Natural selection favors copper tolerance in all soils near the old mine, not only in the contaminated soils. nearly 100% of monkey flowers growing in copper-contaminated soil are copper tolerant. copper contamination in the soil created copper-tolerant plants.

1. 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.
2. copper-tolerant plants are found only in contaminated soils.
3. the population that existed before mining must have included both copper-tolerant and copper-intolerant plants.

The population that existed before mining must have included both copper tolerant and copper intolerant

Explanation:

Natural selection is a form of evolution where individuals having a certain variation gives them an advantage at survival and reproduction compared to the ones that do not have the variation.

For natural selection to occur, the variation should initially be present in the population.

Therefore, for this population of Monkey flowers growing in a copper -contaminated soil.  The population must have included both the copper tolerant and the copper intolerant plants before mining.