Which of the following statements correctly explains the evolution of copper tolerance in populations of the grass Agrostis capillaris growing on soil contaminated by copper mine tailings?
Exposure to high concentrations of copper ions in the soil actively induces targeted mutations in the grass genome to generate the copper-tolerance allele.
The evolution of copper tolerance in these populations is a classic example of stabilizing selection, as it acts to minimize phenotypic variation within the grass population.
The rapid increase in the frequency of the copper-tolerance allele is an example of directional selection, where copper-polluted soil acts as a selective pressure favoring the survival of tolerant individuals.
The increase in copper-tolerant individuals is primarily driven by genetic drift, as the toxic soil randomly eliminates non-tolerant plants via non-selective mortality.
