UPSC CDS 2 2021 GK Paper

All variations in a species will nothave equal chance of survival asaccording to 'Survival of the fittest',only the species with adaptablevariation which can adapt themselvesto the environment can survive.Selection of the variants occurs by thedifferent environmental factorsharmful. Variations that are notsuitable or advantageous to theorganism in the prevailingenvironmental conditions are notmaintained.