Biology in modern times. Biology in modern natural science. Characteristics of the “images” of biology (traditional, physico-chemical, evolutionary). Basic methods of biology
Lecture No. 1 Modern stage development biology
1. Introduction. History of the development of biology
Biology is the science of life. Its name arose from the combination of two Greek words bios - life and logos - teaching. This term was first proposed by the outstanding French naturalist and evolutionist Jean Baptiste Lamarck (1802) to designate the science of life as a special natural phenomenon.
Biology studies the structure, manifestations of vital activity, and the habitat of all living organisms: bacteria, fungi, plants, animals.
Life on Earth is represented by an extraordinary variety of forms, many types of living beings. Currently, about 500 thousand species of plants, more than 1.5 million species of animals, and a large number of species of fungi and prokaryotes inhabiting our planet are already known.
The main tasks of biology include the following:
1 Disclosure of the general properties of living organisms;
2 Explanation of the reasons for their diversity;
3 Identification of connections between the structure and environmental conditions.
An important place in this science is occupied by the issues of the origin and laws of development of life on Earth - the doctrine of evolution. Understanding these issues not only serves as the basis of a scientific worldview, but is also necessary for solving practical problems.
Biology originated with the ancient Greeks and Romans, who described the plants and animals known to them.
Aristotle (384 - 322 BC) - the founder of many sciences - was the first to try to organize knowledge about nature, dividing it into “stages”: inorganic world, plant, animal, human. In the work of the ancient Roman physician Galen (131-200 AD) “On the Parts of the Human Body,” the first anatomical and physiological description of a person is given.
In the Middle Ages, “herbal books” were compiled, which included descriptions of medicinal plants.
During the Renaissance, interest in wildlife intensified. Botany and zoology emerged.
The invention of the microscope in the early 17th century by Galileo (1564-1642) deepened our understanding of the structure of living things and marked the beginning of the study of cells and tissues.
A. Leeuwenhoek (1632-1723) saw protozoa, bacteria and sperm under a microscope, i.e. was the founder of microbiology.
One of the main achievements of the 18th century is the creation by Carl Linnaeus (1735) of a system for classifying animals and plants. And at the beginning of the 19th century J.-B. Lamarck, in his book “Philosophy of Zoology” (1809), was the first to clearly formulate the idea of evolution organic world.
Among the most important achievements of the 19th century is the creation cell theory M. Schleiden and T. Schwann (1838-1839), discovery of the laws of heredity by Mendel in 1859
A revolution in biology was made by the teachings of Charles Darwin in 1859, who discovered the driving forces of evolution.
The beginning of the 20th century was marked by the birth of genetics. This science arose as a result of the rediscovery by K. Correns, E. Cermak and G. de Vries of the laws of heredity, which had previously been discovered by G. Mendel, but remained unknown to biologists of that time, as well as thanks to the work of T. Morgan, who substantiated the chromosomal theory of heredity.
In the 1950s, significant progress was made in the study of the fine structure of matter. In 1953, D. Watson and F. Crick proposed a model of the structure of DNA in the form of a double helix and proved that it carries hereditary information.
Modern biology, along with a detailed study of individual structures and organisms, is characterized by a tendency towards a holistic knowledge of living nature, as evidenced by the development of ecology.
The development of biology followed the path of consistent simplification of the subject of research. As a result, numerous biological disciplines have emerged that specialize in the study of the structural and functional characteristics of certain organisms. This path of knowledge - from complex to simple - is called reductionist. Reductionism reduces knowledge to the study of the most elementary forms of existence of matter. This applies to both living and inanimate nature. With this approach, a person learns the laws of nature by studying its individual parts instead of a single whole.
Another approach is based on vitalistic principles. In this case, life is seen as completely special and unique phenomenon, which cannot be explained only by the laws of physics or chemistry.
Therefore, the main task of biology as a science is to interpret all phenomena of living nature, based on scientific laws and not forgetting that the whole organism has properties that are fundamentally different from the properties of the parts that make them up. For example, a neurophysiologist can describe the work of an individual neuron in the language of physics and chemistry, but the phenomenon of consciousness itself cannot be described in this way. Consciousness arises as a result of collective work and simultaneous changes in the electrochemical state of millions of nerve cells, but we still do not know how thought arises and what its chemical bases are.
Currently, the importance of biology is increasing every year. Many biological disciplines have emerged and their number is constantly increasing. This is due to the fact that biology is divided into separate sciences according to the subject of study: microbiology, botany, zoology; areas of biology that study the general properties of living organisms emerged and developed: genetics– patterns of inheritance of traits; biochemistry – pathways of transformation of organic molecules; ecology– relationships between organisms and environment. Studies the functions of living organisms physiology.
In accordance with the level of organization of living matter, the following disciplines were distinguished:
molecular biology, cytology- the doctrine of the cell, histology- the study of tissues.
As the field of knowledge about living organisms expands, new biological branches of science appear.
Virology Cytology Molecular
biology
Bacteriology Microbiology Histology
Mycology Physiology
Plant pathology Botany BIOLOGY Anatomy
Ornithology
Biochemistry Enzymology
Veterinary Zoology Genetics Gennaya
Entomology Ecology engineering
Embryology
2 Use of achievements of biological sciences in human activities
Biology is of great importance in solving practical problems. The main tasks of the UN are food, health, fuel and energy, and environmental protection.
A global problem modernity is food production. The population of our planet is approaching 10 billion people. Therefore, the problem of providing the population with food, and nutritious food, is becoming increasingly acute.
Basically, these problems are solved by technological sciences: plant growing and animal husbandry, which are based on the achievements of fundamental biological disciplines, such as genetics and selection, physiology and biochemistry, molecular biology and ecology.
Based on selection methods developed and enriched by modern genetics, an intensive process of creating more productive varieties of plants and animal breeds is underway all over the world. An important quality of new varieties of agricultural crops is their adaptability to cultivation under intensive technologies. Agricultural animals, along with high productivity, must have specific morphological, anatomical and physiological characteristics that allow them to be bred in poultry farms, farms with electric milking and stabling, and in fur farm cages.
Every year the deficit of protein foods, especially animal proteins, increases; this deficit reaches 2.5 billion tons per year. Already, according to WHO, 4% of the world’s population is on the verge of starvation, and 10% of the planet’s population is chronically undernourished.
There are 2 sources of food - animal and plant. It is much faster and easier to produce plant food than animal food. Therefore, opportunities are being sought to obtain food protein of non-animal origin, primarily from plants - from green parts, as well as from seeds.
Soybean occupies the leading place in protein extraction; it is the main oilseed crop in the USA and Japan. In addition to vegetable oil, soybeans contain a lot of biologically complete protein (about 44%), which is used in food after the oil is extracted from the seeds.
Protein products from soybeans have become widespread in Western countries only in the last 20-30 years, while in China and Japan they have been used as food for more than 2 millennia. In these countries, traditional products are such as tofu - soybean curd, kori-tofu - frozen bean curd, soy milk, yuba - films removed from soy milk when boiled, and other products.
In 1987, 330 new soy protein products were launched into the consumer market in the United States, with plant proteins used in a wide variety of products: from sausages to ice cream, cheeses, yogurts, and salad dressings.
Plant proteins are very widely used in instant products that do not require complex culinary or rather long heat treatment. This is especially true in the United States, where food is increasingly being used that can be consumed anywhere and at any time - these are all kinds of ready-made breakfasts, lunch dishes, cereals, sticks, pillows, etc. Moreover, such dishes are used not only to save time, but also for reasons of “healthy eating”.
Plant proteins are also widely used in the preparation of analogues of milk and dairy products. In practice Food Industry It is known to produce reconstituted milk from powder obtained from defatted soy flour. There are also a range of refreshing, protein-containing nutritious drinks available. For example, in France, Sweden, and Hungary there are fully automated plants for the production of liquid soy products, soy drinks or dessert dishes with natural vanilla or chocolate flavor. The composition of these products corresponds to a balanced diet, but they do not contain lactose and cholesterol, which determines the intended purpose for people suffering from gastrointestinal and cardiovascular diseases.
Plant proteins are also widely used as wheat flour fortifiers in the production of bread and bakery products. Their use improves the properties of the dough during kneading and extends the shelf life of fresh dough.
Proteins are also used in the confectionery industry. In addition to traditional soy flour additives, proteins from sunflower seeds are also used in the preparation of cookies, breakfast cereals, and cake mixes. Proteins from other plants are also used - cotton, lupine, beans, mustard, peanuts, rapeseed, and rapeseed. These proteins have high biological value; in addition, their yield from oil and fat industry waste reaches 62%.
Plant proteins are used in the manufacture of food products as:
1 protein fortifiers;
2 substitutes and analogues of meat products;
3 allergen-free and lactose-free cow's milk substitutes for baby and dietary nutrition;
4 structure formers and fillers, as well as for the formation, stabilization and destruction of foam, for example, when preparing imitation minced meat, meat, when preparing dough, sausages, whipped products (decorations on confectionery products), creams, etc.;
5 diluents for regulating the calorie content and biological value of dietary foods to create low-calorie “light” products.
Recently, in addition to plant proteins, attempts have been made to use proteins of microbial origin, with researchers paying especially much attention to yeast. The growth and development of microorganisms does not depend on the time of year or weather conditions. As a substrate for the proliferation of microorganisms, waste from agriculture, alcohol, pulp and paper industries, as well as oil and gas can be used. In terms of reproduction speed, microorganisms have no equal in the world of living beings. For example, the body of a cow weighing 500 kg per day with enhanced nutrition produces 0.5 kg of protein, and 500 kg of yeast during the same time synthesizes more than 50 tons of protein, i.e. 100 thousand times more.
The production of feed and food proteins, both plant and microbial, is based on the implementation of the principles of biotechnology on an industrial scale. Based on the principles of biotechnology, microbiological synthesis of organic acids, amino acids, enzymes, vitamins, growth stimulants, and plant protection products has been widely established.
To obtain more productive forms of microorganisms, genetic engineering methods are used, i.e. direct manipulation of individual genes. For example, the green mold Penicillium glaucum produces the antibiotic penicillin in small quantities, and the mold Penicillium notatum used in industry produces this antibiotic 1000 times more, etc.
Using gene transplantation, breeding biologists are working to create plants with controlled flowering periods, increased resistance to diseases, soil salinity, and the ability to fix atmospheric nitrogen (for example, tomatoes with simultaneous fruit ripening, which ensures mechanical harvesting).
Theoretical achievements of biology, especially genetics, are widely used in medicine. The study of human heredity makes it possible to develop methods for early diagnosis, treatment and prevention of hereditary diseases associated with genes, as well as chromosomal mutations and anomalies. For example, hemophilia, sickle cell anemia - sickle-shaped red blood cells, anemia, bone changes, etc.; phenylketonuria, etc.
In the context of growing human impact on nature, one of the fundamental problems is the greening of society and human consciousness. The task is not only to identify and eliminate the negative effects of human influence on nature, for example, local pollution of the environment with some substances, but mainly to scientifically substantiate the regimes for the rational use of biosphere reserves. Negative consequences economic activities have taken on the character of an environmental crisis in recent decades and have become dangerous not only for human health, but also for the natural environment as a whole. Therefore, another of the tasks facing biology is ensuring the preservation of the biosphere and nature’s ability to reproduce.
26. Biology in modern natural science. Characteristics of the “images” of biology (traditional, physico-chemical, evolutionary).
Biology is the science of living things, their structure, forms of their activity, their structure, communities of living organisms, their distribution, development, connections between themselves and their environment.
Modern biological science is the result of a long process of development. But only in the first ancient civilized societies did people begin to study living organisms more carefully, compile lists of animals and plants inhabiting different regions and classify them. One of the first biologists of antiquity was Aristotle.
Currently, biology is a whole complex of sciences about living nature. Its structure can be viewed from different points of view.
By objects of study biology is divided into virology, bacteriology, botany, zoology and anthropology.
According to the properties of the manifestation of living things in biology there are:
1) morphology- the science of the structure of living organisms;
2) physiology- the science of the functioning of organisms;
3) molecularbiology studies the microstructure of living tissues and cells;
4) ecology examines the lifestyle of plants and animals and their relationships with the environment;
5) genetics explores the laws of heredity and variability.
According to the level of organization of the living objects under study, the following are distinguished:
1) anatomy studies the macroscopic structure of animals;
2) histology studies the structure of tissues;
3) cytology studies the structure of living cells.
This diversity of the complex of biological sciences is due to the extraordinary diversity of the living world. To date, biologists have discovered and described more than 1 million species of animals, about 500 thousand plants, several hundred thousand species of fungi, and more than 3 thousand species of bacteria.
Moreover, the world of wildlife has not been fully explored. The number of undescribed species is estimated at at least 1 million.
In the development of biology there are three main stages:
1) taxonomy(C. Linnaeus);
2) evolutionary(C. Darwin);
3) biologymicroworld(G. Mendel).
Each of them is associated with a change in ideas about the living world and the very foundations of biological thinking.
Three “images” of biology.
Traditional or naturalistic biology.
The object of study of traditional biology has always been and remains living nature in its natural state and undivided integrity.
Traditional biology has early origins. They go back to the Middle Ages, and its formation into an independent science, called “naturalistic biology,” occurred in the 18th-19th centuries.
Its method was careful observation and description of natural phenomena, the main task was their classification, and the real prospect was to establish the patterns of their existence, meaning and significance for nature as a whole.
The first stage of naturalistic biology was marked by the first classifications of animals and plants. Principles for grouping them into taxa of various levels were proposed. The name of C. Linnaeus is associated with the introduction of binary (designation of genus and species) nomenclature, which has survived almost unchanged to this day, as well as the principle of hierarchical subordination of taxa and their names - classes, orders, genera, species, varieties. However, the disadvantage of Linnaeus's artificial system was that he did not give any instructions regarding the criteria of kinship, which reduced the merit of this system.
More “natural”, i.e. reflecting family ties were systems created by botanists - A. L. Jussier (1748-1836), O. P. Decandolle (1778-1841) and, in particular, J. B. Lamarck (1744-1829).
Lamarck's work was built on the idea of development from simple to complex, and the main question was the question of the origin of individual groups and the family ties between them.
It should be noted that during the period of the formation of traditional biology, a comprehensive, as we say today, systematic approach to the study of nature was laid down.
Physico-chemical, or experimental biology.
The term “physicochemical biology” was introduced in the 1970s by the organic chemist Yu. A. Ovchinnikov, a supporter of the close integration of the natural sciences and the introduction of modern precise physical and chemical methods into biology in order to study the elementary levels of the organization of living matter - molecular and supramolecular .
The concept of “physicochemical biology” is two-dimensional.
On the one hand, this concept means that the subject of study of physicochemical biology is objects of living nature studied at the molecular and supramolecular levels.
On the other hand, its original meaning is preserved: the use of physical and chemical methods to decipher the structures and functions of living nature at all levels of its organization.
Although this distinction is rather arbitrary, the main thing is considered to be the following: physical and chemical biology contributed most to the rapprochement of biology with the exact physical and chemical sciences and the establishment of natural science as a unified science of nature.
This does not mean that biology has lost its individuality. Just the opposite. The study of the structure, functions and self-reproduction of the fundamental molecular structures of living matter, the results of which were reflected in the form of postulates or axioms, did not deprive biology of its special position in the system of natural science. The reason for this is that these molecular structures perform biological functions.
It should be noted that in no other field of natural science, as in biology, is such a deep connection found between the methods and techniques of experiment, on the one hand, and the emergence of new ideas, hypotheses, and concepts, on the other.
When considering the history of methods of physical and chemical biology, five stages can be distinguished, which are located among themselves in both historical and logical sequence. In other words, innovations at one stage invariably stimulated the transition to the next.
What are these methods?
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Ministry of Education Russian Federation
St. Petersburg State Institute Psychology and Social Work
By discipline: Concepts of modern natural science
Subject: Biology in modern natural science
Completed by: 1st year student
Faculty applied psychology
Brave Karina Yumovna
Checked:
Ph.D., Associate Professor, Department Psychophysiology and GNI
Bydanova. N.B.
Saint Petersburg
Biology and its subject. History of biology.
Traditional or naturalistic biology.
Modern biology and physicochemical method.
Evolutionary biology. History of evolutionary teaching.
Biology and its subject. History of biology
Biology (from the Greek bios - life, logos - science) is the science of life, the general laws of existence and development of living beings. The subject of its study is living organisms, their structure, functions, development, relationships with the environment and origin. Like physics and chemistry, it belongs to the natural sciences, the subject of study of which is nature.
Although the concept of biology as a special natural science arose in the 19th century, biological disciplines originated earlier in medicine and natural history. Usually their tradition comes from such ancient scientists as Aristotle and Galen through the Arab physicians al-Jahizhttp://ru.wikipedia.org/wiki/%D0%91%D0%B8%D0%BE%D0%BB%D0%BE% D0%B3 - cite_note-3, Ibn-Sinu, Ibn-Zuhra and Ibn-al-Nafiz.
During the Renaissance, biological thought in Europe was revolutionized by the invention of printing and the spread of printed works, interest in experimental research, and the discovery of many new species of animals and plants during the Age of Discovery. At this time, outstanding minds Andrei Vesalius and William Harvey worked, who laid the foundations of modern anatomy and physiology. Somewhat later, Linnaeus and Buffon did a great job of classifying the forms of living and fossil creatures. Microscopy opened up a previously unknown world of microorganisms for observation, laying the foundation for the development of cell theory. The development of natural science, partly due to the emergence of mechanistic philosophy, contributed to the development of natural history.
TO early XIX century, some modern biological disciplines, such as botany and zoology, have reached professional level. Lavoisier and other chemists and physicists began to bring together ideas about living and inanimate nature. Naturalists such as Alexander Humboldt explored the interaction of organisms with the environment and its dependence on geography, laying the foundations of biogeography, ecology and ethology. In the 19th century, the development of the doctrine of evolution gradually led to an understanding of the role of extinction and variability of species, and the cell theory showed in a new light the fundamentals of the structure of living matter. Combined with data from embryology and paleontology, these advances allowed Charles Darwin to create a holistic theory of evolution through natural selection. TO end of the 19th century centuries, the ideas of spontaneous generation finally gave way to the theory of an infectious agent as a causative agent of diseases. But the mechanism of inheritance of parental characteristics still remained a mystery.
At the beginning of the 20th century, Thomas Morgan and his students rediscovered the laws studied in the mid-19th century by Gregor Mendel, after which genetics began to develop rapidly. By the 1930s, the combination of population genetics and the theory of natural selection gave rise to modern evolutionary theory, or neo-Darwinism. Thanks to the development of biochemistry, enzymes were discovered and a grandiose work began to describe all metabolic processes. The discovery of the structure of DNA by Watson and Crick gave a powerful impetus to the development of molecular biology. It was followed by the postulation of the central dogma, the deciphering of the genetic code, and by the end of the 20th century - the complete deciphering of the genetic code of humans and several other organisms that are most important for medicine and agriculture. Thanks to this, the new disciplines of genomics and proteomics have emerged. Although the increase in the number of disciplines and the extreme complexity of the subject of biology have given rise and continue to give rise to increasingly narrow specialization among biologists, biology continues to remain a single science, and the data of each of the biological disciplines, especially genomics, are applicable to all others.
Traditional or naturalistic biology
Its object of study is living nature in its natural state and undivided integrity - the “Temple of Nature,” as Erasmus Darwin called it. The origins of traditional biology go back to the Middle Ages, although it is quite natural to recall here the works of Aristotle, who considered issues of biology, biological progress, and tried to systematize living organisms (“the ladder of Nature”). The formation of biology into an independent science - naturalistic biology - dates back to the 18th and 19th centuries. The first stage of naturalistic biology was marked by the creation of classifications of animals and plants. These include the well-known classification of K. Linnaeus (1707 - 1778), which is a traditional systematization of the plant world, as well as the classification of J.-B. Lamarck, who applied an evolutionary approach to the classification of plants and animals. Traditional biology has not lost its importance even today. As evidence, they cite the position of ecology among the biological sciences and also in all natural sciences. Its position and authority are currently extremely high, and it is primarily based on the principles of traditional biology, since it studies the relationships of organisms with each other (biotic factors) and with the environment (abiotic factors).
Modern biology and physicochemical methods
Throughout the history of the development of biology, physical and chemical methods have been the most important tools for studying biological phenomena and processes of living nature. The importance of introducing such methods into biology is confirmed by experimental results obtained using modern methods research originating in related branches of natural science - physics and chemistry. In this regard, it is no coincidence that in the 1970s a new term “physical and chemical biology” appeared in the domestic scientific lexicon. The appearance of this term indicates not only the synthesis of physical, chemical and biological knowledge, but also a qualitatively new level of development of natural science, in which there is certainly mutual support for its individual branches. Physico-chemical biology contributes to the rapprochement of biology with the exact sciences - physics and chemistry, as well as the establishment of natural science as a unified science of nature.
At the same time, the study of the structure, functions and reproduction of the fundamental molecular structures of living matter does not deprive biology of its individuality and special position in natural science, since molecular structures are endowed with biological functions and have a very specific specificity.
The introduction of physical and chemical methods contributed to the development of experimental biology, the origins of which were prominent scientists: C. Bernard (1813-1878), G. Helmholtz (1821-1894), L. Pasteur (1822-1895), I.M. Sechenov (1829-1905), I.P. Pavlov (1849-1936), S.N. Vinogradsky (1856-1953), K.A. Timiryazev (1843-1920), I.I. Mechnikov (1845-1916) and many others.
Experimental biology comprehends the essence of life processes mainly using precise physical and chemical methods, while sometimes resorting to the dismemberment of biological integrity, that is, a living organism in order to penetrate into the secrets of its functioning.
Modern experimental biology has armed itself with the latest methods that allow us to penetrate into the submicroscopic, molecular and supramolecular world of living nature. We can name several widely used methods: the method of isotope indicators, methods of X-ray diffraction analysis and electron microscopy, fractionation methods, methods of intravital analysis, etc. Let us give them brief description.
The isotope tracer method, formerly called the tracer method, was proposed shortly after the discovery of radioactivity. Its essence lies in the fact that with the help of radioactive (labeled) atoms introduced into the body, the movement and transformation of substances in the body can be traced.
Using this method, it was possible to establish the dynamism of metabolic processes, monitor their initial, intermediate and final stages, and identify the influence of individual structures of the body on the course of processes. The isotope tracer method allows one to study metabolic processes in a living organism. This is one of its advantages. Constant renewal of proteins and membranes, biosynthesis of proteins and nucleic acids, intermediate metabolism of carbohydrates and fats, as well as many other important microprocesses were discovered using this method.
X-ray structural analysis has proven to be very effective in studying the structures of macromolecules that underlie the life activity of living organisms. He made it possible to establish the double-stranded structure (double helix) of information carrier molecules and the filamentous structure of proteins. With the advent of X-ray diffraction studies, molecular biology was born.
The possibilities of molecular biology have expanded significantly with the use of electron microscopic studies, which have made it possible to establish the multilayer structure of the sheath of nerve fibers consisting of alternating protein and lipid layers. Electron microscopic observations made it possible to decipher the molecular organization of a living cell and the mechanism of membrane functioning, on the basis of which the modern membrane theory was created in the early 50s; its founders were the English physiologists A. Hodgkin (1914-1994), A. Huxley (b. 1917) and the Australian physiologist J. Eccles.
The membrane theory has important general biological significance. Its essence is as follows. On both sides of the membrane, due to the counter flow of potassium and sodium ions, a potential difference is created. This process is accompanied by excitation and depolarization of the previously quiescent polarized membrane and a change in the sign of its electrical potential. The change in potential difference is the same for all membrane systems. It simultaneously provides the functions of barriers and peculiar pumping mechanisms. Such functions of membrane systems contribute to the active penetration of substances both inside and outside the cell. Due to the membranes, spatial insulation is also achieved structural elements body.
The discovery of the structure of membrane systems and the mechanism of their functioning is a major achievement not only in biology, but also in natural science in general.
In physicochemical biology, various fractionation methods based on one or another physical or chemical phenomenon are widely used. A rather effective fractionation method was proposed by the Russian biologist and biochemist M.S. Color (1872-1919). The essence of his method is the separation of a mixture of substances based on absorption by the surface solids components of the separated mixture, on ion exchange and on the formation of precipitation.
Radio spectroscopy, high-speed X-ray diffraction analysis, ultrasonic probing and many other modern research tools make up the arsenal of intravital analysis methods. All these methods are not only widely used in physical and chemical biology, but also adopted by modern medicine. Nowadays, not a single clinical institution can do without fluoroscopic, ultrasound and other equipment that makes it possible to determine structural and sometimes functional changes in the body without harm to the patient.
The experimental technique of modern physical and chemical biology necessarily includes certain computational tools that greatly facilitate the labor-intensive work of the experimenter and allow one to obtain more reliable information about the properties of the living object under study.
Feature modern physical and chemical biology - its rapid development. It is difficult to list all her achievements, but some of them deserve special attention. In 1957, the tobacco mosaic virus was reconstructed from its constituent components. In 1968-1971 Artificial synthesis of a gene for one of the transport molecules was carried out by sequentially introducing new nucleotides into the test tube with the gene being synthesized. The results of studies on deciphering the genetic code turned out to be very important: it was shown that when artificially synthesized molecules are introduced into a cell-free system, that is, a system without a living cell, information sections are discovered consisting of three consecutive nucleotides, which are discrete units of the genetic code. The authors of this work are American biochemists M. Nirenberg (b. 1927), X. Korana (b. 1922) and R. Holley (b. 1922).
Decoding various types self-regulation is also an important achievement of physicochemical biology. Self-regulation as a characteristic property of living nature manifests itself in various forms, such as the transfer of hereditary information - the genetic code; regulation of protein biosynthetic processes (enzymes) depending on the nature of the substrate and under the control of a genetic mechanism; regulation of rates and directions of enzymatic processes; regulation of growth and morphogenesis, i.e. formation of structures different levels organizations; regulation of the analyzing and control functions of the nervous system.
Living organisms are a very complex object for research. But still, modern technical means allow us to penetrate deeper and deeper into the secrets of living matter.
Evolutionary biology. History of evolutionary teaching
Evolutionary biology is a branch of biology that studies the origin of species from common ancestors, heredity and variability of their characteristics, reproduction and diversity of forms in a historical context.
Evolutionary doctrine (biol.) - a complex of knowledge about the historical development (evolution) of living nature. Evolutionary teaching deals with the analysis of the formation of adaptation (adaptations), the evolution of individual development of organisms, factors directing evolution, and specific paths historical development individual groups of organisms and the organic world as a whole. The basis of evolutionary teaching is evolutionary theory. Evolutionary teaching also includes the concepts of the origin of life and the origin of man.
The first ideas about the development of life, contained in the works of Empedocles, Democritus, Lucretius Cara and other ancient philosophers, were in the nature of brilliant guesses and were not substantiated by biological facts. In the 18th century, Transformism was formed in biology - the doctrine of the variability of animal and plant species, opposed to Creationism, based on the concept of divine creation and the immutability of species. The most prominent transformists of the second half of the 18th and first half of the 19th centuries - J. Buffon and E. J. Saint-Hilaire in France, E. Darwin in England, J. W. Goethe in Germany, C. F. Roulier in Russia - substantiated changeability species mainly by two facts: the presence of transitional forms between closely related species and the unity of the structural plan of organisms of large groups of animals and plants. However, they did not consider the causes and factors of species change.
The first attempt to create a holistic evolutionary theory belongs to the French naturalist J.B. Lamarck, who outlined his ideas about the driving forces of evolution in his “Philosophy of Zoology” (1809). According to Lamarck, the transition from lower forms of life to higher ones - Gradation - occurs as a result of the immanent and universal desire of organisms for perfection. Lamarck explained the diversity of species at each level of organization by the gradation-modifying influence of environmental conditions. According to Lamarck’s first “law”, exercise of organs leads to their progressive development, and lack of exercise leads to reduction; According to the second “law”, the results of exercise and non-exercise of organs, with a sufficient duration of exposure, are fixed in the heredity of organisms and are further transmitted from generation to generation, regardless of the environmental influences that caused them. Lamarck’s “laws” are based on the erroneous idea that nature is characterized by a desire for improvement and the inheritance of acquired properties by organisms.
The true factors of evolution were revealed by Charles Darwin, thereby creating a scientifically based evolutionary theory (set out in the book “The Origin of Species by Means of Natural Selection, or the Preservation of Favored Breeds in the Struggle for Life,” 1859). The driving forces of evolution, according to Darwin, are: indefinite variability - the hereditarily determined diversity of organisms in each population of any species, the struggle for existence, during which less adapted organisms die or are eliminated from reproduction, and natural selection - the survival of more adapted individuals, as a result of which they accumulate and beneficial hereditary changes are summed up and new adaptations arise. Lamarckism and Darwinism in the interpretation of evolution are diametrically opposed: Lamarckism explains evolution by adaptation, and Darwinism explains adaptation by evolution. In addition to Lamarckism, there are a number of other concepts that deny the importance of selection, such as driving force evolution. The development of biology confirmed the correctness of Darwin's theory. Therefore, in modern biology, the terms “Darwinism” and “evolutionary teaching” are often used as synonyms. The term “synthetic theory of evolution” is also close in meaning, which emphasizes the combination of the main provisions of Darwin’s theory, genetics and a number of evolutionary generalizations from other areas of biology.
The development of genetics has made it possible to understand the mechanism of the emergence of uncertain hereditary variability, which provides material for evolution. This phenomenon is based on persistent changes in hereditary structures - Mutations. Mutational variability is not directed: newly emerging mutations are not adequate to environmental conditions and, as a rule, disrupt already existing adaptations. For organisms that do not have a formed nucleus, mutational variability serves as the main material for evolution. For organisms whose cells have a formed nucleus, combinative variability - the combination of genes during sexual reproduction - is of great importance. The elementary unit of evolution is the Population. The relative isolation of populations leads to their reproductive isolation—limiting the freedom of interbreeding of individuals from different populations. Reproductive isolation ensures the uniqueness of the Gene Pool - the genetic composition of each population - and thereby the possibility of its independent evolution. In the process of struggle for existence, the biological diversity of the individuals composing a population is manifested, determined by combinative and mutational variability. In this case, some individuals die, while others survive and reproduce. As a result of natural selection, newly emerging mutations are combined with the genes of individuals that have already been selected, their phenotypic expression changes, and new adaptations arise on their basis. Thus, it is selection that is the main driving factor in evolution, causing the emergence of new adaptations, the transformation of organisms and speciation. Selection can manifest itself in different forms: stabilizing, ensuring the preservation of already formed adaptations in unchanged environmental conditions, driving, or leading, leading to the development of new adaptations, and disruptive, or breaking, causing the emergence of Polymorphism with multidirectional changes in the population’s habitat.
In modern evolutionary teaching, the idea of evolutionary factors has been enriched by identifying the population as elementary unit evolution, the theory of isolation and the deepening of the theory of natural selection. Analysis of isolation as a factor providing an increase in the diversity of life forms underlies modern ideas about speciation and species structure. Allopatric speciation associated with the dispersal of the species and geographic isolation of marginal populations has been most fully studied. Less studied is sympatric speciation caused by ecological, chronological or ethological (behavioral) isolation. Evolutionary processes occurring within a species and culminating in speciation are often combined under the general name of microevolution. Macroevolution is the historical development of groups of organisms (taxa) of supraspecific rank. The evolution of supraspecific taxa is the result of speciation occurring under the influence of natural selection. However, the use of different time scales (the evolution of large taxa consists of many stages of speciation) and study methods (the use of paleontological data, comparative morphology, embryology, etc.) makes it possible to identify patterns that elude the study of microevolution. The most important tasks of the concept of macroevolution are the analysis of the relationship between the individual and historical development of organisms, the analysis of the patterns of phylogenesis and the main directions of the evolutionary process. In 1866, the German naturalist E. Haeckel formulated the Biogenetic Law, according to which the stages of phylogenesis of a given systematic group are briefly repeated in ontogenesis. Mutations appear in the phenotype of an adult organism as a result of the fact that they change the processes of its ontogenesis. Therefore, natural selection of adult individuals leads to the evolution of ontogenetic processes - the interdependencies of developing organs, called ontogenetic correlations by I. I. Shmalgauzen. The restructuring of the system of ontogenetic correlations under the influence of driving selection leads to the occurrence of changes - phylembryogenesis, through which new characteristics of organisms are formed during phylogenesis. In the event that a change occurs at the final stage of organ development, further evolution of the ancestral organs occurs; There are also deviations in ontogenesis at intermediate stages, which leads to the restructuring of organs; changes in the formation and development of early rudiments can lead to the emergence of organs that were absent in the ancestors. However, the evolution of ontogenetic correlations under the influence of stabilizing selection leads to the preservation of only those correlations that most reliably support the processes of ontogeny. These correlations are recapitulations - repetitions in the ontogenesis of descendants of the phylogenetic states of their ancestors; thanks to them, the biogenetic law is ensured. The direction of phylogeny of each systematic group is determined by the specific relationship between the environment in which the evolution of a given taxon takes place and its organization. Divergence (divergence of characters) of two or more taxa arising from a common ancestor is due to differences in environmental conditions; it begins at the population level, causes an increase in the number of species and continues at the level of supraspecific taxa. It is divergent evolution (which determines the taxonomic diversity of living beings. Parallel evolution is less common. It occurs in cases where the initially divergent taxa remain in similar environmental conditions and develop similar adaptations on the basis of a similar organization inherited from a common ancestor. Convergence (convergence of characters) occurs in cases where unrelated taxa adapt to the same conditions. Biological progress can be achieved through a general increase in the level of organization, causing the adaptation of organisms to environmental conditions broader and more diverse than those in which their ancestors lived. Such changes - aromorphoses - occur rarely and necessarily give way to Allomorphoses - divergence and adaptation to more specific conditions in the process of mastering a new habitat. The development of narrow adaptations in the phylogeny of a group leads to specialization. The 4 main types of specialization identified by Schmalhausen - Telomorphosis, Hypomorphosis, Hypermorphosis and Catamorphosis - differ in the nature of adaptations, but all lead to a slowdown in the pace of evolution and, due to the loss of multifunctionality by the organs of specialized animals, to a decrease in evolutionary plasticity. If stable environmental conditions are maintained, specialized species can exist indefinitely. This is how “living fossils” arise, for example, many genera of mollusks and brachiopods that have existed from the Cambrian to the present day. With sudden changes in living conditions, specialized species die out, while more flexible ones manage to adapt to these changes.
The doctrine of evolution and mainly its theoretical core - evolutionary theory - serve as both an important natural science justification for dialectical materialism and one of methodological foundations modern biology.
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2. Big Soviet encyclopedia 1970
3. Kuznetsov V.I., Idlis G.M., Gutina V.N. Natural science. M., 1996
4. Karpenkov S.Kh. Concepts of modern natural science. 6th ed., revised. and additional - M.: Higher. school, 2003.
This is the science of life. Currently, it represents the totality of sciences about living nature.
Biology studies all manifestations of life: structure, functions, development and origin living organisms, their relationships in natural communities with the environment and with other living organisms.
Since man began to realize his difference from the animal world, he began to study the world around him.
At first his life depended on it. To primitive people it was necessary to know which living organisms could be eaten, used as medicine, for making clothing and housing, and which of them were poisonous or dangerous.
With the development of civilization, man was able to afford the luxury of engaging in science for educational purposes.
Research The cultures of ancient peoples showed that they had extensive knowledge about plants and animals and widely used them in everyday life.
Modern biology - complex the science, which is characterized by the interpenetration of ideas and methods of various biological disciplines, as well as other sciences - primarily physics, chemistry and mathematics.
Main directions of development of modern biology. Currently, three directions in biology can be roughly distinguished.
Firstly, this is classical biology. It is represented by natural scientists who study the diversity of living things. nature. They objectively observe and analyze everything that happens in living nature, study living organisms and classify them. It is wrong to think that in classical biology all discoveries have already been made.
In the second half of the 20th century. not only many new species were described, but also large taxa were discovered, up to kingdoms (Pogonophora) and even superkingdoms (Archebacteria, or Archaea). These discoveries forced scientists to take a new look at the whole history of development living nature, For real natural scientists, nature is its own value. Every corner of our planet is unique for them. That is why they are always among those who acutely sense the danger to the nature around us and actively advocate for its protection.
The second direction is evolutionary biology.
In the 19th century the author of the theory of natural selection, Charles Darwin, began as an ordinary naturalist: he collected, observed, described, traveled, revealing the secrets of living nature. However, the main result of it work What made him a famous scientist was the theory that explained organic diversity.
Currently, the study of the evolution of living organisms is actively continuing. The synthesis of genetics and evolutionary theory led to the creation of the so-called synthetic theory of evolution. But even now there is still a lot unresolved issues, the answers to which evolutionary scientists are looking for.
Created at the beginning of the 20th century. our outstanding biologist Alexander Ivanovich Oparin was the first scientific theory the origin of life was purely theoretical. Currently under active experimental studies this problem and thanks to the use of advanced physical and chemical methods have already been made important discoveries and we can expect new interesting results.
New discoveries made it possible to supplement the theory of anthropogenesis. But the transition from the animal world to humans still remains one of the biggest mysteries of biology.
The third direction is physical and chemical biology, which studies the structure of living objects using modern physical and chemical methods. This is a rapidly developing area of biology, important both theoretically and practically. It is safe to say that new discoveries await us in physical and chemical biology that will allow us to solve many problems facing humanity.
Development of biology as a science. Modern biology has its roots in antiquity and is associated with the development of civilization in the Mediterranean countries. We know the names of many outstanding scientists who contributed to the development of biology. Let's name just a few of them.
Hippocrates (460 - ca. 370 BC) gave the first relatively detailed description of the structure of humans and animals, and pointed out the role of the environment and heredity in the occurrence of diseases. He is considered the founder of medicine.
Aristotle (384-322 BC) divided the world into four kingdoms: the inanimate world of earth, water and air; world of plants; the animal world and the human world. He described many animals and laid the foundation for taxonomy. The four biological treatises he wrote contained almost all the information about animals known at that time. Aristotle's merits are so great that he is considered the founder of zoology.
Theophrastus (372-287 BC) studied plants. He described more than 500 plant species, provided information about the structure and reproduction of many of them, and introduced many botanical terms into use. He is considered the founder of botany.
Guy Pliny the Elder (23-79) collected information about living organisms known at that time and wrote 37 volumes of the Natural History encyclopedia. Almost until the Middle Ages, this encyclopedia was the main source of knowledge about nature.
Claudius Galen in his scientific research made extensive use of mammalian dissections. He was the first to make a comparative anatomical description of man and monkey. Studied central and peripheral nervous system. Historians of science consider him the last great biologist of antiquity.
In the Middle Ages, the dominant ideology was religion. Like other sciences, biology during this period had not yet emerged as an independent field and existed in the general mainstream of religious and philosophical views. And although the accumulation of knowledge about living organisms continued, biology as a science in that period can only be spoken of conditionally.
The Renaissance is a transition from the culture of the Middle Ages to the culture of modern times. The radical socio-economic transformations of that time were accompanied by new discoveries in science.
The most famous scientist of this era, Leonardo da Vinci (1452 - 1519), made a certain contribution to the development of biology.
He studied the flight of birds, described many plants, ways of connecting bones in joints, the activity of the heart and the visual function of the eye, the similarity of human and animal bones.
In the second half of the 15th century. natural science knowledge begins to develop rapidly. This was facilitated by geographical discoveries, which made it possible to significantly expand information about animals and plants. The rapid accumulation of scientific knowledge about living organisms led to the division of biology into separate sciences.
In the XVI-XVII centuries. Botany and zoology began to develop rapidly.
The invention of the microscope (early 17th century) made it possible to study the microscopic structure of plants and animals. Microscopically small living organisms - bacteria and protozoa - were discovered, invisible to the naked eye.
Carl Linnaeus made a great contribution to the development of biology, proposing a system of classification of animals and plants,
Karl Maksimovich Baer (1792-1876) in his works formulated the basic principles of the theory of homologous organs and the law of germinal similarity, which laid the scientific foundations of embryology.
In 1808, in his work “Philosophy of Zoology,” Jean Baptiste Lamarck raised the question of the causes and mechanisms of evolutionary transformations and outlined the first theory of evolution.
The cell theory played a huge role in the development of biology, which scientifically confirmed the unity of the living world and served as one of the prerequisites for the emergence of Charles Darwin's theory of evolution. The authors of the cell theory are considered to be the zoologist Theodor Ivann (1818-1882) and the botanist Matthias Jakob Schleiden (1804-1881).
Based on numerous observations, Charles Darwin published his main work in 1859, “On the Origin of Species by Natural Selection or the Preservation of Favored Breeds in the Struggle for Life,” in which he formulated the basic principles of the theory of evolution, proposed mechanisms of evolution and ways of evolutionary transformations of organisms.
In the 19th century Thanks to the work of Louis Pasteur (1822-1895), Robert Koch (1843-1910), and Ilya Ilyich Mechnikov, microbiology took shape as an independent science.
The 20th century began with the rediscovery of Gregor Mendel's laws, which marked the beginning of the development of genetics as a science.
In the 40-50s of the XX century. in biology, ideas and methods of physics, chemistry, mathematics, cybernetics and other sciences began to be widely used, and microorganisms were used as objects of research. As a result, biophysics, biochemistry, molecular biology, radiation biology, bionics, etc. arose and began to rapidly develop as independent sciences. Research in space contributed to the emergence and development of space biology.
In the 20th century a direction of applied research appeared - biotechnology. This direction will undoubtedly develop rapidly in the 21st century. You will learn more about this direction of development of biology when studying the chapter “Fundamentals of selection and biotechnology.”
Currently, biological knowledge is used in all spheres of human activity: in industry and agriculture, medicine and energy.
Ecological research is extremely important. We finally began to realize that the fragile balance that exists on our small planet can be easily destroyed. Humanity is faced with a tremendous task - preserving the biosphere in order to maintain the conditions of existence and development of civilization. It is impossible to solve it without biological knowledge and special research. Thus, biology has now become a real productive force and rational scientific basis relationship between man and nature.
Classical biology. Evolutionary biology. Physico-chemical biology.
1. What directions in the development of biology can you highlight?
2. Which great scientists of antiquity made a significant contribution to the development of biological knowledge?
3. Why in the Middle Ages could one speak only conditionally about biology as a science?
4. Why is modern biology considered a complex science?
5. What is the role of biology in modern society?
6. Prepare a message on one of the following topics:
7. The role of biology in modern society.
8. The role of biology in space research.
9. The role of biological research in modern medicine.
10. The role of outstanding biologists - our compatriots in the development of world biology.
How much scientists' views on the diversity of living things have changed can be demonstrated by the example of the division of living organisms into kingdoms. Back in the 40s of the 20th century, all living organisms were divided into two kingdoms: Plants and Animals. The plant kingdom also included bacteria and fungi. Later, a more detailed study of organisms led to the identification of four kingdoms: Prokaryotes (Bacteria), Fungi, Plants and Animals. This system is given in school biology.
In 1959, it was proposed to divide the world of living organisms into five kingdoms: Prokaryotes, Protists (Protozoa), Fungi, Plants and Animals.
This system is often cited in biological (especially translated) literature.
Other systems have been developed and continue to be developed, including 20 or more kingdoms. For example, it has been proposed to distinguish three superkingdoms: Prokaryotes, Archaea (Archebacteria) and Eukaryotes. Each superkingdom includes several kingdoms.
Kamensky A. A. Biology 10-11 grade
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The importance of biology in human life becomes clear if we draw a parallel between the main problems of an individual’s life, for example, health, nutrition, and the choice of optimal living conditions. Today, there are numerous sciences that have separated from biology, becoming no less important and independent. These include zoology, botany, microbiology, and virology. Of these, it is difficult to single out the most significant; they all represent a complex of valuable fundamental knowledge accumulated by civilization.
Outstanding scientists worked in this field of knowledge, such as Claudius Galen, Hippocrates, Carl Linnaeus, Charles Darwin, Alexander Oparin, Ilya Mechnikov and many others. Thanks to their discoveries, especially the study of living organisms, the science of morphology appeared, as well as physiology, which collected knowledge about the systems of organisms of living beings. Genetics has played an invaluable role in the development of hereditary diseases.
Biology has become a solid foundation in medicine, sociology and ecology. It is important that this science, like any other, is not static, but is constantly updated with new knowledge, which is transformed in the form of new biological theories and laws.
The role of biology in modern society, and especially in medicine, is invaluable. It was with its help that methods of treating bacteriological and rapidly spreading viral diseases were found. Every time we think about the role of biology in modern society, we remember that it was thanks to the heroism of medical biologists that centers of terrible epidemics disappeared from planet Earth: plague, cholera, anthrax, smallpox and others no less life-threatening human diseases.
We can safely say, based on the facts, that the role of biology in modern society is growing continuously. It's impossible to imagine modern life without selection, genetic research, production of new food products, as well as environmentally friendly energy sources.
The main importance of biology is that it represents the foundation and theoretical basis for many promising sciences, such as genetic engineering and bionics. She owns a great discovery - decoding A direction such as biotechnology was also created on the basis of knowledge combined in biology. Currently, technologies of this nature make it possible to create safe medicines for prevention and treatment that do not harm the body. As a result, it is possible to increase not only life expectancy, but also its quality.
The role of biology in modern society lies in the fact that there are areas where its knowledge is simply necessary, for example, the pharmaceutical industry, gerontology, criminology, Agriculture, construction, and space exploration.
The unstable environmental situation on Earth requires a rethinking of production activities, and the importance of biology in human life is moving to a new level. Every year we become witnesses of large-scale disasters that affect both the poorest countries and highly developed ones. They are largely caused by the growth of unreasonable use of energy sources, as well as existing economic and social contradictions in modern society.
The present clearly indicates to us that the very continued existence of civilization is possible only if there is harmony in Only compliance with biological laws, as well as the widespread use of progressive biotechnologies based on ecological thinking, will ensure natural safe coexistence for all inhabitants of the planet without exception.
The role of biology in modern society is expressed in the fact that it has now transformed into a real force. Thanks to her knowledge, the prosperity of our planet is possible. That is why, to the question of what is the role of biology in modern society, the answer may be this - it is the treasured key to harmony between nature and man.
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