Why is variation

Variation is useful for the survival of species than individuals because sometimes for a species, the environmental conditions change so drastically that their survival becomes difficult. If all the organisms of a population are living in a particular habitat, then there is a danger that all of them may die and no one would survive under drastic conditions. Only few variants which are resistant to these drastic changes would be able to survive. However, if these variants were not there, then the entire species of that organism would have been destroyed. Thus, variation is useful to species but not the individual.