In 1978, scientists studied how the fitness of marine sticklebacks would be affected if they were introduced into a freshwater environment. They collected 90 male and 90 female sticklebacks from a marine population and 10 male and 10 female sticklebacks from a freshwater population. The 200 sticklebacks were introduced into a freshwater environment that had no stickleback fish previously.

Recently a scientist decided to repeat this study, but relocated a population of sticklebacks from a freshwater environment into a marine environment. Which of the following best predicts how the frequency of the allele would change over time if a population of sticklebacks from a freshwater environment was placed into a marine environment?