In the sierra nevada mountains of california, there are many populations of the checkerspot butterfly, euphydryas editha. you notice that females of one population (population a) lay their eggs near the tip of a plant's stem. females of another population in the same area (population b) lay their eggs at the base of the stem on a different type of plant. the young hatch out as caterpillars; they live on the host plant and eat its leaves.

you breed a member of population a with a member of population b. you raise the hybrid caterpillars on paper towels in the lab. you cross all the female hybrids with members of population a, and then you release the pregnant hybrid females back into the natural environment. all of the hybrid females lay their eggs at the center of the stems (not at the top or the bottom). what does this suggest about the trait of female egg placement on stems?