Genetic drift is change in the allele frequency of a population due to

Why is it important to reduce the number of chromosomes in half when forming gametes for sexual reproduction?

Compare the composition of the moon's surface with the composition of the earth's surface.

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.