A respiratory disease spreads through a population of
hummingbirds. Many of them die. A rare allele coding for red eyes
is lost from the population when the birds carrying the allele die
from the disease. (Eye color does not affect the probability of
death from the disease.) The change in the population is an example
of:

A. an adaptation

B. genetic divergence between populations

C. evolution by genetic drift

D. Speciation

E. Evolution by natural selection