Laboratory Selection Experiments with Fruit Flies Have Demonstrated That

Multiple Choice

Laboratory selection experiments with fruit flies have demonstrated that

A) bristle number is not genetically controlled.
B) bristle number is not genetically controlled, but changes in bristle number are caused by the environment in which the fly is raised.
C) bristle number is genetically controlled, but there is little variation on which natural selection can act.
D) bristle number is genetically controlled, but selection cannot result in flies having more bristles than any individual in the original population had.
E) bristle number is genetically controlled, and selection can result in flies having more, or fewer, bristles than any individual in the original population had.