Related Experiment Video
Updated: Sep 30, 2026

Mating and Tetrad Separation of Chlamydomonas reinhardtii for Genetic Analysis
Published on: August 12, 2009
Cline Widths, Barriers to Gene Flow and Reproductive Isolation: A Comment on Gippner et al. 2026
Roger Butlin1,2, Sean Stankowski3
1Ecology and Evolutionary Biology, School of Bioscience, The University of Sheffield, Sheffield, UK.
Abstract:
Hybrid zones provide opportunities to study the operation of barriers to gene flow as they play out in natural environments. However, comparative analysis is difficult because both hybrid zones and the methods used to analyse them vary widely. Gippner et al. (2026) brought together data on 108 animal hybrid zones. They argued that cline width in these zones provides a proxy for reproductive isolation (RI). Here, we comment on what cline widths do and don't tell us about the evolutionary progression towards the completion of speciation.
Related Concept Videos
Gene Flow
Understanding Species and Reproductive Barriers
Mutation, Gene Flow, and Genetic Drift
Genetic Drift
Genetics of Speciation
Hybrid Zones

