In the laboratory, fruit flies (Drosophila) were artificially selected for the number of bristles on their bodies. One population (R) was selected for low numbers of bristles, a second population (S) for high numbers of bristles.
A major implication of this study of Drosophila is
A. absolutely no data to prove or disprove the theory of evolution.
B. it takes thousands to millions of generations to see evolutionary change, if at all.
C. dramatic variation may be present within a population, but may not be observable unless strong selection occurs.
D. dramatic mutations may occur within a population under strong selection.
E. although evolutionary change was observed, this would not be expected in higher organisms such as mice.
Answer: C