Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Reproductive isolation occurs when different species are unable to interbreed and produce viable offspring due to physical, behavioral, or genetic barriers.
Related terms
Prezygotic Barriers: These prevent mating or fertilization between species. It's like not even being able to start a conversation because you don't understand any words the other person is saying.
Postzygotic Barriers: These occur after mating and fertilization but prevent hybrid offspring from being viable or fertile. It's like having a conversation where you understand some words, but still can't fully comprehend or respond effectively.
Hybrid Inviability/Infertility: This happens when interspecies mating produces an offspring that either cannot survive (inviability) or reproduce (infertility). It's like managing to have a broken conversation, but it doesn't lead anywhere productive because there are too many misunderstandings.