Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Hybrid Zones

Hybrid Zones

Hybrid zones are narrow regions where two closely related species interact, mate, and produce hybrids. Relative to either parent species, hybrids may possess distinct phenotypic or genetic differences that impact their survival and reproductive success. The genetic variances introduced by hybridization influence species diversity and speciation processes within the hybrid zone.

Speciation Rates

Speciation Rates

Genetics of Speciation

Genetics of Speciation

Speciation is the evolutionary process resulting in the formation of new, distinct species—groups of reproductively isolated populations.

Formation of Species

Formation of Species

Speciation describes the formation of one or more new species from one or sometimes multiple original species. The resulting species are discrete from the parent species, and barriers to reproduction will typically exist. There are two primary mechanisms, speciation with and without geographic isolation—allopatric and sympatric speciation, respectively.

What is a Species?

What is a Species?

Evolutionary Relationships through Genome Comparisons

Evolutionary Relationships through Genome Comparisons

Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Continuous <i>in silico</i> screening of fish, amphibians, reptiles, and birds expands the diversity of bornavirids and reveals unexpected genomic architectures.

Virus evolution·2026

Same author

Interplay of Diet, Heat Stress, and the Microbiome Shapes Health and Escape Behaviour in Amphibian Larvae.

Environmental microbiology·2026

Same author

Five Hidden Species in a Widespread European Vertebrate: Disentangling the Alpine Newt Cryptic Species Complex Through Genomic Phylogeography.

Molecular ecology·2026

Same author

Embryos are largely understudied in a representative sample of journals in conservation physiology.

Conservation physiology·2026

Same author

Leaving no Species Behind: Moving Beyond the "Winners and Losers" Dichotomy in Climate Warming Risk Assessments.

Global change biology·2025

Same author

Size matters: a new genus of tarantula with the longest male palps, and an integrative revision of <i>Monocentropus</i> Pocock, 1897 (Araneae, Theraphosidae, Eumenophorinae).

ZooKeys·2025

Same journal

Demography and Environment Shapes Genetic Variation: Spatiotemporal Genetic Dynamics in Cyclic Voles at Low Latitudes.

Molecular ecology·2026

Same journal

Gut Microbiome-Metabolome Reconfiguration Associates With Phenotypic Plasticity of Daphnia Under Predation Risk.

Molecular ecology·2026

Same journal

Population Genomics Highlight the Vulnerability of Coral-Dwelling Gobies to Ecological Losses due to Climatic Disturbances.

Molecular ecology·2026

Same journal

Ancient Divergences of the Maritime Alpine Tree Larix lyallii (Pinaceae) Contrasts With Patterns in Other Pacific Northwest Coastal Disjuncts.

Molecular ecology·2026

Same journal

Ontogenetic Sequence of Differential Gene Expression in Predator-Induced Daphnia pulex.

Molecular ecology·2026

Same journal

Disentangling Environmental and Within-Host Drivers of Parasite Dynamics in Natural Populations.

Molecular ecology·2026

See all related articles

Search research articles

Related Experiment Video

Updated: May 7, 2026

Genotyping and Quantification of In Situ Hybridization Staining in Zebrafish

Genotyping and Quantification of In Situ Hybridization Staining in Zebrafish

Published on: January 28, 2020

Inferring Time-to-Speciation From Hybrid Zone Analysis Informs Assessments of Taxonomic Inflation.

Sven Gippner¹, Katharina Ruthsatz^1,2, Christophe Dufresnes³

¹Institute for Cell- and Neurobiology, Technische Universität Braunschweig, Braunschweig, Germany.

Molecular Ecology

|May 6, 2026

Summary

This summary is machine-generated.

Gene flow across hybrid zones reveals reproductive isolation (RI) between lineages. Older lineages (over 7 million years) are typically reproductively isolated, impacting species delimitation and potentially leading to taxonomic inflation or deflation.

Keywords:

cline width hybrid zone reproductive isolation species delimitation taxonomic inflation

More Related Videos

A Concoction Pipeline for Generating Molecular Operational Taxonomic Units (MOTUs) Among Riparian and Aquatic Beetles

A Concoction Pipeline for Generating Molecular Operational Taxonomic Units (MOTUs) Among Riparian and Aquatic Beetles

Published on: July 11, 2025

In Situ Hybridization Combined with Immunohistochemistry in Cryosectioned Zebrafish Embryos

In Situ Hybridization Combined with Immunohistochemistry in Cryosectioned Zebrafish Embryos

Published on: March 3, 2022

Related Experiment Videos

Last Updated: May 7, 2026

Genotyping and Quantification of In Situ Hybridization Staining in Zebrafish

Genotyping and Quantification of In Situ Hybridization Staining in Zebrafish

Published on: January 28, 2020

A Concoction Pipeline for Generating Molecular Operational Taxonomic Units (MOTUs) Among Riparian and Aquatic Beetles

A Concoction Pipeline for Generating Molecular Operational Taxonomic Units (MOTUs) Among Riparian and Aquatic Beetles

Published on: July 11, 2025

In Situ Hybridization Combined with Immunohistochemistry in Cryosectioned Zebrafish Embryos

In Situ Hybridization Combined with Immunohistochemistry in Cryosectioned Zebrafish Embryos

Published on: March 3, 2022

Area of Science:

Evolutionary Biology
Speciation Science
Genetics and Genomics

Background:

Measuring gene flow across hybrid zones offers direct evaluation of reproductive isolation (RI) between divergent lineages.
Geographic-explicit modeling of gene flow, known as cline analysis, is a gold standard for species delimitation under the biological species criterion.

Purpose of the Study:

To investigate the relationship between divergence time and post-zygotic RI, as inferred from hybrid zone cline width.
To assess the implications for species delimitation and taxonomic practices across various taxa.

Main Methods:

Analysis of hybrid zone cline width data from studies on amphibians, reptiles, birds, mammals, and insects.
Correlation of cline width with divergence time to infer RI.
Simulation of past species descriptions to evaluate trends in new species delimitations.

Main Results:

A significant negative correlation was found between cline width and divergence time across taxa, indicating older lineages are generally reproductively isolated.
In amphibians, divergence times of <2.6 million years (Ma) and >7 Ma correspond to shallow (subspecies) and steep (species) hybrid zones, respectively.
A trend of increasingly younger lineages being described as new species over time was observed, with birds and mammals showing the highest proportion of post-Pliocene species.

Conclusions:

Older lineage pairs (>7 Ma) are usually reproductively isolated, supporting their status as distinct species.
A notable increase in newly described amphibian species with divergence times <2.6 Ma suggests potential taxonomic inflation.
Careful evaluation of taxonomic hypotheses is needed to avoid both taxonomic inflation (over-splitting) and deflation (lumping).