Final answer:
Allopatric speciation involves geographic isolation leading to the evolution of new species, whereas sympatric speciation happens within the same area without a physical barrier, as populations evolve reproductive barriers.
Step-by-step explanation:
Allopatry and sympatry are two forms of speciation in which new species emerge. Allopatry refers to the process where populations of a species are separated by geographic barriers and evolve independently.
This geographic isolation can result from various events such as the formation of new rivers, valleys, or the dispersal of organisms to new locations where they cannot return, leading to different evolutionary paths and the inability to interbreed. On the contrary, sympatric speciation occurs when new species arise within the same geographic area without physical separation, facilitated by mechanisms such as polyploidy or behavioral isolation, allowing populations to diverge while remaining in the same environment.
Allopatry occurs when populations are in separate, non-overlapping geographic areas, resulting in the formation of new species. Sympatry, on the other hand, occurs when populations are in the same area and new species arise without geographic separation.
In allopatry, some type of geographic barrier, such as a river or mountain range, prevents gene flow between populations, allowing them to evolve independently. In sympatry, speciation occurs within a shared habitat, often due to factors like polyploidy or other mechanisms that result in reproductive isolation.