Suppose that in gerbils, there are two alleles for fur color. Gerbils with a dominant allele are brown, and black fur color is recessive. If 35% of a gerbil population has black fur, what percent is expected to be heterozygous?

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.