Define environmental science​

Environmental impacts on evolution : mastery test

Ascientist is conducting an investigation that involves water, silver, carbon dioxide, and oxygen gas which group of statements best describes all of the materials he is using in the 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.