Question

Explain the basic postulates of Darwinism.

Answer 1

The basic postulates of Darwinism are:

Enormous power of fertility:

1. Every living organism has the power to reproduce rapidly.
2. Hence, there is a danger of population overrunning the food and other facilities.
3. As a result, there are chances of elimination of a number of individuals because the available resources are limited and that has resulted in competition among organisms where every individual tries to be better than the other.
4. Darwin suggested that population of each species remains more or less constant because offspring perish in good number before themselves becoming capable of reproduction.

The struggle for existence:

1. Overpopulation resulted in the struggle which Darwin called the struggle for existence.

Variations and Heredity:

1. During the competition, every individual tries to become better and shows variation.
2. But all the variations are not significant from the evolutionary point of view, some may be useful and some harmful. The useful variations are inherited in the progeny of those organisms in which they arose and therefore, the progeny have better chances of survival.

Survival of the fittest or natural selection:

1. During the struggle for existence only those individuals which are better adapted to the environment and show favourable variations are selected.
2. The less fit and unfit individuals are rejected by nature.
3. Darwin stated that the variations are sorted out naturally.
4. Therefore, the organisms which are sorted out by such variations are said to be fittest.

Origin of species:

1. According to Darwin, new variations appear in every generation and get inherited to the new generation.
2. As a result, the offspring are distinct from their ancestors.
3. This results in the formation of new species.
4. Gradual modification of the existing species leading to the formation of new species is known as speciation.