Question

how does the creation of variations in a species promote survival?

Answer 1

Sometimes for a species, the environmental conditions change so drastically that their survival becomes difficult. For example, if the temperature of water increases suddenly, most of the bacteria living in that water would die. Only few variants resistant to heat would be able to survive. If these variants were not there, then the entire species of bacteria would have been destroyed. Thus, these variants help in the survival of the species

Answer 2

All the variations in the species do not have equal chances of survival in the environment. The survival of the variations depends upon the nature of variation. Different individuals have different chances. Selection of variants by environmental factors forms the basis for evolutionary processes.These variations may lead to increased survival advantages of the individuals due to positive adoption of traits or may merely contribute to the genetic drift.