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Noguerales V, Arjona Y, García-Olivares V, Machado A, López H, Patiño J, Emerson BC. Genetic legacies of mega-landslides: Cycles of isolation and contact across flank collapses in an oceanic island. Mol Ecol 2024; 33:e17341. [PMID: 38576177 DOI: 10.1111/mec.17341] [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: 07/08/2023] [Revised: 02/16/2024] [Accepted: 02/21/2024] [Indexed: 04/06/2024]
Abstract
Catastrophic flank collapses are recognized as important drivers of insular biodiversity dynamics, through the disruption of species ranges and subsequent allopatric divergence. However, little empirical data supports this conjecture, with their evolutionary consequences remaining poorly understood. Using genome-wide data within a population genomics and phylogenomics framework, we evaluate how mega-landslides have impacted evolutionary and demographic history within a species complex of weevils (Curculionidae) within the Canary Island of Tenerife. We reveal a complex genomic landscape, within which individuals of single ancestry were sampled in areas characterized by long-term geological stability, relative to the timing of flank collapses. In contrast, individuals of admixed ancestry were almost exclusively sampled within the boundaries of flank collapses. Estimated divergence times among ancestral populations aligned with the timings of mega-landslide events. Our results provide first evidence for a cyclical dynamic of range fragmentation and secondary contact across flank collapse landscapes, with support for a model where this dynamic is mediated by Quaternary climate oscillations. The context within which we reveal climate and topography to interact cyclically through time to shape the geographic structure of genetic variation, together with related recent work, highlights the importance of topoclimatic phenomena as an agent of diversification within insular invertebrates.
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Affiliation(s)
- Víctor Noguerales
- Instituto de Productos Naturales y Agrobiología (IPNA-CSIC), San Cristóbal de La Laguna, Canary Islands, Spain
| | - Yurena Arjona
- Instituto de Productos Naturales y Agrobiología (IPNA-CSIC), San Cristóbal de La Laguna, Canary Islands, Spain
- Department of Botany, Ecology and Plant Physiology, University of La Laguna, San Cristóbal de La Laguna, Canary Islands, Spain
| | - Víctor García-Olivares
- Plataforma Genómica de Alto Rendimiento para el Estudio de la Biodiversidad, Instituto de Productos Naturales y Agrobiología (IPNA-CSIC), San Cristóbal de La Laguna, Canary Islands, Spain
- Genomics Division, Instituto Tecnológico y de Energías Renovables (ITER), Santa Cruz de Tenerife, Canary Islands, Spain
| | - Antonio Machado
- C/Chopin 1, San Cristóbal de La Laguna, Canary Islands, Spain
| | - Heriberto López
- Instituto de Productos Naturales y Agrobiología (IPNA-CSIC), San Cristóbal de La Laguna, Canary Islands, Spain
| | - Jairo Patiño
- Instituto de Productos Naturales y Agrobiología (IPNA-CSIC), San Cristóbal de La Laguna, Canary Islands, Spain
- Department of Botany, Ecology and Plant Physiology, University of La Laguna, San Cristóbal de La Laguna, Canary Islands, Spain
| | - Brent C Emerson
- Instituto de Productos Naturales y Agrobiología (IPNA-CSIC), San Cristóbal de La Laguna, Canary Islands, Spain
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2
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Dufresnes C, Poyarkov N, Jablonski D. Acknowledging more biodiversity without more species. Proc Natl Acad Sci U S A 2023; 120:e2302424120. [PMID: 37748058 PMCID: PMC10556632 DOI: 10.1073/pnas.2302424120] [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] [Indexed: 09/27/2023] Open
Abstract
Delimiting and naming biodiversity is a vital step toward wildlife conservation and research. However, species delimitation must be consistent across biota so that the limited resources available for nature protection can be spent effectively and objectively. To date, newly discovered lineages typically are either left undescribed and thus remain unprotected or are being erroneously proposed as new species despite mixed evidence for completed speciation, in turn contributing to the emerging problem of taxonomic inflation. Inspired by recent conceptual and methodological progress, we propose a standardized workflow for species delimitation that combines phylogenetic and hybrid zone analyses of genomic datasets ("genomic taxonomy"), in which phylogeographic lineages that do not freely admix are ranked as species, while those that have remained fully genetically compatible are ranked as subspecies. In both cases, we encourage their formal taxonomic naming, diagnosis, and description to promote social awareness toward biodiversity. The use of loci throughout the genome overcomes the unreliability of widely used barcoding genes when phylogeographic patterns are complex, while the evaluation of divergence and reproductive isolation unifies the long-opposed concepts of lineage species and biological species. We suggest that a shift in conservation assessments from a single level (species) toward a two-level hierarchy (species and subspecies) will lead to a more balanced perception of biodiversity in which both intraspecific and interspecific diversity are valued and more adequately protected.
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Affiliation(s)
- Christophe Dufresnes
- Laboratory of Amphibian Systematics and Evolutionary Research, College of Biology and Environment, Nanjing Forestry University, Nanjing210037, People’s Republic of China
| | - Nikolay Poyarkov
- Joint Russian-Vietnamese Tropical Research and Technological Center, Hanoi122000, Vietnam
- Department of Vertebrate Zoology, Lomonosov Moscow State University, Moscow119234, Russia
| | - Daniel Jablonski
- Department of Zoology, Comenius University in Bratislava, Bratislava84215, Slovakia
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3
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Burbrink FT, Crother BI, Murray CM, Smith BT, Ruane S, Myers EA, Pyron RA. Empirical and philosophical problems with the subspecies rank. Ecol Evol 2022; 12:e9069. [PMID: 35845367 PMCID: PMC9271888 DOI: 10.1002/ece3.9069] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 06/01/2022] [Accepted: 06/10/2022] [Indexed: 11/12/2022] Open
Abstract
Species‐level taxonomy derives from empirical sources (data and techniques) that assess the existence of spatiotemporal evolutionary lineages via various species “concepts.” These concepts determine if observed lineages are independent given a particular methodology and ontology, which relates the metaphysical species concept to what “kind” of thing a species is in reality. Often, species concepts fail to link epistemology back to ontology. This lack of coherence is in part responsible for the persistence of the subspecies rank, which in modern usage often functions as a placeholder between the evolutionary events of divergence or collapse of incipient species. Thus, prospective events like lineages merging or diverging require information from unknowable future information. This is also conditioned on evidence that the lineage already has a detectably distinct evolutionary history. Ranking these lineages as subspecies can seem attractive given that many lineages do not exhibit intrinsic reproductive isolation. We argue that using subspecies is indefensible on philosophical and empirical grounds. Ontologically, the rank of subspecies is either identical to that of species or undefined in the context of evolutionary lineages representing spatiotemporally defined individuals. Some species concepts more inclined to consider subspecies, like the Biological Species Concept, are disconnected from evolutionary ontology and do not consider genealogy. Even if ontology is ignored, methods addressing reproductive isolation are often indirect and fail to capture the range of scenarios linking gene flow to species identity over space and time. The use of subspecies and reliance on reproductive isolation as a basis for an operational species concept can also conflict with ethical issues governing the protection of species. We provide a way forward for recognizing and naming species that links theoretical and operational species concepts regardless of the magnitude of reproductive isolation.
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Affiliation(s)
- Frank T Burbrink
- Department of Herpetology American Museum of Natural History New York New York USA
| | - Brian I Crother
- Department of Biological Sciences Southeastern Louisiana University Hammond Louisiana USA
| | - Christopher M Murray
- Department of Biological Sciences Southeastern Louisiana University Hammond Louisiana USA
| | - Brian Tilston Smith
- Department of Ornithology American Museum of Natural History New York New York USA
| | - Sara Ruane
- Life Sciences Section, Negaunee Integrative Research Center Field Museum of Natural History Chicago Illinois USA
| | - Edward A Myers
- Department of Herpetology American Museum of Natural History New York New York USA.,Department of Biological Sciences Clemson University Clemson South Carolina USA.,Department of Vertebrate Zoology Smithsonian Institution, National Museum of Natural History Washington District of Columbia USA
| | - Robert Alexander Pyron
- Department of Vertebrate Zoology Smithsonian Institution, National Museum of Natural History Washington District of Columbia USA.,Department of Biological Sciences The George Washington University Washington District of Columbia USA
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4
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Wolfgramm H, Martens J, Töpfer T, Vamberger M, Pathak A, Stuckas H, Päckert M. Asymmetric allelic introgression across a hybrid zone of the coal tit ( Periparus ater) in the central Himalayas. Ecol Evol 2021; 11:17332-17351. [PMID: 34938512 PMCID: PMC8668783 DOI: 10.1002/ece3.8369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 10/26/2021] [Accepted: 11/02/2021] [Indexed: 11/07/2022] Open
Abstract
In the Himalayas, a number of secondary contact zones have been described for vicariant vertebrate taxa. However, analyses of genetic divergence and admixture are missing for most of these examples. In this study, we provide a population genetic analysis for the coal tit (Periparus ater) hybrid zone in Nepal. Intermediate phenotypes between the distinctive western "spot-winged tit" (P. a. melanolophus) and Eastern Himalayan coal tits (P. a. aemodius) occur across a narrow range of <100 km in western Nepal. As a peculiarity, another distinctive cinnamon-bellied form is known from a single population so far. Genetic admixture of western and eastern mitochondrial lineages was restricted to the narrow zone of phenotypically intermediate populations. The cline width was estimated 46 km only with a center close to the population of the cinnamon-bellied phenotype. In contrast, allelic introgression of microsatellite loci was asymmetrical from eastern P. a. aemodius into far western populations of phenotypic P. a. melanolophus but not vice versa. Accordingly, the microsatellite cline was about 3.7 times wider than the mitochondrial one.
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Affiliation(s)
- Hannes Wolfgramm
- Senckenberg Natural History Collections DresdenDresdenGermany
- Present address:
Department of Functional GenomicsInterfaculty Institute of Genetics and Functional GenomicsUniversity Medicine GreifswaldGreifswaldGermany
| | - Jochen Martens
- Institute of Organismic and Molecular Evolution (iomE)Johannes Gutenberg UniversityMainzGermany
| | - Till Töpfer
- Leibniz Institute for the Analysis of Biodiversity ChangeZoological Research Museum Alexander KoenigBonnGermany
| | | | - Abhinaya Pathak
- Department of National Parks and Wildlife ConservationKathmanduNepal
| | - Heiko Stuckas
- Senckenberg Natural History Collections DresdenDresdenGermany
| | - Martin Päckert
- Senckenberg Natural History Collections DresdenDresdenGermany
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5
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Tang Q, Burri R, Liu Y, Suh A, Sundev G, Heckel G, Schweizer M. Seasonal migration patterns and the maintenance of evolutionary diversity in a cryptic bird radiation. Mol Ecol 2021; 31:632-645. [PMID: 34674334 PMCID: PMC9298432 DOI: 10.1111/mec.16241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 10/07/2021] [Accepted: 10/12/2021] [Indexed: 02/03/2023]
Abstract
Morphological differentiation associated with evolutionary diversification is often explained with adaptive benefits but the processes and mechanisms maintaining cryptic diversity are still poorly understood. Using genome‐wide data, we show here that the pale sand martin Riparia diluta in Central and East Asia consists of three genetically deeply differentiated lineages which vary only gradually in morphology but broadly reflect traditional taxonomy. We detected no signs of gene flow along the eastern edge of the Qinghai‐Tibetan plateau between lowland south‐eastern Chinese R. d. fohkienensis and high‐altitude R. d. tibetana. Largely different breeding and migration timing between these low and high altitude populations as indicated by phenology data suggests that allochrony might act as prezygotic isolation mechanism in the area where their ranges abut. Mongolian populations of R. d. tibetana, however, displayed signs of limited mixed ancestries with Central Asian R. d. diluta. Their ranges meet in the area of a well‐known avian migratory divide, where western lineages take a western migration route around the Qinghai‐Tibetan plateau to winter quarters in South Asia, and eastern lineages take an eastern route to Southeast Asia. This might also be the case between western R. d. diluta and eastern R. d. tibetana as indicated by differing wintering grounds. We hypothesize that hybrids might have nonoptimal intermediate migration routes and selection against them might restrict gene flow. Although further potential isolation mechanisms might exist in the pale sand martin, our study points towards contrasting migration behaviour as an important factor in maintaining evolutionary diversity under morphological stasis.
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Affiliation(s)
- Qindong Tang
- Institute of Ecology and Evolution, University of Bern, Bern, Switzerland.,Natural History Museum, Bern, Switzerland
| | - Reto Burri
- Schweizerische Vogelwarte, Sempach, Switzerland
| | - Yang Liu
- State Key Laboratory of Biocontrol, College of Ecology School of Life Science, Sun Yat-sen University, Guangzhou, China
| | - Alexander Suh
- School of Biological Sciences-Organisms and the Environment, University of East Anglia, Norwich, UK.,Department of Organismal Biology - Systematic Biology, Evolutionary Biology Centre (EBC), Uppsala University, Uppsala, Sweden
| | - Gombobaatar Sundev
- National University of Mongolia and Mongolian Ornithological Society, Ulaanbaatar, Mongolia
| | - Gerald Heckel
- Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Manuel Schweizer
- Institute of Ecology and Evolution, University of Bern, Bern, Switzerland.,Natural History Museum, Bern, Switzerland
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6
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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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7
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Del-Rio G, Rego MA, Whitney BM, Schunck F, Silveira LF, Faircloth BC, Brumfield RT. Displaced clines in an avian hybrid zone (Thamnophilidae: Rhegmatorhina) within an Amazonian interfluve. Evolution 2021; 76:455-475. [PMID: 34626500 DOI: 10.1111/evo.14377] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 08/25/2021] [Accepted: 09/01/2021] [Indexed: 12/24/2022]
Abstract
Secondary contact between species often results in the formation of a hybrid zone, with the eventual fates of the hybridizing species dependent on evolutionary and ecological forces. We examine this process in the Amazon Basin by conducting the first genomic and phenotypic characterization of the hybrid zone formed after secondary contact between two obligate army-ant-followers: the White-breasted Antbird (Rhegmatorhina hoffmannsi) and the Harlequin Antbird (Rhegmatorhina berlepschi). We found a major geographic displacement (∼120 km) between the mitochondrial and nuclear clines, and we explore potential hypotheses for the displacement, including sampling error, genetic drift, and asymmetric cytonuclear incompatibilities. We cannot exclude roles for sampling error and genetic drift in contributing to the discordance; however, the data suggest expansion and unidirectional introgression of hoffmannsi into the distribution of berlepschi.
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Affiliation(s)
- Glaucia Del-Rio
- Museum of Natural Science, Louisiana State University, Baton Rouge, Louisiana, 70803.,Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803
| | - Marco A Rego
- Museum of Natural Science, Louisiana State University, Baton Rouge, Louisiana, 70803.,Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803
| | - Bret M Whitney
- Museum of Natural Science, Louisiana State University, Baton Rouge, Louisiana, 70803.,Museu de Zoologia, Universidade de São Paulo, São Paulo, SP, 04263-000, Brazil
| | - Fabio Schunck
- Museu de Zoologia, Universidade de São Paulo, São Paulo, SP, 04263-000, Brazil
| | - Luís F Silveira
- Museu de Zoologia, Universidade de São Paulo, São Paulo, SP, 04263-000, Brazil
| | - Brant C Faircloth
- Museum of Natural Science, Louisiana State University, Baton Rouge, Louisiana, 70803.,Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803
| | - Robb T Brumfield
- Museum of Natural Science, Louisiana State University, Baton Rouge, Louisiana, 70803.,Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803
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8
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Burbrink FT, Ruane S. Contemporary Philosophy and Methods for Studying Speciation and Delimiting Species. ICHTHYOLOGY & HERPETOLOGY 2021. [DOI: 10.1643/h2020073] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Frank T. Burbrink
- Department of Herpetology, American Museum of Natural History, Central Park West at 79th Street, New York, New York 10024; . Send reprint requests to this address
| | - Sara Ruane
- Earth and Environmental Sciences: Ecology and Evolution, Rutgers University–Newark, 195 University Avenue, Newark, New Jersey 07102
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9
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Faria R, Johannesson K, Stankowski S. Speciation in marine environments: Diving under the surface. J Evol Biol 2021; 34:4-15. [PMID: 33460491 DOI: 10.1111/jeb.13756] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/31/2020] [Accepted: 01/03/2021] [Indexed: 12/28/2022]
Abstract
Marine environments are inhabited by a broad representation of the tree of life, yet our understanding of speciation in marine ecosystems is extremely limited compared with terrestrial and freshwater environments. Developing a more comprehensive picture of speciation in marine environments requires that we 'dive under the surface' by studying a wider range of taxa and ecosystems is necessary for a more comprehensive picture of speciation. Although studying marine evolutionary processes is often challenging, recent technological advances in different fields, from maritime engineering to genomics, are making it increasingly possible to study speciation of marine life forms across diverse ecosystems and taxa. Motivated by recent research in the field, including the 14 contributions in this issue, we highlight and discuss six axes of research that we think will deepen our understanding of speciation in the marine realm: (a) study a broader range of marine environments and organisms; (b) identify the reproductive barriers driving speciation between marine taxa; (c) understand the role of different genomic architectures underlying reproductive isolation; (d) infer the evolutionary history of divergence using model-based approaches; (e) study patterns of hybridization and introgression between marine taxa; and (f) implement highly interdisciplinary, collaborative research programmes. In outlining these goals, we hope to inspire researchers to continue filling this critical knowledge gap surrounding the origins of marine biodiversity.
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Affiliation(s)
- Rui Faria
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Laboratório Associado, Universidade do Porto, Vairão, Portugal.,CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Portugal.,Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom
| | - Kerstin Johannesson
- Department of Marine Sciences-Tjärnö, University of Gothenburg, Strömstad, Sweden
| | - Sean Stankowski
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom.,IST Austria, Klosterneuburg, Austria
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10
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Brandler OV, Tukhbatullin AR, Kapustina SY, Schepetov DM, Titov SV, Ermakov OA. Variability of Mitochondrial DNA Control Region and Phylogeography of Russet Ground Squirrel (Spermophilus major, Sciuridae, Rodentia). RUSS J GENET+ 2021. [DOI: 10.1134/s102279542107005x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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11
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Grummer JA, Avila LJ, Morando MM, Leaché AD. Four Species Linked by Three Hybrid Zones: Two Instances of Repeated Hybridization in One Species Group (Genus Liolaemus). Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.624109] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Hybridization is an evolutionary process that can generate diverse outcomes, such as reinforcing species boundaries, generating new species, or facilitating the introgression of locally-adapted alleles into new genomic backgrounds. Liolaemus is a highly diverse clade of South American lizards with ~260 species and as many as ten new species are described each year. Previous Liolaemus studies have detected gene flow and introgression among species using phylogenetic network methods and/or through comparisons of nuclear and mitochondrial DNA patterns, yet no study has systematically studied hybrid zones between Liolaemus species. Here, we compared three hybrid zones between four species in the Liolaemus fitzingerii group of lizards in Central Argentina where two species, L. melanops and L. xanthoviridis, each hybridize with two other species (L. shehuen and L. fitzingerii). We sampled three transects that were each ~120 km in length and sequenced both mitochondrial and genome-wide SNP data for 267 individuals. In our analyses of nuclear DNA, we also compared bi-allelic SNPs to phased alleles (50 bp RAD loci). Population structure analyses confirmed that boundaries separating species are sharp, and all clines are <65 km wide. Cline center estimates were consistent between SNPs and phased alleles, but cline width estimates were significantly different with the SNPs producing wider estimates. The mitochondrial clines are narrower and shifted 4–20 km southward in comparison to the nuclear clines in all three hybrid zones, indicating that either each of the species has sex-biased dispersal (males northward or females southward), the population densities are unequal, or that the hybrid zones are moving north over time. These comparisons indicate that some patterns of hybridization are similar across hybrid zones (mtDNA clines all narrower and shifted to the south), whereas cline width is variable. Hybridization in the L. fitzingerii group is common and geographically localized; further studies are needed to investigate whether hybrid zones act as hard species boundaries or promoters of speciation through processes such as reinforcement. Nonetheless, this study provides insights into both biotic and abiotic mechanisms helping to maintain species boundaries within the speciose Liolaemus system.
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12
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Doña J, Sweet AD, Johnson KP. Comparing rates of introgression in parasitic feather lice with differing dispersal capabilities. Commun Biol 2020; 3:610. [PMID: 33097824 PMCID: PMC7584577 DOI: 10.1038/s42003-020-01345-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 09/30/2020] [Indexed: 12/14/2022] Open
Abstract
Organisms vary in their dispersal abilities, and these differences can have important biological consequences, such as impacting the likelihood of hybridization events. However, there is still much to learn about the factors influencing hybridization, and specifically how dispersal ability affects the opportunities for hybridization. Here, using the ecological replicate system of dove wing and body lice (Insecta: Phthiraptera), we show that species with higher dispersal abilities exhibited increased genomic signatures of introgression. Specifically, we found a higher proportion of introgressed genomic reads and more reticulated phylogenetic networks in wing lice, the louse group with higher dispersal abilities. Our results are consistent with the hypothesis that differences in dispersal ability might drive the extent of introgression through hybridization. Jorge Doña, Andrew Sweet and Kevin Johnson find that dove lice species with higher dispersal abilities have stronger genomic signatures of introgression. By using sequence data from multiple species of both wing and body lice from the same species of hosts, the authors are able to control for nearly all factors besides dispersal ability, demonstrating the power of this study system.
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Affiliation(s)
- Jorge Doña
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, 1816 S. Oak St., Champaign, IL, 61820, USA. .,Departamento de Biología Animal, Universidad de Granada, 18001, Granada, Spain.
| | - Andrew D Sweet
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, 1816 S. Oak St., Champaign, IL, 61820, USA.,Department of Entomology, Purdue University, 901 W. State St., West Lafayette, IN, 47907, USA
| | - Kevin P Johnson
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, 1816 S. Oak St., Champaign, IL, 61820, USA.
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13
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Stewart KA, Taylor SA. Leveraging eDNA to expand the study of hybrid zones. Mol Ecol 2020; 29:2768-2776. [PMID: 32557920 PMCID: PMC7496085 DOI: 10.1111/mec.15514] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 04/18/2020] [Accepted: 06/05/2020] [Indexed: 02/06/2023]
Abstract
Hybrid zones are important windows into ecological and evolutionary processes. Our understanding of the significance and prevalence of hybridization in nature has expanded with the generation and analysis of genome‐spanning data sets. That said, most hybridization research still has restricted temporal and spatial resolution, which limits our ability to draw broad conclusions about evolutionary and conservation related outcomes. Here, we argue that rapidly advancing environmental DNA (eDNA) methodology could be adopted for studies of hybrid zones to increase temporal sampling (contemporary and historical), refine and geographically expand sampling density, and collect data for taxa that are difficult to directly sample. Genomic data in the environment offer the potential for near real‐time biological tracking of hybrid zones, and eDNA provides broad, but as yet untapped, potential to address eco‐evolutionary questions.
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Affiliation(s)
- Kathryn A Stewart
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Scott A Taylor
- Department Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO, USA
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