Biology / Unit 8 Bio 1721 short lesson, about 20 seconds
Postzygotic Reproductive Isolation, Overview
Captions available
The idea
A postzygotic barrier acts after a zygote has already formed, preventing a hybrid offspring from developing, surviving, or reproducing successfully.
In practice
A hybrid embryo that fails to develop normally past an early stage is blocked by a postzygotic barrier, not a prezygotic one.
Where people slip
Students sometimes misclassify a failed mating attempt as postzygotic failure — it blocks fertilization itself, making it prezygotic instead.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Something wrong in this lesson? Flag it · Sources for Biology