Research Summary: Insects were sampled before and after pesticide treatment. Before treatment, allele R occurred in 12 percent of insects. After treatment, 70 percent of R carriers survived compared with 15 percent of noncarriers, and allele R rose to 46 percent only in treated fields. Untreated fields stayed near 12 percent. Claim: Allele R increased by natural selection from pesticide tolerance. Which response best supports the claim?