The Isthmus of Panama began to appear around 10 million years ago, and completely connected North and South America by 3 million years ago, which divided the Caribbean and Pacific oceans. An original 15 snapping shrimp species are hypothesized to have become 30 different species after being split into separate populations by the Isthmus of Panama. What kind of speciation is most likely to have caused this increase in snapping shrimp species around the Isthmus of Panama?

A. Parapatric speciation

B. Temporal speciation

C. Sympatric speciation

D. Allopatric speciation

D. Since the population of new species of snapping shrimp were formed by geographical barrier, This is Allopatric speciation.

Explanation:

Allopatric speciation refers to emergence of new species of organism which were separated from the original population by geographical isolation.

The selection pressure on the new habitat leads to changes in the physiology, morphology, and behavioural features of the new snapping shrimp species. Thus a new species is formed.

Since the barrier prevented the mixing or interbreeding between the separated species and the original species, if they were reintroduced they refused to mate, thus leading to emergence of a new specie.

Thus the type of speciation due to geographical isolation (Isthmus of Panama) leading to emergence of two new species of snapping shrimps is called Allopatric speciation.