State two ways in which the degree of water pollution caused by sewage can be reduced

Match each term to its best definition? sedimentary depositional enviornment

Why did adult crab numbers decline in he ecosystem, even though sea stars were still available?

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.