postzygotic Barriers
67
which in that case,Post zygotic barriers prevent a hybrid zygote from developing into a viable, fertile adult.
HYBRID INVIABILITY
the hybrid offspring of two species do not mature normally and usually die in the embryonic stage of development. Sometimes hybrid offspring mature normally but are not able to reproduce successfully.
HYBRID STERILITY
often occurs because the gametes are abnormal in some way. Mules are sterile hybrids formed by mating a female horse with a male donkey.
HYBRID BREAKDOWN
mating between two F1 hybrids produces a second hybrid generation, this F2 generation may be unable to reproduce because of hybrid breakdown(offspring of hybrids are weak or infertile).
Thank you for your attention!
Post zygotic behaviors
—hybrid in viability,
--- hybrid sterility, and
hybrid breakdown
Post zygotic barriers operate AFTER hybrid zygotes are formed. Hybrid zygotes are fertilized eggs resulting from the union between gametes of two different species.