A narrow hybrid zone separates the toad species Bombina bombina and B. variegata. A genetic study identified a locus where one allele (R) occurred in all B. variegata, occurred in a few B. bombina at the edge of the hybrid zone, and was replaced totally by another allele (r) in B. bombina that lived far from the hybrid zone. Which of the following statements is most likely to be accurate with regard to the frequency of V1 in the hybrid zone?

Question

Quizplus · Accepted Answer

The frequency of the R allele declines in hybrids closer to B. bombina because it is replaced by the r allele in B. bombina populations far from the hybrid zone, indicating a gradient of allele frequency across the hybrid zone.

A Narrow Hybrid Zone Separates the Toad Species Bombina Bombina