Presentation on the topic "The evolutionary teachings of Ch. Darwin". Presentation for the lesson "Charles Darwin: the main provisions of the theory of speciation" Darwin's evolutionary theory presentation

Charles Darwin was born in 1809. uHe studied at the medical and theological faculties, he was going to become a priest. uIn 1831, he went on a 5-year voyage on the ship Beagle as a naturalist.

1859 - "The origin of species by means of natural selection" The main provisions of the theory of Charles Darwin uOrganisms are changeable. uFor evolution, only hereditary (indeterminate) variability matters. uCauses of evolution: the struggle for existence and natural selection.

The mechanism of evolution (according to the theory of Ch.Darwin) The ability of organisms to unlimited reproduction The limited resources of the environment Hereditary variability The struggle for existence Natural selection The emergence of adaptations The emergence of species The results of evolution

Forms of variability (according to Darwin) u Defined, group, non-hereditary (modern - modification). Caused by the influence of the external environment. uIndefinite, individual, hereditary (modern - mutational). u Correlative, correlative - a change in one organ causes a change in others.

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Charles Robert Darwin (1809-1882) is the founder of evolutionary biology. C. Darwin was born on February 12, 1809 in the family of a doctor. While studying at the Universities of Edinburgh and Cambridge, Darwin gained a thorough knowledge of zoology, botany and geology, skills and a taste for field research. An important role in shaping his scientific outlook was played by the book of the outstanding English geologist Charles Lyell "Principles of Geology". In 1854-1855, Darwin began to work closely on the theory of evolution: he collected materials on the variability, heredity and evolution of wild species of animals and plants, as well as data on the methods of breeding domestic animals and cultivated plants, comparing the results of artificial and natural selection. He began to write a book, which, according to his estimates, should have consisted of 3-4 volumes. By the summer of 1858 he had written ten chapters of this work. This work was never completed and was first published in the UK in 1975. In 1859, Darwin published The Origin of Species by Means of Natural Selection, or the Preservation of Favored Breeds in the Struggle for Life, in which he called natural selection and indeterminate variability the main driving force of evolution. In 1868, Darwin published his second work, The Change in Domestic Animals and Cultivated Plants, which included many examples of the evolution of organisms. In 1871, his work "The Origin of Man and Sexual Selection" appeared, where Darwin substantiated the hypothesis of the origin of man from an ape-like ancestor.

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Scientific prerequisites E. Kant (1724-1804) in his famous work "The General Natural History and Theory of the Sky" rejected the myth of the first shock and came to the conclusion that the Earth and the whole solar system- something that has arisen in time. Thanks to the works of E. Kant, P. Laplace and V. Hertel, the Earth and the solar system began to be considered not as once created, but as developing in time. In 1830, the English naturalist, founder of historical geology Ch. Lyell (1797-1875) substantiated the idea of ​​the Earth's various reasons and laws: climate, water, volcanic forces, organic factors. Lyell suggested that the organic world is gradually changing, and this was confirmed by the results of paleontological research by the French zoologist J. Cuvier (1769-1832). In the first half of the XIX century. developed the idea of ​​the unity of all nature. The Swedish chemist I. Berzelius (1779-1848) proved that all animals and plants consist of the same elements as the bodies of inanimate nature. The German chemist F. Wöhler (1800-1882) for the first time in 1824 in the laboratory chemically synthesized oxalic acid, and in 1828 - urea, thus showing that the formation organic matter perhaps without the participation of some "life force" inherent in living organisms.

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Scientific background In the XVIII-XIX centuries. due to the prevailing historical conditions (colonization of vast territories and their research), ideas about the diversity of organic world, about the patterns of its distribution over the continents of the globe. Systematics is intensively developing: all the diversity of the organic world required its classification and bringing into a certain system, which had importance to develop the idea of ​​the relatedness of living beings, and then of the unity of their origin. In the first half of the XIX century. begins a detailed study of the geographical distribution of organisms; biogeography and ecology begin to develop, the first generalizing conclusions of which were important for substantiating the idea of ​​evolution. So, in 1807, the German naturalist A. Humboldt (1769-1859) expressed the idea that the geographical distribution of organisms depends on the conditions of existence. The Russian scientist K. F. Rulye (1814-1858) tries to interpret the historical change in the face of the Earth and the conditions of life on it and to explain the influence of these changes on the change in animals and plants. His student N. A. Severtsov (1827-1885) expressed ideas about the relationship of organisms with the environment, about the formation of new species as an adaptive (adaptive) process. Comparative morphology and anatomy develops. Her success contributed to the elucidation of not only the similarity of the structure various kinds animals, but also such a similarity in their organization, which suggested a deep connection between them, their unity. Comparative embryology is taking shape. In 1817-1818. I. Kh. Pander discovered germ layers and the versatility of their laying in animal embryogenesis. The German researcher M. Rathke applied the theory of germ layers to invertebrates (1829). At the end of the 20s of the XIX century. Russian embryologist K. M. Baer (1792-1870) established the main stages of embryonic development and proved that all vertebrates develop according to a single plan. Subsequently, Baer's generalizations were called by Darwin the law of germinal similarity and used by him to prove evolution. A remarkable sign of embryonic similarity is, for example, the presence of gill slits in the walls of the pharynx in the embryos of all vertebrates, including humans. In 1839, the German zoologist T. Schwann created a cell theory that substantiated the common microstructure and development of animals and plants.

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Socio-economic background A. Smith created the doctrine of "free competition". He believed that the engine of the development of production is free competition, which is based on the "natural self-interest" or "natural egoism" of a person, which serves as a source of national wealth. Unadapted competitors are eliminated in the process of free competition. The idea of ​​competitive relations, characteristic of the transition from feudalism to capitalism, influenced, paradoxically, the formation of ideas about the development of wildlife (Ch. Darwin subsequently substantiated the idea competitive relations between living organisms). T. Malthus believed that the human population is growing exponentially, while food production - only in arithmetic. As a result of overpopulation, there is a lack of means of subsistence. Malthus explains this by the "eternal natural law of nature", believing that its action can be limited only by a decrease in the population. Otherwise, nature itself will restore the balance with the help of hunger, disease, etc., sharply increasing the intensity of competition. The idea of ​​overpopulation in living nature, arising as a result of the ability of organisms to multiply exponentially, will be used by Charles Darwin to explain the emergence of the struggle for existence.

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Ch. Darwin's round-the-world voyage Charles Darwin's round-the-world voyage on the English ship Beagle (1831-1836) was of no small importance for the creation of evolutionary theory. In connection with the tasks assigned to the expedition to study the outlines of the coasts of South America and other territories, Charles Darwin had the opportunity to make long excursions, explore the geological rocks, flora and fauna of the visited areas. During the journey, he collected numerous facts that testified in favor of the variability of species and undermined the belief in their creation. These facts can be grouped into three groups.

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The first group of facts ... ... testifies to the historical connection between extinct and living animals. Darwin discovered, for example, a significant similarity between the fossil representatives of the fauna of South America and modern sloths and armadillos.

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The second group of facts ... ... refuted the concept of the constancy of species, revealed patterns in the geographical distribution of animal species. Comparing the fauna of South and North America, Darwin thought about the reasons for their significant difference. In South America, there are species (American monkey, llama, tapirs, anteaters, armadillos) that are not in North America; in turn, the latter contains forms not found in South America. In analyzing these facts, Darwin applied the historical method, evaluating the fauna of North and South America in its change, in accordance with its geological past. He believed that originally North and South America were inhabited by similar forms. Subsequently, in connection with the emergence of a vast plateau in the southern part of the Mississippi, the isolation of the faunas of these continents occurred. The original species died out, and those that replaced them, due to isolation, developed in different directions, which led to the difference between the fauna of North and South America.

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The third group of facts... ...is related to the fauna of the Galapagos Islands. On these volcanic islands, C. Darwin discovered nowhere else, but very similar to South American species of finches, mockingbirds, the Galapagos buzzard, an owl, a lizard, turtles, etc. Each island of the Galapagos archipelago has its own form, for example, finches , but all of them, taken together, form one natural group. C. Darwin suggested that all the Galapagos finches apparently descended from one ancestral species that came here from the mainland.

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The main provisions of the evolutionary doctrine 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.

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The main provisions of the evolutionary doctrine 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. It is 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. 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.

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Artificial selection is the preservation and reproduction of specimens of plants and animals that are in some way advantageous or useful to people

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Forms of artificial selection Unconscious selection is a selection in which the goal is not to create a new variety or breed. People keep the best, in their opinion, individuals and destroy (cull out) the worst. Unconscious selection arose long ago, from the moment of domestication of the dog. Unconscious selection leads to a change in plants and animals, to the improvement of breeds and varieties, to the creation of new local breeds and varieties. The desired result with this selection is formed slowly, but it can be impressive. Methodological selection is a selection carried out by a person according to a specific plan, with a specific goal - to create a breed or variety. Features: a goal is set: the breeder decides which traits need to be changed and in which direction, i.e., the direction of selection is determined (egg production, meatiness, beautiful crest, beautiful tail, beautiful plumage); a plan is drawn up for creating a breed (variety): what breeds (varieties) and in what order should be crossed, what types of crossbreeding should be used; special living conditions are created; methodological selection is creativity.

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Material for selection In the change of breeds of domestic animals and plants cultivated by people, two main points are involved: VARIABILITY, which provides material for breeding new breeds; HEREDITY - common property of all living beings, thanks to which the characteristics of the parents are transmitted to offspring *Darwin personally studied all the breeds of domestic pigeons available to him and found that they all descended from a wild rock pigeon. From one form, setting special requirements each time when creating a new breed, people received both large pouts with high legs, and a small pigeon - a seagull, and carrier pigeons with their fast flight, and peacock pigeons with a fan-shaped tail, and many others.

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Natural selection has two sides: differential (selective) survival differential mortality *i.e. natural selection has positive and negative sides. The negative side of natural selection is elimination. The positive side is the preservation of phenotypes most appropriate to the conditions of the ecosystem in this moment. *Natural selection increases the frequency of these phenotypes, and hence the frequency of the genes that form these phenotypes.

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Comparative characteristics artificial and natural selection Features of the evolutionary process Evolution of cultural forms Evolution of species in nature Background and driving forces of evolution Hereditary variability. Artificial selection Hereditary variability. Struggle for existence. Natural selection Rates of evolution Fast (it takes from 8-10 to 20 years to create a variety or breed) Slow (thousands and millions of years) Results Diversity of varieties, breeds Diversity of species Adaptability Living organisms are adapted to human needs. Forms with less useful properties, are discarded. Living organisms are adapted to environmental conditions. Forms with less useful features die out.

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Outcome evolutionary theory Darwin fundamentally undermined the metaphysical ideas about the constancy and immutability of species and their creation by God. This theory became the basis for the further development of the science of the evolution of the organic world, as well as for all biological sciences.

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Slides captions:

The evolutionary teachings of Charles Darwin Biology lesson in grade 11 Teacher: Ivanova O. V.

Prerequisites for the emergence of the teachings of Ch. Darwin Socio-economic Natural science Expeditionary material of Ch. Darwin

Socio-economic prerequisites: The development of capitalism The demand of industry for raw materials and the population for food Development Agriculture Breeding development

Adam Smith and his theory of free competition under capitalism (the unfit perishes). Thomas Malthus and his article "On Population", which asserts the obligatory "struggle for existence" between rapidly multiplying people due to the slow growth in the production of goods.

Natural science prerequisites: Comparative anatomy and morphology: a single plan of the structure of vertebrates (Goethe, Bronn, Saint-Hilaire) Embryology: the law of germline similarity (K. Baer) Cell theory: the unity of the origin of plants and animals Paleontology: the foundations of geochronology, catastrophe theory (J. Cuvier ) I. Kant laid the foundation for ideas about the possibility of the evolution of cosmic bodies Geologist C. Lyell developed the theory of the evolution of the Earth

Charles Robert Darwin (1809-1882) English naturalist, creator of the theory of evolution. Darwin studied medicine at the University of Edinburgh (1825-1827), theology at Cambridge (1827-1831), where he received a bachelor's degree. In 1831-1836. travels around the world on the Beagle as a naturalist, from which he returns as a man of science. 1859 "The Origin of Species by Means of Natural Selection". 1866 "Changing Domestic Animals and Cultivated Plants". 1871 "The Origin of Man and Sexual Selection"

Expedition material of Charles Darwin: Paleontological finds: fossil giant sloths and armadillos Comparison of the fauna of South and North America Analysis of island flora and fauna (Galapagos archipelago): animals came to the islands from the mainland and changed as a result of adaptation to new habitat conditions

The main provisions of the evolutionary teachings of Charles Darwin The diversity of animal and plant species is the result of the historical development of the organic world. The main driving forces of evolution are the struggle for existence and natural selection. The material for selection provides hereditary variability. The stability of the species is ensured by heredity.

The evolution of the organic world mainly followed the path of complicating the organization of living beings. The adaptation of organisms to conditions environment is the result of natural selection. Both favorable and unfavorable changes can be inherited. But the "owners" of the latter, as a rule, are destroyed in the struggle for existence.

The diversity of modern breeds of domestic animals and varieties of agricultural plants is the result of artificial selection. Human evolution is associated with historical development ancient apes.

Significance of Ch. Darwin's evolutionary doctrine Regularities of transformation of one organic form into another are revealed. The reasons for the expediency of organic forms are explained. The law of natural selection has been discovered. The essence of artificial selection is clarified. The driving forces of evolution are determined.

Properties of the environment Properties of organisms Heterogeneity Limited and uneven distribution of resources Heredity Variability Intensity of reproduction Struggle for existence Natural selection Diversity of the organic world Different directions of evolution Simultaneous existence of primitive and highly organic forms Adaptation to the environment

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Charles Robert Darwin1809-1882

“The more we know the immutable laws of nature, the more incredible miracles become for us”

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Charles Darwin

English scientist naturalist and traveler One of the first to realize and clearly demonstrate that all types of living organisms evolve in time from common ancestors. In his theory, Darwin called natural selection and uncertain variability the main driving force of evolution. Darwin's ideas and discoveries form the foundation modern theory evolution and form the basis of biology

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Biography

Born February 12, 1809 in Shrewsbury Father - Robert Darwin, son of the famous poet and scientist Erasmus Darwin

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1827 - studied theology for three years at the University of Cambridge 1831 - after graduating from the university, he went on a trip around the world on the expedition ship of the Royal Navy "Beagle". During the journey, Darwin visited the Cape Verde Islands, the coast of Brazil, Argentina, Uruguay, Tierra del Fuego, Tasmania and the Cocos Islands and made a large number of observations. The results were presented in the works Diary of Surveys, Zoology of Travel on the Beagle Ship, Structure and Distribution of Coral Reefs, etc.

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Voyage on the Royal Navy Expeditionary Vessel Beagle