Pervasive gene flow despite strong and varied reproductive barriers in swordtails

Nature Ecology & Evolution, Journal Year: 2025, Volume and Issue: unknown

Published: March 26, 2025

Abstract The evolution of reproductive barriers leads to the formation new species. However, recent research has demonstrated that hybridization been pervasive across tree life even in presence strong barriers. Using swordtail fishes (genus Xiphophorus ), an emerging model system, we document overlapping mechanisms act as gene flow between birchmanni and cortezi by combining genomic sequencing from natural hybrid populations, experimental laboratory crosses, behavioural assays, sperm measures developmental studies. We show assortative mating plays a role maintaining subpopulations with distinct ancestry within populations. F 2 hybrids identify several regions strongly impact viability. Strikingly, two these underlie genetic incompatibilities X. its sister species malinche . Our results demonstrate ancient played origin this shared incompatibility. Moreover, mismatch at incompatible remarkably similar consequences for phenotypes survival × hybrids. findings varied shape exchange naturally hybridizing highlight complex evolutionary outcomes hybridization.

Language: Английский

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The extent of introgression between incipient Clarkia species is determined by temporal environmental variation and mating system

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 121(12)

Published: March 11, 2024

Introgression is pervasive across the tree of life but varies taxa, geography, and genomic regions. However, factors modulating this variation how they may be affected by global change are not well understood. Here, we used 200 genomes a 15-y site-specific environmental dataset to investigate effects mating system divergence on magnitude introgression between recently diverged outcrosser-selfer pair annual plants in genus Clarkia . These sister taxa very subsequently came into secondary sympatry where form replicated contact zones. Consistent with observations other pairs, found that was asymmetric substantially more from selfer outcrosser. This asymmetry caused bias direction initial F1 hybrid formation subsequent backcrossing. We also extensive outcrosser’s admixture proportion among zones, which predicted nearly entirely interannual variance spring precipitation. Greater fluctuations precipitation resulted higher proportions, likely mediated expression traits determine premating reproductive isolation. Climate-driven hybridization dynamics particularly change, potentially reshaping species boundaries adaptation novel environments.

Language: Английский

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Pervasive gene flow despite strong and varied reproductive barriers in swordtails

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: April 20, 2024

One of the mechanisms that can lead to formation new species occurs through evolution reproductive barriers. However, recent research has demonstrated hybridization been pervasive across tree life even in presence strong Swordtail fishes (genus

Language: Английский

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Admixture mapping reveals evidence for multiple mitonuclear incompatibilities in swordtail fish hybrids

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 31, 2025

Abstract How barriers to gene flow arise between closely related species is one of the oldest questions in evolutionary biology. Classic models biology predict that negative epistatic interactions variants genomes diverged lineages, known as hybrid incompatibilities, will reduce viability or fertility hybrids. The genetic architecture these and paths through which they have profound implications for efficacy incompatibilities species. While been studied using theoretical approaches several decades, only recently has it become possible map larger numbers empirically. Here, we use admixture mapping natural populations swordtail fish ( Xiphophorus ) identify involving mitochondrial nuclear genomes. We find at least nine regions genome are involved mitonuclear vary their architecture, strength selection experience, degree limit populations. Our results build a deeper understanding complex against naturally hybridizing highlight an important role evolution reproductive

Language: Английский

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Fluctuating reproductive isolation and stable ancestry structure in a fine-scaled mosaic of hybridizing Mimulus monkeyflowers

PLoS Genetics, Journal Year: 2025, Volume and Issue: 21(3), P. e1011624 - e1011624

Published: March 31, 2025

Hybridization among taxa impacts a variety of evolutionary processes from adaptation to extinction. We seek understand both patterns hybridization across and the ecological forces driving those patterns. To this end, we use whole-genome low-coverage sequencing 458 wild-grown 1565 offspring individuals characterize structure, stability, mating dynamics admixed populations Mimulus guttatus nasutus decade sampling. In three streams, genomes are common M. organellar haplotype is fixed in guttatus, but new events rare. Admixture strongly unidirectional, each stream has unique distribution ancestry proportions. one stream, distinct cohorts spatially structured at ~20-50m resolution stable years. Mating system provides almost complete isolation , partial barrier between cohorts. Isolation due phenology near-complete nasutus. Phenological strong some years cohorts, much weaker other years, providing potential bridge for gene flow. These fluctuations associated with differences water availability supporting role climate mediating strength reproductive isolation. Together, accurately predict assortative which estimate directly using paired maternal genotypes. Climate-driven may promote longer-term stability complex mosaic hybrid ancestry, preventing either or collapse species barriers.

Language: Английский

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Hybridization contributes to reproductive isolation

Nature Ecology & Evolution, Journal Year: 2025, Volume and Issue: unknown

Published: March 26, 2025

Language: Английский

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