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प्रश्न
Give the principles of Darwin's theory of natural selection.
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उत्तर
Principles of Darwinism:
Darwin’s theory of organic evolution by natural selection is based on the following principles:
- Over production or prodigality of production:
All organisms have a natural tendency to over produce.
If this tendency is not checked, then even a single species of a plant or animal will occupy
the entire space available on the earth. - Struggle for existence: Organisms multiply in geometric ratio, but space and food remain
constant leading to competition for survival. Increase in the number of species leads to a
competition called struggle for existence - Variations and Heredity:The differences which occur between the closely related organisms are called variations.It is universal law of nature. Variations may be favourable or unfavourable.
- Survival of the fittest or natural selection:According to Darwin, in the struggle for existence, the fittest individuals survive andreproduce, while the unfit individuals perish.
- Origin of new species:According Darwin, useful variations appear in every generation and are inherited from one generation to another.
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