Some monkey flowers (Mimulus guttatus) living near the sites of copper mines can grow in soil containing high concentrations of copper, which is toxic to most plants. Copper tolerance is a heritable trait.
The map below shows the area near an old copper mine, which contaminated the nearby soil with copper. The dark areas on the map represent copper-contaminated soil, and the light areas represent uncontaminated soil. A stream flows past the mine toward the lake at the bottom right of the map. Closed circles represent sites where nearly 100% of the monkey flower plants are copper tolerant at 0.5 μg/cm3, and open circles represent sites where less than 20% of the plants are copper tolerant.
Use the map to determine which of the statements below are true.
Select the three statements that are true.
Copper-tolerant plants are found only in contaminated soils.
Natural selection favors copper tolerance in all soils near the old mine, not only in the contaminated soils.
Copper contamination in the soil created copper-tolerant plants.
The population that existed before mining included both copper-tolerant and copper-intolerant plants.
If you were to test monkey flowers growing on the shore of the lake, you would expect nearly 100% of them to be copper tolerant.
Nearly 100% of monkey flowers growing in copper-contaminated soil are copper tolerant.