To the question: What is Charles Darwin’s main service to science? given by the author Victor Elin the best answer is Darwin's main merit is that he explained the mechanism of the evolutionary process and created the theory of natural selection. Numerous individual phenomena organic life Darwin connected it 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 main merit is that he established the mechanism of evolution, which explains both the diversity of living beings and their amazing expediency and adaptability to the conditions of existence. This mechanism is the gradual natural selection of random undirected hereditary changes.
Charles Darwin was the first to substantiate the materialistic theory of evolution. He proved the reality of the existence of a developing species that originates, evolves and disappears. Darwin substantiated the principle of the unity of discontinuity and continuity in the emergence of a species, and showed how uncertain random changes under the influence of natural selection are transformed into adaptive characteristics of a species. The scientist identified the material causes of this phenomenon and showed the formation of relative expediency. Charles Darwin's merit in science lies not so much in the fact that he proved the existence of evolution, but in the fact that he explained how it could occur.
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Answer from Neuropathologist[newbie]
Darwin's main merit is that he explained the mechanism of the evolutionary process and created the theory of natural selection. Darwin connected numerous individual 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 main merit is that he explained the mechanism of the evolutionary process and created the theory of natural selection. Darwin connected numerous individual 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.
Answer from Dmitry Bespalov[guru]
undermined faith in the DIVINE origin of species, but in vain....
Answer from precocious[active]
He has no merit! He was an absolute senile!!! And his theory was refuted a long time ago - by civilized, modern evidence, facts, scientific research, etc. Darwinism was very necessary and useful in Soviet times! It’s clear why and for what! No normal person would believe this nonsense! ..The bear came from the whale, and man came from the monkey!)))).... Only, evolution has bypassed some of the remaining monkeys to this day!))))....
The main merit of Charles Darwin is that he was the first to reveal the mechanism of evolution, explaining the process of formation of new species.
Darwin noted that each species has the potential to produce many more individuals than it survives to adulthood (“Important Characteristics of a Population”). Only a small part survives, while the rest die in the struggle for existence. This is the first important conclusion. Darwin further noted the well-known fact that among all plant and animal organisms variability of characteristics is observed; even in the offspring of one pair of parents there are no completely identical individuals.
Variability can be hereditary and non-hereditary. Only the first one matters for evolution. By modern ideas in this case, the changes affect the genotype of the individual, and therefore the trait can be transmitted to the offspring. Non-hereditary variability is one of the options for the manifestation of a trait within one genotype. For example, with absolutely the same genotype, plants can form wide leaves if they develop in the shade, or narrow leaves if they develop in good light.
Having compared variability and the struggle for existence, Darwin made the most important conclusion: in nature there is a selective destruction of some individuals and the reproduction of others. That's what it is natural selection. In the struggle for existence, even minor differences can give an individual an advantage. Such individuals survive and reproduce, and the trait that gave them advantages in the struggle for existence is inherited by their descendants. As a result, the number of individuals possessing a trait that is favorable in specific conditions becomes more and more, and in a certain territory they completely displace other individuals of this species. A group of individuals is formed with a new adaptation - adaptation to exist in these conditions, and on its basis a new species may appear in the future.
It should be remembered that adaptation is never final and universal. For example, the white color of the white hare helps it out in winter, but in spring and autumn, on the contrary, it betrays it to a predator. In the process of evolution, adaptations are “polished” and adjusted more and more precisely to certain conditions of existence. But these conditions are not constant, and their change gives impetus to the consolidation of new characteristics by selection. Therefore, the process of evolution does not stop, as evidenced by the diversity of living beings that inhabited and now inhabit our planet.
Darwin saw one of the proofs of the reality of the existence of selection in the origin of breeds of domestic animals and plant varieties. When breeding them, people consciously or unconsciously left for reproduction the individuals in which the useful trait was most pronounced. In other words, he spent artificial selection, as a result of which breeds and varieties with properties beneficial to humans were bred. These properties can be harmful to the plants or animals themselves. With natural selection, only those traits are selected that increase the chance of leaving offspring.
The essence of Darwin's evolutionary theory is that the source material for evolution is supplied by hereditary variability, and natural selection discards those less adapted to given environmental conditions and leaves the most adapted. Consequently, selection plays a driving role in the process of evolution.
Evolution... the main condition for which
must henceforth obey and satisfy
all theories, hypotheses, systems, if they want
be reasonable and true...
P. Teilhard de Chardin
How did evolutionary ideas develop before Darwin? What is the essence of Charles Darwin's teachings? What evidence is there for the evolution of living things? How is the evolutionary process studied?
Lesson-lecture
The processes of formation and development of life on Earth cannot be understood without knowledge of the basic principles of the evolution of living organisms. The significance of these concepts goes far beyond the science of biology. The widespread introduction of ideas about the evolution of the organic world in the 19th century, along with the discovery of the laws of thermodynamics, served as a powerful impetus for the transition from a mechanistic picture of the world to an evolutionary one, to the development of the idea of global evolutionism.
EVOLUTIONARY CONCEPTS BEFORE DARWIN. The ideas of unity and development of living nature can already be traced in the works of ancient thinkers of India, China, Mesopotamia, Egypt and Greece. These ideas were reborn at the end of the Middle Ages during the Renaissance and especially spread in the 17th-18th centuries. and the first half of the 19th century, when naturalists intensively accumulated factual material, comparative anatomy, biogeography, and paleontology developed. The ideas of evolutionism have been expressed by many scientists, but they have not yet developed into a coherent doctrine of evolution.
George Richmond. C. Darwin
The dominant views at that time were based on two theses: nature is absolutely unchangeable and every organism is initially purposeful (in other words, cats were created to eat mice, and mice were created to be eaten by cats). The acceptance of these theses inevitably leads to the recognition of the “creator of all things.” Hence the name of all currents of this kind - creationism(from Latin creation). The exponent of such ideas was the “father of systematics” Carl Linnaeus, who believed that “there are as many species as the number of different forms the pre-eternal essence created.”
The honor of creating the first evolutionary doctrine belongs to Jean-Baptiste Lamarck (1744-1829). In his opinion, evolution is the result of the internal striving of organisms for perfection, which was laid down by the Creator. Species, according to Lamarck, are formed by adaptation to external conditions. These adaptations are always expedient and inheritable. For example, Lamarck explained the long legs of wading birds by their desire not to dip their bodies in water. Birds made efforts to lengthen their legs and, as a result of long-term habit (“exercise of the organs,” according to Lamarck), their legs gradually lengthened from generation to generation. These views did not have factual confirmation, and Lamarck’s ideas about evolution were not widespread among his contemporaries.
CLASSICAL DARWINISM. The main merit of Charles Darwin is that he was the first to reveal the mechanism of evolution, explaining the process of formation of new species.
Darwin drew attention to the fact that each species is potentially capable of producing many more individuals than survive to adulthood (remember the material in § 34). Only a small part survives, while the rest die in the struggle for existence. This is the first important conclusion. Darwin further noted the well-known fact that among all plant and animal organisms variability of characteristics is observed; even in the offspring of one pair of parents there are no completely identical individuals.
Variability can be hereditary and non-hereditary. Only the first one matters for evolution. According to modern concepts, in this case, changes affect the genotype of the individual, and therefore the trait can be transmitted to offspring. Non-hereditary variability is one of the options for the manifestation of a trait within one genotype. For example, with absolutely the same genotype, plants can form wide leaves if they develop in the shade, or narrow leaves if they develop in good light.
Having compared variability and the struggle for existence, Darwin made the most important conclusion: in nature there is a selective destruction of some individuals and the reproduction of others. This is natural selection. In the struggle for existence, even minor differences can give an individual an advantage. Such individuals survive and reproduce, and the trait that gave them an advantage in the struggle for existence is inherited by their descendants. As a result, the number of individuals possessing a trait that is favorable in specific conditions becomes more and more, and in a certain territory they completely displace other individuals of this species. A group of individuals is formed with a new adaptation - adaptation to exist in these conditions, and on its basis a new species may appear in the future.
It should be remembered that adaptation is never final and universal. For example, the white color of the white hare helps it out in winter, but in spring and autumn, on the contrary, it betrays it to a predator. In the process of evolution, adaptations are “polished” and adjusted more and more precisely to certain conditions of existence. But these conditions are not constant, and their change gives impetus to the consolidation of new characteristics by selection. Therefore, the process of evolution does not stop, as evidenced by the diversity of living beings that inhabited and now inhabit our planet.
Darwin saw one of the proofs of the reality of the existence of selection in the origin of breeds of domestic animals and plant varieties. When breeding them, people consciously or unconsciously left for reproduction the individuals in which the useful trait was most pronounced. In other words, he spent artificial selection, as a result of which breeds and varieties with properties beneficial to humans were bred. These properties can be harmful to the plants or animals themselves. With natural selection, only those traits are selected that increase the chance of leaving offspring.
The essence of Darwin's evolutionary theory is that the source material for evolution is supplied by hereditary variability, and natural selection discards those less adapted to given environmental conditions and leaves the most adapted. Consequently, selection plays a driving role in the process of evolution.
EVIDENCE OF EVOLUTION AND METHODS FOR STUDYING IT. We have already repeatedly emphasized that the molecular organization of living things is one. The methods of storing, transmitting and implementing genetic information, the mechanisms of plastic and energy metabolism, photosynthesis, and the enzymes that ensure these processes are similar in all groups of living organisms, which indicates the unity of the origin of life.
Paleontology, the study of fossil organisms, actually directly examines the process of evolution. By studying the distribution of remains of living organisms (fossils, imprints, mummies) in rocks, it is possible to obtain objective information about life in distant geological times. A clear pattern can be traced: the level of organization of living beings becomes more complex as we move from ancient earth layers to new ones.
By analyzing fossil organisms from successive layers, one can obtain the true sequence of the emergence and change of forms in evolution (Fig. 97).
Rice. 97. The sequence of changes in the fossil forms of the mollusk of the genus Giraulus
Biogeography, a science that studies the patterns of distribution and distribution of living beings on Earth, allows us to analyze the course of the evolutionary process on different scales. Knowing the time of separation of certain areas of land, seas and islands, it is possible to compare the changes in flora and fauna that occurred in areas separated by a barrier. For example, the fauna of Northern Eurasia and North America is similar, since relatively recently both continents were connected by the Bering Land Bridge, and the Bering Strait that separated them appeared only about 1 million years ago. Australia, which has not been connected to other continents for more than 120 million years, is a different matter. During this time, the fauna of marsupials and oviparous mammals independently developed here.
Morphology allows, by studying the similarities in the structure of organisms, to identify the relatedness of the compared forms. For example, different appearance and functions, the limbs of mammals consist of similar elements: the scapula, bones of the shoulder, forearm, wrist, metacarpus and phalanges of the fingers. Comparison of similar organs of related groups makes it possible to determine the sequence of evolutionary transformations.
Thus, in the tapir-horse series, a reduction in the number of toes can be observed, which is associated with a change in the habitat and lifestyle of the animals (Fig. 98). The tapir lives in tropical rainforests, while the horse lives in open spaces. For fast running, which is the key to escape from predators in open areas, resting on one finger is most advantageous, as it ensures quick repulsion.
Rice. 98. Comparative anatomical row of the forelimbs
Evidence of evolution is also provided by the rudimentary organs found in living organisms. In cetaceans, for example, small pelvic bones are preserved in the skeleton, which confirms the fact of their origin from land mammals with developed hind limbs. In humans, examples of rudimentary formations include the ear muscles, appendix, and wisdom teeth. Sometimes there are cases of a return to the characteristics of ancestors - atavisms. In humans, atavisms are the tail, thick hair on the surface of the body, etc.
Embryology has a whole arsenal of methods for studying the evolutionary process. A comparative analysis of the early stages of vertebrate ontogenesis showed that the embryos of fish, amphibians, reptiles, birds and mammals are very similar at first, then features characteristic of fish and amphibians appear, and even later - features of reptiles, birds and mammals (Fig. 99). Thus, during the development of the embryo, certain features of the development of ancestral forms are repeated, moreover, in the early stages these are signs of distant ancestors (less related forms), and in later stages - of close ones.
Rice. 99. Comparison of vertebrate embryos at different stages of development
One of the widely used methods molecular biology is based on the analysis of nucleotide substitutions in a certain region of the genome. To analyze the relationship between organisms, identical sections of their DNA are compared. The more differences in the nucleotide sequence, the further away the organisms being compared are from each other. The received data is processed using special computer programs, which allow us to reconstruct the evolutionary paths of the studied group of living beings.
Numerous data clearly indicate the unity of origin of all living beings inhabiting the Earth and confirm the fact of their evolution. The use of methods of paleontology, biogeography, morphology, embryology and molecular biology makes it possible to determine family relationships between living organisms and explore the features of the evolutionary process
- Which form of variation is most important for evolution?
- Explain the mechanism of natural selection?
- What facts speak in favor of the unity of the organic world?
- What types of evidence for evolution does modern science have?
- What is the difference between natural selection and artificial selection?
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And of course, the most important prerequisite for the emergence of Charles Darwin’s evolutionary theory was Charles Darwin himself, whose genius was able to embrace, analyze all the enormous material and create a theory that laid the foundations of Darwinism - the doctrine of the evolution of living organisms.
The main provisions of the evolutionary theory of Charles Darwin.
The theory of evolution by natural selection was formulated by Charles Darwin in 1839. The evolutionary views of Charles Darwin are presented in full in the book “The Origin of Species by Means of Natural Selection, or the Preservation of Favored Breeds in the Struggle for Life.”
The very title of the book suggests that Darwin did not set himself the goal of proving the existence of evolution, the presence of which was also pointed out by Confucius. At the time the book was written, no one doubted the existence of evolution. The main merit of Charles Darwin is that he explained how evolution can occur.
The voyage on the Beagle allowed Darwin to collect a wealth of data on the variability of organisms, which convinced him that species cannot be considered immutable. Returning to England, Charles Darwin began the practice of breeding pigeons and other domestic animals, which led him to the concept of artificial selection as a method of breeding breeds of domestic animals and varieties of cultivated plants. By selecting the deviations he needed, man, bringing these deviations to the necessary requirements, created the breeds and varieties he needed.
According to Charles Darwin, the driving forces of this process were hereditary variability and human selection.
However, Charles Darwin had to solve the problem of the action of selection in natural conditions. The mechanism of action of selection prompted Charles Darwin from the ideas outlined in 1778 by T. Malthus in his work “Treatise on Population.” Malthus vividly described the situation that could result from population growth if left unchecked. Darwin transferred Malthus's reasoning to other organisms and drew attention to the following factors: despite the high reproductive potential, the population size remains constant. Comparing a huge amount of information, he came to the conclusion that in conditions of fierce competition between members of the population, any changes that are favorable in these conditions would increase the ability of an individual to reproduce and leave behind fertile offspring, while unfavorable changes are obviously disadvantageous, even for those who have them organisms, the chances of successful reproduction are reduced. All this served as the basis for determining the driving forces (factors) of evolution, which according to Darwin are variability, heredity, the struggle for existence, natural selection.
In essence, the main meaning of Charles Darwin's evolutionary theory is that evolution occurs on the basis of the emergence of heritable changes, weighing them against the struggle for existence and the selection of changes that allow organisms to win in intense competition. The result of evolution according to Charles Darwin is the emergence of new species, which leads to a diversity of flora and fauna.
Driving forces (factors) of evolution.
The driving forces in evolution are: heredity, variability, struggle for existence, natural selection.
Heredity.
Heredity is the property of all living organisms to preserve and transmit characteristics and properties from ancestors to offspring. At the time of Charles Darwin, the nature of this phenomenon was unknown. Darwin, as well, assumed the presence of hereditary factors. Criticism of these statements by opponents forced Darwin to abandon his views on the location of factors, but the very idea of the presence of material factors of heredity permeates his entire teaching. The essence of the phenomenon became clear after T. Morgan developed the chromosome theory. When the structure of the gene was deciphered and understood, the mechanism of heredity became completely clear. It is based on the following factors: the characteristics of an organism (phenotype) are determined by the genotype and environment (reaction norm); the characteristics of an organism are determined by a set of proteins that are formed from polypeptide chains synthesized on ribosomes, information about the structure of the synthesized polypeptide chain is contained on i-RNA, i-RNA receives this information during matrix synthesis on a section of DNA, which is the gene; genes are passed from parents to children and are the material basis of heredity. In interkinesis, DNA duplication occurs, and hence gene duplication occurs. During the formation of germ cells, the number of chromosomes is reduced, and during fertilization, female and male chromosomes are combined in the zygote. The formation of the embryo and the organism occurs under the influence of genes of both the maternal and paternal organism. Inheritance of traits occurs in accordance with the laws of heredity of G. Mendel or according to the principle of the intermediate nature of the inheritance of traits. Both discrete and mutated genes are inherited.
Thus, heredity itself acts, on the one hand, as a factor preserving already established characteristics, and on the other hand, ensures the entry of new elements into the structure of the body.
Variability.
Variability is a universal property of organisms in the process of ontogenesis to acquire new characteristics. C. Darwin noted that there are no two identical individuals in one litter, no two identical plants grown from parental seeds. The concept of forms of variability was developed by Charles Darwin based on the study of breeds of domestic animals. According to Charles Darwin, there are the following forms of variability: definite, indefinite, correlative, hereditary, non-hereditary.
A certain variability is associated with the occurrence of large number individuals or all individuals of a given species, variety or breed during the period of ontogenesis. Darwinian mass variability can be associated with certain conditions environment. A well-chosen diet will lead to increased milk yield for all members of the herd. The combination of favorable conditions contributes to an increase in the size of grains in all wheat individuals. In this way, changes arising from a certain variability can be predicted.
Uncertain variability is associated with the occurrence of traits in individual or several individuals. Such changes cannot be explained by the action of environmental factors.
Relative variability is a very interesting phenomenon. The appearance of some signs leads to the appearance of others. Thus, an increase in the length of the ear of cereals leads to a decrease in the length of the stem. So getting good harvest, we are losing straw. Enlargement of limbs in insects leads to enlargement of muscles. And there are many such examples.
Charles Darwin noted that some changes that occur during ontogenesis appear in the offspring, while others do not appear. He attributed the first to hereditary variability, the second to non-hereditary. Darwin also noted the fact that changes associated with indefinite and relative variability are inherited mainly.