Karie read the following definition of the term scientific method: "the series of steps that scientists use to answer questions and solve problems" do scientists always follow one fixed scientific method during real life investigation?

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.