Question

Hybrid inviability in Drosophila melanogaster/D. simulans hybrids results from incompatible interactions between two genes, Hmr and Lhr. Several mutations have been fixed in the D. melanogaster Hmr gene, while other mutations have been fixed in the D. simulans Lhr gene. This finding supports:

(a) Haldane’s rule

(b) Vicariant allopatric speciation

(c) Dobzhansky-Muller model

(d) Ecological speciation

Answer 1

Dobzhansky-Muller model.

Explanation:

As the question states. several mutations have been fixed in the D. melanogaster Hmr gene, while other mutations have been fixed in the D. simulans Lhr gene. This makes the hybrid inviability.

Dobzhansky-Muller model states that if any mutation is fixed in one gene and another mutation is fixed in another gene and a hybrid consisting both of them makes it inviable for the genes to work. So the answer is option c.