What do prezygotic barriers do?

Prezygotic barriers are mechanisms that prevent mating or fertilization between different species. These barriers operate before the formation of a zygote, meaning they occur prior to fertilization, thus stopping the reproductive process at an earlier stage.

Prezygotic barriers can function in several ways, including temporal isolation (where species mate at different times), behavioral isolation (where species have different mating rituals or behaviors), mechanical isolation (where reproductive structures do not fit together or function properly), and gametic isolation (where sperm and egg from different species fail to fuse). By preventing the mating or fertilization of different species, prezygotic barriers contribute to the process of speciation by maintaining the genetic distinctiveness of species.

The other choices refer to different biological concepts. The development of hybrid species relates to postzygotic barriers, which occur after fertilization and can lead to hybrid inviability or infertility. Ensuring the viability of offspring is also a focus of postzygotic barriers, which evaluate whether hybrids can survive and reproduce. Facilitating mating between different species contradicts the primary function of prezygotic barriers, as these barriers explicitly aim to prevent such interspecies reproduction.