Question

Explain Darwin's theory of evolution by natural selection.

Answer 1

Charles Darwin proposed the theory of natural selection in his book On the Origin of Species (1859). According to this theory, organisms with favourable heritable variations survive and reproduce more successfully, leading to evolution over generations.

The main principles of Darwin's theory are:

1. Overproduction: Organisms produce more offspring than can survive.
2. Struggle for existence: Due to limited food, space and other resources, organisms struggle for survival.
3. Variations: Individuals of the same species show variations in their characteristics.
4. Survival of the fittest: Individuals with favourable variations are better adapted to their environment and have greater chances of survival and reproduction.
5. Natural selection: Nature favours individuals with beneficial heritable variations, which are passed on to the next generation.
6. Origin of new species: Accumulation of favourable variations over many generations may lead to the formation of new species.