tags: 
  - bio
topic: Biodiversity
date: 2023-10-27

Introduction

key concepts

Reproductive isolation refers to the methods that prevent different populations from interbreeding.
There are two kinds: prezygotic (before fertilisation) and postzygotic (after fertilisation)

Prezygotic Isolation

Isolation Type	Description
Temporal Isolation::	Two populations are fertile or active at different times, preventing them from mating. e.g., plants that flower at different times of the year, or two frog species that live in the same pond but do not breed at the same time.
Behavioural Isolation::	A certain population utilises a specific behaviour (e.g mating ritual) that other populations are incapable of replicating. Without this behaviour, potential mates remain unresponsive to efforts to mate. e.g., birds that only respond to species-specific mating calls
Mechanical Isolation::	The two populations contain incompatible sexual organs and hence are unable to breed.
Gamete Isolation::	The gametes from the two populations are incapable of fertilisation.

Isolation Type	Description
Hybrid Unviability::	Although a hybrid can be formed, it has a decreased chance of survival (usually weak) and is usually unable to reach reproductive age (thus unable to contribute to the gene pool).
Hybrid Sterility::	Although a hybrid can be formed, this hybrid is sterile, and is incapable of reproduction (thus unable to contribute to the gene pool).