In the desert environment of the southwestern United States, small mice called pocket rock mice live in areas which have light colored rocks and soil, as well as areas which have dark colored rocks and soil. The rock pocket mice that live on dark colored soil tend to have dark fur, and the rock pocket mice that live on light colored soil tend to have light fur. How would you explain why these two color variations happen in terms of genetic variation and environmental factors?
A
Genetic variation results in the two fur colors, and the different colored soils are the environmental factors that provide selection pressure for the fur colors to remain in the populations.
B
The different colored soils cause the two fur colors, and the genetics of the mice cause these environmental pressures to increase over time.
C
The light colored soil causes the appearance of light colored mice, and the dark colored soil causes the appearance of dark colored mice.
D
The different colored soils occur randomly, and the fur color occurs on purpose as a result.