The evolutionary theory of C. Darwin is considered the most significant work in biology in the last more than a hundred years. However, disputes over this work have been going on since its publication.
Darwin's evolutionary theory developed under the influence of widespread ideas in England, reflecting the socio-economic conditions of that time - freedom of competition and the general struggle for existence in society. At that time they were considered the universal law of nature.
Darwin's evolutionary theory was also formed in accordance with his own discoveries, which the scientist made while traveling on a Beagle ship. After studying the geology of South American lands, he established himself in the belief that natural factors are of great importance both in the history of the earth’s surface and in the origin of plants and animals that inhabit the planet.
Paleontological finds allow us to determine the similarity between the animals that inhabited the territory of South America at that time, and extinct species. Darwin discovers some "transitional forms" that combine the characteristics of several units.
Equally important was the geographical distribution of organisms. Thus, Darwin found that the fauna of South America contains forms that are absent in the fauna of North America. But the scientist believed that the similarity of the animal worlds of both of these territories existed earlier. Isolation of faunas, in his opinion, subsequently occurred in connection with the appearance of the plateau in the southern territory of Mexico.
Of particular interest were the data obtained by Darwin on the Galapagos Islands, which lie 950 kilometers from the western South American coast in the Pacific Ocean. These islands are of volcanic origin, and geologically are a young territory. During the study, the scientist noted a certain similarity of their fauna with the animal world of South America. However, there were differences.
Thus, by the beginning of the 19th century, on the basis of the collected factual material, some conclusions and generalizations were formulated on which Darwin's evolutionary theory is based. Provisions on the variability of species and unity in terms of the structure of all organisms, on natural groups, on the strengthening of similarity and change of forms, the historical development of the earth's surface, as well as on the similarity of embryos belonging to systematically distant animal groups were deduced.
Darwin's evolutionary theory has become the largest generalization of natural science of the nineteenth century. This teaching was prepared by the general course of development of scientific thought and socio-economic conditions.
It should be noted that before the advent of Darwinism, many scientists expressed ideas close to the provisions expressed in it. But, despite the constant development of natural science and the accumulation of facts contrary to metaphysical teaching, views on natural immutability continued to dominate. The teachings of Darwin's predecessors did not solve the main issues. So, the possibility of a new species form from one species has not been proven. The problem of the feasibility and adaptability of the new organic form to environmental conditions has not been resolved either. And finally, the question was opened about the driving forces and development factors.
According to Darwin, evolution solved the most important issues of the development of living nature from the point of view of natural historical materialism. Having a tremendous impact on the development of all biological sciences, the doctrine contributed to strengthening the understanding of wildlife in general by applying a materialistic explanation to the phenomena of expediency. Darwin in his theory not only applied practical data, but also critically reviewed his own conclusions, taking into account the achievements of agriculture and biology in general.