Question

Data corresponding to three different populations of a land snail species are tabulated below. Each population inhabits a different region within the boundaries of a U.S. national park, and at this time, no migration takes place between any of the populations. Which of the following predictions is most likely if migration suddenly becomes possible between populations B and C?

Options:
a. Increased genetic diversity in population B and decreased genetic diversity in population C.
b. Decreased genetic diversity in population B and increased genetic diversity in population C.
c. No change in genetic diversity in either population.
d. Both populations will experience increased genetic diversity.

Answer 1

If migration between populations B and C of a land snail species becomes possible, both populations are likely to experience increased genetic diversity. This is a result of new genetic combinations from gene flow as individuals move and interbreed between these previously isolated populations.

Step-by-step explanation:

The question pertains to the impact of gene flow on genetic diversity within isolated populations of a land snail species when migration becomes possible between them. When migration is introduced between population B and population C, the most likely prediction is that both populations will experience increased genetic diversity. This increase is due to the mixing of different alleles and genotypes as individuals move between these populations and reproduce, which adds new genetic combinations to each of the populations. This concept is supported by the understanding that a geographically continuous population has a more homogeneous gene pool due to the free movement and interbreeding of individuals within the species' range, leading to similar allele frequencies across the population. Conversely, when populations are geographically discontinuous, they evolve along different trajectories with more divergent allele frequencies due to independent mutation occurrences and different pressures from natural selection and genetic drift. In this case, the sudden possibility of migration would reduce the discontinuity between populations B and C, leading to increased gene flow and greater genetic variability.