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Updated: Aug 14, 2026
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Following the Dynamics of Structural Variants in Experimentally Evolved Populations
Published on: February 3, 2023
Chromosomal inversions accelerate genetic evolution and drive ecological speciation across an island gradient
Ines Gómez-Ramos1, Rogelio Sánchez-Villegas2, Ashwini V Mohan3
1Department of Plant Biology and Ecology, Faculty of Biology, University of Seville, Seville 41012, Spain.
Summary
Large-scale inversions accelerate protein evolution in rapidly diverging Carex species. These structural variants facilitate adaptation by relaxing purifying selection, enabling faster exploitation of new ecological niches.
Area of Science:
- Evolutionary Biology
- Genomics
- Speciation
Background:
- Chromosomal rearrangements are theorized to drive speciation by reducing recombination in adapted genomic regions.
- The impact of these rearrangements on evolutionary rates during rapid divergence is not well understood.
Purpose of the Study:
- To investigate the genomic architecture and evolutionary rates of two rapidly diverging sister Carex species.
- To determine how large-scale inversions influence protein evolution and adaptation to contrasting environments.
Main Methods:
- Chromosome-level genome assemblies
- Population genomics
- Analysis of protein evolution rates (dN/dS, ω)
- Functional analysis of genes within inversions
- Environmental association studies
Main Results:
- Genomic divergence is concentrated within large-scale inversions, not uniform across the genome.
- Genes within inversions show significantly accelerated protein evolution (elevated ω) compared to collinear regions.
- Inversions on chromosomes 14 and 28 contain adaptive genes (e.g., ion channels, auxin transport) linked to arid adaptation.
- Intraspecific adaptation is polygenic across the collinear genome.
Conclusions:
- Genomic architecture, particularly large-scale inversions, actively shapes evolutionary rates.
- Recombination suppression within inversions may lead to relaxed purifying selection, driving rapid protein evolution.
- Structural variants can enable lineages to rapidly adapt and exploit new ecological opportunities.
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