After a copper smelter begins operation, local downwind populations of plants begin to adapt to the resulting air pollution. Scientists document, for example, that the acid tolerance of several plant species has increased significantly in the polluted area. This is an example of
A) stabilizing selection.
B) disruptive selection.
C) directional selection.
D) genetic drift.

Question

Quizplus · Accepted Answer

This is an example of directional selection, as the environmental pressure caused by the air pollution has led to an increase in the prevalence of certain traits (in this case, acid tolerance) within the plant population. The other options (stabilizing selection, disruptive selection, genetic drift) do not fit the scenario described.

After a Copper Smelter Begins Operation, Local Downwind Populations of Plants