The genes H and K act in accordance with the Dobzhansky-Muller model, leading to sterility in hybrids between two species of monkeyflowers.Any combination of the H2 and the K1 alleles causes hybrids to be sterile.Based on the Dobzhansky-Muller model, which genotype should have high fitness?
A) H1H1; K1K1
B) H1H2; K2K2
C) H2H0; K1K2
D) H1H2; K0K1
E) H1H2; K1K1

Question

Quizplus · Accepted Answer

According to the Dobzhansky-Muller model, hybrid sterility results from incompatibilities between genes from different species. Since any combination of H2 and K1 alleles results in hybrid sterility, it can be inferred that these are two genes from different species that have become incompatible. Therefore, the best genotype with high fitness would be those that have two copies of the same allele for both genes (H1H1; K1K1), as this would avoid the incompatibilities that lead to hybrid sterility. The other genotypes all have one allele from each species, which would result in hybrid sterility according to the Dobzhansky-Muller model.

The Genes H and K Act in Accordance with the Dobzhansky-Muller