Final answer:
The correct answer is option b. Two species emerging in different habitats after segregation from their parent population is an example of allopatric speciation. This occurs due to geographic separation which limits gene flow and allows the populations to evolve independent genetic differences, eventually leading to the formation of new species.
Step-by-step explanation:
When two species emerge in different habitats after one has been separated from its parent population, they have undergone allopatric speciation. This process involves geographic separation of populations from a parent species and subsequent evolution. In various ways, such as a river forming a new branch, invasion by glaciers, or displacement to distant locations, can create this geographic separation, leading to reproductive isolation. Over time, the genetically isolated populations evolve independently, experiencing different environmental pressures, and diverge genetically to the point where they can no longer interbreed even if they come back into contact. Well-documented examples of allopatric speciation include Darwin's finches and the differing species of squirrels on either side of the Grand Canyon.
Gene flow refers to the transfer of alleles or genes from one population to another. In allopatric speciation, geographic barriers hinder gene flow, allowing populations to evolve separately. This separation gives rise to new species that are genetically distinct from their ancestors and from each other.
Speciation can also occur without geographic barriers, which is known as sympatric speciation. However, in the context of the question, where two species emerge in different habitats after geographic separation, it is a clear case of allopatric speciation. Therefore, the correct option for this question is (b) Allopatric speciation.