A scientist finds what she thinks is a new species of rodent on a small Pacific island.However, some similar-looking rodents inhabit some nearby islands.She mates the new rodent with the nearby rodents and gets viable but infertile offspring.Why?

Question

Quizplus · Accepted Answer

The fact that the scientist found similar-looking rodents on nearby islands suggests that the new rodent species probably underwent dispersive allopatric speciation, where a population becomes geographically isolated and evolves into a new species. The viable but infertile offspring suggest that the new and nearby rodent populations have diverged enough to prevent successful interbreeding, but are not genetically different enough to be considered distinct species. This is a common outcome of allopatric speciation. Option A is incorrect because vicariance typically refers to the splitting of a single population into two or more isolated groups that evolve separately, so it doesn't apply to the situation described in the question. Option C is incorrect because allopolyploid speciation typically results in fertile offspring since it involves the merging of two or more species that have different chromosome numbers.

A Scientist Finds What She Thinks Is a New Species