ANATOMY

Detailed explanation-1: -Why did dark-colored rock pocket mice first appear in a population of light-colored rock pocket mice? Individuals change color to blend in with the environment. There is dark lava rock in the area where they live.

Detailed explanation-2: -The dark coloration in the rock pocket mouse did not arise because there was a lava flow. Rather, a random mutation proved adaptive to the mice living in areas of dark-colored volcanic rock.

Detailed explanation-3: -The illustrations and short film show that there is natural variation of coat color in the population of rock pocket mice living on the lava flow. The short film explains that mutations can cause a change in coat color, and that these genetic changes are being passed on to offspring.

Detailed explanation-4: -Sample answer: The dark-colored mouse has a selective advantage in a habitat such as the Pinacate lava flow, which has a dark-colored substrate. Since rock pocket mice reproduce quickly and often, the frequency of this favored trait would spread rapidly through the population.

Detailed explanation-5: -Because a lot of their habitat involves a desert, light colored rock pocket mice are able to blend into the surroundings to avoid predators. However, some mutations in the Mc1r gene changed the fur color of the mice, leading to some of the mice being darker in color.