Question

Give the principles of Darwin's theory of natural selection.

Answer 1

Principles of Darwinism:
Darwin’s theory of organic evolution by natural selection is based on the following principles:

1. 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. 
2.  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
3. 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.
4. 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. 
5. Origin of new species:According Darwin, useful variations appear in every generation and are inherited from one generation to another.