Why are pre mating and post mating barriers to recombination and reproduction?

Pre-mating barriers, such as temporal isolation or behavioral differences, prevent different species from mating in the first place, thus reducing the likelihood of hybridization and the mixing of genetic material. Post-mating barriers, like gametic incompatibility or hybrid inviability, occur after mating but before successful reproduction, further ensuring that even if mating occurs, viable offspring are unlikely to be produced. Together, these barriers maintain species integrity by limiting gene flow between populations, which can promote speciation and biodiversity.