Morphological and genetic comparisons group 30 species of snapping shrimp (genus Alpheus) into 15 pairs of closely related species. What is the best explanation for the fact that one member of each pair lives on the Atlantic side of the Isthmus of Panama, whereas the other member of each pair lives on the Pacific side

species rose by allopatric speciation when Isthmus of Panama separated the ancestral species.

Explanation:

The causes of the morphological and the genetic comparison of the groups of 30 species can be explained by the part of the species that have an allopatric specialization. Suggest the mode of the specialization that occurs when the biological population of the same species becomes isolated with each other  This prevents the interference of the gene flow. The isthmus of the Panama is a narrow strip of the lands and contains the countries of the Panama and was formed about  2.8 million years ago.

Iam pretty sure it is answer c. meep i hope you have a great day ^^