A friend tells you a story about his grandmother, who moved to your city from her home across the ocean when she was very young, bringing with her a pair of mice that were commonly kept as pets where she was born. Shortly after arriving, however, the mice escaped. After listening to this story, you do some research and discover that the wild mice that live in your city have only been documented within the past half century and, although they share distinctive traits with domesticated mice that only exist near your friend’s grandmother’s birthplace, they are unable to interbreed. Which statement could be true?

Question

a. The mice in your city have acquired a mutation that renders them incapable of reproduction.
b. The two populations of mice are unable to reproduce due to reinforcement.
c. Your friend’s grandmother inadvertently caused allopatric speciation via dispersal.
d. The similarity between these two species of mice can be explained by vicariance.

Answer 1

c. Your friend’s grandmother inadvertently caused allopatric speciation via dispersal.