Prezygotic Reproductive Isolation, Overview
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State
A prezygotic barrier prevents fertilization from occurring at all between two populations, blocking reproduction before any zygote can form.
Show
Two populations whose breeding seasons no longer overlap cannot fertilize each other, a prezygotic barrier operating before any mating attempt succeeds.
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A prezygotic barrier acts before fertilization — a postzygotic barrier, covered separately, instead acts after a zygote has already formed.