A group of mice used to include many mice with spotted fur and a few with solid fur. Then, the habitat changed from sunny to shady. A student predicted that natural selection should result in a population that has more solid mice than spotted mice.

Question

Student's Explanation: Mice with solid fur will be more difficult to see in the shady habitat, so fewer predators will find them. This means that more solid mice will pass their fur color trait to the next generation.
Change In Fur Color Tralt In Mouse Population
Number of Generations After the Habitat Changed
0
10
Ratio of Spotted Fur to Solid Fur
4:1
20
30
7:3
1:1
1:3
Why does the evidence in the table support the student's explanation? Select the two statements that apply.
A. The ratio increased over time.
B. The ratio decreased over time.
C. The ratio increased and then decreased over time.
D. More solid mice than spotted mice survived in the first ten generations after the habitat changed.
E. Gradually, a higher proportion of solid mice than spotted mice survived after the habitat changed.

Answer 1

The two statements that apply and support the student's explanation are:

B. The ratio decreased over time.

• This is supported as the proportion of spotted mice (indicated by the ratio) decreased as the number of generations increased.

E. Gradually, a higher proportion of solid mice than spotted mice survived after the habitat changed.

• This is evidenced by the increase in the prevalence of solid mice in the ratios shown over generations, indicating that solid mice were indeed more successful in surviving and reproducing in the new shady habitat.