Answer:
Variation refers to the differences between members of the same species. Having variation within a species means that if the environment changes there may be individuals within the species more able to withstand the change and survive. There is usually extensive genetic variation within a population of organisms or a species.
The advantages of sexual reproduction:
it produces variation in the offspring
the species can adapt to new environments due to variation, which gives them a survival advantage
a disease or change in environment is less likely to affect all the individuals in a population
Humans can speed up natural selection through selective breeding, which can increase food productions.