Question

which of the following could result in speciation from biogeographic isolation?
the isolation of two populations of the same species
the isolation of two individuals of the same species
the isolation of two populations of different species
the isolation of two individuals of different species

Explanation:

Speciation occurs when a new species is formed. Biogeographic isolation refers to the separation of populations of a species due to geographical barriers. When two populations of the same species are isolated, over time, they may evolve differently (due to different environmental pressures, genetic drift etc.) and can eventually become different species (speciation). Isolating two individuals (too small a sample for a new species to form from just two) or two populations of different species (they are already different species, so no speciation from them) won't result in speciation from biogeographic isolation in the context of what speciation is (formation of new species from an existing one).

Answer:

the isolation of two populations of the same species