What is natural selection? Today this question is first asked in high school, during a biology course. In the scientific world, this concept was first popularized by the Englishman Charles Darwin.
The question of what is natural selection arose in the mid-nineteenth century in connection with the Darwinian theory of evolution. The development of science for several centuries has pushed the church from its once strong position.
Great travelers in practice have shown that our planet is round, doctors have proved that a person should be treated with scientific methods, not the prayers of monks, and that diseases are caused by completely earthly microorganisms, and not by divine punishment. And so the concept of “natural selection” came to the scientific world. The definition of the term in its brief form says that this is a process due to which the number of individuals maximally adapted to environmental conditions in the population grows. That is, this phenomenon completely revealed the evolutionary theory according to which unadapted organisms were forced to change and mutate in order to exist in the world. Actually, this explains the origin of terrestrial species of animals and humans: from primitive to highly developed creatures.
What is natural selection: natural evolution and its forms
In the study of this phenomenon, researchers identified a number of multidirectional processes, which, however, lead to equally successful results. Based on the nature of the influence of selection forms on changes in certain characteristics of a population, three forms of selection were identified:
- Driving - in this case, the mutation is activated when the environmental change is directed specifically at the population.
- Stabilizing - this selection is aimed at the destruction of individuals with too large deviations from the average norm in the population.
- Disruptive is a form that occurs when external conditions are favorable for the occurrence of two or more variants of mutations. That is, two species can develop from one population.
More clearly, these options are presented in the following table.
Forms of natural selection: a table of variations
Sign | Moving | Stabilizing | Disruptive |
Terms of Action | In the case of mild translational changes in living conditions. | In the case of constant living conditions. | During a period of sharp changes in the external conditions in which the body lives. |
Action focus | In favor of individuals that have a certain deviation from the average norms of the trait. | It leads to the destruction of individuals with extreme values of the trait. | It acts against individuals with average trait values . |
Changes | Mutants with one mean trait are replaced by mutants with another mean. | A group of mutants with wide reaction norms is replaced by mutants with narrower norms. | In the process, a group of mutants is eliminated, which has average values of traits. |
Change result | A new norm of the sign appears, which is more consistent with external conditions. | The average rate of the trait is maintained and maintained. | In place of one, two new average norms are now being formed. |
Examples | Insects and rodents that are capable of developing resistance to poisons. | Insect-pollinated plants retain their shape and size to fit the needs of the insect. | Frequent oceanic winds lead to the fact that only coastal insects survive with either well-developed or rudimentary wings. |
What is natural selection: the social dimension
With the popularization of sociology, the theory of evolution began to be applied also to the public organism. Here, this law looked the same as in the natural world, but acted among people: the strongest survive (achieve success). One who can adapt to society. The concept is called "social Darwinism."