Background: According to museum
collections from the early 1900s, the population of one beetle
species in California’s central valley used to have individuals
with different colors, including red, blue, yellow and brown. The
beetles were found feeding on various native plants. 50 years after
almond farming became widespread, most beetles were brown-colored
and found living on the bark of almond trees. Observations indicate
that birds are the primary predators of beetles.
Question: How and why did the
population of beetles...