Afemale impala has one or two calves and then spends months feeding and protecting them. a female salmon lays thousands of eggs and then returns to the ocean. what are some advantages of each type of life cycle?

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.