A population of insects exposed to pesticide was sampled annually. The frequency of the resistance allele R was tracked over 10 generations.
The data are best explained by:
- A
Random mutation creating R individuals every generation.
- B
Genetic drift in a large stable population.
- C
Stabilizing selection maintaining the average phenotype.
- Dcheck_circle
Directional selection favoring R in the presence of pesticide.
Explanation
A steady, large rise in R allele frequency under a consistent selection pressure (pesticide) is classic directional selection.