Question

The most likely reason for the disappearance of a hybrid zone in parapatric speciation, resulting in completion of the speciation process is

A. Hybrid individuals likely have the right combination of traits for high fitness in the intermediate habitat.

B. Strong selection outside the hybrid zone on traits that lead to fewer mating events with individuals on the opposite side of the cline.

C. Stabilizing selection in the hybrid zone.

D. Negative assortative mating across the hybrid zone.

Answer 1

The most likely reason for the disappearance of a hybrid zone in parapatric speciation is Strong selection outside the hybrid zone on traits that lead to fewer mating events with individuals on the opposite side of the cline.The disappearance of hybrid zone leads to complete separation of species.

As the selection pressure increases against the hybrids to reduce frequency of hybridization , it leads to complete disappearance of hybrid zone.Stabilizing selection in hybrid zone and high fitness would lead to their more strong establishment and not their disappearance.