What is meant by survival of the fittest?

Explanation

1. Variations which are useful are retained, while those which are harmful are lost.
2. In a population where thee is a struggle, the fittest will be survived.
3. Nature favours only useful variations.
4. Each species tends to produce large number of offspeing. ltbr.gt 5 They compete with each other for food, space, mating and other species.
6 In this struggle for existence, only the fittest can survive, This is called survival of the fittest.
7 Over long period of time this leads to formation of new species.