NCEA Level 3 Biology – Speciation (AS91605) Practice Exam

Sympatric speciation refers to the process of speciation that occurs without geographical barriers separating populations. Instead, it is driven by mechanisms such as reproductive isolation, where groups within a population diverge into different species despite living in the same geographical area. This can happen through a variety of factors, including niche differentiation, polyploidy in plants, or behavioral changes that affect mating preferences.

In sympatric speciation, the development of reproductive barriers—such as changes in mating calls, timing of reproduction, or habitat preferences—can lead to populations becoming distinct over time. Because the individuals are not separated by physical distance, this type of speciation exemplifies how ecological and behavioral factors can drive the evolution of new species while maintaining close spatial proximity.

Geographical isolation, environmental changes, and physical separation of populations illustrate mechanisms more associated with allopatric speciation, where populations are split by physical barriers leading to divergence. Thus, sympatric speciation is characterized by the lack of such barriers, making the process of divergence fundamentally different.