Darwin's theory of evolution - one of the main theories of development of the organic world.According to Darwin, the driving forces of evolution - natural selection, variation, inheritance.New symptoms arise in the functions and structure of the organisms in relation to variation.The latter is defined and undefined.Definitions (direction) variability occurs when environmental conditions have the same effect on all or most of a certain type of individuals.It is not genetically fixed in the next generations.Some individuals may experience vague (non-directional) changes that are random and hereditary.Indefinite variability is of two types - combinative and mutational.In the first case during meiosis in the formation of new combinations appear offspring of paternal and maternal chromosomes, which sometimes share parts with each generation combination of genes increases.In the second case, change the genetic structure of an organism: the number of chromosomes, their structure, or the structure of genes.
Darwin's theory of evolution and its members believe that the changes occurring organisms under the influence of the environment.As a result of natural selection, survival of the offspring of carriers useful traits that have arisen as a result of recombination or gene mutations.The selection is a major factor in the evolution that contributes to speciation organisms.It can be expressed in three forms: driving, stabilizing and disruptive.The first leads to the emergence of new adaptations.The highest probability of leaving offspring is present in individuals that have changed on some basis, compared with the average value.In the second form of adaptation saved formed in constant environmental conditions.In this case, in a population of individuals retained, having an average traits.When under the influence of a third form of countervailing changes in the environment is the emergence of polymorphism.That is, the selection occurs on two or more types of deviation.
Darwin's theory of evolution has proved that the main driving force of evolution - natural selection.Now as a result of interbreeding produced new kinds of populations.The theory used in a variety of disciplines, including history (Karl Marx) and psychology (Sigmund Freud).
modern theory of evolution has undergone significant changes.In contrast to the original Darwinian theory, it clearly highlighted the elementary structure (population), which begins with the evolution.The modern theory of a reasoned, it is reasonably clear and interprets the driving forces and factors, highlighting the basic and non-basic.An elementary manifestation of a sustained change in the genotype of the population.The main task of the modern theory is the study of the mechanism of evolutionary processes, the ability to predict the changes.
Darwin's theory of evolution is closely linked with the theory of biochemical evolution, which consists in the fact that the first organic compounds in the formation of the planets were hydrocarbons formed from simple compounds in the ocean.As a result of further hydrocarbon compounds with a number of chemical elements formed of complex organic substances.These processes have evolved under the influence of intense solar radiation and thunderstorm electrical discharges, to allocate the necessary amount of ultraviolet radiation.Accumulating organic matter in the ocean created a strong molecular bonds that are resistant to the damaging effects of ultraviolet radiation.After a long evolution of carbon compounds originated life.The theory of evolution has evolved biochemical Aleksei Oparin, Stanley Miller, John Haldane and others.
