1
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McFarlane SE, Jahner JP, Lindtke D, Buerkle CA, Mandeville EG. Selection leads to remarkable variability in the outcomes of hybridisation across replicate hybrid zones. Mol Ecol 2024; 33:e17359. [PMID: 38699787 DOI: 10.1111/mec.17359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 04/03/2024] [Accepted: 04/05/2024] [Indexed: 05/05/2024]
Abstract
Hybrid zones have been viewed as an opportunity to see speciation in action. When hybrid zones are replicated, it is assumed that if the same genetic incompatibilities are maintaining reproductive isolation across all instances of secondary contact, those incompatibilities should be identifiable by consistent patterns in the genome. In contrast, changes in allele frequencies due to genetic drift should be idiosyncratic for each hybrid zone. To test this assumption, we simulated 20 replicates of each of 12 hybrid zone scenarios with varied genetic incompatibilities, rates of migration, selection and different starting population size ratios of parental species. We found remarkable variability in the outcomes of hybridisation in replicate hybrid zones, particularly with Bateson-Dobzhansky-Muller incompatibilities and strong selection. We found substantial differences among replicates in the overall genomic composition of individuals, including admixture proportions, inter-specific ancestry complement and number of ancestry junctions. Additionally, we found substantial variation in genomic clines among replicates at focal loci, regardless of locus-specific selection. We conclude that processes other than selection are responsible for some consistent outcomes of hybridisation, whereas selection on incompatibilities can lead to genomically widespread and highly variable outcomes. We highlight the challenge of mapping between pattern and process in hybrid zones and call attention to how selection against incompatibilities will commonly lead to variable outcomes. We hope that this study informs future research on replicate hybrid zones and encourages further development of statistical techniques, theoretical models and exploration of additional axes of variation to understand reproductive isolation.
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Affiliation(s)
- S Eryn McFarlane
- Department of Botany, University of Wyoming, Laramie, Wyoming, USA
- Department of Biology, York University, Toronto, Ontario, Canada
| | - Joshua P Jahner
- Department of Botany, University of Wyoming, Laramie, Wyoming, USA
| | | | - C Alex Buerkle
- Department of Botany, University of Wyoming, Laramie, Wyoming, USA
| | - Elizabeth G Mandeville
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
- Biology Department, Northern Michigan University, Marquette, Michigan, USA
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2
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Martins ARP, Warren NB, McMillan WO, Barrett RDH. Spatiotemporal dynamics in butterfly hybrid zones. INSECT SCIENCE 2024; 31:328-353. [PMID: 37596954 DOI: 10.1111/1744-7917.13262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 07/13/2023] [Accepted: 07/21/2023] [Indexed: 08/21/2023]
Abstract
Evaluating whether hybrid zones are stable or mobile can provide novel insights for evolution and conservation biology. Butterflies exhibit high sensitivity to environmental changes and represent an important model system for the study of hybrid zone origins and maintenance. Here, we review the literature exploring butterfly hybrid zones, with a special focus on their spatiotemporal dynamics and the potential mechanisms that could lead to their movement or stability. We then compare different lines of evidence used to investigate hybrid zone dynamics and discuss the strengths and weaknesses of each approach. Our goal with this review is to reveal general conditions associated with the stability or mobility of butterfly hybrid zones by synthesizing evidence obtained using different types of data sampled across multiple regions and spatial scales. Finally, we discuss spatiotemporal dynamics in the context of a speciation/divergence continuum, the relevance of hybrid zones for conservation biology, and recommend key topics for future investigation.
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Affiliation(s)
- Ananda R Pereira Martins
- Redpath Museum, McGill University, 859 Sherbrooke Street West, Montreal, Quebec, Canada
- Smithsonian Tropical Research Institute, Gamboa, Panama City, Panama
| | - Natalie B Warren
- Redpath Museum, McGill University, 859 Sherbrooke Street West, Montreal, Quebec, Canada
| | - W Owen McMillan
- Smithsonian Tropical Research Institute, Gamboa, Panama City, Panama
| | - Rowan D H Barrett
- Redpath Museum, McGill University, 859 Sherbrooke Street West, Montreal, Quebec, Canada
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3
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Mantel SJ, Sweigart AL. Postzygotic barriers persist despite ongoing introgression in hybridizing Mimulus species. Mol Ecol 2024; 33:e17261. [PMID: 38174628 PMCID: PMC10922885 DOI: 10.1111/mec.17261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/04/2023] [Accepted: 12/12/2023] [Indexed: 01/05/2024]
Abstract
The evolution of postzygotic isolation is thought to be a key step in maintaining species boundaries upon secondary contact, yet the dynamics and persistence of hybrid incompatibilities in naturally hybridizing species are not well understood. Here, we explore these issues using genetic mapping in three independent populations of recombinant inbred lines between naturally hybridizing monkeyflowers, Mimulus guttatus and Mimulus nasutus, from the sympatric Catherine Creek population. We discover that the three M. guttatus founders differ dramatically in admixture history, with nearly a quarter of one founder's genome introgressed from M. nasutus. Comparative genetic mapping in the three RIL populations reveals three new putative inversions, each one segregating among the M. guttatus founders, two due to admixture. We find strong, genome-wide transmission ratio distortion in all RILs, but patterns are highly variable among the three populations. At least some of this distortion appears to be explained by epistatic selection favouring parental genotypes, but tests of inter-chromosomal linkage disequilibrium also reveal multiple candidate Dobzhansky-Muller incompatibilities. We also map several genetic loci for hybrid pollen viability, including two interacting pairs that coincide with peaks of distortion. Remarkably, even with this limited sample of three M. guttatus lines, we discover abundant segregating variation for hybrid incompatibilities with M. nasutus, suggesting this population harbours diverse contributors to postzygotic isolation. Moreover, even with substantial admixture, hybrid incompatibilities between Mimulus species persist, suggesting postzygotic isolation might be a potent force in maintaining species barriers in this system.
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Affiliation(s)
- Samuel J. Mantel
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA
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4
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Firneno TJ, Semenov G, Dopman EB, Taylor SA, Larson EL, Gompert Z. Quantitative Analyses of Coupling in Hybrid Zones. Cold Spring Harb Perspect Biol 2023; 15:a041434. [PMID: 37739809 PMCID: PMC10691479 DOI: 10.1101/cshperspect.a041434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/24/2023]
Abstract
In hybrid zones, whether barrier loci experience selection mostly independently or as a unit depends on the ratio of selection to recombination as captured by the coupling coefficient. Theory predicts a sharper transition between an uncoupled and coupled system when more loci affect hybrid fitness. However, the extent of coupling in hybrid zones has rarely been quantified. Here, we use simulations to characterize the relationship between the coupling coefficient and variance in clines across genetic loci. We then reanalyze 25 hybrid zone data sets and find that cline variances and estimated coupling coefficients form a smooth continuum from high variance and weak coupling to low variance and strong coupling. Our results are consistent with low rates of hybridization and a strong genome-wide barrier to gene flow when the coupling coefficient is much greater than 1, but also suggest that this boundary might be approached gradually and at a near constant rate over time.
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Affiliation(s)
- Thomas J Firneno
- Department of Biology, University of Denver, Denver, Colorado 80208, USA
| | - Georgy Semenov
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, Colorado 80211, USA
| | - Erik B Dopman
- Department of Biology, Tufts University, Medford, Massachusetts 02155, USA
| | - Scott A Taylor
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, Colorado 80211, USA
| | - Erica L Larson
- Department of Biology, University of Denver, Denver, Colorado 80208, USA
| | - Zachariah Gompert
- Department of Biology, Utah State University, Logan, Utah 84321, USA
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5
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Mantel SJ, Sweigart AL. Postzygotic barriers persist despite ongoing introgression in hybridizing Mimulus species. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.05.552095. [PMID: 37577468 PMCID: PMC10418264 DOI: 10.1101/2023.08.05.552095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
The evolution of postzygotic isolation is thought to be a key step in maintaining species boundaries upon secondary contact, yet the dynamics and persistence of hybrid incompatibilities in sympatric species are not well understood.Here, we explore these issues using genetic mapping in three populations of recombinant inbred lines between naturally hybridizing monkeyflowers Mimulus guttatus and M. nasutus from the sympatric Catherine Creek population.The three M. guttatus founders differ dramatically in admixture history. Comparative genetic mapping also reveals three putative inversions segregating among the M. guttatus founders, two due to admixture. We observe strong, genome-wide transmission ratio distortion, but patterns are highly variable among populations. Some distortion is explained by epistatic selection favoring parental genotypes, but tests of inter-chromosomal linkage disequilibrium also reveal multiple candidate Dobzhansky-Muller incompatibilities. We also map several genetic loci for hybrid fertility, including two interacting pairs coinciding with peaks of distortion.Remarkably, in this limited sample of M. guttatus, we discover abundant segregating variation for hybrid incompatibilities with M. nasutus, suggesting this population harbors diverse contributors to postzygotic isolation. Moreover, even with substantial admixture, hybrid incompatibilities between Mimulus species persist, suggesting postzygotic isolation might be a potent force in maintaining species barriers in this system.
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Affiliation(s)
- Samuel J. Mantel
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA
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6
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Bruni G, Chiocchio A, Nascetti G, Cimmaruta R. Different patterns of introgression in a three species hybrid zone among European cave salamanders. Ecol Evol 2023; 13:e10437. [PMID: 37636870 PMCID: PMC10447881 DOI: 10.1002/ece3.10437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 08/01/2023] [Accepted: 08/07/2023] [Indexed: 08/29/2023] Open
Abstract
Hybrid zones occur where genetically distinct populations meet, mate and produce offspring with mixed ancestry. In Plethodontid salamanders, introgressive hybridization is a common phenomenon, where hybrids backcross with parental populations leading to the spread of new alleles into the parental genomes. Whereas many hybrid zones have been reported in American Plethodontid salamanders, only a single hybrid zone has been documented in European plethodontids so far, which is located at the Apuan Alps in the Italian Peninsula. Here, we describe a previously unreported hybrid zone in the Northern Apennines involving all the three Plethodontid salamander species inhabiting the Italian Peninsula. We found 21 new Speleomantes sites of occurrence, from a hitherto unexplored area located at the boundaries between three Speleomantes species ranges. Using mitochondrial (Cytb and ND2 genes) and nuclear markers (two diagnostic SNPs at the NCX1 gene), we revealed a three-way contact zone where all the three mainland species hybridize: S. strinatii, S. ambrosii and S. italicus. We observed a strong mitonuclear discordance, with mitochondrial markers showing a conspicuous geographic pattern, while diagnostic nuclear SNPs coexisted in both the same populations and individuals, providing evidence of hybridization in many possible combinations. The introgression is asymmetric, with S. italicus mitogenome usually associated with S. a. ambrosii and, to a lesser extent, to S. strinatii nuclear alleles. This finding confirms that Plethodontid are a group of choice to investigate hybridization mechanisms and suggests that behavioural, genetic and ecological components may concur in determining the direction and extent of introgression.
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Affiliation(s)
| | - Andrea Chiocchio
- Department of Ecological and Biological SciencesTuscia UniversityViterboItaly
| | - Giuseppe Nascetti
- Department of Ecological and Biological SciencesTuscia UniversityViterboItaly
| | - Roberta Cimmaruta
- Department of Ecological and Biological SciencesTuscia UniversityViterboItaly
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7
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van Riemsdijk I, Arntzen JW, Bucciarelli GM, McCartney-Melstad E, Rafajlović M, Scott PA, Toffelmier E, Shaffer HB, Wielstra B. Two transects reveal remarkable variation in gene flow on opposite ends of a European toad hybrid zone. Heredity (Edinb) 2023; 131:15-24. [PMID: 37106116 PMCID: PMC10313803 DOI: 10.1038/s41437-023-00617-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 03/27/2023] [Accepted: 04/12/2023] [Indexed: 04/29/2023] Open
Abstract
Speciation entails a reduction in gene flow between lineages. The rates at which genomic regions become isolated varies across space and time. Barrier markers are linked to putative genes involved in (processes of) reproductive isolation, and, when observed over two transects, indicate species-wide processes. In contrast, transect-specific putative barrier markers suggest local processes. We studied two widely separated transects along the 900 km hybrid zone between Bufo bufo and B. spinosus, in northern and southern France, for ~1200 RADseq markers. We used genomic and geographic cline analyses to identify barrier markers based on their restricted introgression, and found that some markers are transect-specific, while others are shared between transects. Twenty-six barrier markers were shared across both transects, of which some are clustered in the same chromosomal region, suggesting that their associated genes are involved in reduced gene flow across the entire hybrid zone. Transect-specific barrier markers were twice as numerous in the southern than in the northern transect, suggesting that the overall barrier effect is weaker in northern France. We hypothesize that this is consistent with a longer period of secondary contact in southern France. The smaller number of introgressed genes in the northern transect shows considerably more gene flow towards the southern (B. spinosus) than the northern species (B. bufo). We hypothesize that hybrid zone movement in northern France and hybrid zone stability in southern France explain this pattern. The Bufo hybrid zone provides an excellent opportunity to separate a general barrier effect from localized gene flow-reducing conditions.
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Affiliation(s)
- I van Riemsdijk
- Naturalis Biodiversity Center, Leiden, the Netherlands.
- Institute of Biology Leiden, Leiden University, Leiden, the Netherlands.
- Institute for Evolution and Ecology, Plant Evolutionary Ecology, Tübingen University, Tübingen, Germany.
| | - J W Arntzen
- Naturalis Biodiversity Center, Leiden, the Netherlands
- Institute of Biology Leiden, Leiden University, Leiden, the Netherlands
| | - G M Bucciarelli
- Department of Ecology and Evolutionary Biology, UCLA, Los Angeles, CA, USA
- La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, UCLA, Los Angeles, CA, USA
- Institute of the Environment, UC Davis, Davis, CA, USA
- Department of Wildlife, Fish, and Conservation Biology, UC Davis, Davis, CA, USA
| | - E McCartney-Melstad
- Department of Ecology and Evolutionary Biology, UCLA, Los Angeles, CA, USA
- La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, UCLA, Los Angeles, CA, USA
| | - M Rafajlović
- Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
- The Linnaeus Centre for Marine Evolutionary Biology, University of Gothenburg, Gothenburg, Sweden
| | - P A Scott
- Department of Ecology and Evolutionary Biology, UCLA, Los Angeles, CA, USA
- Natural Sciences Collegium, Eckerd College, 4200 54 Ave S, St Petersburg, FL, 33711, USA
| | - E Toffelmier
- Department of Ecology and Evolutionary Biology, UCLA, Los Angeles, CA, USA
- La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, UCLA, Los Angeles, CA, USA
| | - H B Shaffer
- Department of Ecology and Evolutionary Biology, UCLA, Los Angeles, CA, USA
- La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, UCLA, Los Angeles, CA, USA
| | - B Wielstra
- Naturalis Biodiversity Center, Leiden, the Netherlands
- Institute of Biology Leiden, Leiden University, Leiden, the Netherlands
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8
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Caeiro-Dias G, Brelsford A, Meneses-Ribeiro M, Crochet PA, Pinho C. Hybridization in late stages of speciation: Strong but incomplete genome-wide reproductive isolation and 'large Z-effect' in a moving hybrid zone. Mol Ecol 2023. [PMID: 37316984 DOI: 10.1111/mec.17035] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 04/27/2023] [Accepted: 05/12/2023] [Indexed: 06/16/2023]
Abstract
In organisms reproducing sexually, speciation occurs when increasing divergence results in pre- or post-zygotic reproductive isolation between lineages. Studies focusing on reproductive isolation origin in early stages of speciation are common and many rely on genomic scans to infer introgression providing limited information on the genomic architecture of reproductive isolation long-term maintenance. This study analyses a natural hybrid zone between two species in a late stage of speciation. We used ddRADseq genotyping in the contact between Podarcis bocagei and P. carbonelli to examine admixture extent, analyse hybrid zone stability and assess genome-wide variation in selection against introgression. We confirmed strong but incomplete reproductive isolation in a bimodal hybrid zone. New findings revealed population genetic structure within P. carbonelli in the contact zone; geographical and genomic clines analysis suggested strong selection against gene flow, but a relatively small proportion of the loci can introgress, mostly within the narrow contact zone. However, geographical clines revealed that a few introgressed loci show signs of potential positive selection, particularly into P. bocagei. Geographical clines also detected a signal of hybrid zone movement towards P. bocagei distribution. Genomic cline analysis revealed heterogeneous patterns of introgression among loci within the syntopy zone, but the majority maintain a strong association with the genomic background of origin. However, incongruences between both cline approaches were found, potentially driven by confounding effects on genomic clines. Last, an important role of the Z chromosome in reproductive isolation is suggested. Importantly, overall patterns of restricted introgression seem to result from numerous strong intrinsic barriers across the genome.
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Affiliation(s)
- Guilherme Caeiro-Dias
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Universidade do Porto, Vairão, Portugal
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
- CEFE, CNRS, Univ Montpellier, EPHE, IRD, Montpellier, France
| | - Alan Brelsford
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Biology Department, University of California Riverside, Riverside, California, USA
| | - Mariana Meneses-Ribeiro
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Universidade do Porto, Vairão, Portugal
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal
| | - Pierre-André Crochet
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Catarina Pinho
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Universidade do Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal
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9
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Stiller J, Wilson NG, Rouse GW. Range-wide population genomics of common seadragons shows secondary contact over a former barrier and insights on illegal capture. BMC Biol 2023; 21:129. [PMID: 37248474 DOI: 10.1186/s12915-023-01628-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 05/16/2023] [Indexed: 05/31/2023] Open
Abstract
BACKGROUND Common seadragons (Phyllopteryx taeniolatus, Syngnathidae) are an emblem of the diverse endemic fauna of Australia's southern rocky reefs, the newly recognized "Great Southern Reef." A lack of assessments spanning this global biodiversity hotspot in its entirety is currently hampering an understanding of the factors that have contributed to its diversity. The common seadragon has a wide range across Australia's entire temperate south and includes a geogenetic break over a former land bridge, which has called its status as a single species into question. As a popular aquarium display that sells for high prices, common seadragons are also vulnerable to illegal capture. RESULTS Here, we provide range-wide nuclear sequences (986 variable Ultraconserved Elements) for 198 individuals and mitochondrial genomes for 140 individuals to assess species status, identify genetic units and their diversity, and trace the source of two poached individuals. Using published data of the other two seadragon species, we found that lineages of common seadragons have diverged relatively recently (< 0.63 Ma). Within common seadragons, we found pronounced genetic structure, falling into three major groups in the western, central, and eastern parts of the range. While populations across the Bassian Isthmus were divergent, there is also evidence for secondary contact since the passage opened. We found a strong cline of genetic diversity from the range center tapering symmetrically towards the range peripheries. Based on their genetic similarities, the poached individuals were inferred to have originated from around Albany in southwestern Australia. CONCLUSIONS We conclude that common seadragons constitute a single species with strong geographic structure but coherence through gene flow. The low genetic diversity on the east and west coasts is concerning given that these areas are projected to face fast climate change. Our results suggest that in addition to their life history, geological events and demographic expansions have all played a role in shaping populations in the temperate south. These insights are an important step towards understanding the historical determinants of the diversity of species endemic to the Great Southern Reef.
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Affiliation(s)
- Josefin Stiller
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, 92093 , USA.
- Centre for Biodiversity Genomics, University of Copenhagen, 2100, Copenhagen, Denmark.
| | - Nerida G Wilson
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, 92093 , USA
- Research & Collections, Western Australian Museum, Perth, Western Australia, 6106, Australia
- School of Biological Sciences, University of Western Australia, Perth, Western Australia, 6009, Australia
| | - Greg W Rouse
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, 92093 , USA.
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10
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Lin XQ, Hou YM, Yang WZ, Shi SC, Zheng PY, Shih CK, Jiang JP, Xie F, Jiang JP, Xie F. A wide hybrid zone mediated by precipitation contributed to confused geographical structure of Scutiger boulengeri. Zool Res 2023; 44:3-19. [PMID: 36171715 PMCID: PMC9841186 DOI: 10.24272/j.issn.2095-8137.2022.108] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Confused geographical structure of a population and mitonuclear discordance are shaped by a combination of rapid changes in population demographics and shifts in ecology. In this study, we generated a time-calibrated phylogeny of Scutiger boulengeri, an endemic Xizang alpine toad occurring in mountain streams on the Qinghai-Xizang (Tibet) Plateau (QTP). Based on three mitochondrial DNA (mtDNA) genes, eight clades were assigned to three deeply divergent lineages. Analysis of nuclear DNA (nuDNA) genes revealed three distinct clusters without geographic structure, indicating significantly high rates of gene flow. Coalescent theory framework analysis (approximate Bayesian computation model DIYABC and Migrate-N) suggested that divergence of the main intraspecific clusters was the result of hybridization after secondary contact in the Holocene around 0.59 million years ago (Ma). The ratio of mtDNA F ST (fixation index) to nuDNA F ST was 2.3, thus failing to show male-biased dispersal. Geographic cline analysis showed that a wide hybrid zone was initially established in southwestern China, without significant reproductive isolation but with strong introgression in S. boulengeri, suggesting high hybrid fitness. Furthermore, mtDNA genes exhibited isolation by distance (IBD) while nuDNA genes exhibited significant isolation by environment (IBE). Results suggested that mitonuclear discordance may have initially been caused by geographic isolation, followed by precipitation-mediated hybridization, producing a wide hybrid zone and geographic structure confusion of nuDNA genes in S. boulengeri. This study indicated that complicated historical processes may have led to specific genetic patterns, with a specific climate factor facilitating gene flow in the system.
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Affiliation(s)
- Xiu-Qin Lin
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yin-Meng Hou
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei-Zhao Yang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Sheng-Chao Shi
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Pu-Yang Zheng
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chung-Kun Shih
- College of Life Sciences, Capital Normal University, Beijing 100048, China,Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington DC 20013–7012, USA
| | - Jian-Ping Jiang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China,University of Chinese Academy of Sciences, Beijing 100049, China,Mangkang Biodiversity and Ecological Station, Xizang Ecological Safety Monitor Network, Changdu, Xizang 854500, China
| | - Feng Xie
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China,University of Chinese Academy of Sciences, Beijing 100049, China,Mangkang Biodiversity and Ecological Station, Xizang Ecological Safety Monitor Network, Changdu, Xizang 854500, China,E-mail:
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11
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Alexander A, Robbins MB, Holmes J, Moyle RG, Peterson AT. Limited movement of an avian hybrid zone in relation to regional variation in magnitude of climate change. Mol Ecol 2022; 31:6634-6648. [PMID: 36210655 PMCID: PMC9729445 DOI: 10.1111/mec.16727] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 09/26/2022] [Accepted: 09/28/2022] [Indexed: 01/13/2023]
Abstract
Studies of natural hybrid zones can provide documentation of range shifts in response to climate change and identify loci important to reproductive isolation. Using a temporal (36-38 years) comparison of the black-capped (Poecile atricapillus) and Carolina (P. carolinensis) chickadee hybrid zone, we investigated movement of the western portion of the zone (western Missouri) and assessed whether loci and pathways underpinning reproductive isolation were similar to those in the eastern portion of the hybrid zone. Using 92 birds sampled along the hybrid zone transect in 2016 and 68 birds sampled between 1978 and 1980, we generated 11,669 SNPs via ddRADseq. These SNPs were used to assess movement of the hybrid zone through time and to evaluate variation in introgression among loci. We demonstrate that the interface has moved ~5 km to the northwest over the last 36-38 years, that is, at only one-fifth the rate at which the eastern portion (e.g., Pennsylvania, Ohio) of the hybrid zone has moved. Temperature trends over the last 38 years reveal that eastern areas have warmed 50% more than western areas in terms of annual mean temperature, possibly providing an explanation for the slower movement of the hybrid zone in Missouri. Our results suggest hybrid zone movement in broadly distributed species, such as chickadees, will vary between areas in response to local differences in the impacts of climate change.
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Affiliation(s)
- Alana Alexander
- Biodiversity Institute, University of Kansas, Lawrence, Kansas 66045, USA.,Department of Anatomy, University of Otago, Dunedin 9016, New Zealand.,Corresponding author.
| | - Mark B. Robbins
- Biodiversity Institute, University of Kansas, Lawrence, Kansas 66045, USA
| | - Jesse Holmes
- Biodiversity Institute, University of Kansas, Lawrence, Kansas 66045, USA.,Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas 66045, USA
| | - Robert G. Moyle
- Biodiversity Institute, University of Kansas, Lawrence, Kansas 66045, USA.,Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas 66045, USA
| | - A. Townsend Peterson
- Biodiversity Institute, University of Kansas, Lawrence, Kansas 66045, USA.,Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas 66045, USA
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12
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vonHoldt BM, Brzeski KE, Aardema ML, Schell CJ, Rutledge LY, Fain SR, Shutt AC, Linderholm A, Murphy WJ. Persistence and expansion of cryptic endangered red wolf genomic ancestry along the American Gulf coast. Mol Ecol 2022; 31:5440-5454. [PMID: 34585803 DOI: 10.1111/mec.16200] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 09/03/2021] [Accepted: 09/22/2021] [Indexed: 12/24/2022]
Abstract
Admixture and introgression play a critical role in adaptation and genetic rescue that has only recently gained a deeper appreciation. Here, we explored the geographical and genomic landscape of cryptic ancestry of the endangered red wolf that persists within the genome of a ubiquitous sister taxon, the coyote, all while the red wolf has been extinct in the wild since the early 1980s. We assessed admixture across 120,621 single nucleotiode polymorphism (SNP) loci genotyped in 293 canid genomes. We found support for increased red wolf ancestry along a west-to-east gradient across the southern United States associated with historical admixture in the past 100 years. Southwestern Louisiana and southeastern Texas, the geographical zone where the last red wolves were known prior to extinction in the wild, contained the highest and oldest levels of red wolf ancestry. Further, given the paucity of inferences based on chromosome types, we compared patterns of ancestry on the X chromosome and autosomes. We additionally aimed to explore the relationship between admixture timing and recombination rate variation to investigate gene flow events. We found that X-linked regions of low recombination rates were depleted of introgression, relative to the autosomes, consistent with the large X effect and enrichment with loci involved in maintaining reproductive isolation. Recombination rate was positively correlated with red wolf ancestry across coyote genomes, consistent with theoretical predictions. The geographical and genomic extent of cryptic red wolf ancestry can provide novel genomic resources for recovery plans targeting the conservation of the endangered red wolf.
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Affiliation(s)
- Bridgett M vonHoldt
- Ecology & Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
| | - Kristin E Brzeski
- College of Forest Resources and Environment Science, Michigan Technological University, Houghton, Michigan, USA
| | - Matthew L Aardema
- Department of Biology, Montclair State University, Montclair, New Jersey, USA.,Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, New York, USA
| | - Christopher J Schell
- Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, California, USA
| | - Linda Y Rutledge
- Biology Department, Trent University, Peterborough, Ontario, Canada
| | - Steven R Fain
- USFWS, Clark R. Bavin National Forensics Laboratory, Ashland, Oregon, USA
| | | | - Anna Linderholm
- Department of Anthropology, Texas A&M University, College Station, Texas, USA
| | - William J Murphy
- Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
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13
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Pereira Martins AR, Martins LP, Ho W, McMillan WO, Ready JS, Barrett R. Scale-dependent environmental effects on phenotypic distributions in Heliconius butterflies. Ecol Evol 2022; 12:e9286. [PMID: 36177141 PMCID: PMC9471044 DOI: 10.1002/ece3.9286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 08/08/2022] [Accepted: 08/17/2022] [Indexed: 01/26/2023] Open
Abstract
Identifying the relative importance of different mechanisms responsible for the emergence and maintenance of phenotypic diversity can be challenging, as multiple selective pressures and stochastic events are involved in these processes. Therefore, testing how environmental conditions shape the distribution of phenotypes can offer important insights on local adaptation, divergence, and speciation. The red-yellow Müllerian mimicry ring of Heliconius butterflies exhibits a wide diversity of color patterns across the Neotropics and is involved in multiple hybrid zones, making it a powerful system to investigate environmental drivers of phenotypic distributions. Using the distantly related Heliconius erato and Heliconius melpomene co-mimics and a multiscale distribution approach, we investigated whether distinct phenotypes of these species are associated with different environmental conditions. We show that Heliconius red-yellow phenotypic distribution is strongly driven by environmental gradients (especially thermal and precipitation variables), but that phenotype and environment associations vary with spatial scale. While co-mimics are usually predicted to occur in similar environments at large spatial scales, patterns at local scales are not always consistent (i.e., different variables are best predictors of phenotypic occurrence in different locations) or congruent (i.e., co-mimics show distinct associations with environment). We suggest that large-scale analyses are important for identifying how environmental factors shape broad mimetic phenotypic distributions, but that local studies are essential to understand the context-dependent biotic, abiotic, and historical mechanisms driving finer-scale phenotypic transitions.
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Affiliation(s)
- Ananda R. Pereira Martins
- Redpath MuseumMcGill UniversityMontrealQuebecCanada,Smithsonian Tropical Research InstitutePanama CityPanama
| | - Lucas P. Martins
- School of Biological SciencesUniversity of CanterburyChristchurchNew Zealand
| | | | | | - Jonathan S. Ready
- Instituto de Ciências BiológicasUniversidade Federal do ParáBelémBrazil
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14
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Pyron RA, O’Connell KA, Lemmon EM, Lemmon AR, Beamer DA. Candidate‐species delimitation in
Desmognathus
salamanders reveals gene flow across lineage boundaries, confounding phylogenetic estimation and clarifying hybrid zones. Ecol Evol 2022; 12:e8574. [PMID: 35222955 PMCID: PMC8848459 DOI: 10.1002/ece3.8574] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 01/05/2022] [Accepted: 01/10/2022] [Indexed: 12/19/2022] Open
Abstract
Dusky Salamanders (genus Desmognathus) currently comprise only 22 described, extant species. However, recent mitochondrial and nuclear estimates indicate the presence of up to 49 candidate species based on ecogeographic sampling. Previous studies also suggest a complex history of hybridization between these lineages. Studies in other groups suggest that disregarding admixture may affect both phylogenetic inference and clustering‐based species delimitation. With a dataset comprising 233 Anchored Hybrid Enrichment (AHE) loci sequenced for 896 Desmognathus specimens from all 49 candidate species, we test three hypotheses regarding (i) species‐level diversity, (ii) hybridization and admixture, and (iii) misleading phylogenetic inference. Using phylogenetic and population‐clustering analyses considering gene flow, we find support for at least 47 candidate species in the phylogenomic dataset, some of which are newly characterized here while others represent combinations of previously named lineages that are collapsed in the current dataset. Within these, we observe significant phylogeographic structure, with up to 64 total geographic genetic lineages, many of which hybridize either narrowly at contact zones or extensively across ecological gradients. We find strong support for both recent admixture between terminal lineages and ancient hybridization across internal branches. This signal appears to distort concatenated phylogenetic inference, wherein more heavily admixed terminal specimens occupy apparently artifactual early‐diverging topological positions, occasionally to the extent of forming false clades of intermediate hybrids. Additional geographic and genetic sampling and more robust computational approaches will be needed to clarify taxonomy, and to reconstruct a network topology to display evolutionary relationships in a manner that is consistent with their complex history of reticulation.
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Affiliation(s)
- Robert Alexander Pyron
- Department of Biological Sciences The George Washington University Washington District of Columbia USA
- Division of Amphibians and Reptiles Department of Vertebrate Zoology National Museum of Natural History Smithsonian Institution Washington District of Columbia USA
| | - Kyle A. O’Connell
- Department of Biological Sciences The George Washington University Washington District of Columbia USA
- Division of Amphibians and Reptiles Department of Vertebrate Zoology National Museum of Natural History Smithsonian Institution Washington District of Columbia USA
- Global Genome Initiative National Museum of Natural History Smithsonian Institution Washington District of Columbia USA
- Biomedical Data Science Lab Deloitte Consulting LLP Arlington Virginia USA
| | | | - Alan R. Lemmon
- Department of Scientific Computing Florida State University Tallahassee Florida USA
| | - David A. Beamer
- Department of Natural Sciences Nash Community College Rocky Mount North Carolina USA
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15
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Kataoka K, Togawa Y, Sanno R, Asahi T, Yura K. Dissecting cricket genomes for the advancement of entomology and entomophagy. Biophys Rev 2022; 14:75-97. [PMID: 35340598 PMCID: PMC8921346 DOI: 10.1007/s12551-021-00924-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 11/30/2021] [Indexed: 12/13/2022] Open
Abstract
Significant advances in biophysical methods such as next-generation sequencing technologies have now opened the way to conduct evolutionary and applied research based on the genomic information of greatly diverse insects. Crickets belonging to Orthoptera (Insecta: Polyneoptera), one of the most flourishing groups of insects, have contributed to the development of multiple scientific fields including developmental biology and neuroscience and have been attractive targets in evolutionary ecology for their diverse ecological niches. In addition, crickets have recently gained recognition as food and feed. However, the genomic information underlying their biological basis and application research toward breeding is currently underrepresented. In this review, we summarize the progress of genomics of crickets. First, we outline the phylogenetic position of crickets in insects and then introduce recent studies on cricket genomics and transcriptomics in a variety of fields. Furthermore, we present findings from our analysis of polyneopteran genomes, with a particular focus on their large genome sizes, chromosome number, and repetitive sequences. Finally, how the cricket genome can be beneficial to the food industry is discussed. This review is expected to enhance greater recognition of how important the cricket genomes are to the multiple biological fields and how basic research based on cricket genome information can contribute to tackling global food security.
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Affiliation(s)
- Kosuke Kataoka
- Comprehensive Research Organization, Waseda University, Tokyo, Japan
| | - Yuki Togawa
- School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | - Ryuto Sanno
- Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | - Toru Asahi
- Comprehensive Research Organization, Waseda University, Tokyo, Japan
- School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
- Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
- Institute for Advanced Research of Biosystem Dynamics, Waseda Research Institute for Science and Engineering, Waseda University, Tokyo, Japan
- Research Organization for Nano & Life Innovation, Waseda University, Tokyo, Japan
| | - Kei Yura
- School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
- Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
- Research Organization for Nano & Life Innovation, Waseda University, Tokyo, Japan
- Computational Bio Big-Data Open Innovation Laboratory (CBBD-OIL), National Institute of Advanced Industrial Science and Technology, Tokyo, Japan
- Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo, Japan
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16
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Combe FJ, Jaster L, Ricketts A, Haukos D, Hope AG. Population genomics of free-ranging Great Plains white-tailed and mule deer reflects a long history of interspecific hybridization. Evol Appl 2022; 15:111-131. [PMID: 35126651 PMCID: PMC8792484 DOI: 10.1111/eva.13330] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 09/21/2021] [Accepted: 11/22/2021] [Indexed: 12/11/2022] Open
Abstract
Hybridization is a natural process at species-range boundaries that may variably promote the speciation process or break down species barriers but minimally will influence management outcomes of distinct populations. White-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus) have broad and overlapping distributions in North America and a recognized capacity for interspecific hybridization. In response to contemporary environmental change to any of one or multiple still-unknown factors, mule deer range is contracting westward accompanied by a westward expansion of white-tailed deer, leading to increasing interactions, opportunities for gene flow, and associated conservation implications. To quantify genetic diversity, phylogenomic structure, and dynamics of hybridization in sympatric populations of white-tailed and mule deer, we used mitochondrial cytochrome b data coupled with SNP loci discovered with double-digest restriction site-associated DNA sequencing. We recovered 25,018 SNPs across 92 deer samples from both species, collected from two regions of western Kansas. Eight individuals with unambiguous external morphology representing both species were of hybrid origin (8.7%), and represented the product of multi-generational backcrossing. Mitochondrial data showed both ancient and recent directional discordance with morphological species assignments, reflecting a legacy of mule deer males mating with white-tailed deer females. Mule deer had lower genetic diversity than white-tailed deer, and both mitochondrial and nuclear data suggest contemporary mule deer effective population decline. Landscape genetic analyses show relative isolation between the two study regions for white-tailed deer, but greater connectivity among mule deer, with predominant movement from north to south. Collectively, our results suggest a long history of gene flow between these species in the Great Plains and hint at evolutionary processes that purge incompatible functional genomic elements as a result of hybridization. Surviving hybrids evidently may be reproductive, but with unknown consequences for the future integrity of these species, population trajectories, or relative susceptibility to emerging pathogens.
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Affiliation(s)
- Fraser J. Combe
- Division of BiologyKansas State UniversityManhattanKansasUSA
| | - Levi Jaster
- Kansas Department of Wildlife and ParksTopekaKansasUSA
| | - Andrew Ricketts
- Department of Horticulture and Natural Sciences, Wildlife and Outdoor Enterprise ManagementKansas State UniversityManhattanKansasUSA
| | - David Haukos
- Division of BiologyU.S. Geological SurveyKansas Cooperative Fish and Wildlife Research UnitKansas State UniversityManhattanKansasUSA
| | - Andrew G. Hope
- Division of BiologyKansas State UniversityManhattanKansasUSA
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17
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Cruzan MB, Thompson PG, Diaz NA, Hendrickson EC, Gerloff KR, Kline KA, Machiorlete HM, Persinger JM. Weak coupling among barrier loci and waves of neutral and adaptive introgression across an expanding hybrid zone. Evolution 2021; 75:3098-3114. [PMID: 34668193 PMCID: PMC9298192 DOI: 10.1111/evo.14381] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 09/14/2021] [Accepted: 09/19/2021] [Indexed: 01/02/2023]
Abstract
Hybridization can serve as an evolutionary stimulus, but we have little understanding of introgression at early stages of hybrid zone formation. We analyze reproductive isolation and introgression between a range‐limited and a widespread species. Reproductive barriers are estimated based on differences in flowering time, ecogeographic distributions, and seed set from crosses. We find an asymmetrical mating barrier due to cytonuclear incompatibility that is consistent with observed clusters of coincident and concordant tension zone clines (barrier loci) for mtDNA haplotypes and nuclear SNPs. These groups of concordant clines are spread across the hybrid zone, resulting in weak coupling among barrier loci and extensive introgression. Neutral clines had nearly equal introgression into both species’ ranges, whereas putative cases of adaptive introgression had exceptionally wide clines with centers shifted toward one species. Analyses of cline shape indicate that secondary contact was initiated within the last 800 generations with the per‐generation dispersal between 200 and 400 m, and provide some of the first estimates of the strength of selection required to account for observed levels of adaptive introgression. The weak species boundary between these species appears to be in early stages of dissolution, and ultimately will precipitate genetic swamping of the range‐limited species.
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Affiliation(s)
- Mitchell B Cruzan
- Department of Biology, Portland State University, Portland, Oregon, 97201
| | - Pamela G Thompson
- Department of Biology, Portland State University, Portland, Oregon, 97201
| | - Nicolas A Diaz
- Department of Biology, Portland State University, Portland, Oregon, 97201
| | | | - Katie R Gerloff
- Department of Biology, Portland State University, Portland, Oregon, 97201
| | - Katie A Kline
- Department of Biology, Portland State University, Portland, Oregon, 97201
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18
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Fraïsse C, Sachdeva H. The rates of introgression and barriers to genetic exchange between hybridizing species: sex chromosomes vs autosomes. Genetics 2021; 217:6042694. [PMID: 33724409 DOI: 10.1093/genetics/iyaa025] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 11/23/2020] [Indexed: 12/14/2022] Open
Abstract
Interspecific crossing experiments have shown that sex chromosomes play a major role in reproductive isolation between many pairs of species. However, their ability to act as reproductive barriers, which hamper interspecific genetic exchange, has rarely been evaluated quantitatively compared to Autosomes. This genome-wide limitation of gene flow is essential for understanding the complete separation of species, and thus speciation. Here, we develop a mainland-island model of secondary contact between hybridizing species of an XY (or ZW) sexual system. We obtain theoretical predictions for the frequency of introgressed alleles, and the strength of the barrier to neutral gene flow for the two types of chromosomes carrying multiple interspecific barrier loci. Theoretical predictions are obtained for scenarios where introgressed alleles are rare. We show that the same analytical expressions apply for sex chromosomes and autosomes, but with different sex-averaged effective parameters. The specific features of sex chromosomes (hemizygosity and absence of recombination in the heterogametic sex) lead to reduced levels of introgression on the X (or Z) compared to autosomes. This effect can be enhanced by certain types of sex-biased forces, but it remains overall small (except when alleles causing incompatibilities are recessive). We discuss these predictions in the light of empirical data comprising model-based tests of introgression and cline surveys in various biological systems.
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Affiliation(s)
- Christelle Fraïsse
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria.,CNRS, Univ. Lille, UMR 8198 - Evo-Eco-Paleo, F-59000 Lille, France
| | - Himani Sachdeva
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria.,Mathematics and BioSciences Group, Faculty of Mathematics, University of Vienna, A-1090 Vienna, Austria
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19
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Wen G, Fu J. Isolation and reconnection: Demographic history and multiple contact zones of the green odorous frog (Odorrana margaretae) around the Sichuan Basin. Mol Ecol 2021; 30:4103-4117. [PMID: 34145663 DOI: 10.1111/mec.16021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Revised: 05/27/2021] [Accepted: 06/10/2021] [Indexed: 01/25/2023]
Abstract
The green odorous frog (Odorrana margaretae) displays a circular distribution around the Sichuan Basin of western China and possesses multiple replicate hybrid zones between lineages with high levels of divergence. To gain an understanding of the speciation process, we obtained 1540 SNPs from 29 populations and 227 individuals using ddRAD sequencing. Population structure analysis revealed three groups within the species: the West, North & South, and East groups. Demographic inference showed that they were initially isolated at ~2 million years ago, and subsequent post-glacial expansion produced the current circular distribution with four secondary contact zones. Hybridization in those zones involved lineages with various levels of divergence and produced greatly different patterns of introgression. Contact zones between the East and North & South groups (E-S and E-N) had contrast admixture levels but both showed a general lack of potential barrier loci. Meanwhile, the reconnection of the West and North & South groups produced two contact zones along the rim of the Basin. The S-W zone had extensive admixture while the N-W zone had limited admixture within a narrow geographic distance. Both showed substantial barrier effects, and a large number of potential barrier loci were shared. We also detected strong coupling among these loci. The N-W hybrid zone involved two highly-diverged lineages (FST = 0.704) and many loci have reached fixation around the hybrid zone. This study system offers a unique opportunity to understand the dynamics of introgression in contact zones and the architecture of reproductive isolation at different stages of speciation.
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Affiliation(s)
- Guannan Wen
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Jinzhong Fu
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China.,Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
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20
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Gao Y, Harris AJ, Li H, Gao X. Hybrid Speciation and Introgression Both Underlie the Genetic Structures and Evolutionary Relationships of Three Morphologically Distinct Species of Lilium (Liliaceae) Forming a Hybrid Zone Along an Elevational Gradient. FRONTIERS IN PLANT SCIENCE 2020; 11:576407. [PMID: 33365039 PMCID: PMC7750405 DOI: 10.3389/fpls.2020.576407] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 11/02/2020] [Indexed: 05/28/2023]
Abstract
We studied hybrid interactions of Lilium meleagrinum, Lilium gongshanense, and Lilium saluenense using an integrative approach combining population genetics, fieldwork, and phenological research. These three species occur along an elevational gradient, with L. meleagrinum occurring at lower elevations, L. saluenense at higher elevations, and L. gongshanense between them. The species show strong morphological differentiation despite there being no clear environmental barriers to gene flow among them. Lilium gongshanense is likely to have a hybrid origin based on our prior work, but its progenitors remain uncertain. We sought to determine whether gene flow occurs among these three parapatric species, and, if so, whether L. gongshanense is a hybrid of L. meleagrinum and/or L. saluenense. We analyzed data from multiple chloroplast genes and spacers, nuclear internal transcribed spacer (ITS), and 18 nuclear Expressed Sequence Tag-Simple Sequence Repeat (EST-SSR) microsatellites for accessions of the three species representing dense population-level sampling. We also inferred phenology by examining species in the field and using herbarium specimens. We found that there are only two types of chloroplast genomes shared among the three species and that L. gongshanense forms two distinct groups with closest links to other species of Lilium based on ITS. Taken together, L. gongshanense is unlikely to be a hybrid species resulting from a cross between L. meleagrinum and L. saluenense, but gene flow is occurring among the three species. The gene flow is likely to be rare according to evidence from all molecular datasets, and this is corroborated by detection of only one putative hybrid individual in the field and asynchronous phenology. We suspect that the rarity of hybridization events among the species facilitates their continued genetic separation.
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Affiliation(s)
- Yundong Gao
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - AJ Harris
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Huaicheng Li
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
- Institut für Biologie, Freie Universität Berlin, Berlin, Germany
| | - Xinfen Gao
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
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21
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McEntee JP, Burleigh JG, Singhal S. Dispersal Predicts Hybrid Zone Widths across Animal Diversity: Implications for Species Borders under Incomplete Reproductive Isolation. Am Nat 2020; 196:9-28. [PMID: 32552108 DOI: 10.1086/709109] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Hybrid zones occur as range boundaries for many animal taxa. One model for how hybrid zones form and stabilize is the tension zone model, a version of which predicts that hybrid zone widths are determined by a balance between random dispersal into hybrid zones and selection against hybrids. Here, we examine whether random dispersal and proxies for selection against hybrids (genetic distances between hybridizing pairs) can explain variation in hybrid zone widths across 131 hybridizing pairs of animals. We show that these factors alone can explain ∼40% of the variation in zone width among animal hybrid zones, with dispersal explaining far more of the variation than genetic distances. Patterns within clades were idiosyncratic. Genetic distances predicted hybrid zone widths particularly well for reptiles, while this relationship was opposite tension zone predictions in birds. Last, the data suggest that dispersal and molecular divergence set lower bounds on hybrid zone widths in animals, indicating that there are geographic restrictions on hybrid zone formation. Overall, our analyses reinforce the fundamental importance of dispersal in hybrid zone formation and more generally in the ecology of range boundaries.
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22
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Slager DL, Epperly KL, Ha RR, Rohwer S, Wood C, Van Hemert C, Klicka J. Cryptic and extensive hybridization between ancient lineages of American crows. Mol Ecol 2020; 29:956-969. [PMID: 32034818 DOI: 10.1111/mec.15377] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 12/30/2019] [Accepted: 02/05/2020] [Indexed: 01/02/2023]
Abstract
Most species and therefore most hybrid zones have historically been defined using phenotypic characters. However, both speciation and hybridization can occur with negligible morphological differentiation. Recently developed genomic tools provide the means to better understand cryptic speciation and hybridization. The Northwestern Crow (Corvus caurinus) and American Crow (Corvus brachyrhynchos) are continuously distributed sister taxa that lack reliable traditional characters for identification. In this first population genomic study of Northwestern and American crows, we use genomic SNPs (nuDNA) and mtDNA to investigate the degree of genetic differentiation between these crows and the extent to which they may hybridize. Our results indicate that American and Northwestern crows have distinct evolutionary histories, supported by two nuDNA ancestry clusters and two 1.1%-divergent mtDNA clades dating to the late Pleistocene, when glacial advances may have isolated crow populations in separate refugia. We document extensive hybridization, with geographic overlap of mtDNA clades and admixture of nuDNA across >900 km of western Washington and western British Columbia. This broad hybrid zone consists of late-generation hybrids and backcrosses, but not recent (e.g., F1) hybrids. Nuclear DNA and mtDNA clines had concordant widths and were both centred in southwestern British Columbia, farther north than previously postulated. Overall, our results suggest a history of reticulate evolution in American and Northwestern crows, perhaps due to recurring neutral expansion(s) from Pleistocene glacial refugia followed by lineage fusion(s). However, we do not rule out a contributing role for more recent potential drivers of hybridization, such as expansion into human-modified habitats.
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Affiliation(s)
- David L Slager
- Department of Biology, University of Washington, Seattle, WA, USA.,Burke Museum of Natural History and Culture, Seattle, WA, USA
| | - Kevin L Epperly
- Department of Biology, University of Washington, Seattle, WA, USA.,Burke Museum of Natural History and Culture, Seattle, WA, USA
| | - Renee R Ha
- Department of Psychology, University of Washington, Seattle, WA, USA
| | - Sievert Rohwer
- Department of Biology, University of Washington, Seattle, WA, USA.,Burke Museum of Natural History and Culture, Seattle, WA, USA
| | - Chris Wood
- Burke Museum of Natural History and Culture, Seattle, WA, USA
| | | | - John Klicka
- Department of Biology, University of Washington, Seattle, WA, USA.,Burke Museum of Natural History and Culture, Seattle, WA, USA
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23
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Heggeseth B, Sim D, Partida L, Maroja LS. Influence of female cuticular hydrocarbon (CHC) profile on male courtship behavior in two hybridizing field crickets Gryllus firmus and Gryllus pennsylvanicus. BMC Evol Biol 2020; 20:21. [PMID: 32019492 PMCID: PMC7001378 DOI: 10.1186/s12862-020-1587-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 01/27/2020] [Indexed: 11/10/2022] Open
Abstract
Background The hybridizing field crickets, Gryllus firmus and Gryllus pennsylvanicus have several barriers that prevent gene flow between species. The behavioral pre-zygotic mating barrier, where males court conspecifics more intensely than heterospecifics, is important because by acting earlier in the life cycle it has the potential to prevent a larger fraction of hybridization. The mechanism behind such male mate preference is unknown. Here we investigate if the female cuticular hydrocarbon (CHC) profile could be the signal behind male courtship. Results While males of the two species display nearly identical CHC profiles, females have different, albeit overlapping profiles and some females (between 15 and 45%) of both species display a male-like profile distinct from profiles of typical females. We classified CHC females profile into three categories: G. firmus-like (F; including mainly G. firmus females), G. pennsylvanicus-like (P; including mainly G. pennsylvanicus females), and male-like (ML; including females of both species). Gryllus firmus males courted ML and F females more often and faster than they courted P females (p < 0.05). Gryllus pennsylvanicus males were slower to court than G. firmus males, but courted ML females more often (p < 0.05) than their own conspecific P females (no difference between P and F). Both males courted heterospecific ML females more often than other heterospecific females (p < 0.05, significant only for G. firmus males). Conclusions Our results suggest that male mate preference is at least partially informed by female CHC profile and that ML females elicit high courtship behavior in both species. Since ML females exist in both species and are preferred over other heterospecific females, it is likely that this female type is responsible for most hybrid offspring production.
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Affiliation(s)
- Brianna Heggeseth
- Department of Mathematics and Statistics, Williams College, Williamstown, MA, USA.,Department of Mathematics, Statistics, and Computer Science, Macalester College, St. Paul, MN, USA
| | - Danielle Sim
- Department of Biology, Williams College, Williamstown, MA, USA
| | - Laura Partida
- Department of Biology, Williams College, Williamstown, MA, USA
| | - Luana S Maroja
- Department of Biology, Williams College, Williamstown, MA, USA.
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Mitchell N, Campbell LG, Ahern JR, Paine KC, Giroldo AB, Whitney KD. Correlates of hybridization in plants. Evol Lett 2019; 3:570-585. [PMID: 31867119 PMCID: PMC6906982 DOI: 10.1002/evl3.146] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 10/02/2019] [Accepted: 10/03/2019] [Indexed: 01/08/2023] Open
Abstract
Hybridization is a biological phenomenon increasingly recognized as an important evolutionary process in both plants and animals, as it is linked to speciation, radiation, extinction, range expansion and invasion, and allows for increased trait diversity in agricultural and horticultural systems. Estimates of hybridization frequency vary across taxonomic groups, but causes of this variation are unknown. Here, we ask on a global scale whether hybridization is linked to any of 11 traits related to plant life history, reproduction, genetic predisposition, and environment or opportunity. Given that hybridization is not evenly distributed across the plant tree of life, we use phylogenetic generalized least squares regression models and phylogenetic path analysis to detect statistical associations between hybridization and plant traits at both the family and genus levels. We find that perenniality and woodiness are each weakly associated with an increased frequency of hybridization in univariate analyses, but path analysis suggests that the direct linkage is between perenniality and increased hybridization (with woodiness having only an indirect relationship with hybridization via perenniality). Weak associations between higher rates of hybridization and higher outcrossing rates, abiotic pollination syndromes, vegetative reproductive modes, larger genomes, and less variable genome sizes are detectable in some cases but not others. We argue that correlational evidence at the global scale, such as that presented here, provides a robust framework for forming hypotheses to examine and test drivers of hybridization at a more mechanistic level.
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Affiliation(s)
- Nora Mitchell
- Department of BiologyUniversity of New MexicoAlbuquerqueNew Mexico87131
- Department of BiologyUniversity of Wisconsin–Eau ClaireEau ClaireWisconsin54701
| | - Lesley G. Campbell
- Department of Chemistry and BiologyRyerson UniversityTorontoOntarioM5B 2K3Canada
| | - Jeffrey R. Ahern
- Department of BiologyUniversity of New MexicoAlbuquerqueNew Mexico87131
| | - Kellen C. Paine
- Department of BiologyUniversity of New MexicoAlbuquerqueNew Mexico87131
| | - Aelton B. Giroldo
- Departamento de EnsinoInstituto Federal de Educação, Ciência e Tecnologia do Ceará – Campus Crateús, CrateúsBrazil
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Arntzen JW. An amphibian species pushed out of Britain by a moving hybrid zone. Mol Ecol 2019; 28:5145-5154. [PMID: 31643124 PMCID: PMC6900066 DOI: 10.1111/mec.15285] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 10/17/2019] [Accepted: 10/21/2019] [Indexed: 02/06/2023]
Abstract
Classical theory states that hybrid zones will be stable in troughs of low population density where dispersal is hampered. Yet, evidence for moving hybrid zones is mounting. One possible reason that moving zones have been underappreciated is that they may drive themselves into oblivion and with just the superseding species remaining, morphological and genetic signals of past species replacement may be difficult to appreciate. Using genetic data (32 diagnostic single nucleotide polymorphisms) from a clinal hybrid zone of the common toad (Bufo bufo) and the spined toad (Bufo spinosus) in France for comparison, alleles of the latter species were documented in common toads in the south of Great Britain, at frequencies in excess of 10%. Because long distance dispersal across the Channel is unlikely, the conclusion reached was that the continental toad hybrid zone which previously extended into Britain, moved southwards and extirpated B. spinosus. Species distribution models for the mid-Holocene and the present support that climate has locally changed in favour of B. bufo. The system bears resemblance with the demise of Homo neanderthalensis and the rise of Homo sapiens and provides an example that some paleoanthropologists demanded in support of a hominin "leaky replacement" scenario. The toad example is informative just because surviving pure B. spinosus and an extant slowly moving interspecific hybrid zone are available for comparison.
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Zieliński P, Dudek K, Arntzen JW, Palomar G, Niedzicka M, Fijarczyk A, Liana M, Cogǎlniceanu D, Babik W. Differential introgression across newt hybrid zones: Evidence from replicated transects. Mol Ecol 2019; 28:4811-4824. [DOI: 10.1111/mec.15251] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 09/16/2019] [Accepted: 09/19/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Piotr Zieliński
- Institute of Environmental Sciences Faculty of Biology Jagiellonian University Kraków Poland
| | - Katarzyna Dudek
- Institute of Environmental Sciences Faculty of Biology Jagiellonian University Kraków Poland
| | | | - Gemma Palomar
- Institute of Environmental Sciences Faculty of Biology Jagiellonian University Kraków Poland
| | - Marta Niedzicka
- Institute of Environmental Sciences Faculty of Biology Jagiellonian University Kraków Poland
| | - Anna Fijarczyk
- Département de Biologie Faculté des Sciences et de génie Université Laval Québec QC Canada
| | | | - Dan Cogǎlniceanu
- Faculty of Natural Sciences and Agricultural Sciences University Ovidius Constanţa Constanţa Romania
| | - Wiesław Babik
- Institute of Environmental Sciences Faculty of Biology Jagiellonian University Kraków Poland
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27
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García G, Ríos N, Gutiérrez V, Serra S, Loureiro M. Transcriptome-Based SNP Discovery and Validation in the Hybrid Zone of the Neotropical Annual Fish Genus Austrolebias. Genes (Basel) 2019; 10:genes10100789. [PMID: 31614537 PMCID: PMC6826752 DOI: 10.3390/genes10100789] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 09/13/2019] [Accepted: 09/15/2019] [Indexed: 02/04/2023] Open
Abstract
The genus Austrolebias (Cyprinodontiformes: Rivulidae) represents a specious group of taxa following annual life cycles in the neotropical ichthyofauna. They live in temporary ponds and each generation must be completed in a few months, depending on environmental stochasticity. Annual fish survive the dry season through diapausing eggs buried in the substrate of these ponds. A hypothesized bimodal hybrid zone between two taxa of the genus, A. charrua and A. reicherti from Dos Patos Merin lagoon system, was recently proposed based on genetics and morphological analyses. However, hundreds of additional nuclear molecular markers should be used to strongly support this hypothesized bimodal pattern. In the present paper, we conducted RNA-seq-based sequencing of the transcriptomes from pools of individuals of A. charrua, A. reicherti and their putative natural hybrids from the previously characterized hybrid zone. As a result, we identified a set of 111,725 SNP (single nucleotide polymorphism) markers, representing presumably fixed allelic differences among the two species. The present study provided the first panel of 106 SNP markers as a single diagnostic multiplex assay and validated their capacity to reconstruct the patterns of the hybrid zone between both taxa. These nuclear markers combined with Cytb gene and morphological analyses detected a population structure in which some groups among the hybrid swarms showed different level of introgression towards one or the other parental species according to their geographic distribution. High-quality transcriptomes and a large set of gene-linked SNPs should greatly facilitate functional and population genomics studies in the hybrid zone of these endangered species.
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Affiliation(s)
- Graciela García
- Sección Genética Evolutiva, Facultad de Ciencias, UdelaR, Iguá 4225, Montevideo 11400, Uruguay.
| | - Néstor Ríos
- Sección Genética Evolutiva, Facultad de Ciencias, UdelaR, Iguá 4225, Montevideo 11400, Uruguay.
| | - Verónica Gutiérrez
- Sección Genética Evolutiva, Facultad de Ciencias, UdelaR, Iguá 4225, Montevideo 11400, Uruguay.
| | - Sebastián Serra
- Sección Genética Evolutiva, Facultad de Ciencias, UdelaR, Iguá 4225, Montevideo 11400, Uruguay.
- Departamento de Ecología y Evolución, Facultad de Ciencias, UdelaR, Iguá 4225, Montevideo 11400, Uruguay.
- Sección Ictiología, Museo Nacional de Historia Natural, Montevideo 11400, Uruguay.
| | - Marcelo Loureiro
- Departamento de Ecología y Evolución, Facultad de Ciencias, UdelaR, Iguá 4225, Montevideo 11400, Uruguay.
- Sección Ictiología, Museo Nacional de Historia Natural, Montevideo 11400, Uruguay.
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29
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Ginsberg PS, Humphreys DP, Dyer KA. Ongoing hybridization obscures phylogenetic relationships in the Drosophila subquinaria species complex. J Evol Biol 2019; 32:1093-1105. [PMID: 31385638 DOI: 10.1111/jeb.13512] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 07/30/2019] [Indexed: 12/28/2022]
Abstract
Inferring evolutionary relationships among recently diverged lineages is necessary to understand how isolating barriers produce independent lineages. Here, we investigate the phylogenetic relationships between three incompletely isolated and closely related mushroom-feeding Drosophila species. These species form the Drosophila subquinaria species complex and consist of one Eurasian species (D. transversa) and two widespread North American species (D. subquinaria and D. recens) that are sympatric in central Canada. Although patterns of pre- and post-mating isolation among these species are well characterized, previous work on their phylogenetic relationships is limited and conflicting. In this study, we generated a multi-locus data set of 29 loci from across the genome sequenced in a population sample from each species, and then, we inferred species relationships and patterns of introgression. We find strong statistical support that D. subquinaria is paraphyletic, showing that samples from the geographic region sympatric with D. recens are most closely related to D. recens, whereas samples from the geographic region allopatric with D. recens are most closely related to D. transversa. We present several lines of evidence that both incomplete lineage sorting and gene flow are causing phylogenetic discordance. We suggest that ongoing gene flow primarily from D. recens into D. subquinaria in the sympatric part of their ranges causes phylogenetic uncertainty in the evolutionary history of these species. Our results highlight how population genetic data can be used to disentangle the sources of phylogenetic discordance among closely related species.
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Affiliation(s)
- Paul S Ginsberg
- Department of Genetics, University of Georgia, Athens, GA, USA
| | | | - Kelly A Dyer
- Department of Genetics, University of Georgia, Athens, GA, USA
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30
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Bourgeois Y, Ruggiero RP, Manthey JD, Boissinot S. Recent Secondary Contacts, Linked Selection, and Variable Recombination Rates Shape Genomic Diversity in the Model Species Anolis carolinensis. Genome Biol Evol 2019; 11:2009-2022. [PMID: 31134281 PMCID: PMC6681179 DOI: 10.1093/gbe/evz110] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/23/2019] [Indexed: 12/14/2022] Open
Abstract
Gaining a better understanding on how selection and neutral processes affect genomic diversity is essential to gain better insights into the mechanisms driving adaptation and speciation. However, the evolutionary processes affecting variation at a genomic scale have not been investigated in most vertebrate lineages. Here, we present the first population genomics survey using whole genome resequencing in the green anole (Anolis carolinensis). Anoles have been intensively studied to understand mechanisms underlying adaptation and speciation. The green anole in particular is an important model to study genome evolution. We quantified how demography, recombination, and selection have led to the current genetic diversity of the green anole by using whole-genome resequencing of five genetic clusters covering the entire species range. The differentiation of green anole's populations is consistent with a northward expansion from South Florida followed by genetic isolation and subsequent gene flow among adjacent genetic clusters. Dispersal out-of-Florida was accompanied by a drastic population bottleneck followed by a rapid population expansion. This event was accompanied by male-biased dispersal and/or selective sweeps on the X chromosome. We show that the interaction between linked selection and recombination is the main contributor to the genomic landscape of differentiation in the anole genome.
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Affiliation(s)
| | | | - Joseph D Manthey
- New York University Abu Dhabi, United Arab Emirates
- Department of Biological Sciences, Texas Tech University
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31
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Billerman SM, Cicero C, Bowie RCK, Carling MD. Phenotypic and genetic introgression across a moving woodpecker hybrid zone. Mol Ecol 2019; 28:1692-1708. [DOI: 10.1111/mec.15043] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 01/22/2019] [Indexed: 01/05/2023]
Affiliation(s)
- Shawn M. Billerman
- Department of Zoology and Physiology University of Wyoming Laramie Wyoming
- Program in Ecology University of Wyoming Laramie Wyoming
| | - Carla Cicero
- Museum of Vertebrate Zoology University of California Berkeley California
| | - Rauri C. K. Bowie
- Museum of Vertebrate Zoology University of California Berkeley California
- Department of Integrative Biology University of California Berkeley California
| | - Matthew D. Carling
- Department of Zoology and Physiology University of Wyoming Laramie Wyoming
- Program in Ecology University of Wyoming Laramie Wyoming
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32
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Rifkin JL, Castillo AS, Liao IT, Rausher MD. Gene flow, divergent selection and resistance to introgression in two species of morning glories (Ipomoea). Mol Ecol 2019; 28:1709-1729. [PMID: 30451335 DOI: 10.1111/mec.14945] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 09/03/2018] [Accepted: 11/01/2018] [Indexed: 02/03/2023]
Abstract
Gene flow is thought to impede genetic divergence and speciation by homogenizing genomes. Recent theory and research suggest that sufficiently strong divergent selection can overpower gene flow, leading to loci that are highly differentiated compared to others. However, there are also alternative explanations for this pattern. Independent evidence that loci in highly differentiated regions are under divergent selection would allow these explanations to be distinguished, but such evidence is scarce. Here, we present multiple lines of evidence that many of the highly divergent SNPs in a pair of sister morning glory species, Ipomoea cordatotriloba and I. lacunosa, are the result of divergent selection in the face of gene flow. We analysed a SNP data set across the genome to assess the amount of gene flow, resistance to introgression and patterns of selection on loci resistant to introgression. We show that differentiation between the two species is much lower in sympatry than in allopatry, consistent with interspecific gene flow in sympatry. Gene flow appears to be substantially greater from I. lacunosa to I. cordatotriloba than in the reverse direction, resulting in sympatric and allopatric I. cordatotriloba being substantially more different than sympatric and allopatric I. lacunosa. Many SNPs highly differentiated in allopatry have experienced divergent selection, and, despite gene flow in sympatry, resist homogenization in sympatry. Finally, five out of eight floral and inflorescence characteristics measured exhibit asymmetric convergence in sympatry. Consistent with the pattern of gene flow, I. cordatotriloba traits become much more like those of I. lacunosa than the reverse. Our investigation reveals the complex interplay between selection and gene flow that can occur during the early stages of speciation.
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Affiliation(s)
- Joanna L Rifkin
- Department of Biology, Duke University, Durham, North Carolina
| | | | - Irene T Liao
- Department of Biology, Duke University, Durham, North Carolina
| | - Mark D Rausher
- Department of Biology, Duke University, Durham, North Carolina
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33
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Riquet F, Liautard-Haag C, Woodall L, Bouza C, Louisy P, Hamer B, Otero-Ferrer F, Aublanc P, Béduneau V, Briard O, El Ayari T, Hochscheid S, Belkhir K, Arnaud-Haond S, Gagnaire PA, Bierne N. Parallel pattern of differentiation at a genomic island shared between clinal and mosaic hybrid zones in a complex of cryptic seahorse lineages. Evolution 2019; 73:817-835. [PMID: 30854632 DOI: 10.1111/evo.13696] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 01/19/2019] [Accepted: 01/24/2019] [Indexed: 01/02/2023]
Abstract
Diverging semi-isolated lineages either meet in narrow clinal hybrid zones, or have a mosaic distribution associated with environmental variation. Intrinsic reproductive isolation is often emphasized in the former and local adaptation in the latter, although both reduce gene flow between groups. Rarely are these two patterns of spatial distribution reported in the same study system. Here, we report that the long-snouted seahorse Hippocampus guttulatus is subdivided into discrete panmictic entities by both types of hybrid zones. Along the European Atlantic coasts, a northern and a southern lineage meet in the southwest of France where they coexist in sympatry-i.e., in the same geographical zone-with little hybridization. In the Mediterranean Sea, two lineages have a mosaic distribution, associated with lagoon-like and marine habitats. A fifth lineage was identified in the Black Sea. Genetic homogeneity over large spatial scales contrasts with isolation maintained in sympatry or close parapatry at a fine scale. A high variation in locus-specific introgression rates provides additional evidence that partial reproductive isolation must be maintaining the divergence. We find that fixed differences between lagoon and marine populations in the Mediterranean Sea belong to the most differentiated SNPs between the two Atlantic lineages, against the genome-wide pattern of structure that mostly follow geography. These parallel outlier SNPs cluster on a single chromosome-wide island of differentiation. Since Atlantic lineages do not map to lagoon-sea habitat variation, genetic parallelism at the genomic island suggests a shared genetic barrier contributes to reproductive isolation in contrasting contexts-i.e., spatial versus ecological. We discuss how a genomic hotspot of parallel differentiation could have evolved and become associated both with space and with a patchy environment in a single study system.
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Affiliation(s)
- Florentine Riquet
- Institut des Sciences de l'Evolution de Montpellier, Université Montpellier, Montpellier, France.,CNRS Institut des Sciences de l'Evolution, UMR5554 UM-CNRS-IRD-EPHE, Sète, France
| | - Cathy Liautard-Haag
- Institut des Sciences de l'Evolution de Montpellier, Université Montpellier, Montpellier, France.,CNRS Institut des Sciences de l'Evolution, UMR5554 UM-CNRS-IRD-EPHE, Sète, France
| | - Lucy Woodall
- Department of Zoology, University of Oxford, Wytham, OX2 8QJ, United Kingdom.,Natural History Museum, London, SW7 5BD, United Kingdom
| | - Carmen Bouza
- Department of Genetics, Faculty of Veterinary Science, Universidade de Santiago de Compostela, Lugo, Spain
| | - Patrick Louisy
- ECOMERS Laboratory, University of Nice Sophia Antipolis, Faculty of Sciences, Parc Valrose, Nice, France.,Association Peau-Bleue, 46 rue des Escais, Agde, France
| | - Bojan Hamer
- Center for Marine Research, Ruder Boskovic Institute, Giordano Paliaga 5, 52210, Rovinj, Croatia
| | - Francisco Otero-Ferrer
- Grupo en Biodiversidad y Conservación, IU-ECOAQUA, Universidad de Las Palmas de Gran Canaria, Crta. Taliarte s/n, 35214, Telde, Spain
| | - Philippe Aublanc
- Institut océanographique Paul Ricard, Ile des Embiez, Six-Fours-les-Plages, France
| | - Vickie Béduneau
- Océarium du Croisic, Avenue de Saint Goustan, Le Croisic, France
| | - Olivier Briard
- Aquarium de Biarritz, Biarritz Océan, Plateau de l'Atalaye, Biarritz, France
| | - Tahani El Ayari
- Institut des Sciences de l'Evolution de Montpellier, Université Montpellier, Montpellier, France.,CNRS Institut des Sciences de l'Evolution, UMR5554 UM-CNRS-IRD-EPHE, Sète, France
| | - Sandra Hochscheid
- Stazione Zoologica Anton Dohrn, Department Research Infrastructures for Marine Biological Resources, Aquarium Unit, Napoli, Italy
| | - Khalid Belkhir
- Institut des Sciences de l'Evolution de Montpellier, Université Montpellier, Montpellier, France.,CNRS Institut des Sciences de l'Evolution, UMR5554 UM-CNRS-IRD-EPHE, Sète, France
| | - Sophie Arnaud-Haond
- Institut des Sciences de l'Evolution de Montpellier, Université Montpellier, Montpellier, France.,Ifremer-MARine Biodiversity, Exploitation and Conservation, UMR 9190 IRD-IFREMER-UM-CNRS, Sète, France
| | - Pierre-Alexandre Gagnaire
- Institut des Sciences de l'Evolution de Montpellier, Université Montpellier, Montpellier, France.,CNRS Institut des Sciences de l'Evolution, UMR5554 UM-CNRS-IRD-EPHE, Sète, France
| | - Nicolas Bierne
- Institut des Sciences de l'Evolution de Montpellier, Université Montpellier, Montpellier, France.,CNRS Institut des Sciences de l'Evolution, UMR5554 UM-CNRS-IRD-EPHE, Sète, France
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Cortés-Ortiz L, Baiz MD, Hermida-Lagunes J, García-Orduña F, Rangel-Negrín A, Kitchen DM, Bergman TJ, Dias PAD, Canales-Espinosa D. Reduced Introgression of Sex Chromosome Markers in the Mexican Howler Monkey ( Alouatta palliata × A. pigra) Hybrid Zone. INT J PRIMATOL 2019; 40:114-131. [PMID: 30880850 PMCID: PMC6394575 DOI: 10.1007/s10764-018-0056-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 06/07/2018] [Indexed: 01/12/2023]
Abstract
Interspecific hybridization allows the introgression or movement of alleles from one genome to another. While some genomic regions freely exchange alleles during hybridization, loci associated with reproductive isolation do not intermix. In many model organisms, the X chromosome displays limited introgression compared to autosomes owing to the presence of multiple loci associated with hybrid sterility or inviability (the "large X-effect"). Similarly, if hybrids are produced, the heterogametic sex is usually inviable or sterile, a pattern known as Haldane's rule. We analyzed the patterns of introgression of genetic markers located in the mitochondrial (control region) and nuclear (autosomal microsatellites and sex chromosome genes) genomes of two howler monkey species (Alouatta palliata and A. pigra) that form a natural hybrid zone in southern Mexico, to evaluate whether the large X-effect and Haldane's rule affect the outcomes of hybridization between these sister species. To identify the level of admixture of each individual in the hybrid zone (N = 254) we analyzed individuals sampled outside the hybrid zone (109 A. pigra and 39 A. palliata) to determine allele frequencies of parental species and estimated a hybrid index based on nuclear markers. We then performed a cline analysis using individuals in the hybrid zone to determine patterns of introgression for each locus. Our analyses show that although the hybrid zone is bimodal (with no known F1 s and few recent generation hybrids) and quite narrow, there has been extensive introgression in both directions, and there is a large array of admixed individuals in the hybrid zone. Mitochondrial and most autosomal markers showed bidirectional introgression, but some had biased introgression toward one species or the other. All markers on the sex chromosomes and a few autosomal markers showed highly restricted introgression. This pattern is consistent with the hypothesis that the sex chromosomes make a disproportionate contribution to reproductive isolation, and our results broaden the taxonomic representation of these patterns across animal taxa.
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Affiliation(s)
- Liliana Cortés-Ortiz
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48103 USA
| | - Marcella D Baiz
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48103 USA
| | | | | | | | - Dawn M Kitchen
- Department of Anthropology, The Ohio State University, Columbus, OH 43210 USA
| | - Thore J Bergman
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48103 USA.,Department of Psychology, University of Michigan, Ann Arbor, MI 48109 USA
| | - Pedro A D Dias
- Instituto de Neuroetología, Universidad Veracruzana, Xalapa, Veracruz, Mexico
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35
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Gainey DP, Kim JY, Maroja LS. Mapping reduced introgression loci to the X chromosome of the hybridizing field crickets, Gryllus firmus and G. pennsylvanicus. PLoS One 2018; 13:e0208498. [PMID: 30566487 PMCID: PMC6300192 DOI: 10.1371/journal.pone.0208498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 11/18/2018] [Indexed: 11/19/2022] Open
Abstract
The genomic architecture of barriers to gene exchange during the speciation process is poorly understood. The genomic islands model suggests that loci associated with barriers to gene exchange prevent introgression of nearby genomic regions via linkage disequilibrium. But few analyses of the actual genomic location of non-introgressing loci in closely related species exist. In a previous study Maroja et al. showed that in the hybridizing field crickets, Gryllus firmus and G. pennsylvanicus, 50 non-introgressing loci are localized on two autosomal regions and the X chromosome, but they were not able to map the loci along the X chromosome because they used a male informative cross. Here, we localize the introgressing and non-introgressing loci on the X chromosome, and reveal that all X-linked non-introgressing loci are restricted to a 50-cM region with 10 of these loci mapped to a single location. We discuss the implications of this finding to speciation.
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Affiliation(s)
- D. Patrick Gainey
- Department of Biology, Williams College, Williamstown, Massachusetts, United States of America
| | - Jeremiah Y. Kim
- Department of Biology, Williams College, Williamstown, Massachusetts, United States of America
| | - Luana S. Maroja
- Department of Biology, Williams College, Williamstown, Massachusetts, United States of America
- * E-mail:
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36
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Moran PA, Pascoal S, Cezard T, Risse JE, Ritchie MG, Bailey NW. Opposing patterns of intraspecific and interspecific differentiation in sex chromosomes and autosomes. Mol Ecol 2018; 27:3905-3924. [DOI: 10.1111/mec.14725] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 04/13/2018] [Accepted: 04/18/2018] [Indexed: 12/24/2022]
Affiliation(s)
- Peter A. Moran
- School of Biological, Earth and Environmental Sciences; University College Cork; Cork Ireland
| | - Sonia Pascoal
- Department of Zoology; University of Cambridge; Cambridge UK
| | | | - Judith E. Risse
- Bioinformatics; Department of Plant Sciences; Wageningen University; Wageningen The Netherlands
| | - Michael G. Ritchie
- Centre for Biological Diversity; School of Biology; University of St Andrews; St Andrews UK
| | - Nathan W. Bailey
- Centre for Biological Diversity; School of Biology; University of St Andrews; St Andrews UK
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37
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Blackburn GS, Brunet BMT, Muirhead K, Cusson M, Béliveau C, Levesque RC, Lumley LM, Sperling FAH. Distinct sources of gene flow produce contrasting population genetic dynamics at different range boundaries of aChoristoneurabudworm. Mol Ecol 2017; 26:6666-6684. [DOI: 10.1111/mec.14386] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 09/26/2017] [Accepted: 10/07/2017] [Indexed: 12/14/2022]
Affiliation(s)
- Gwylim S. Blackburn
- Department of Biological Sciences; CW405 Biosciences Centre; University of Alberta; Edmonton AB Canada
- Laurentian Forestry Centre; Natural Resources Canada; Canadian Forest Service; Quebec City QC Canada
- Institut de Biologie Intégrative et des Systèmes (IBIS); Université Laval; Québec QC Canada
| | - Bryan M. T. Brunet
- Department of Biological Sciences; CW405 Biosciences Centre; University of Alberta; Edmonton AB Canada
| | - Kevin Muirhead
- Department of Biological Sciences; CW405 Biosciences Centre; University of Alberta; Edmonton AB Canada
| | - Michel Cusson
- Laurentian Forestry Centre; Natural Resources Canada; Canadian Forest Service; Quebec City QC Canada
| | - Catherine Béliveau
- Laurentian Forestry Centre; Natural Resources Canada; Canadian Forest Service; Quebec City QC Canada
| | - Roger C. Levesque
- Institut de Biologie Intégrative et des Systèmes (IBIS); Université Laval; Québec QC Canada
| | - Lisa M. Lumley
- Department of Biological Sciences; CW405 Biosciences Centre; University of Alberta; Edmonton AB Canada
- Laurentian Forestry Centre; Natural Resources Canada; Canadian Forest Service; Quebec City QC Canada
| | - Felix A. H. Sperling
- Department of Biological Sciences; CW405 Biosciences Centre; University of Alberta; Edmonton AB Canada
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38
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Gompert Z, Mandeville EG, Buerkle CA. Analysis of Population Genomic Data from Hybrid Zones. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2017. [DOI: 10.1146/annurev-ecolsys-110316-022652] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Zachariah Gompert
- Department of Biology and Ecology Center, Utah State University, Logan, Utah 84322
| | - Elizabeth G. Mandeville
- Department of Botany and Wyoming Cooperative Fish and Wildlife Research Unit, University of Wyoming, Laramie, Wyoming 82071
| | - C. Alex Buerkle
- Department of Botany and Program in Ecology, University of Wyoming, Laramie, Wyoming 82071
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Delahaie B, Cornuault J, Masson C, Bertrand JAM, Bourgeois YXC, Milá B, Thébaud C. Narrow hybrid zones in spite of very low population differentiation in neutral markers in an island bird species complex. J Evol Biol 2017; 30:2132-2145. [DOI: 10.1111/jeb.13177] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 07/26/2017] [Accepted: 09/07/2017] [Indexed: 02/06/2023]
Affiliation(s)
- B. Delahaie
- Laboratoire Évolution et Diversité Biologique (EDB); UMR 5174 Centre National de la Recherche Scientifique (CNRS) - Université Paul Sabatier - Ecole Nationale de Formation Agronomique (ENFA); Toulouse France
- Centre d'Ecologie Fonctionnelle et Evolutive; CNRS-UMR5175 CEFE; Montpellier France
| | - J. Cornuault
- Laboratoire Évolution et Diversité Biologique (EDB); UMR 5174 Centre National de la Recherche Scientifique (CNRS) - Université Paul Sabatier - Ecole Nationale de Formation Agronomique (ENFA); Toulouse France
| | - C. Masson
- Laboratoire Évolution et Diversité Biologique (EDB); UMR 5174 Centre National de la Recherche Scientifique (CNRS) - Université Paul Sabatier - Ecole Nationale de Formation Agronomique (ENFA); Toulouse France
| | - J. A. M. Bertrand
- Laboratoire Évolution et Diversité Biologique (EDB); UMR 5174 Centre National de la Recherche Scientifique (CNRS) - Université Paul Sabatier - Ecole Nationale de Formation Agronomique (ENFA); Toulouse France
| | - Y. X. C. Bourgeois
- Laboratoire Évolution et Diversité Biologique (EDB); UMR 5174 Centre National de la Recherche Scientifique (CNRS) - Université Paul Sabatier - Ecole Nationale de Formation Agronomique (ENFA); Toulouse France
| | - B. Milá
- National Museum of Natural Sciences; Spanish National Research Council (CSIC); Madrid Spain
| | - C. Thébaud
- Laboratoire Évolution et Diversité Biologique (EDB); UMR 5174 Centre National de la Recherche Scientifique (CNRS) - Université Paul Sabatier - Ecole Nationale de Formation Agronomique (ENFA); Toulouse France
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40
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Fouet C, Kamdem C, Gamez S, White BJ. Genomic insights into adaptive divergence and speciation among malaria vectors of the Anopheles nili group. Evol Appl 2017; 10:897-906. [PMID: 29151881 PMCID: PMC5680430 DOI: 10.1111/eva.12492] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 04/27/2017] [Indexed: 01/16/2023] Open
Abstract
Ongoing speciation in the most important African malaria vectors gives rise to cryptic populations, which differ remarkably in their behavior, ecology, and capacity to vector malaria parasites. Understanding the population structure and the drivers of genetic differentiation among mosquitoes is crucial for effective disease control because heterogeneity within vector species contributes to variability in malaria cases and allow fractions of populations to escape control efforts. To examine population structure and the potential impacts of recent large-scale control interventions, we have investigated the genomic patterns of differentiation in mosquitoes belonging to the Anopheles nili group-a large taxonomic group that diverged ~3 Myr ago. Using 4,343 single nucleotide polymorphisms (SNPs), we detected strong population structure characterized by high-FST values between multiple divergent populations adapted to different habitats within the Central African rainforest. Delineating the cryptic species within the Anopheles nili group is challenging due to incongruence between morphology, ribosomal DNA, and SNP markers consistent with incomplete lineage sorting and/or interspecific gene flow. A very high proportion of loci are fixed (FST = 1) within the genome of putative species, which suggests that ecological and/or reproductive barriers are maintained by strong selection on a substantial number of genes.
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Affiliation(s)
- Caroline Fouet
- Department of EntomologyUniversity of CaliforniaRiversideCAUSA
| | - Colince Kamdem
- Department of EntomologyUniversity of CaliforniaRiversideCAUSA
| | - Stephanie Gamez
- Department of EntomologyUniversity of CaliforniaRiversideCAUSA
| | - Bradley J. White
- Department of EntomologyUniversity of CaliforniaRiversideCAUSA
- Center for Disease Vector ResearchInstitute for Integrative Genome BiologyUniversity of CaliforniaRiversideCAUSA
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41
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Scordato ESC, Wilkins MR, Semenov G, Rubtsov AS, Kane NC, Safran RJ. Genomic variation across two barn swallow hybrid zones reveals traits associated with divergence in sympatry and allopatry. Mol Ecol 2017; 26:5676-5691. [DOI: 10.1111/mec.14276] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 07/19/2017] [Accepted: 07/24/2017] [Indexed: 12/31/2022]
Affiliation(s)
| | - Matthew R. Wilkins
- Department of Ecology and Evolutionary Biology The University of Colorado Boulder CO USA
- School of Biological Sciences University of Nebraska‐Lincoln Lincoln NE USA
| | - Georgy Semenov
- Department of Ecology & Evolutionary Biology University of Arizona Tucson AZ USA
- Institute of Systematics and Ecology of Animals Novosibirsk Russia
| | | | - Nolan C. Kane
- Department of Ecology and Evolutionary Biology The University of Colorado Boulder CO USA
| | - Rebecca J. Safran
- Department of Ecology and Evolutionary Biology The University of Colorado Boulder CO USA
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42
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Winger BM. Consequences of divergence and introgression for speciation in Andean cloud forest birds. Evolution 2017; 71:1815-1831. [DOI: 10.1111/evo.13251] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 03/31/2017] [Indexed: 12/16/2022]
Affiliation(s)
- Benjamin M. Winger
- Committee on Evolutionary Biology The University of Chicago Chicago Illinois 60637
- Life Sciences Section, Integrative Research Center The Field Museum of Natural History Chicago Illinois 60605
- Current Addresses: Museum of Zoology and Department of Ecology and Evolutionary Biology, University of Michigan 1109 Geddes Avenue Ann Arbor Michigan 48109
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43
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Bouchemousse S, Liautard-Haag C, Bierne N, Viard F. Distinguishing contemporary hybridization from past introgression with postgenomic ancestry-informative SNPs in strongly differentiated Ciona species. Mol Ecol 2016; 25:5527-5542. [PMID: 27662427 DOI: 10.1111/mec.13854] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/09/2016] [Accepted: 09/16/2016] [Indexed: 12/13/2022]
Abstract
Biological introductions bring into contact species that can still hybridize. The evolutionary outcomes of such secondary contacts may be diverse (e.g. adaptive introgression from or into the introduced species) but are not yet well examined in the wild. The recent secondary contact between the non-native sea squirt Ciona robusta (formerly known as C. intestinalis type A) and its native congener C. intestinalis (formerly known as C. intestinalis type B), in the Western English Channel, provides an excellent case study to examine. To examine contemporary hybridization between the two species, we developed a panel of 310 ancestry-informative SNPs from a population transcriptomic study. Hybridization rates were examined on 449 individuals sampled in eight sites from the sympatric range and five sites from allopatric ranges. The results clearly showed an almost complete absence of contemporary hybridization between the two species in syntopic localities, with only one-first-generation hybrid and no other genotype compatible with recent backcrosses. Despite the almost lack of contemporary hybridization, shared polymorphisms were observed in sympatric and allopatric populations of both species. Furthermore, one allopatric population from SE Pacific exhibited a higher rate of shared polymorphisms compared to all other C. robusta populations. Altogether, these results indicate that the observed level of shared polymorphism is more probably the outcome of ancient gene flow spread afterwards at a worldwide scale. They also emphasize efficient reproductive barriers preventing hybridization between introduced and native species, which suggests hybridization should not impede too much the expansion and the establishment of the non-native species in its introduction range.
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Affiliation(s)
- Sarah Bouchemousse
- UPMC Univ Paris 6, UMR 7144, Equipe DIVCO, Sorbonne Universités, Station Biologique de Roscoff, Place Georges Teissier, 29680, Roscoff, France.,CNRS, UMR 7144, Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Place Georges Teissier, 29680, Roscoff, France
| | - Cathy Liautard-Haag
- Station Marine - OSU OREME, Université de Montpellier, 2 Rue des Chantiers, 34200, Sète, France.,CNRS-UM-IRD-EPHE, UMR 5554, Institut des Sciences de l'Evolution, Place Eugène Bataillon, 34095, Montpellier, France
| | - Nicolas Bierne
- Station Marine - OSU OREME, Université de Montpellier, 2 Rue des Chantiers, 34200, Sète, France.,CNRS-UM-IRD-EPHE, UMR 5554, Institut des Sciences de l'Evolution, Place Eugène Bataillon, 34095, Montpellier, France
| | - Frédérique Viard
- UPMC Univ Paris 6, UMR 7144, Equipe DIVCO, Sorbonne Universités, Station Biologique de Roscoff, Place Georges Teissier, 29680, Roscoff, France. .,CNRS, UMR 7144, Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Place Georges Teissier, 29680, Roscoff, France.
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44
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Grossen C, Seneviratne SS, Croll D, Irwin DE. Strong reproductive isolation and narrow genomic tracts of differentiation among three woodpecker species in secondary contact. Mol Ecol 2016; 25:4247-66. [DOI: 10.1111/mec.13751] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Revised: 06/25/2016] [Accepted: 06/27/2016] [Indexed: 12/29/2022]
Affiliation(s)
- Christine Grossen
- Department of Zoology and Biodiversity Research Centre; University of British Columbia; 6270 University Blvd. Vancouver BC V6T 1Z4 Canada
- Institute of Evolutionary Biology and Environmental Studies; University of Zürich; Winterthurerstrasse 190 CH-8057 Zürich Switzerland
| | - Sampath S. Seneviratne
- Department of Zoology and Biodiversity Research Centre; University of British Columbia; 6270 University Blvd. Vancouver BC V6T 1Z4 Canada
- Avian Evolution Node; Department of Zoology; University of Colombo; PO Box 1490 Colombo 03 Sri Lanka
| | - Daniel Croll
- Integrative Biology; ETH Zürich; Universitätstrasse 2 CH-8092 Zürich Switzerland
| | - Darren E. Irwin
- Department of Zoology and Biodiversity Research Centre; University of British Columbia; 6270 University Blvd. Vancouver BC V6T 1Z4 Canada
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45
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Dupuis JR, Sperling FAH. Hybrid dynamics in a species group of swallowtail butterflies. J Evol Biol 2016; 29:1932-1951. [DOI: 10.1111/jeb.12931] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Revised: 04/22/2016] [Accepted: 06/27/2016] [Indexed: 01/15/2023]
Affiliation(s)
- J. R. Dupuis
- Department of Biological Sciences; University of Alberta; Edmonton AB Canada
| | - F. A. H. Sperling
- Department of Biological Sciences; University of Alberta; Edmonton AB Canada
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46
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Stuglik MT, Babik W. Genomic heterogeneity of historical gene flow between two species of newts inferred from transcriptome data. Ecol Evol 2016; 6:4513-25. [PMID: 27386093 PMCID: PMC4930998 DOI: 10.1002/ece3.2152] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 04/02/2016] [Accepted: 04/04/2016] [Indexed: 01/31/2023] Open
Abstract
The role of gene flow in species formation is a major unresolved issue in speciation biology. Progress in this area requires information on the long-term patterns of gene flow between diverging species. Here, we used thousands of single-nucleotide polymorphisms derived from transcriptome resequencing and a method modeling the joint frequency spectrum of these polymorphisms to reconstruct patterns of historical gene flow between two Lissotriton newts: L. vulgaris (Lv) and L. montandoni (Lm). We tested several models of divergence including complete isolation and various scenarios of historical gene flow. The model of secondary contact received the highest support. According to this model, the species split from their common ancestor ca. 5.5 million years (MY) ago, evolved in isolation for ca. 2 MY, and have been exchanging genes for the last 3.5 MY Demographic changes have been inferred in both species, with the current effective population size of ca. 0.7 million in Lv and 0.2 million in Lm. The postdivergence gene flow resulted in two-directional introgression which affected the genomes of both species, but was more pronounced from Lv to Lm. Interestingly, we found evidence for genomic heterogeneity of interspecific gene flow. This study demonstrates the complexity of long-term gene flow between distinct but incompletely reproductively isolated taxa which divergence was initiated millions of years ago.
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Affiliation(s)
- Michał T. Stuglik
- Institute of Environmental SciencesJagiellonian UniversityGronostajowa 730387KrakowPoland
| | - Wiesław Babik
- Institute of Environmental SciencesJagiellonian UniversityGronostajowa 730387KrakowPoland
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47
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Stankowski S, Sobel JM, Streisfeld MA. Geographic cline analysis as a tool for studying genome‐wide variation: a case study of pollinator‐mediated divergence in a monkeyflower. Mol Ecol 2016; 26:107-122. [DOI: 10.1111/mec.13645] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 04/07/2016] [Accepted: 04/08/2016] [Indexed: 01/04/2023]
Affiliation(s)
- Sean Stankowski
- Institute of Ecology and Evolution 335 Pacific Hall 5289 University of Oregon, Eugene OR 97403‐5289 USA
| | - James M. Sobel
- Department of Biological Sciences Binghamton University PO Box 6000, Binghamton NY 13902 USA
| | - Matthew A. Streisfeld
- Institute of Ecology and Evolution 335 Pacific Hall 5289 University of Oregon, Eugene OR 97403‐5289 USA
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48
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Kenney AM, Sweigart AL. Reproductive isolation and introgression between sympatric
Mimulus
species. Mol Ecol 2016; 25:2499-517. [DOI: 10.1111/mec.13630] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 03/18/2016] [Accepted: 03/22/2016] [Indexed: 01/19/2023]
Affiliation(s)
- Amanda M. Kenney
- Department of Genetics University of Georgia Athens GA 30602 USA
- Department of Biological Sciences St. Edward's University Austin TX 78704 USA
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49
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Puppo P, Curto M, Meimberg H. Genetic structure of Micromeria (Lamiaceae) in Tenerife, the imprint of geological history and hybridization on within-island diversification. Ecol Evol 2016; 6:3443-3460. [PMID: 28725348 PMCID: PMC5513284 DOI: 10.1002/ece3.2094] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 02/26/2016] [Accepted: 03/03/2016] [Indexed: 01/17/2023] Open
Abstract
Geological history of oceanic islands can have a profound effect on the evolutionary history of insular flora, especially in complex islands such as Tenerife in the Canary Islands. Tenerife results from the secondary connection of three paleo‐islands by a central volcano, and other geological events that further shaped it. This geological history has been shown to influence the phylogenetic history of several taxa, including genus Micromeria (Lamiaceae). Screening 15 microsatellite markers in 289 individuals representing the eight species of Micromeria present in Tenerife, this study aims to assess the genetic diversity and structure of these species and its relation with the geological events on the island. In addition, we evaluate the extent of hybridization among species and discuss its influence on the speciation process. We found that the species restricted to the paleo‐islands present lower levels of genetic diversity but the highest levels of genetic differentiation suggesting that their ranges might have contracted over time. The two most widespread species in the island, M. hyssopifolia and M. varia, present the highest genetic diversity levels and a genetic structure that seems correlated with the geological composition of the island. Samples from M. hyssopifolia from the oldest paleo‐island, Adeje, appear as distinct while samples from M. varia segregate into two main clusters corresponding to the paleo‐islands of Anaga and Teno. Evidence of hybridization and intraspecific migration between species was found. We argue that species boundaries would be retained despite hybridization in response to the habitat's specific conditions causing postzygotic isolation and preserving morphological differentiation.
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Affiliation(s)
- Pamela Puppo
- CIBIO Research Center in Biodiversity and Genetic Resources/InBio Associated Laboratory University of Porto Campus Vairão Vairão 4485-661 Portugal.,Institute for Integrative Nature Conservation Research University of Natural Resources and Life Sciences A-1180 Vienna Austria
| | - Manuel Curto
- CIBIO Research Center in Biodiversity and Genetic Resources/InBio Associated Laboratory University of Porto Campus Vairão Vairão 4485-661 Portugal.,Institute for Integrative Nature Conservation Research University of Natural Resources and Life Sciences A-1180 Vienna Austria
| | - Harald Meimberg
- Institute for Integrative Nature Conservation Research University of Natural Resources and Life Sciences A-1180 Vienna Austria
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50
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Walsh J, Shriver WG, Olsen BJ, Kovach AI. Differential introgression and the maintenance of species boundaries in an advanced generation avian hybrid zone. BMC Evol Biol 2016; 16:65. [PMID: 27000833 PMCID: PMC4802838 DOI: 10.1186/s12862-016-0635-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 03/10/2016] [Indexed: 12/31/2022] Open
Abstract
Background Evolutionary processes, including selection and differential fitness, shape the introgression of genetic material across a hybrid zone, resulting in the exchange of some genes but not others. Differential introgression of molecular or phenotypic markers can thus provide insight into factors contributing to reproductive isolation. We characterized patterns of genetic variation across a hybrid zone between two tidal marsh birds, Saltmarsh (Ammodramus caudacutus) and Nelson’s (A. nelsoni) sparrows (n = 286), and compared patterns of introgression among multiple genetic markers and phenotypic traits. Results Geographic and genomic cline analyses revealed variable patterns of introgression among marker types. Most markers exhibited gradual clines and indicated that introgression exceeds the spatial extent of the previously documented hybrid zone. We found steeper clines, indicating strong selection for loci associated with traits related to tidal marsh adaptations, including for a marker linked to a gene region associated with metabolic functions, including an osmotic regulatory pathway, as well as for a marker related to melanin-based pigmentation, supporting an adaptive role of darker plumage (salt marsh melanism) in tidal marshes. Narrow clines at mitochondrial and sex-linked markers also offer support for Haldane’s rule. We detected patterns of asymmetrical introgression toward A. caudacutus, which may be driven by differences in mating strategy or differences in population density between the two species. Conclusions Our findings offer insight into the dynamics of a hybrid zone traversing a unique environmental gradient and provide evidence for a role of ecological divergence in the maintenance of pure species boundaries despite ongoing gene flow. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0635-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jennifer Walsh
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH, USA. .,Cornell Lab of Ornithology, Cornell University, Ithaca, NY, USA.
| | - W Gregory Shriver
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE, USA
| | - Brian J Olsen
- School of Biology and Ecology, University of Maine, Orono, ME, USA
| | - Adrienne I Kovach
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH, USA
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