Allopatric speciation is most likely to occur in which of the following scenarios?
A) A large lake is divided into two smaller lakes by a geological process, dividing a single species of fish into two different groups.
B) All of the "parent" species of a new species go extinct, reducing gene flow between populations.
C) There are two distinct possible feeding strategies within a given population, causing the rise of two species living in the same geographic area.
D) A mutation changes the mating ritual followed by a subset of individuals in a population, and they end up forming an all-new species.

Question

Quizplus · Accepted Answer

Allopatric speciation occurs when a physical barrier, like a geological process, divides a population into two or more isolated subpopulations. The separation of the large lake into two smaller ones would create a physical barrier, preventing gene flow between the fish populations and leading to independent evolutionary changes, ultimately resulting in two distinct fish species. Choices B, C, and D describe other types of speciation. Choice B describes peripatric speciation, where a small isolated subpopulation splinters off from the main population and evolves into a separate species. Choice C describes sympatric speciation, where a population evolves into two separate species without a physical barrier. Choice D describes speciation through disruptive selection where differences in mating rituals within a population lead to the evolution of separate species.

Allopatric Speciation Is Most Likely to Occur in Which of the Following