Question

through 6 refer to the following.
e undertaken a long-term study of populations of rock pocket
us intermedius, in arizona and new mexico. rock pocket
er dark or light in color. most of the populations studied live in
colored granite rocks; however, some areas are dominated by
ks from ancient lava flows. researchers collected mice from
na and recorded their coat colors. figure 1 shows the study
olors, and the distribution of coat colors.
chart (map and table) here
conditions.
which of the following best explains the relationship between coat color and
predation rate in the rock pocket mouse population on the lava flow rocks with
respect to the different coat color phenotypes?

a a dark coat color provides camouflage to mice on the
lava flow rocks; therefore, mice with dark coats have a
lower predation rate in that habitat.

b at night, predators have reduced vision, so there is no
relationship between coat color and predation rate on
rock pocket mice.

c a dark coat color reflects less light and therefore mice
with dark coats have a lower predation rate.

d a light coat color reflects more light and therefore
mice with light coats have a lower predation rate.

Explanation:

To solve this, we analyze each option:

• Option A: Lava flow rocks are dark. A dark coat color camouflages mice on these rocks, making them less visible to predators, so predation rate is lower. This aligns with natural selection (camouflage reducing predation).
• Option B: Predators still hunt at night, and coat color would matter for visibility (e.g., owls have good night vision), so this is incorrect.
• Option C: The key is camouflage (matching the environment) not just light reflection. The relationship is about blending into the habitat, not light reflection alone, so this is not the best explanation.
• Option D: Lava flow rocks are dark, so light - colored mice would be more visible, leading to higher predation, not lower. So this is incorrect.

Answer:

A. A dark coat color provides camouflage to mice on the lava flow rocks; therefore, mice with dark coats have a lower predation rate in that habitat.