8. The population sizes of different species of Darwin's finches have varied since records of their
numbers have been kept. The drawings show several different species of the finches and their beaks.
Darwin's finches live in the same habitat and are subject to the same environmental pressures. Yet, as
one population size increases, another decreases, and then the reverse may occur. Which stimulus is
MOST likely to cause these changes in population size?
A) a decrease in nesting materials
B) changes in the predator population
C) a loss of habitat due to human encroachment
D) changes in the size and hardness of available seed food