kovalevsky, Vladimir Onufrievich Vladimir Onufrievich Kovalevsky (years) is an outstanding paleontologist, the founder of evolutionary paleontology. He was the successor of the best materialistic traditions of Russian biological science, developed under the influence of the great Russian materialist philosophers. The studies of V. O. Kovalevsky, his ideas and conclusions concerning the general laws of evolution, were the initial data for the successful development of the problems of evolutionary paleontology and, in particular, issues directly related to the phylogeny of the animal world.
In the 19th century In Russia, science has made great strides in medicine as well. Physiology has also made significant progress. Since the 18th century (under Peter I) systematic training of medical workers began in Russia. In the 19th century many Russian scientists worked in the field of anatomy and physiology.
Pirogov The works of P. A. Zagorsky, I. V. Builsky, N. I. Pirogov had a great influence on the development of Russian anatomy. The brilliant Russian scientist N. I. Pirogov (gg.) Worked in the field of surgery, anatomy and other branches of medicine. He developed the basics of topographic (interposition) anatomy, is the founder of military field surgery, developed a clear system for organizing surgical care for the wounded in the war, proposed a number of new methods of ether anesthesia.
A special role in the development of physiology was played by I.M. Sechenov and I.P. Pavlov. Of exceptional importance was the book by I. M. Sechenov "Reflexes of the brain" (1863), in which for the first time the position was expressed that all brain activity is reflex in nature. Pavlov, Ivan Petrovich Sechenov, Ivan Mikhailovich
IP Pavlov (gg.) for more than 60 years of scientific activity developed a number of different problems of physiology, which had a great influence on the development of not only medicine, but biology as a whole. He made the greatest discoveries in various branches of physiology - blood circulation, digestion and the study of the work of the cerebral hemispheres. In the works of I. P. Pavlov, the idea expressed by I. M. Sechenov about the reflex nature of the activity of organs was brilliantly confirmed. Of particular importance are the studies of IP Pavlov devoted to the study of the cerebral cortex. He established that the basis of the activity of the cerebral cortex is the process of formation of conditioned reflexes (1895).
A great contribution to the development was made by P. F. Lesgaft (gg.), V. P. Vorobyov (gg.), V. N. Tonkov (gg.) and many others, and in the development of physiology - V. A. Basov, N A. Mislavsky, V. F. Ovsyannikov, A. Ya. Kulyabko, S. P. Botkin, etc.
Thus, outstanding Russian scientists have made a great contribution to the formation and development of the system of biological sciences. In general, in the XIX century. the heyday of the taxonomy of the animal and plant kingdoms began. Systematics has ceased to be a descriptive science, dealing with a simple enumeration of forms on the basis of an artificial classification, has become an exact part of research, in which the search for causes and natural relationships has come to the fore.
The most significant events of the first half of the 19th century were the formation of paleontology and the biological foundations of stratigraphy, the emergence of cell theory, the formation of comparative anatomy and comparative embryology. The central events of the second half of the 19th century were the publication of Charles Darwin's On the Origin of Species and the spread of the evolutionary approach to many biological disciplines.
cell theory
The cell theory was formulated in 1839 by the German zoologist and physiologist T. Schwann. According to this theory, all organisms have a cellular structure. The cell theory asserted the unity of the animal and plant world, the presence of a single element of the body of a living organism - the cell. Like any major scientific generalization, the cell theory did not emerge suddenly: it was preceded by separate discoveries by various researchers.
At the beginning of the XIX century. attempts were made to study the internal contents of the cell. In 1825, the Czech scientist J. Purkynė discovered the nucleus in the egg of birds. In 1831, the English botanist R. Brown first described the nucleus in plant cells, and in 1833 he came to the conclusion that the nucleus is an essential part of the plant cell. Thus, at this time, the idea of the structure of the cell changes: the main thing in its organization was considered not the cell wall, but the contents.
The German botanist M. Schleiden came closest to the formulation of the cell theory, who established that the body of plants consists of cells.
Numerous observations regarding the structure of the cell, the generalization of the accumulated data allowed T. Schwann in 1839 to draw a number of conclusions, which were later called the cell theory. The scientist showed that all living organisms consist of cells, that the cells of plants and animals are fundamentally similar to each other.
Cell theory includes the following main provisions:
1) A cell is an elementary unit of the living, capable of self-renewal, self-regulation and self-reproduction, and is a unit of structure, functioning and development of all living organisms.
2) The cells of all living organisms are similar in structure, chemical composition and basic manifestations of vital activity.
3) Cell reproduction occurs by dividing the original mother cell.
4) In a multicellular organism, cells specialize in functions and form tissues from which organs and their systems are built, interconnected by intercellular, humoral and nervous forms of regulation.
The creation of the cell theory has become a major event in biology, one of the decisive proofs of the unity of living nature. The cell theory had a significant impact on the development of biology as a science, served as the foundation for the development of such disciplines as embryology, histology and physiology. It made it possible to create the foundations for understanding life, the individual development of organisms, and for explaining the evolutionary connection between them. The main provisions of the cell theory have retained their significance even today, although for more than one hundred and fifty years new information has been obtained on the structure, vital activity and development of the cell.
The evolutionary theory of Ch. Darwin
A revolution in science was made by the book of the great English natural scientist Charles Darwin, "The Origin of Species", written in 1859. Summarizing the empirical material of contemporary biology and breeding practice, using the results of his own observations during his travels, he revealed the main factors in the evolution of the organic world. In the book "Changing Domestic Animals and Cultivated Plants" (1868), he presented additional factual material to the main work. In the book "The Origin of Man and Sexual Selection" (1871), he put forward the hypothesis of the origin of man from an ape-like ancestor.
The essence of the Darwinian concept of evolution is reduced to a number of logical, experimentally verified and confirmed by a huge amount of factual data provisions:
1) Within each species of living organisms, there is a huge range of individual hereditary variability in morphological, physiological, behavioral and any other characteristics. This variability may be continuous, quantitative, or discontinuous qualitative, but it always exists.
2) All living organisms reproduce exponentially.
3) Life resources for any kind of living organisms are limited, and therefore there must be a struggle for existence either between individuals of the same species, or between individuals of different species, or with natural conditions. In the concept of "struggle for existence" Darwin included not only the actual struggle of an individual for life, but also the struggle for success in reproduction.
4) In the conditions of the struggle for existence, the most adapted individuals survive and give offspring, having those deviations that accidentally turned out to be adaptive to given environmental conditions. This is a fundamentally important point in Darwin's argument. Deviations do not occur in a directed way - in response to the action of the environment, but by chance. Few of them are useful in specific conditions. The descendants of a surviving individual who inherit a beneficial variation that allowed their ancestor to survive are better adapted to the environment than other members of the population.
5) The survival and preferential reproduction of adapted individuals Darwin called natural selection.
6) The natural selection of individual isolated varieties under different conditions of existence gradually leads to divergence (divergence) of the characteristics of these varieties and, ultimately, to speciation.
At the heart of Darwin's theory is the property of organisms to repeat in a number of generations similar types of metabolism and individual development in general - the property of heredity. Heredity, together with variability, ensures the constancy and diversity of life forms and underlies the evolution of living nature. One of the basic concepts of his theory of evolution - the concept of "struggle for existence" - Darwin used to denote the relationship between organisms, as well as the relationship between organisms and abiotic conditions, leading to the death of the less adapted and the survival of the more adapted individuals.
Darwin identified two main forms of variability:
A certain variability - the ability of all individuals of the same species in certain environmental conditions to respond in the same way to these conditions (climate, soil);
Uncertain variability, the nature of which does not correspond to changes in external conditions.
In modern terminology, indefinite variability is called a mutation. Mutation - indefinite variability, in contrast to a certain one, is hereditary. According to Darwin, minor changes in the first generation are amplified in subsequent ones. Darwin emphasized that it is precisely indefinite variability that plays a decisive role in evolution. It is usually associated with deleterious and neutral mutations, but mutations that turn out to be promising are also possible. The inevitable result of the struggle for existence and the hereditary variability of organisms, according to Darwin, is the process of survival and reproduction of organisms that are most adapted to environmental conditions, and death in the course of evolution of the unadapted - natural selection.
The mechanism of natural selection in nature operates similarly to breeders, i.e. It adds up insignificant and indefinite individual differences and forms from them the necessary adaptations in organisms, as well as interspecies differences. This mechanism discards unnecessary forms and forms new species.
The thesis of natural selection, along with the principles of the struggle for existence, heredity and variability, is the basis of Darwin's theory of evolution.
Cell theory and Darwin's theory of evolution are the most significant achievements of biology in the 19th century. But I think that other rather important discoveries should also be mentioned.
With the development of physics and chemistry, there are also changes in medicine. Over time, the areas of application of electricity are becoming more and more. Its use in medicine marked the beginning of electro- and iontophoresis. The discovery of X-rays by Roentgen aroused particular interest among physicians. The physics laboratories where the equipment used by Roentgen to produce X-rays were created were attacked by doctors and their patients, who suspected that they contained needles, buttons, etc., once swallowed. The history of medicine has never known such a rapid implementation of discoveries in the field of electricity, as happened with a new diagnostic tool - x-rays.
From the end of the 19th century, experiments on animals began to determine the threshold - dangerous - values of current and voltage. The determination of these values was caused by the need to create protective measures.
A significant discovery in the field of medicine and biology was the discovery of vitamins. Back in 1820, our compatriot P. Vishnevsky for the first time suggested the existence of a certain substance in antiscorbutic products that contributes to the proper functioning of the body. Actually, the discovery of vitamins belongs to N. Lunin, who proved in 1880 that certain vital elements are included in the composition of food. The term "vitamins" is derived from Latin roots: "vita" - life and "amine" - nitrogen compound.
In the 19th century, the fight against infectious diseases began. The English doctor Jenner invented the vaccine, Robert Koch discovered the causative agent of tuberculosis - Koch's bacillus, and also developed preventive measures against epidemics and created medicines.
Development of microbiology in the 19th century
Louis Pasteur gave the world a new science - microbiology.
This man, who made a number of the brightest discoveries, had to defend his truths in useless disputes all his life. Natural scientists all over the world have been debating whether or not there is a "self-generation" of living organisms. Pasteur did not argue, Pasteur worked. Why does wine ferment? Why does milk sour? Pasteur established that the process of fermentation is a biological process caused by microbes.
In Pasteur's laboratory, there is still an amazingly shaped flask - a fragile structure with a bizarrely curved spout. More than 100 years ago, young wine was poured into it. It has not turned sour to this day - the secret of the form protects it from fermentation microbes.
Pasteur's experiments were of great importance for the creation of methods for sterilization and pasteurization (heating a liquid to 80 ° C to kill microorganisms, and then rapidly cooling it) of various products. He developed methods of protective vaccinations against contagious diseases. His research served as the basis for the teachings on immunity.
Genetics
In 1865, the results of work on the hybridization of pea varieties were published, where the most important laws of heredity were discovered. The author of these works, the Czech researcher Gregor Mendel, showed that the characteristics of organisms are determined by discrete hereditary factors. However, these works remained practically unknown for almost 35 years - from 1865 to 1900.
