Question

Both pathways that isolate a population reproductively in some form, allopatric and sympatric describe what, which means the creation of new species?

Answer 1

speciation

18.2 Formation of New Species Speciation occurs along two main pathways: geographic separation  allopatric speciation  and through mechanisms that occur within a shared habitat  sympatric speciation . Both pathways isolate a population reproductively in some form. Mechanisms of reproductive isolation act as barriers between closely related species, enabling them to diverge and exist as genetically independent species. Prezygotic barriers block reproduction prior to formation of a zygote, whereas postzygotic barriers block reproduction after fertilization occurs. For a new species to develop, something must cause a breach in the reproductive barriers. Sympatric speciation can occur through errors in meiosis that form gametes with extra chromosomes  polyploidy . Autopolyploidy occurs within a single species, whereas allopolyploidy occurs between closely related species.