True or false?: A small earthquake, called a foreshock, can occur seconds to weeks before a large
earthquake.

How can you keep track of variables in a science experiment?

What enzyme is most important for dna replication and why?

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.