A large population of mice (2000 individuals) lives in an area dominated by small shrubs in the desert. When the population size got too high, a small group of 6 individuals left and colonized an area adjacent to the original population's home, but this area is primarily dominated by trees instead of shrubs. There is no gene flow between the dispersers and the original population. A researcher sequenced the genomes of representative individuals from both populations and found substantial genetic differences between them. Which of the following would MOST account for the amount of genetic differences observed?
A)Divergence between the two populations was caused solely by drift.
B)Divergence between the two groups is high because of gene flow.
C)Since the original dispersal event, the small population will have diverged more than the large population.
D)The divergence between populations could only have been caused by stabilizing selection.

Question

Quizplus · Accepted Answer

Since the small group that dispersed from the larger population is a bottleneck population, it will have reduced genetic diversity. This means that it is more prone to genetic drift, which can cause divergence over time. In contrast, the larger population will have more genetic diversity and genetic drift will have a smaller effect on overall genetic variation. Consequently, the small population that dispersed from the larger population will have diverged more than the larger population over time.

A Large Population of Mice (2000 Individuals) Lives in an Area