Question

How does the creation of variation in a species ensure its survival

Answer 1

The great advantage of variation to a species is that it increases their chances of survival in a changing environment. For example, the accumulation of heat resistant variation in some bacteria will ensure its survival even when the temperature in its environment rises too much, due to a heat wave or any other reason. On the other hand, the bacteria which did not have this variation to withstand heat would not survive under these circumstances, and die.