The theory of Charles Darwin: the driving forces of evolution

The essence of the concept of the evolution of Charles Darwin is reduced to a line of logical, confirmed by experiments and other studies, provisions. Thus, it was proved to him that all types of living organisms are characterized by individual hereditary variability by any signs; They all multiply in geometric progression; Within the species there is a struggle for existence because of the limitation of life resources; In this struggle only the adapted individuals survive and then multiply.

Thus, the main driving forces of evolution are hereditary variability, natural selection and the struggle for existence. Let us consider in more detail each of them.

1. Hereditary variability is an improvement in chromosomes and genes, as well as the appearance of various combinations in the offspring of parental traits, that is, it arises from mutations. The variety of heritable traits is explained by the repetition of mutations and the contact of individuals with each other, and their habitat plays a role here.

The evolution of living organisms involves changing the genetic environment and creating those living units whose chromosomes form successful combinations. An increase in the number of carriers of these genes leads to hereditary changes in the signs of the organism that are manifested in the mutations, and therefore these individuals become more resilient.

Variability is of three types:

A) definite - the acquisition by a certain number of units of one type of new characteristics;

B) Uncertain variability - the emergence of a variety of minor features that can not be explained in representatives of the same species;

C) correlative - the interdependence of the acquired features of the organism.

Thus, the driving forces of evolution, namely hereditary variability, arise from the interaction of hereditary information and the conditions of a particular external environment. In this case, the acquired characteristics are preserved for many generations.

2. Struggle for existence - the mechanism of interrelations between organisms and factors of inanimate nature, caused by the ability of individuals to multiply (increase in their numbers) and the limited resources (territory, food, etc.). Allocate its following forms:

A) struggle against critical environmental conditions, such as excess or lack of light, moisture, change in air temperature;

B) struggle within a certain species - arises as a result of the similarity of the needs of representatives of a given species;

C) interspecific struggle - is expressed in the relationships between representatives of different species.

Thus, such The driving forces of evolution, like the variability and the battle for existence, are closely interrelated, since the former contributes to the adaptation of the species to the conditions of inanimate nature, which leads to biological progress.

3. Natural selection - identifies the survival mechanism of units with the necessary hereditary changes and their further multiplication. Selection is the result of the struggle for existence. Allocate its following mechanisms:

A) the formation of hereditary changes;

B) the survival and conservation of individuals with these changes in their respective habitats;

C) the reproduction of these units, the growth of their numbers and the spread of useful hereditary changes.

The driving forces of evolution, interacting with each other, make it possible to explain the formation of other species in nature. Materials accumulated in different sections of biology have a logical conclusion only when they correspond to the principle of evolution.

The great merit of Charles Darwin is to explain the process of development and formation of species. It was this fact that made Darwin's evolutionary doctrine a generally accepted theory.