1
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Rakotoarivelo AR, Rambuda T, Taron UH, Stalder G, O'Donoghue P, Robovský J, Hartmann S, Hofreiter M, Moodley Y. Complex patterns of gene flow and convergence in the evolutionary history of the spiral-horned antelopes (Tragelaphini). Mol Phylogenet Evol 2024; 198:108131. [PMID: 38909875 DOI: 10.1016/j.ympev.2024.108131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 05/19/2024] [Accepted: 06/15/2024] [Indexed: 06/25/2024]
Abstract
The Tragelaphini, also known as spiral-horned antelope, is a phenotypically diverse mammalian tribe comprising a single genus, Tragelaphus. The evolutionary history of this tribe has attracted the attention of taxonomists and molecular geneticists for decades because its diversity is characterised by conflicts between morphological and molecular data as well as between mitochondrial, nuclear and chromosomal DNA. These inconsistencies point to a complex history of ecological diversification, coupled by either phenotypic convergence or introgression. Therefore, to unravel the phylogenetic relationships among spiral-horned antelopes, and to further investigate the role of divergence and gene flow in trait evolution, we sequenced genomes for all nine accepted species of the genus Tragelaphus, including a genome each for the highly divergent bushbuck lineages (T. s. scriptus and T. s. sylvaticus). We successfully reconstructed the Tragelaphus species tree, providing genome-level support for the early Pliocene divergence and monophyly of the nyala (T. angasii) and lesser kudu (T. imberbis), the monophyly of the two eland species (T. oryx and T. derbianus) and, importantly, the monophyly of kéwel (T. s. scriptus) and imbabala (T. s. sylvaticus) bushbuck. We found strong evidence for gene flow in at least four of eight nodes on the species tree. Among the six phenotypic traits assessed here, only habitat type mapped onto the species tree without homoplasy, showing that trait evolution was the result of complex patterns of divergence, introgression and convergent evolution.
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Affiliation(s)
- Andrinajoro R Rakotoarivelo
- Department of Biological Sciences, University of Venda, Private Bag X5050, Thohoyandou 0950, Republic of South Africa; Department of Zoology and Entomology, University of the Free State: QwaQwa Campus, Private Bag X13, Phuthaditjhaba 9866, Republic of South Africa
| | - Thabelo Rambuda
- Department of Biological Sciences, University of Venda, Private Bag X5050, Thohoyandou 0950, Republic of South Africa; Department of Genetics, University of Pretoria, Private Bag X20, Hatfield 0028, Republic of South Africa
| | - Ulrike H Taron
- Evolutionary Adaptive Genomics, Institute for Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Strasse 24-25, 14476 Potsdam, Germany
| | - Gabrielle Stalder
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Savoyenstraße 1, A-1160 Wien, Austria
| | | | - Jan Robovský
- Department of Zoology, Faculty of Science, University of South Bohemia, Branišovská 1760, 37005 České Budějovice, Czech Republic
| | - Stefanie Hartmann
- Evolutionary Adaptive Genomics, Institute for Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Strasse 24-25, 14476 Potsdam, Germany
| | - Michael Hofreiter
- Evolutionary Adaptive Genomics, Institute for Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Strasse 24-25, 14476 Potsdam, Germany
| | - Yoshan Moodley
- Department of Biological Sciences, University of Venda, Private Bag X5050, Thohoyandou 0950, Republic of South Africa.
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2
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Lorioux-Chevalier U, Chouteau M, Roland AB. The importance of reproductive isolation in driving diversification and speciation within Peruvian mimetic poison frogs (Dendrobatidae). Sci Rep 2024; 14:19803. [PMID: 39191906 PMCID: PMC11349946 DOI: 10.1038/s41598-024-70744-5] [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: 04/02/2024] [Accepted: 08/20/2024] [Indexed: 08/29/2024] Open
Abstract
To explain how populations with distinct warning signals coexist in close parapatry, we experimentally assessed intrinsic mechanisms acting as reproductive barriers within three poison-frog species from the Peruvian Amazon belonging to a Müllerian mimetic ring (Ranitomeya variabilis, Ranitomeya imitator and Ranitomeya fantastica). We tested the role of prezygotic and postzygotic isolation barriers between phenotypically different ecotypes of each species, using no-choice mating experiments and offspring survival analysis. Our results show that prezygotic mating preference did not occur except for one specific ecotype of R. imitator, and that all three species were able to produce viable inter-population F1 hybrids. However, while R. variabilis and R. imitator hybrids were able to produce viable F2 generations, we found that for R. fantastica, every F1 hybrid males were sterile while females remained fertile. This unexpected result, echoing with Haldane's rule of speciation, validated phylogenetic studies which tentatively diagnose these populations of R. fantastica as two different species. Our work suggests that postzygotic genetic barriers likely participate in the extraordinary phenotypic diversity observed within Müllerian mimetic Ranitomeya populations, by maintaining species boundaries.
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Affiliation(s)
- Ugo Lorioux-Chevalier
- Laboratoire Écologie, Évolution, Interactions des Systèmes Amazoniens, UAR 3456, CNRS, IFREMER, Université de Guyane, Cayenne, France.
| | - Mathieu Chouteau
- Laboratoire Écologie, Évolution, Interactions des Systèmes Amazoniens, UAR 3456, CNRS, IFREMER, Université de Guyane, Cayenne, France
| | - Alexandre-Benoit Roland
- Laboratoire Écologie, Évolution, Interactions des Systèmes Amazoniens, UAR 3456, CNRS, IFREMER, Université de Guyane, Cayenne, France.
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3
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Dopman EB, Shaw KL, Servedio MR, Butlin RK, Smadja CM. Coupling of Barriers to Gene Exchange: Causes and Consequences. Cold Spring Harb Perspect Biol 2024; 16:a041432. [PMID: 38191516 PMCID: PMC11293547 DOI: 10.1101/cshperspect.a041432] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
Coupling has emerged as a concept to describe the transition from differentiated populations to newly evolved species through the strengthening of reproductive isolation. However, the term has been used in multiple ways, and relevant processes have sometimes not been clearly distinguished. Here, we synthesize existing uses of the concept of coupling and find three main perspectives: (1) coupling as the build-up of linkage disequilibrium among loci underlying barriers to gene exchange, (2) coupling as the build-up of genome-wide linkage disequilibrium, and (3) coupling as the process generating a coincidence of distinct barrier effects. We compare and contrast these views, show the diverse processes involved and the complexity of the relationships among recombination, linkage disequilibrium, and reproductive isolation, and, finally, we emphasize how each perspective can guide new directions in speciation research. Although the importance of coupling for evolutionary divergence and speciation is well established, many theoretical and empirical questions remain unanswered.
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Affiliation(s)
- Erik B Dopman
- Department of Biology, Tufts University, Medford, Massachusetts 02155, USA
| | - Kerry L Shaw
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York 14853, USA
| | - Maria R Servedio
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Roger K Butlin
- Ecology and Evolutionary Biology, School of Biosciences, The University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom
- Department of Marine Sciences, University of Gothenburg, Gothenburg 40530, Sweden
| | - Carole M Smadja
- Institut des Sciences de l'Evolution de Montpellier ISEM, Universite de Montpellier, CNRS, IRD, Montpellier 34095, France
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4
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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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5
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Opatova V, Bourguignon K, Bond JE. Species delimitation with limited sampling: An example from rare trapdoor spider genus Cyclocosmia (Mygalomorphae, Halonoproctidae). Mol Ecol Resour 2024; 24:e13894. [PMID: 37971187 DOI: 10.1111/1755-0998.13894] [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: 07/04/2023] [Revised: 10/24/2023] [Accepted: 10/31/2023] [Indexed: 11/19/2023]
Abstract
The outcome of species delimitation depends on many factors, including conceptual framework, study design, data availability, methodology employed and subjective decision making. Obtaining sufficient taxon sampling in endangered or rare taxa might be difficult, particularly when non-lethal tissue collection cannot be utilized. The need to avoid overexploitation of the natural populations may thus limit methodological framework available for downstream data analyses and bias the results. We test species boundaries in rare North American trapdoor spider genus Cyclocosmia Ausserer (1871) inhabiting the Southern Coastal Plain biodiversity hotspot with the use of genomic data and two multispecies coalescent model methods. We evaluate the performance of each methodology within a limited sampling framework. To mitigate the risk of species over splitting, common in taxa with highly structured populations, we subsequently implement a species validation step via genealogical diversification index (gdi), which accounts for both genetic isolation and gene flow. We delimited eight geographically restricted lineages within sampled North American Cyclocosmia, suggesting that major river drainages in the region are likely barriers to dispersal. Our results suggest that utilizing BPP in the species discovery step might be a good option for datasets comprising hundreds of loci, but fewer individuals, which may be a common scenario for rare taxa. However, we also show that such results should be validated via gdi, in order to avoid over splitting.
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Affiliation(s)
- Vera Opatova
- Department of Zoology, Faculty of Sciences, Charles University, Prague 2, Czech Republic
| | - Kellie Bourguignon
- Department of Biological Sciences, Auburn University, Auburn, Alabama, USA
| | - Jason E Bond
- Department of Entomology and Nematology, University of California, Davis, California, USA
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6
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Berdan EL, Aubier TG, Cozzolino S, Faria R, Feder JL, Giménez MD, Joron M, Searle JB, Mérot C. Structural Variants and Speciation: Multiple Processes at Play. Cold Spring Harb Perspect Biol 2024; 16:a041446. [PMID: 38052499 PMCID: PMC10910405 DOI: 10.1101/cshperspect.a041446] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Research on the genomic architecture of speciation has increasingly revealed the importance of structural variants (SVs) that affect the presence, abundance, position, and/or direction of a nucleotide sequence. SVs include large chromosomal rearrangements such as fusion/fissions and inversions and translocations, as well as smaller variants such as duplications, insertions, and deletions (CNVs). Although we have ample evidence that SVs play a key role in speciation, the underlying mechanisms differ depending on the type and length of the SV, as well as the ecological, demographic, and historical context. We review predictions and empirical evidence for classic processes such as underdominance due to meiotic aberrations and the coupling effect of recombination suppression before exploring how recent sequencing methodologies illuminate the prevalence and diversity of SVs. We discuss specific properties of SVs and their impact throughout the genome, highlighting that multiple processes are at play, and possibly interacting, in the relationship between SVs and speciation.
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Affiliation(s)
- Emma L Berdan
- Department of Marine Sciences, Gothenburg University, Gothenburg 40530, Sweden
- Bioinformatics Core, Department of Biostatistics, Harvard T.H. Chan School of Public Health, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Thomas G Aubier
- Laboratoire Évolution & Diversité Biologique, Université Paul Sabatier Toulouse III, UMR 5174, CNRS/IRD, 31077 Toulouse, France
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Salvatore Cozzolino
- Department of Biology, University of Naples Federico II, Complesso Universitario di Monte S. Angelo, 80126 Napoli, Italia
| | - Rui Faria
- 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, 4485-661 Vairão, Portugal
| | - Jeffrey L Feder
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Mabel D Giménez
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Genética Humana de Misiones (IGeHM), Parque de la Salud de la Provincia de Misiones "Dr. Ramón Madariaga," N3300KAZ Posadas, Misiones, Argentina
- Facultad de Ciencias Exactas, Químicas y Naturales, Universidad Nacional de Misiones, N3300LQH Posadas, Misiones, Argentina
| | - Mathieu Joron
- Centre d'Ecologie Fonctionnelle et Evolutive, Université de Montpellier, CNRS, EPHE, IRD, Montpellier, France
| | - Jeremy B Searle
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York 14853, USA
| | - Claire Mérot
- CNRS, UMR 6553 Ecobio, OSUR, Université de Rennes, 35000 Rennes, France
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7
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Merrill RM, Arenas-Castro H, Feller AF, Harenčár J, Rossi M, Streisfeld MA, Kay KM. Genetics and the Evolution of Prezygotic Isolation. Cold Spring Harb Perspect Biol 2024; 16:a041439. [PMID: 37848246 PMCID: PMC10835618 DOI: 10.1101/cshperspect.a041439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2023]
Abstract
The significance of prezygotic isolation for speciation has been recognized at least since the Modern Synthesis. However, fundamental questions remain. For example, how are genetic associations between traits that contribute to prezygotic isolation maintained? What is the source of genetic variation underlying the evolution of these traits? And how do prezygotic barriers affect patterns of gene flow? We address these questions by reviewing genetic features shared across plants and animals that influence prezygotic isolation. Emerging technologies increasingly enable the identification and functional characterization of the genes involved, allowing us to test established theoretical expectations. Embedding these genes in their developmental context will allow further predictions about what constrains the evolution of prezygotic isolation. Ongoing improvements in statistical and computational tools will reveal how pre- and postzygotic isolation may differ in how they influence gene flow across the genome. Finally, we highlight opportunities for progress by combining theory with appropriate data.
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Affiliation(s)
- Richard M Merrill
- Faculty of Biology, Division of Evolutionary Biology, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Henry Arenas-Castro
- School of Biological Sciences, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Anna F Feller
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Arnold Arboretum of Harvard University, Boston, Massachusetts 02131, USA
| | - Julia Harenčár
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, California 95060, USA
| | - Matteo Rossi
- Faculty of Biology, Division of Evolutionary Biology, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Matthew A Streisfeld
- Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon 97403-5289, USA
| | - Kathleen M Kay
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, California 95060, USA
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8
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Pyron RA, Kakkera A, Beamer DA, O'Connell KA. Discerning structure versus speciation in phylogeographic analysis of Seepage Salamanders (Desmognathus aeneus) using demography, environment, geography, and phenotype. Mol Ecol 2024; 33:e17219. [PMID: 38015012 DOI: 10.1111/mec.17219] [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: 08/04/2023] [Revised: 10/26/2023] [Accepted: 11/13/2023] [Indexed: 11/29/2023]
Abstract
Numerous mechanisms can drive speciation, including isolation by adaptation, distance, and environment. These forces can promote genetic and phenotypic differentiation of local populations, the formation of phylogeographic lineages, and ultimately, completed speciation. However, conceptually similar mechanisms may also result in stabilizing rather than diversifying selection, leading to lineage integration and the long-term persistence of population structure within genetically cohesive species. Processes that drive the formation and maintenance of geographic genetic diversity while facilitating high rates of migration and limiting phenotypic differentiation may thereby result in population genetic structure that is not accompanied by reproductive isolation. We suggest that this framework can be applied more broadly to address the classic dilemma of "structure" versus "species" when evaluating phylogeographic diversity, unifying population genetics, species delimitation, and the underlying study of speciation. We demonstrate one such instance in the Seepage Salamander (Desmognathus aeneus) from the southeastern United States. Recent studies estimated up to 6.3% mitochondrial divergence and four phylogenomic lineages with broad admixture across geographic hybrid zones, which could potentially represent distinct species supported by our species-delimitation analyses. However, while limited dispersal promotes substantial isolation by distance, microhabitat specificity appears to yield stabilizing selection on a single, uniform, ecologically mediated phenotype. As a result, climatic cycles promote recurrent contact between lineages and repeated instances of high migration through time. Subsequent hybridization is apparently not counteracted by adaptive differentiation limiting introgression, leaving a single unified species with deeply divergent phylogeographic lineages that nonetheless do not appear to represent incipient species.
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Affiliation(s)
- R Alexander Pyron
- Department of Biological Sciences, The George Washington University, Washington, District of Columbia, USA
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, District of Columbia, USA
| | - Anvith Kakkera
- Thomas Jefferson High School for Science and Technology, Alexandria, Virginia, USA
| | - David A Beamer
- Office of Research, Economic Development and Engagement, East Carolina University, Greenville, North Carolina, USA
| | - Kyle A O'Connell
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, District of Columbia, USA
- Deloitte Consulting LLP, Health and Data AI, Arlington, Virginia, USA
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9
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Lackey ACR, Murray AC, Mirza NA, Powell THQ. The role of sexual isolation during rapid ecological divergence: Evidence for a new dimension of isolation in Rhagoletis pomonella. J Evol Biol 2023. [PMID: 37173822 DOI: 10.1111/jeb.14179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 03/05/2023] [Accepted: 03/23/2023] [Indexed: 05/15/2023]
Abstract
The pace of divergence and likelihood of speciation often depends on how and when different types of reproductive barriers evolve. Questions remain about how reproductive isolation evolves after initial divergence. We tested for the presence of sexual isolation (reduced mating between populations due to divergent mating preferences and traits) in Rhagoletis pomonella flies, a model system for incipient ecological speciation. We measured the strength of sexual isolation between two very recently diverged (~170 generations) sympatric populations, adapted to different host fruits (hawthorn and apple). We found that flies from both populations were more likely to mate within than between populations. Thus, sexual isolation may play an important role in reducing gene flow allowed by early-acting ecological barriers. We also tested how warmer temperatures predicted under climate change could alter sexual isolation and found that sexual isolation was markedly asymmetric under warmer temperatures - apple males and hawthorn females mated randomly while apple females and hawthorn males mated more within populations than between. Our findings provide a window into the early speciation process and the role of sexual isolation after initial ecological divergence, in addition to examining how environmental conditions could shape the likelihood of further divergence.
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Affiliation(s)
- Alycia C R Lackey
- University of Louisville, Louisville, Kentucky, USA
- Binghamton University, Binghamton, New York, USA
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10
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Zhang H, Zhang X, Wu G, Dong C, Liu J, Li M. Genomic divergence and introgression among three Populus species. Mol Phylogenet Evol 2023; 180:107686. [PMID: 36586545 DOI: 10.1016/j.ympev.2022.107686] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 12/15/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022]
Abstract
Genomic divergence with gene flow is very common in both plants and animals. However, divergence and gene flow are two counteracting factors during speciation. Identifying the types of genes that are likely to be introgressed and what genetic factors restrict further effective reproduction of interspecific hybrids is of great interest to biologists. We aimed to address these issues using three related tree species, Populus alba (Pa), P. tremula (Pt), and P. tremuloides (Ps), and the interspecific hybrid of the former two species, P. × canescens (Pc). We collected 105 genomes for these four poplar lineages, including 28 Pa, 38Pt, 21 Ps, and 18 Pc individuals, to reconstruct their evolutionary histories. Our coalescence-based simulations indicated that Pa diverged earliest from Ps and Pt, and asymmetrical gene flow existed between any two lineages, with especially large ancient gene flow occurring between Pa and Pt. The genomic landscape of divergence between pairs of the three species are highly heterogeneous, which may have arisen through both divergent sorting of ancient polymorphisms and ongoing gene flow. We found that extant regions of the genome with introgressed ancestry reduced genetic divergence but elevated recombination rates and accounted for 5.76 % of the total genome. Introgressed genes were functionally associated with stress resistance, including innate immune response, anti-adversity response, and programmed cell death. However, candidate genes underlying postmating barriers of Pc were homozygous and resistant to introgression due to the incompatibility of alleles between loci after hybridization and were associated with endosperm and gamete formation and disease resistance. Our study revealed genomic dynamics during speciation with gene flow and identified regions of the genome that were likely introgressed and adaptive as well as candidate loci responsible for hybrid incompatibility that resulted in the formation of postmating barriers after hybridization.
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Affiliation(s)
- Han Zhang
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China
| | - Xu Zhang
- Internet Medical and System Applications of National Engineering Laboratory, Zhengzhou University First Affiliated Hospital, Zhengzhou 450000, China
| | - Guili Wu
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China
| | - Congcong Dong
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China
| | - Jianquan Liu
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China; Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, China
| | - Minjie Li
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China.
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11
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Carnicero P, Kröll J, Schönswetter P. Homoploid hybrids are common but evolutionary dead ends, whereas polyploidy is not linked to hybridization in a group of Pyrenean saxifrages. Mol Phylogenet Evol 2023; 180:107703. [PMID: 36632928 DOI: 10.1016/j.ympev.2023.107703] [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: 10/25/2022] [Revised: 12/28/2022] [Accepted: 01/06/2023] [Indexed: 01/09/2023]
Abstract
Hybridization and polyploidy are major forces in plant evolution. Homoploid hybridization can generate new species via hybrid speciation, or modify extant evolutionary lineages through introgression. Polyploidy enables instantaneous reproductive isolation from the parental lineage(s) and is often coupled with evolutionary innovations, especially when linked to hybridization. While allopolyploidy is a well-known and common mechanism of plant speciation, the evolutionary role of autopolyploidy might have been underestimated. Here, we studied the saxifrages of Saxifraga subsection Saxifraga in the Pyrenees, which easily hybridise and include polyploid populations of uncertain origin, as a model to unravel evolutionary consequences and origin of hybridization and polyploidy. Additionally, we investigate the phylogenetic relationship between the two subspecies of the endemic S. pubescens to ascertain whether they should rather be treated as different species. For these purposes, we combined ploidy-informed restriction associated DNA analyses, plastid DNA sequences and morphological data on a comprehensive population sample of seven species. Our results unravel multiple homoploid hybridization events at the diploid level between different species pairs, but with limited evolutionary impact. The ploidy-informed analyses reveal that all tetraploid populations detected in the present study belong to the widespread alpine species S. moschata. Although of autopolyploid origin, they are to some extent morphologically differentiated and underwent a different evolutionary pathway than their diploid parent. However, the high plastid DNA diversity and the internal structure within eastern and western population groups suggest multiple origins of the polyploids. Finally, our phylogenetic analyses show that S. pubescens and S. iratiana are clearly not sister lineages, and should consequently be considered as independent species.
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Affiliation(s)
- Pau Carnicero
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria.
| | - Joelle Kröll
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Peter Schönswetter
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
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12
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Zhang L, Chaturvedi S, Nice CC, Lucas LK, Gompert Z. Population genomic evidence of selection on structural variants in a natural hybrid zone. Mol Ecol 2023; 32:1497-1514. [PMID: 35398939 DOI: 10.1111/mec.16469] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 03/18/2022] [Accepted: 03/28/2022] [Indexed: 12/01/2022]
Abstract
Structural variants (SVs) can promote speciation by directly causing reproductive isolation or by suppressing recombination across large genomic regions. Whereas examples of each mechanism have been documented, systematic tests of the role of SVs in speciation are lacking. Here, we take advantage of long-read (Oxford nanopore) whole-genome sequencing and a hybrid zone between two Lycaeides butterfly taxa (L. melissa and Jackson Hole Lycaeides) to comprehensively evaluate genome-wide patterns of introgression for SVs and relate these patterns to hypotheses about speciation. We found >100,000 SVs segregating within or between the two hybridizing species. SVs and SNPs exhibited similar levels of genetic differentiation between species, with the exception of inversions, which were more differentiated. We detected credible variation in patterns of introgression among SV loci in the hybrid zone, with 562 of 1419 ancestry-informative SVs exhibiting genomic clines that deviated from null expectations based on genome-average ancestry. Overall, hybrids exhibited a directional shift towards Jackson Hole Lycaeides ancestry at SV loci, consistent with the hypothesis that these loci experienced more selection on average than SNP loci. Surprisingly, we found that deletions, rather than inversions, showed the highest skew towards excess ancestry from Jackson Hole Lycaeides. Excess Jackson Hole Lycaeides ancestry in hybrids was also especially pronounced for Z-linked SVs and inversions containing many genes. In conclusion, our results show that SVs are ubiquitous and suggest that SVs in general, but especially deletions, might disproportionately affect hybrid fitness and thus contribute to reproductive isolation.
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Affiliation(s)
- Linyi Zhang
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.,Department of Biology, Utah State University, Logan, Utah, USA
| | - Samridhi Chaturvedi
- Department of Integrative Biology, University of California, Berkeley, California, USA
| | - Chris C Nice
- Department of Biology, Texas State University, San Marcos, Texas, USA
| | - Lauren K Lucas
- Department of Biology, Utah State University, Logan, Utah, USA
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13
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Briševac D, Peralta CM, Kaiser TS. An oligogenic architecture underlying ecological and reproductive divergence in sympatric populations. eLife 2023; 12:82825. [PMID: 36852479 PMCID: PMC9977317 DOI: 10.7554/elife.82825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 02/07/2023] [Indexed: 03/01/2023] Open
Abstract
The evolutionary trajectories and genetic architectures underlying ecological divergence with gene flow are poorly understood. Sympatric timing types of the intertidal insect Clunio marinus (Diptera) from Roscoff (France) differ in lunar reproductive timing. One type reproduces at full moon, the other at new moon, controlled by a circalunar clock of yet unknown molecular nature. Lunar reproductive timing is a magic trait for a sympatric speciation process, as it is both ecologically relevant and entails assortative mating. Here, we show that the difference in reproductive timing is controlled by at least four quantitative trait loci (QTL) on three different chromosomes. They are partly associated with complex inversions, but differentiation of the inversion haplotypes cannot explain the different phenotypes. The most differentiated locus in the entire genome, with QTL support, is the period locus, implying that this gene could not only be involved in circadian timing but also in lunar timing. Our data indicate that magic traits can be based on an oligogenic architecture and can be maintained by selection on several unlinked loci.
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Affiliation(s)
- Dušica Briševac
- Max Planck Research Group Biological Clocks, Max Planck Institute for Evolutionary BiologyPloenGermany
| | - Carolina M Peralta
- Max Planck Research Group Biological Clocks, Max Planck Institute for Evolutionary BiologyPloenGermany
| | - Tobias S Kaiser
- Max Planck Research Group Biological Clocks, Max Planck Institute for Evolutionary BiologyPloenGermany
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14
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Wong ELY, Nevado B, Hiscock SJ, Filatov DA. Rapid evolution of hybrid breakdown following recent divergence with gene flow in Senecio species on Mount Etna, Sicily. Heredity (Edinb) 2023; 130:40-52. [PMID: 36494489 PMCID: PMC9814926 DOI: 10.1038/s41437-022-00576-4] [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: 06/17/2022] [Revised: 11/07/2022] [Accepted: 11/08/2022] [Indexed: 12/13/2022] Open
Abstract
How do nascent species evolve reproductive isolation during speciation with on-going gene flow? How do hybrid lineages become stabilised hybrid species? While commonly used genomic approaches provide an indirect way to identify species incompatibility factors, synthetic hybrids generated from interspecific crosses allow direct pinpointing of phenotypic traits involved in incompatibilities and the traits that are potentially adaptive in hybrid species. Here we report the analysis of phenotypic variation and hybrid breakdown in crosses between closely-related Senecio aethnensis and S. chrysanthemifolius, and their homoploid hybrid species, S. squalidus. The two former species represent a likely case of recent (<200 ky) speciation with gene flow driven by adaptation to contrasting conditions of high- and low-elevations on Mount Etna, Sicily. As these species form viable and fertile hybrids, it remains unclear whether they have started to evolve reproductive incompatibility. Our analysis represents the first study of phenotypic variation and hybrid breakdown involving multiple Senecio hybrid families. It revealed wide range of variation in multiple traits, including the traits previously unrecorded in synthetic hybrids. Leaf shape, highly distinct between S. aethnensis and S. chrysanthemifolius, was extremely variable in F2 hybrids, but more consistent in S. squalidus. Our study demonstrates that interspecific incompatibilities can evolve rapidly despite on-going gene flow between the species. Further work is necessary to understand the genetic bases of these incompatibilities and their role in speciation with gene flow.
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Affiliation(s)
- Edgar L. Y. Wong
- grid.4991.50000 0004 1936 8948Department of Biology, University of Oxford, Oxford, UK ,grid.507705.0Senckenberg Biodiversity and Climate Research Centre, Frankfurt am Main, Germany
| | - Bruno Nevado
- grid.4991.50000 0004 1936 8948Department of Biology, University of Oxford, Oxford, UK ,grid.9983.b0000 0001 2181 4263Centre for Ecology, Evolution and Environmental Changes, University of Lisbon, Lisbon, Portugal
| | - Simon J. Hiscock
- grid.4991.50000 0004 1936 8948Department of Biology, University of Oxford, Oxford, UK ,Oxford Botanic Garden and Arboretum, Oxford, UK
| | - Dmitry A. Filatov
- grid.4991.50000 0004 1936 8948Department of Biology, University of Oxford, Oxford, UK
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15
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Recent speciation associated with range expansion and a shift to self-fertilization in North American Arabidopsis. Nat Commun 2022; 13:7564. [PMID: 36481740 PMCID: PMC9732334 DOI: 10.1038/s41467-022-35368-1] [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: 04/20/2022] [Accepted: 11/30/2022] [Indexed: 12/13/2022] Open
Abstract
The main processes classically evoked for promoting reproductive isolation and speciation are geographic separation reducing gene flow among populations, divergent selection, and chance genomic change. In a case study, we present evidence that the additional factors of climate change, range expansion and a shift in mating towards inbreeding can initiate the processes leading to parapatric speciation. At the end of the last Pleistocene glaciation cycle, the North American plant Arabidopsis lyrata expanded its range and concomitantly lost its reproductive mode of outcrossing multiple times. We show that in one of the newly colonized areas, the self-fertilizing recolonization lineage of A. lyrata gave rise to selfing A. arenicola, which expanded its range to subarctic and arctic Canada and Greenland, while the parental species remained restricted to temperate North America. Despite the vast range expansion by the new species, mutational load did not increase, probably because of selfing and quasi-clonal selection. We conclude that such peripheral parapatric speciation combined with range expansion and inbreeding may be an important but so far overlooked mode of speciation.
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16
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Eliášová K, Lucas Lledó JI, Grau JH, Loudová M, Bannikova AA, Zolotareva KI, Beneš V, Hulva P, Černá Bolfíková B. Contrasting levels of hybridization across the two contact zones between two hedgehog species revealed by genome-wide SNP data. Heredity (Edinb) 2022; 129:305-315. [PMID: 36229647 PMCID: PMC9613676 DOI: 10.1038/s41437-022-00567-5] [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: 08/06/2021] [Revised: 09/29/2022] [Accepted: 09/29/2022] [Indexed: 11/09/2022] Open
Abstract
Hybridization and introgression have played important roles in the history of various species, including lineage diversification and the evolution of adaptive traits. Hybridization can accelerate the development of reproductive isolation between diverging species, and thus valuable insight into the evolution of reproductive barrier formation may be gained by studying secondary contact zones. Hedgehogs of the genus Erinaceus, which are insectivores sensitive to changes in climate, are a pioneer model in Pleistocene phylogeography. The present study provides the first genome-wide SNP data regarding the Erinaceus hedgehogs species complex, offering a unique comparison of two secondary contact zones between Erinaceus europaeus and E. roumanicus. Results confirmed diversification of the genus during the Pleistocene period, and detected a new refugial lineage of E. roumanicus outside the Mediterranean basin, most likely in the Ponto-Caspian region. In the Central European zone, the level of hybridization was low, whereas in the Russian-Baltic zone, both species hybridise extensively. Asymmetrical gene flow from E. europaeus to E. roumanicus suggests that reproductive isolation varies according to the direction of the crosses in the hybrid zones. However, no loci with significantly different patterns of introgression were detected. Markedly different pre- and post-zygotic barriers, and thus diverse modes of species boundary maintenance in the two contact zones, likely exist. This pattern is probably a consequence of the different age and thus of the different stage of evolution of reproductive isolating mechanisms in each hybrid zone.
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Affiliation(s)
- Kristýna Eliášová
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic.
- Department of Animal Science and Food Processing, Faculty of Tropical AgriSciences, Czech University of Life Sciences Prague, Prague, Czech Republic.
| | | | - José Horacio Grau
- Evolutionary Adaptive Genomics, University of Potsdam, Potsdam, Germany
- Center for Species Survival, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, USA
| | - Miroslava Loudová
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | | | | | | | - Pavel Hulva
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Barbora Černá Bolfíková
- Department of Animal Science and Food Processing, Faculty of Tropical AgriSciences, Czech University of Life Sciences Prague, Prague, Czech Republic
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17
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Schuldiner‐Harpaz T, Merrill RM, Jiggins CD. Evolution of physical linkage between loci controlling ecological traits and mating preferences. J Evol Biol 2022; 35:1537-1547. [PMID: 36196988 PMCID: PMC9827829 DOI: 10.1111/jeb.14105] [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: 01/06/2022] [Revised: 07/26/2022] [Accepted: 08/08/2022] [Indexed: 01/12/2023]
Abstract
Coupling of multiple barriers to gene-flow, such as divergent local adaptation and reproductive isolation, facilitates speciation. However, alleles at loci that contribute to barrier effects can be dissociated by recombination. Models of linkage between diverging alleles often consider elements that reduce recombination, such as chromosomal inversions and alleles that modify recombination rate between existing loci. In contrast, here, we consider the evolution of linkage due to the close proximity of loci on the same chromosome. Examples of such physical linkage exist in several species, but in other cases, strong associations are maintained without physical linkage. We use an individual-based model to study the conditions under which the physical linkage between loci controlling ecological traits and mating preferences might be expected to evolve. We modelled a single locus controlling an ecological trait that acts also as a mating cue. Mating preferences are controlled by multiple loci, formed by mutations that are randomly placed in the "genome", within varying distances from the ecological trait locus, allowing us to examine which genomic architectures spread across the population. Our model reveals that stronger physical linkage is favoured when mating preferences and selection are weaker. Under such conditions mating among divergent phenotypes is more frequent, and matching ecological trait and mating preference alleles are more likely to become dissociated by recombination, favouring the evolution of genetic linkage. While most theoretical studies on clustering of divergent loci focus on how physical linkage influences speciation, we show how physical linkage itself can arise, establishing conditions that can favour speciation.
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18
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Princepe D, Czarnobai S, Pradella TM, Caetano RA, Marquitti FMD, de Aguiar MAM, Araujo SBL. Diversity patterns and speciation processes in a two-island system with continuous migration. Evolution 2022; 76:2260-2271. [PMID: 36036483 DOI: 10.1111/evo.14603] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 06/22/2022] [Indexed: 01/22/2023]
Abstract
Geographic isolation is a central mechanism of speciation, but perfect isolation of populations is rare. Although speciation can be hindered if gene flow is large, intermediate levels of migration can enhance speciation by introducing genetic novelty in the semi-isolated populations or founding small communities of migrants. Here, we consider a two-island neutral model of speciation with continuous migration and study diversity patterns as a function of the migration probability, population size, and number of genes involved in reproductive isolation (dubbed as genome size). For small genomes, low levels of migration induce speciation on the islands that otherwise would not occur. Diversity, however, drops sharply to a single species inhabiting both islands as the migration probability increases. For large genomes, sympatric speciation occurs even when the islands are strictly isolated. Then species richness per island increases with the probability of migration, but the total number of species decreases as they become cosmopolitan. For each genome size, there is an optimal migration intensity for each population size that maximizes the number of species. We discuss the observed modes of speciation induced by migration and how they increase species richness in the insular system while promoting asymmetry between the islands and hindering endemism.
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Affiliation(s)
- Débora Princepe
- Instituto de Física 'Gleb Wataghin', Universidade Estadual de Campinas, Campinas, Brasil
| | - Simone Czarnobai
- Programa de Pós Graduação em Ecologia e Conservação, Universidade Federal do Paraná, Curitiba, Brasil
| | - Thiago M Pradella
- Instituto de Física 'Gleb Wataghin', Universidade Estadual de Campinas, Campinas, Brasil
| | - Rodrigo A Caetano
- Departamento de Física, Universidade Federal do Paraná, Curitiba, Brasil
| | - Flavia M D Marquitti
- Instituto de Física 'Gleb Wataghin', Universidade Estadual de Campinas, Campinas, Brasil.,Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brasil
| | - Marcus A M de Aguiar
- Instituto de Física 'Gleb Wataghin', Universidade Estadual de Campinas, Campinas, Brasil
| | - Sabrina B L Araujo
- Departamento de Física, Universidade Federal do Paraná, Curitiba, Brasil
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19
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Koch EL, Ravinet M, Westram AM, Johannesson K, Butlin RK. Genetic architecture of repeated phenotypic divergence in Littorina saxatilis ecotype evolution. Evolution 2022; 76:2332-2346. [PMID: 35994296 PMCID: PMC9826283 DOI: 10.1111/evo.14602] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 06/24/2022] [Accepted: 07/23/2022] [Indexed: 01/22/2023]
Abstract
Chromosomal inversions have been shown to play a major role in a local adaptation by suppressing recombination between alternative arrangements and maintaining beneficial allele combinations. However, so far, their importance relative to the remaining genome remains largely unknown. Understanding the genetic architecture of adaptation requires better estimates of how loci of different effect sizes contribute to phenotypic variation. Here, we used three Swedish islands where the marine snail Littorina saxatilis has repeatedly evolved into two distinct ecotypes along a habitat transition. We estimated the contribution of inversion polymorphisms to phenotypic divergence while controlling for polygenic effects in the remaining genome using a quantitative genetics framework. We confirmed the importance of inversions but showed that contributions of loci outside inversions are of similar magnitude, with variable proportions dependent on the trait and the population. Some inversions showed consistent effects across all sites, whereas others exhibited site-specific effects, indicating that the genomic basis for replicated phenotypic divergence is only partly shared. The contributions of sexual dimorphism as well as environmental factors to phenotypic variation were significant but minor compared to inversions and polygenic background. Overall, this integrated approach provides insight into the multiple mechanisms contributing to parallel phenotypic divergence.
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Affiliation(s)
- Eva L. Koch
- School of BiosciencesUniversity of SheffieldSheffieldUK,Department of ZoologyUniversity of CambridgeCambridgeUK
| | - Mark Ravinet
- School of Life SciencesUniversity of NottinghamNottinghamUK
| | - Anja M. Westram
- Institute of Science and Technology Austria (ISTA)KlosterneuburgAustria,Faculty of Biosciences and AquacultureNord UniversityBodøNorway
| | - Kerstin Johannesson
- Marine Science, Tjärnö Marine LaboratoryUniversity of GothenburgGothenburgSweden
| | - Roger K. Butlin
- School of BiosciencesUniversity of SheffieldSheffieldUK,Marine Science, Tjärnö Marine LaboratoryUniversity of GothenburgGothenburgSweden
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20
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Rodriguez AK, Krug PJ. Ecological speciation by sympatric host shifts in a clade of herbivorous sea slugs, with introgression and localized mitochondrial capture between species. Mol Phylogenet Evol 2022; 174:107523. [PMID: 35589054 DOI: 10.1016/j.ympev.2022.107523] [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: 11/11/2021] [Revised: 03/30/2022] [Accepted: 05/06/2022] [Indexed: 11/25/2022]
Abstract
Host shifting in insect-plant systems was historically important to the development of ecological speciation theory, yet surprisingly few studies have examined whether host shifting drives diversification of marine herbivores. When small-bodied consumers feed and also mate on a preferred host, disruptive selection can split a population into host races despite gene flow. Support for host shifts is notably lacking for invertebrates associated with macroalgae, where the scale of dispersal by planktonic larvae often far exceeds the grain of host patchiness, and adults are typically less specialized than terrestrial herbivores. Here, we present a candidate example of ecological speciation in a clade of sea slugs that primarily consume green algae in the genus Caulerpa, including highly invasive species. Ancestral character state reconstructions supported 'sea grapes' (C. racemosa, C. lentillifera) as the ancestral host for a tropical radiation of 12 Elysia spp., with one shift onto alternative Caulerpa spp. in the Indo-Pacific. A Caribbean radiation of three species included symaptric host shifts to Rhipocephalus brevicaulis in the ancestor of E. pratensis Ortea & Espinosa, 1996, and to C. prolifera in E. hamanni Krug, Vendetti & Valdes 2016, plus a niche expansion to a range of Caulerpa spp. in E. subornata Verrill, 1901. All three species are broadly sympatric across the Caribbean but are host-partitioned at a fine grain, and distinct by morphology and at nuclear loci. However, non-recombining mtDNA revealed a history of gene flow between E. pratensis and E. subornata: COI haplotypes from E. subornata were 10.4% divergent from E. pratensis haplotypes from four sites, but closely related to all E. pratensis haplotypes sampled from six Bahamian islands, indicating historical introgression and localized "mitochondrial capture." Disruptive selective likely fueled divergence and adaptation to distinct host environments, indicating ecological speciation may be an under-appreciated driver of diversification for marine herbivores as well as epibionts and other resource specialists.
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Affiliation(s)
- Albert K Rodriguez
- Department of Biological Sciences, California State University, Los Angeles, CA 90032-8201, U.S.A
| | - Patrick J Krug
- Department of Biological Sciences, California State University, Los Angeles, CA 90032-8201, U.S.A.
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21
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Feagles O, Höbel G. Mate preferences and choosiness are distinct components of mate choice in Eastern Gray Treefrogs (Hyla versicolor). Am Nat 2022; 200:506-517. [DOI: 10.1086/720730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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22
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David JR, Ferreira EA, Jabaud L, Ogereau D, Bastide H, Yassin A. Evolution of assortative mating following selective introgression of pigmentation genes between two Drosophila species. Ecol Evol 2022; 12:e8821. [PMID: 35432924 PMCID: PMC9006235 DOI: 10.1002/ece3.8821] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 03/24/2022] [Indexed: 12/03/2022] Open
Abstract
Adaptive introgression is ubiquitous in animals, but experimental support for its role in driving speciation remains scarce. In the absence of conscious selection, admixed laboratory strains of Drosophila asymmetrically and progressively lose alleles from one parental species and reproductive isolation against the predominant parent ceases after 10 generations. Here, we selectively introgressed during 1 year light pigmentation genes of D. santomea into the genome of its dark sibling D. yakuba, and vice versa. We found that the pace of phenotypic change differed between the species and the sexes and identified through genome sequencing common as well as distinct introgressed loci in each species. Mating assays showed that assortative mating between introgressed flies and both parental species persisted even after 4 years (~60 generations) from the end of the selection. Those results indicate that selective introgression of as low as 0.5% of the genome can beget morphologically distinct and reproductively isolated strains, two prerequisites for the delimitation of new species. Our findings hence represent a significant step toward understanding the genome-wide dynamics of speciation-through-introgression.
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Affiliation(s)
- Jean R. David
- Laboratoire Évolution, Génomes, Comportement et ÉcologieCNRSIRDUniversité Paris‐Saclay – Institut DiversitéEcologie et Evolution du Vivant (IDEEV)Gif‐sur‐YvetteFrance
| | - Erina A. Ferreira
- Laboratoire Évolution, Génomes, Comportement et ÉcologieCNRSIRDUniversité Paris‐Saclay – Institut DiversitéEcologie et Evolution du Vivant (IDEEV)Gif‐sur‐YvetteFrance
| | - Laure Jabaud
- Laboratoire Évolution, Génomes, Comportement et ÉcologieCNRSIRDUniversité Paris‐Saclay – Institut DiversitéEcologie et Evolution du Vivant (IDEEV)Gif‐sur‐YvetteFrance
| | - David Ogereau
- Laboratoire Évolution, Génomes, Comportement et ÉcologieCNRSIRDUniversité Paris‐Saclay – Institut DiversitéEcologie et Evolution du Vivant (IDEEV)Gif‐sur‐YvetteFrance
| | - Héloïse Bastide
- Laboratoire Évolution, Génomes, Comportement et ÉcologieCNRSIRDUniversité Paris‐Saclay – Institut DiversitéEcologie et Evolution du Vivant (IDEEV)Gif‐sur‐YvetteFrance
| | - Amir Yassin
- Laboratoire Évolution, Génomes, Comportement et ÉcologieCNRSIRDUniversité Paris‐Saclay – Institut DiversitéEcologie et Evolution du Vivant (IDEEV)Gif‐sur‐YvetteFrance
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23
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Weyna A, Bourouina L, Galtier N, Romiguier J. Detection of F1 hybrids from single-genome data reveals frequent hybridization in Hymenoptera and particularly ants. Mol Biol Evol 2022; 39:6562163. [PMID: 35363317 PMCID: PMC9021736 DOI: 10.1093/molbev/msac071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Hybridization occupies a central role in many fundamental evolutionary processes, such as speciation or adaptation. Yet, despite its pivotal importance in evolution, little is known about the actual prevalence and distribution of current hybridization across the tree of life. Here we develop and implement a new statistical method enabling the detection of F1 hybrids from single-individual genome sequencing data. Using simulations and sequencing data from known hybrid systems, we first demonstrate the specificity of the method, and identify its statistical limits. Next, we showcase the method by applying it to available sequencing data from more than 1,500 species of Arthropods, including Hymenoptera, Hemiptera, Coleoptera, Diptera, and Archnida. Among these taxa, we find Hymenoptera, and especially ants, to display the highest number of candidate F1 hybrids, suggesting higher rates of recent hybridization between previously isolated gene pools in these groups. The prevalence of F1 hybrids was heterogeneously distributed across ants, with taxa including many candidates tending to harbor specific ecological and life-history traits. This work shows how large-scale genomic comparative studies of recent hybridization can be implemented, uncovering the determinants of first-generation hybridization across whole taxa.
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Affiliation(s)
- Arthur Weyna
- Institut des Sciences de l'Evolution (UMR 5554), University of Montpellier, CNRS
| | - Lucille Bourouina
- Institut des Sciences de l'Evolution (UMR 5554), University of Montpellier, CNRS
| | - Nicolas Galtier
- Institut des Sciences de l'Evolution (UMR 5554), University of Montpellier, CNRS
| | - Jonathan Romiguier
- Institut des Sciences de l'Evolution (UMR 5554), University of Montpellier, CNRS
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24
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Kolis KM, Berg CS, Nelson TC, Fishman L. Population genomic consequences of life-history and mating system adaptation to a geothermal soil mosaic in yellow monkeyflowers. Evolution 2022; 76:765-781. [PMID: 35266558 DOI: 10.1111/evo.14469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 01/13/2022] [Accepted: 01/26/2022] [Indexed: 01/21/2023]
Abstract
Local selection can promote phenotypic divergence despite gene flow across habitat mosaics, but adaptation itself may generate substantial barriers to genetic exchange. In plants, life-history, phenology, and mating system divergence have been proposed to promote genetic differentiation in sympatry. In this study, we investigate phenotypic and genetic variation in Mimulus guttatus (yellow monkeyflowers) across a geothermal soil mosaic in Yellowstone National Park (YNP). Plants from thermal annual and nonthermal perennial habitats were heritably differentiated for life-history and mating system traits, consistent with local adaptation to the ephemeral thermal-soil growing season. However, genome-wide genetic variation primarily clustered plants by geographic region, with little variation sorting by habitat. The one exception was an extreme thermal population also isolated by a 200 m geographical gap of no intermediate habitat. Individual inbreeding coefficients (FIS ) were higher (and predicted by trait variation) in annual plants and annual pairs showed greater isolation by distance at local (<1 km) scales. Finally, YNP adaptation does not reuse a widespread inversion that underlies M. guttatus life-history ecotypes range-wide, suggesting a novel genetic mechanism. Overall, this work suggests that life-history and mating system adaptation strong enough to shape individual mating patterns does not necessarily generate incipient speciation without geographical barriers.
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Affiliation(s)
- Kory M Kolis
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812.,Current Address: O'Connor Center for the Rocky Mountain West, University of Montana, Missoula, MT, 59812
| | - Colette S Berg
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812
| | - Thomas C Nelson
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812.,Current Address: Embark Veterinary, Inc., Boston, Massachusetts, 02210
| | - Lila Fishman
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812
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25
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White NJ, Beckerman AP, Snook RR, Brockhurst MA, Butlin RK, Eyres I. Experimental evolution of local adaptation under unidimensional and multidimensional selection. Curr Biol 2022; 32:1310-1318.e4. [DOI: 10.1016/j.cub.2022.01.048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 11/25/2021] [Accepted: 01/18/2022] [Indexed: 01/17/2023]
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26
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The evolutionary history of the Caribbean magnolias (Magnoliaceae): Testing species delimitations and biogeographical hypotheses using molecular data. Mol Phylogenet Evol 2021; 167:107359. [PMID: 34793981 DOI: 10.1016/j.ympev.2021.107359] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 11/02/2021] [Accepted: 11/09/2021] [Indexed: 11/24/2022]
Abstract
The Caribbean islands provide an ideal setting for studying biodiversity, given their complex geological and environmental history, and their historical and current geographical proximity to the American mainland. Magnolia, a flagship tree genus that has 15 endemic and threatened taxa (12 species and 3 subspecies) on the Caribbean islands, offers an excellent case study to empirically test Caribbean biogeographical hypotheses. We constructed phylogenetic hypotheses to: (1) reveal their evolutionary history, (2) test the current largely morphology-based classification and assess species limits, and (3) investigate major biogeographic hypotheses proposed for the region. Nuclear and chloroplast DNA sequence data of all 15 Caribbean Magnolia taxa are included, supplemented by a selection of American mainland species, and species representing most major clades of the Magnoliaceae family. We constructed phylogenetic hypotheses in a time-calibrated Bayesian framework, supplemented with haplotype network analyses and ancestral range estimations. Genetic synapomorphies in the studied markers confirm the species limits of 14 out of 15 morphologically recognizable Caribbean Magnolia taxa. There is evidence for four colonization events of Magnolia into the Caribbean from the American mainland, which most likely occurred by overwater dispersal, given age estimates of maximum 16 mya for their presence on the Caribbean islands.
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27
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Dool SE, Picker MD, Eberhard MJB. Limited dispersal and local adaptation promote allopatric speciation in a biodiversity hotspot. Mol Ecol 2021; 31:279-295. [PMID: 34643310 DOI: 10.1111/mec.16219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 09/30/2021] [Accepted: 10/04/2021] [Indexed: 01/20/2023]
Abstract
Recently diverged or diverging populations can offer unobstructed insights into early barriers to gene flow during the initial stages of speciation. The current study utilised a novel insect system (order Mantophasmatodea) to shed light on the early drivers of speciation. The members of this group have limited dispersal abilities, small allopatric distributions and strong habitat associations in the Cape Floristic Region biodiversity hotspot in South Africa. Sister taxa from the diverse family Austrophasmatidae were chosen as focal species (Karoophasma biedouwense, K. botterkloofense). Population genetics and Generalized Dissimilarity Modelling (GDM) were used to characterise spatial patterns of genetic variation and evaluate the contribution of environmental factors to population divergence and speciation. Extensive sampling confirmed the suspected allopatry of these taxa. However, hybrids were identified in a narrow region occurring between the species' distributions. Strong population structure was found over short geographic distances; particularly in K. biedouwense in which geographic distance accounted for 32% of genetic variation over a scale of 50 km (r = .56, p < .001). GDM explained 42%-78% of the deviance in observed genetic dissimilarities. Geographic distance was consistently indicated to be important for between species and within population differentiation, suggesting that limited dispersal ability may be an important neutral driver of divergence. Temperature, altitude, precipitation and vegetation were also indicated as important factors, suggesting the possible role of adaptation to local environmental conditions for species divergence. The discovery of the hybrid-zone, and the multiple allopatric species pairs in Austrophasmatidae support the idea that this could be a promising group to further our understanding of speciation modes.
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Affiliation(s)
- Serena E Dool
- General and Systematic Zoology, Zoological Institute and Museum, University of Greifswald, Greifswald, Germany.,CBGP, INRAE, CIRAD, IRD, Institut Agro, University of Montpellier, Montpellier, France
| | - Mike D Picker
- Department of Biological Sciences, University of Cape Town, Cape Town, South Africa
| | - Monika J B Eberhard
- General and Systematic Zoology, Zoological Institute and Museum, University of Greifswald, Greifswald, Germany
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28
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Ng CKC, Tan J. Cryptic species and grey zone speciation of the Barbodes binotatus complex (Teleostei, Cyprinidae) in Sundaland. JOURNAL OF FISH BIOLOGY 2021; 99:1256-1273. [PMID: 34159593 DOI: 10.1111/jfb.14829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 06/03/2021] [Accepted: 06/12/2021] [Indexed: 06/13/2023]
Abstract
Morphology-based taxonomy of freshwater fish is effective when there are representative specimens covering large regions. However, in Sundaland, where the presence of cryptic species is high, the technique has its limitations. This is compounded by uncritical descriptions of holotypes in old literature. We demonstrate the problem using Barbodes binotatus first described from an ink drawing. Several species in the Barbodes genus of Sundaland exhibit morphological similarity to B. binotatus. We applied new DNA sequences of 16S, cytochrome c oxidase subunit I (COI), cytochrome b (Cytb) and recombination-activating gene 1 (RAG1), and pigmentation markers to clarify species complex boundaries in the Malay Peninsula, namely B. aff. binotatus "Malay Peninsula", Barbodes cf. banksi and Barbodes rhombeus. Results suggest B. binotatus-like specimens in the Malay Peninsula are B. rhombeus based on a threshold of 3% COI genetic divergence. B. aff. binotatus recorded in Sumatra, Borneo and the Philippines are likely valid but undescribed species. However, if the 2% COI threshold is applied, some populations in the northern Malay Peninsula would qualify as new and undescribed species. The implications of the 2% threshold and the likelihood of "grey zone" incipient populations are discussed. We further found a rapid visual method, not reported previously, to delineate B. aff. binotatus and B. cf. banksi, but it requires further validation. Additionally, we offer fresh perspectives by discussing the roles of biological species concept, morphological species concept, genetic species concept and mate recognition concept in the B. binotatus complex. Our findings reinforce the standpoint that species delineation is not entirely a binary process, but there is a spectrum to consider, especially in biogeography intersection regions.
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Affiliation(s)
- Casey Keat-Chuan Ng
- School of Biological Sciences, Universiti Sains Malaysia, Pulau Pinang, Malaysia
| | - Ji Tan
- Department of Agricultural and Food Sciences, Faculty of Science, Universiti Tunku Abdul Rahman, Kampar, Malaysia
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29
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Levin B, Simonov E, Franchini P, Mugue N, Golubtsov A, Meyer A. Rapid adaptive radiation in a hillstream cyprinid fish in the East African White Nile River basin. Mol Ecol 2021; 30:5530-5550. [PMID: 34409661 DOI: 10.1111/mec.16130] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 08/02/2021] [Accepted: 08/11/2021] [Indexed: 12/14/2022]
Abstract
Adaptive radiation of freshwater fishes was long thought to be possible only in lacustrine environments. Recently, several studies have shown that riverine and stream environments also provide the ecological opportunity for adaptive radiation. In this study, we report on a riverine adaptive radiation of six ecomorphs of cyprinid hillstream fishes of the genus Garra in a river located in the Ethiopian Highlands in East Africa. Garra are predominantly highly specialized algae-scrapers with a wide distribution ranging from Southeast Asia to West Africa. However, adaptive phenotypic diversification in mouth type, sucking disc morphology, gut length and body shape have probably been found among these ecomorphs in a single Ethiopian river. Moreover, we found two novel phenotypes of Garra ("thick-lipped" and "predatory") that had not been discovered before in this species-rich genus (>160 species). Mitochondrial and genome-wide data suggest monophyletic, intrabasin evolution of Garra phenotypic diversity with signatures of gene flow from other local populations. Although sympatric ecomorphs are genetically distinct and can be considered to being young species as suggested by genome-wide single nucleotide polymorphism data, mitochondrial DNA was unable to identify any genetic structure suggesting recent and rapid speciation events. Some data suggest a hybrid origin of the novel "thick-lipped" ecomorph. Here we highlight how, driven by ecological opportunity, an ancestral trophically highly specialized lineage is likely to have rapidly radiated in a riverine environment promoted by the evolution of novel feeding strategies.
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Affiliation(s)
- Boris Levin
- Papanin Institute of Biology of Inland Waters, Russian Academy of Sciences, Borok, Russia.,Zoological Institute of Russian Academy of Sciences, Cherepovets State University, St. Petersburg, Russia
| | - Evgeniy Simonov
- Institute of Environmental and Agricultural Biology (X-BIO), University of Tyumen, Tyumen, Russia
| | - Paolo Franchini
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Nikolai Mugue
- Koltzov Institute for Developmental Biology, Russian Academy of Sciences, Moscow, Russia
| | - Alexander Golubtsov
- Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
| | - Axel Meyer
- Department of Biology, University of Konstanz, Konstanz, Germany
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30
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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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31
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White NJ, Butlin RK. Multidimensional divergent selection, local adaptation, and speciation. Evolution 2021; 75:2167-2178. [PMID: 34263939 DOI: 10.1111/evo.14312] [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: 11/06/2020] [Revised: 06/29/2021] [Accepted: 07/05/2021] [Indexed: 12/24/2022]
Abstract
Divergent selection applied to one or more traits drives local adaptation and may lead to ecological speciation. Divergent selection on many traits might be termed "multidimensional" divergent selection. There is a commonly held view that multidimensional divergent selection is likely to promote local adaptation and speciation to a greater extent than unidimensional divergent selection. We disentangle the core concepts underlying dimensionality as a property of the environment, phenotypes, and genome. In particular, we identify a need to separate the overall strength of selection and the number of loci affected from dimensionality per se, and to distinguish divergence dimensionality from dimensionality of stabilizing selection. We then critically scrutinize this commonly held view that multidimensional selection promotes speciation, re-examining the evidence base from theory, experiments, and nature. We conclude that the evidence base is currently weak and generally suffers from confounding of possible causal effects. Finally, we propose several mechanisms by which multidimensional divergent selection and related processes might influence divergence, both as a driver and as a barrier.
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Affiliation(s)
- Nathan J White
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - Roger K Butlin
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom.,Department of Marine Sciences, University of Gothenburg, Gothenburg, SE-40530, Sweden
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32
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Rodríguez RL, Wood TK, Stearns FW, Snyder RL, Tilmon KJ, Cast MS, Hunt RE, Cocroft RB. Adaptation without Specialization Early in a Host Shift. Am Nat 2021; 198:333-346. [PMID: 34403320 DOI: 10.1086/715629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractStudents of speciation debate the role of performance trade-offs across different environments early in speciation. We tested for early performance trade-offs with a host shift experiment using a member of the Enchenopa binotata species complex of treehoppers (Hemiptera: Membracidae). In this clade of plant-feeding insects, different species live on different host plants and exhibit strong behavioral and physiological host specialization. After five generations, the experimental host shifts resulted either in no adaptation or in adaptation without specialization. The latter result was more likely in sympatry; in allopatry, populations on novel host plants were more likely to become extinct. We conclude that in the early stages of speciation, adaptation to novel host plants does not necessarily bring about performance trade-offs on ancestral environments. Adaptation may be facilitated rather than hindered by gene flow, which prevents extinction. Additional causes of specialization and assortative mating may be required if colonization of novel environments is to result in speciation.
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33
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Westram AM, Faria R, Johannesson K, Butlin R. Using replicate hybrid zones to understand the genomic basis of adaptive divergence. Mol Ecol 2021; 30:3797-3814. [PMID: 33638231 DOI: 10.1111/mec.15861] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 02/12/2021] [Indexed: 12/28/2022]
Abstract
Combining hybrid zone analysis with genomic data is a promising approach to understanding the genomic basis of adaptive divergence. It allows for the identification of genomic regions underlying barriers to gene flow. It also provides insights into spatial patterns of allele frequency change, informing about the interplay between environmental factors, dispersal and selection. However, when only a single hybrid zone is analysed, it is difficult to separate patterns generated by selection from those resulting from chance. Therefore, it is beneficial to look for repeatable patterns across replicate hybrid zones in the same system. We applied this approach to the marine snail Littorina saxatilis, which contains two ecotypes, adapted to wave-exposed rocks vs. high-predation boulder fields. The existence of numerous hybrid zones between ecotypes offered the opportunity to test for the repeatability of genomic architectures and spatial patterns of divergence. We sampled and phenotyped snails from seven replicate hybrid zones on the Swedish west coast and genotyped them for thousands of single nucleotide polymorphisms. Shell shape and size showed parallel clines across all zones. Many genomic regions showing steep clines and/or high differentiation were shared among hybrid zones, consistent with a common evolutionary history and extensive gene flow between zones, and supporting the importance of these regions for divergence. In particular, we found that several large putative inversions contribute to divergence in all locations. Additionally, we found evidence for consistent displacement of clines from the boulder-rock transition. Our results demonstrate patterns of spatial variation that would not be accessible without continuous spatial sampling, a large genomic data set and replicate hybrid zones.
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Affiliation(s)
- Anja M Westram
- IST Austria, Klosterneuburg, Austria.,Animal & Plant Sciences, Western Bank, University of Sheffield, Sheffield, UK.,Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
| | - Rui Faria
- Animal & Plant Sciences, Western Bank, University of Sheffield, Sheffield, UK.,CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Laboratório Associado, Universidade do Porto, Vairão, Portugal.,CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Porto, Portugal
| | - Kerstin Johannesson
- Marine Sciences, Tjärnö Marine Laboratory, University of Gothenburg, Strömstad, Sweden
| | - Roger Butlin
- Animal & Plant Sciences, Western Bank, University of Sheffield, Sheffield, UK.,Marine Sciences, Tjärnö Marine Laboratory, University of Gothenburg, Strömstad, Sweden
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34
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Brachmann MK, Parsons K, Skúlason S, Ferguson MM. The interaction of resource use and gene flow on the phenotypic divergence of benthic and pelagic morphs of Icelandic Arctic charr ( Salvelinus alpinus). Ecol Evol 2021; 11:7315-7334. [PMID: 34188815 PMCID: PMC8216915 DOI: 10.1002/ece3.7563] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 02/09/2021] [Accepted: 03/02/2021] [Indexed: 12/11/2022] Open
Abstract
Conceptual models of adaptive divergence and ecological speciation in sympatry predict differential resource use, phenotype-environment correlations, and reduced gene flow among diverging phenotypes. While these predictions have been assessed in past studies, connections among them have rarely been assessed collectively. We examined relationships among phenotypic, ecological, and genetic variation in Arctic charr (Salvelinus alpinus) from six Icelandic localities that have undergone varying degrees of divergence into sympatric benthic and pelagic morphs. We characterized morphological variation with geometric morphometrics, tested for differential resource use between morphs using stable isotopes, and inferred the amount of gene flow from single nucleotide polymorphisms. Analysis of stable isotopic signatures indicated that sympatric morphs showed similar difference in resource use across populations, likely arising from the common utilization of niche space within each population. Carbon isotopic signature was also a significant predictor of individual variation in body shape and size, suggesting that variation in benthic and pelagic resource use is associated with phenotypic variation. The estimated percentage of hybrids between sympatric morphs varied across populations (from 0% to 15.6%) but the majority of fish had genotypes (ancestry coefficients) characteristic of pure morphs. Despite evidence of reduced gene flow between sympatric morphs, we did not detect the expected negative relationship between divergence in resource use and gene flow. Three lakes showed the expected pattern, but morphs in the fourth showed no detectable hybridization and had relatively low differences in resource use between them. This coupled with the finding that resource use and genetic differentiation had differential effects on body shape variation across populations suggests that reproductive isolation maintains phenotypic divergence between benthic and pelagic morphs when the effects of resource use are relatively low. Our ability to assess relationships between phenotype, ecology, and genetics deepens our understanding of the processes underlying adaptive divergence in sympatry.
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Affiliation(s)
| | - Kevin Parsons
- Institute of Biodiversity, Animal Health and Comparative MedicineSchool of Life ScienceUniversity of GlasgowGlasgowUK
| | - Skúli Skúlason
- Department of Aquaculture and Fish BiologyHólar UniversitySaudárkrókurIceland
- Icelandic Museum of Natural HistoryReykjavíkIceland
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35
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Seabra SG, Rodrigues AS, Silva SE, Neto AC, Pina-Martins F, Marabuto E, Thompson V, Wilson MR, Yurtsever S, Halkka A, Rebelo MT, Borges PA, Quartau JA, Jiggins CD, Paulo OS. Population structure, adaptation and divergence of the meadow spittlebug, Philaenus spumarius (Hemiptera, Aphrophoridae), revealed by genomic and morphological data. PeerJ 2021; 9:e11425. [PMID: 34131518 PMCID: PMC8176912 DOI: 10.7717/peerj.11425] [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: 11/30/2020] [Accepted: 04/17/2021] [Indexed: 11/20/2022] Open
Abstract
Understanding patterns of population differentiation and gene flow in insect vectors of plant diseases is crucial for the implementation of management programs of disease. We investigated morphological and genome-wide variation across the distribution range of the spittlebug Philaenus spumarius (Linnaeus, 1758) (Hemiptera, Auchenorrhyncha, Aphrophoridae), presently the most important vector of the plant pathogenic bacterium Xylella fastidiosa Wells et al., 1987 in Europe. We found genome-wide divergence between P. spumarius and a very closely related species, P. tesselatus Melichar, 1899, at RAD sequencing markers. The two species may be identified by the morphology of male genitalia but are not differentiated at mitochondrial COI, making DNA barcoding with this gene ineffective. This highlights the importance of using integrative approaches in taxonomy. We detected admixture between P. tesselatus from Morocco and P. spumarius from the Iberian Peninsula, suggesting gene-flow between them. Within P. spumarius, we found a pattern of isolation-by-distance in European populations, likely acting alongside other factors restricting gene flow. Varying levels of co-occurrence of different lineages, showing heterogeneous levels of admixture, suggest other isolation mechanisms. The transatlantic populations of North America and Azores were genetically closer to the British population analyzed here, suggesting an origin from North-Western Europe, as already detected with mitochondrial DNA. Nevertheless, these may have been produced through different colonization events. We detected SNPs with signatures of positive selection associated with environmental variables, especially related to extremes and range variation in temperature and precipitation. The population genomics approach provided new insights into the patterns of divergence, gene flow and adaptation in these spittlebugs and led to several hypotheses that require further local investigation.
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Affiliation(s)
- Sofia G. Seabra
- E3c - Centre for Ecology, Evolution and Environmental Changes, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Ana S.B. Rodrigues
- E3c - Centre for Ecology, Evolution and Environmental Changes, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Sara E. Silva
- E3c - Centre for Ecology, Evolution and Environmental Changes, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Ana Carina Neto
- CESAM - Centre for Environmental and Marine Studies, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Francisco Pina-Martins
- E3c - Centre for Ecology, Evolution and Environmental Changes, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Eduardo Marabuto
- E3c - Centre for Ecology, Evolution and Environmental Changes, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | | | - Michael R. Wilson
- National Museum of Wales, Department of Natural Sciences, Cardiff, United Kingdom
| | - Selçuk Yurtsever
- Trakya University, Biology Department, Science Faculty, Edirne, Turkey
| | - Antti Halkka
- Department of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Maria Teresa Rebelo
- CESAM - Centre for Environmental and Marine Studies, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Paulo A.V. Borges
- cE3c - Centre for Ecology, Evolution and Environmental Changes/Azorean Biodiversity Group, Faculty of Agriculture and Environment, Department of Environmental Sciences and Engineering, Universidade dos Açores, Angra do Heroísmo, Açores, Portugal
| | - José A. Quartau
- E3c - Centre for Ecology, Evolution and Environmental Changes, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Chris D. Jiggins
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Octávio S. Paulo
- E3c - Centre for Ecology, Evolution and Environmental Changes, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
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36
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Berdan EL, Blanckaert A, Slotte T, Suh A, Westram AM, Fragata I. Unboxing mutations: Connecting mutation types with evolutionary consequences. Mol Ecol 2021; 30:2710-2723. [PMID: 33955064 DOI: 10.1111/mec.15936] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/30/2021] [Accepted: 04/20/2021] [Indexed: 01/09/2023]
Abstract
A key step in understanding the genetic basis of different evolutionary outcomes (e.g., adaptation) is to determine the roles played by different mutation types (e.g., SNPs, translocations and inversions). To do this we must simultaneously consider different mutation types in an evolutionary framework. Here, we propose a research framework that directly utilizes the most important characteristics of mutations, their population genetic effects, to determine their relative evolutionary significance in a given scenario. We review known population genetic effects of different mutation types and show how these may be connected to different evolutionary outcomes. We provide examples of how to implement this framework and pinpoint areas where more data, theory and synthesis are needed. Linking experimental and theoretical approaches to examine different mutation types simultaneously is a critical step towards understanding their evolutionary significance.
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Affiliation(s)
- Emma L Berdan
- Department of Ecology, Environment and Plant Sciences, Science for Life Laboratory, Stockholm University, Stockholm, Sweden
| | | | - Tanja Slotte
- Department of Ecology, Environment and Plant Sciences, Science for Life Laboratory, Stockholm University, Stockholm, Sweden
| | - Alexander Suh
- School of Biological Sciences - Organisms and the Environment, University of East Anglia, Norwich, UK.,Department of Organismal Biology - Systematic Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Anja M Westram
- IST Austria, Klosterneuburg, Austria.,Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
| | - Inês Fragata
- cE3c - Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
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37
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Kolora SRR, Gysi DM, Schaffer S, Grimm-Seyfarth A, Szabolcs M, Faria R, Henle K, Stadler PF, Schlegel M, Nowick K. Accelerated Evolution of Tissue-Specific Genes Mediates Divergence Amidst Gene Flow in European Green Lizards. Genome Biol Evol 2021; 13:6275683. [PMID: 33988711 PMCID: PMC8382678 DOI: 10.1093/gbe/evab109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/13/2021] [Indexed: 11/12/2022] Open
Abstract
The European green lizards of the Lacerta viridis complex consist of two closely related species, L. viridis and Lacerta bilineata that split less than 7 million years ago in the presence of gene flow. Recently, a third lineage, referred to as the “Adriatic” was described within the L. viridis complex distributed from Slovenia to Greece. However, whether gene flow between the Adriatic lineage and L. viridis or L. bilineata has occurred and the evolutionary processes involved in their diversification are currently unknown. We hypothesized that divergence occurred in the presence of gene flow between multiple lineages and involved tissue-specific gene evolution. In this study, we sequenced the whole genome of an individual of the Adriatic lineage and tested for the presence of gene flow amongst L. viridis, L. bilineata, and Adriatic. Additionally, we sequenced transcriptomes from multiple tissues to understand tissue-specific effects. The species tree supports that the Adriatic lineage is a sister taxon to L. bilineata. We detected gene flow between the Adriatic lineage and L. viridis suggesting that the evolutionary history of the L. viridis complex is likely shaped by gene flow. Interestingly, we observed topological differences between the autosomal and Z-chromosome phylogenies with a few fast evolving genes on the Z-chromosome. Genes highly expressed in the ovaries and strongly co-expressed in the brain experienced accelerated evolution presumably contributing to establishing reproductive isolation in the L. viridis complex.
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Affiliation(s)
- Sree Rohit Raj Kolora
- German Centre for Integrative Biodiversity Research (iDiv) Halle Jena Leipzig, Leipzig, Germany.,Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, Universität Leipzig, Leipzig, Germany.,Molecular Evolution & Animal Systematics, University of Leipzig, Leipzig, Germany.,Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Deisy Morselli Gysi
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, Universität Leipzig, Leipzig, Germany.,Swarm Intelligence and Complex Systems Group, Faculty of Mathematics and Computer Science, University of Leipzig, Leipzig, Germany.,Center for Complex Networks Research, Northeastern University, Boston, MA, USA
| | - Stefan Schaffer
- German Centre for Integrative Biodiversity Research (iDiv) Halle Jena Leipzig, Leipzig, Germany.,Molecular Evolution & Animal Systematics, University of Leipzig, Leipzig, Germany
| | - Annegret Grimm-Seyfarth
- Department of Conservation Biology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Márton Szabolcs
- Department of Tisza River Research, Danube Research Institute, Centre for Ecological Research, Hungarian Academy of Sciences, Debrecen, Hungary
| | - Rui Faria
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Laboratório Associado, Universidade do Porto, Vairão, Portugal
| | - Klaus Henle
- German Centre for Integrative Biodiversity Research (iDiv) Halle Jena Leipzig, Leipzig, Germany.,Department of Conservation Biology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Peter F Stadler
- German Centre for Integrative Biodiversity Research (iDiv) Halle Jena Leipzig, Leipzig, Germany.,Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, Universität Leipzig, Leipzig, Germany.,Competence Center for Scalable Data Services and Solutions Dresden/Leipzig, Universität Leipzig, Leipzig, Germany.,Max-Planck-Institute for Mathematics in the Sciences, Leipzig, Germany.,Department of Theoretical Chemistry, University of Vienna, Wien, Austria.,Facultad de Ciencias, Universidad Nacional de Colombia, Bogotá, Colombia.,Santa Fe Institute, New Mexico, USA
| | - Martin Schlegel
- German Centre for Integrative Biodiversity Research (iDiv) Halle Jena Leipzig, Leipzig, Germany.,Molecular Evolution & Animal Systematics, University of Leipzig, Leipzig, Germany
| | - Katja Nowick
- Institute for Biology, Freie Universität Berlin, Berlin, Germany
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38
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Koch EL, Morales HE, Larsson J, Westram AM, Faria R, Lemmon AR, Lemmon EM, Johannesson K, Butlin RK. Genetic variation for adaptive traits is associated with polymorphic inversions in Littorina saxatilis. Evol Lett 2021; 5:196-213. [PMID: 34136269 PMCID: PMC8190449 DOI: 10.1002/evl3.227] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 02/06/2021] [Accepted: 03/29/2021] [Indexed: 01/11/2023] Open
Abstract
Chromosomal inversions have long been recognized for their role in local adaptation. By suppressing recombination in heterozygous individuals, they can maintain coadapted gene complexes and protect them from homogenizing effects of gene flow. However, to fully understand their importance for local adaptation we need to know their influence on phenotypes under divergent selection. For this, the marine snail Littorina saxatilis provides an ideal study system. Divergent ecotypes adapted to wave action and crab predation occur in close proximity on intertidal shores with gene flow between them. Here, we used F2 individuals obtained from crosses between the ecotypes to test for associations between genomic regions and traits distinguishing the Crab‐/Wave‐adapted ecotypes including size, shape, shell thickness, and behavior. We show that most of these traits are influenced by two previously detected inversion regions that are divergent between ecotypes. We thus gain a better understanding of one important underlying mechanism responsible for the rapid and repeated formation of ecotypes: divergent selection acting on inversions. We also found that some inversions contributed to more than one trait suggesting that they may contain several loci involved in adaptation, consistent with the hypothesis that suppression of recombination within inversions facilitates differentiation in the presence of gene flow.
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Affiliation(s)
- Eva L Koch
- Department of Animal and Plant Sciences University of Sheffield Sheffield United Kingdom
| | - Hernán E Morales
- Evolutionary Genetics Section Globe Institute University of Copenhagen Copenhagen Denmark.,Department of Marine Sciences University of Gothenburg Strömstad 45296 Sweden
| | - Jenny Larsson
- Department of Animal and Plant Sciences University of Sheffield Sheffield United Kingdom
| | - Anja M Westram
- Department of Animal and Plant Sciences University of Sheffield Sheffield United Kingdom.,IST Austria Klosterneuburg Austria
| | - Rui Faria
- Department of Animal and Plant Sciences University of Sheffield Sheffield United Kingdom.,CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos Universidade do Porto Vairão Portugal
| | - Alan R Lemmon
- Department of Scientific Computing Florida State University Tallahassee Florida FL 32306-4120
| | - E Moriarty Lemmon
- Department of Biological Science Florida State University Tallahassee Florida FL 32306-4295
| | - Kerstin Johannesson
- Department of Marine Sciences University of Gothenburg Strömstad 45296 Sweden
| | - Roger K Butlin
- Department of Animal and Plant Sciences University of Sheffield Sheffield United Kingdom.,Department of Marine Sciences University of Gothenburg Strömstad 45296 Sweden
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39
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Stankowski S, Ravinet M. Defining the speciation continuum. Evolution 2021; 75:1256-1273. [PMID: 33754340 DOI: 10.1111/evo.14215] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 03/01/2021] [Accepted: 03/13/2021] [Indexed: 02/06/2023]
Abstract
A primary roadblock to our understanding of speciation is that it usually occurs over a timeframe that is too long to study from start to finish. The idea of a speciation continuum provides something of a solution to this problem; rather than observing the entire process, we can simply reconstruct it from the multitude of speciation events that surround us. But what do we really mean when we talk about the speciation continuum, and can it really help us understand speciation? We explored these questions using a literature review and online survey of speciation researchers. Although most researchers were familiar with the concept and thought it was useful, our survey revealed extensive disagreement about what the speciation continuum actually tells us. This is due partly to the lack of a clear definition. Here, we provide an explicit definition that is compatible with the Biological Species Concept. That is, the speciation continuum is a continuum of reproductive isolation. After outlining the logic of the definition in light of alternatives, we explain why attempts to reconstruct the speciation process from present-day populations will ultimately fail. We then outline how we think the speciation continuum concept can continue to act as a foundation for understanding the continuum of reproductive isolation that surrounds us.
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Affiliation(s)
- Sean Stankowski
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom.,Current Address: Sean Stankowski, IST Austria, Klosterneuburg, 3400, Austria
| | - Mark Ravinet
- Centre for Ecological and Evolutionary Synthesis, University of Oslo, Oslo, 0316, Norway.,School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
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40
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Butlin RK, Servedio MR, Smadja CM, Bank C, Barton NH, Flaxman SM, Giraud T, Hopkins R, Larson EL, Maan ME, Meier J, Merrill R, Noor MAF, Ortiz-Barrientos D, Qvarnström A. Homage to Felsenstein 1981, or why are there so few/many species? Evolution 2021; 75:978-988. [PMID: 33870499 DOI: 10.1111/evo.14235] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/09/2021] [Accepted: 04/12/2021] [Indexed: 02/01/2023]
Abstract
If there are no constraints on the process of speciation, then the number of species might be expected to match the number of available niches and this number might be indefinitely large. One possible constraint is the opportunity for allopatric divergence. In 1981, Felsenstein used a simple and elegant model to ask if there might also be genetic constraints. He showed that progress towards speciation could be described by the build-up of linkage disequilibrium among divergently selected loci and between these loci and those contributing to other forms of reproductive isolation. Therefore, speciation is opposed by recombination, because it tends to break down linkage disequilibria. Felsenstein then introduced a crucial distinction between "two-allele" models, which are subject to this effect, and "one-allele" models, which are free from the recombination constraint. These fundamentally important insights have been the foundation for both empirical and theoretical studies of speciation ever since.
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Affiliation(s)
- Roger K Butlin
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK and Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Maria R Servedio
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599
| | - Carole M Smadja
- Institut des Sciences de l'Evolution de Montpellier, (ISEM-Université de Montpellier, CNRS, IRD), Montpellier, France
| | - Claudia Bank
- Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland and, Gulbenkian Science Institute, Oeiras, Portugal
| | | | - Samuel M Flaxman
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO, 80309
| | - Tatiana Giraud
- Ecologie Systématique et Evolution, CNRS, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Robin Hopkins
- Department of Organismic and Evolutionary Biology, Arnold Arboretum, Harvard University, Boston, MA, 02131
| | - Erica L Larson
- Department of Biological Sciences, University of Denver, Denver, CO, 80208
| | - Martine E Maan
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Joana Meier
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Richard Merrill
- Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Planegg-Martinsried, 82152, Germany
| | | | - Daniel Ortiz-Barrientos
- School of Biological Sciences, The University of Queensland, St Lucia, Queensland, 4072, Australia
| | - Anna Qvarnström
- Department of Ecology and Genetics, Uppsala University, Uppsala, SE-751 05, Sweden
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41
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Godineau C, Ronce O, Devaux C. Assortative mating can help adaptation of flowering time to a changing climate: Insights from a polygenic model. J Evol Biol 2021; 35:491-508. [PMID: 33794053 PMCID: PMC9292552 DOI: 10.1111/jeb.13786] [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: 09/15/2020] [Revised: 01/15/2021] [Accepted: 03/19/2021] [Indexed: 11/28/2022]
Abstract
Several empirical studies report fast evolutionary changes in flowering time in response to contemporary climate change. Flowering time is a polygenic trait under assortative mating, since flowering time of mates must overlap. Here, we test whether assortative mating, compared with random mating, can help better track a changing climate. For each mating pattern, our individual‐based model simulates a population evolving in a climate characterized by stabilizing selection around an optimal flowering time, which can change directionally and/or fluctuate. We also derive new analytical predictions from a quantitative genetics model for the expected genetic variance at equilibrium, and its components, the lag of the population to the optimum and the population mean fitness. We compare these predictions between assortative and random mating, and to our simulation results. Assortative mating, compared with random mating, has antagonistic effects on genetic variance: it generates positive associations among similar allelic effects, which inflates the genetic variance, but it decreases genetic polymorphism, which depresses the genetic variance. In a stationary environment with substantial stabilizing selection, assortative mating affects little the genetic variance compared with random mating. In a changing climate, assortative mating however increases genetic variance compared to random mating, which diminishes the lag of the population to the optimum, and in most scenarios translates into a fitness advantage relative to random mating. The magnitude of this fitness advantage depends on the extent to which genetic variance limits adaptation, being larger for faster environmental changes and weaker stabilizing selection.
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Affiliation(s)
- Claire Godineau
- Institut des Sciences de l'Évolution, Université de Montpellier, CNRS, IRD, EPHE, Montpellier, France
| | - Ophélie Ronce
- Institut des Sciences de l'Évolution, Université de Montpellier, CNRS, IRD, EPHE, Montpellier, France.,CNRS, Biodiversity Research Center, University of British Columbia, Vancouver, BC, Canada
| | - Céline Devaux
- Institut des Sciences de l'Évolution, Université de Montpellier, CNRS, IRD, EPHE, Montpellier, France
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42
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Andersen MJ, McCullough JM, Gyllenhaal EF, Mapel XM, Haryoko T, Jønsson KA, Joseph L. Complex histories of gene flow and a mitochondrial capture event in a nonsister pair of birds. Mol Ecol 2021; 30:2087-2103. [PMID: 33615597 PMCID: PMC8252742 DOI: 10.1111/mec.15856] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 02/02/2021] [Accepted: 02/12/2021] [Indexed: 01/03/2023]
Abstract
Hybridization, introgression, and reciprocal gene flow during speciation, specifically the generation of mitonuclear discordance, are increasingly observed as parts of the speciation process. Genomic approaches provide insight into where, when, and how adaptation operates during and after speciation and can measure historical and modern introgression. Whether adaptive or neutral in origin, hybridization can cause mitonuclear discordance by placing the mitochondrial genome of one species (or population) in the nuclear background of another species. The latter, introgressed species may eventually have its own mtDNA replaced or “captured” by other species across its entire geographical range. Intermediate stages in the capture process should be observable. Two nonsister species of Australasian monarch‐flycatchers, Spectacled Monarch (Symposiachrus trivirgatus) mostly of Australia and Indonesia and Spot‐winged Monarch (S. guttula) of New Guinea, present an opportunity to observe this process. We analysed thousands of single nucleotide polymorphisms (SNPs) derived from ultraconserved elements of all subspecies of both species. Mitochondrial DNA sequences of Australian populations of S. trivirgatus form two paraphyletic clades, one being sister to and presumably introgressed by S. guttula despite little nuclear signal of introgression. Population genetic analyses (e.g., tests for modern and historical gene flow and selection) support at least one historical gene flow event between S. guttula and Australian S. trivirgatus. We also uncovered introgression from the Maluku Islands subspecies of S. trivirgatus into an island population of S. guttula, resulting in apparent nuclear paraphyly. We find that neutral demographic processes, not adaptive introgression, are the most likely cause of these complex population histories. We suggest that a Pleistocene extinction of S. guttula from mainland Australia resulted from range expansion by S. trivirgatus.
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Affiliation(s)
- Michael J Andersen
- Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Jenna M McCullough
- Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Ethan F Gyllenhaal
- Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Xena M Mapel
- Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico, USA.,Animal Genomics, ETH Zürich, Lindau, Switzerland
| | - Tri Haryoko
- Museum Zoologicum Bogoriense, Research Centre for Biology, Indonesian Institute of Sciences (LIPI), Cibinong, Indonesia
| | - Knud A Jønsson
- Natural History Museum of Denmark, University of Copenhagen, Copenhagen Ø, Denmark
| | - Leo Joseph
- Australian National Wildlife Collection, CSIRO National Research Collections, Canberra, Australian Capital Territory, Australia
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43
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Inskeep KA, Doellman MM, Powell THQ, Berlocher SH, Seifert NR, Hood GR, Ragland GJ, Meyers PJ, Feder JL. Divergent diapause life history timing drives both allochronic speciation and reticulate hybridization in an adaptive radiation of Rhagoletis flies. Mol Ecol 2021; 31:4031-4049. [PMID: 33786930 DOI: 10.1111/mec.15908] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 03/01/2021] [Accepted: 03/15/2021] [Indexed: 12/18/2022]
Abstract
Divergent adaptation to new ecological opportunities can be an important factor initiating speciation. However, as niches are filled during adaptive radiations, trait divergence driving reproductive isolation between sister taxa may also result in trait convergence with more distantly related taxa, increasing the potential for reticulated gene flow across the radiation. Here, we demonstrate such a scenario in a recent adaptive radiation of Rhagoletis fruit flies, specialized on different host plants. Throughout this radiation, shifts to novel hosts are associated with changes in diapause life history timing, which act as "magic traits" generating allochronic reproductive isolation and facilitating speciation-with-gene-flow. Evidence from laboratory rearing experiments measuring adult emergence timing and genome-wide DNA-sequencing surveys supported allochronic speciation between summer-fruiting Vaccinium spp.-infesting Rhagoletis mendax and its hypothesized and undescribed sister taxon infesting autumn-fruiting sparkleberries. The sparkleberry fly and R. mendax were shown to be genetically discrete sister taxa, exhibiting no detectable gene flow and allochronically isolated by a 2-month average difference in emergence time corresponding to host availability. At sympatric sites across the southern USA, the later fruiting phenology of sparkleberries overlaps with that of flowering dogwood, the host of another more distantly related and undescribed Rhagoletis taxon. Laboratory emergence data confirmed broadly overlapping life history timing and genomic evidence supported on-going gene flow between sparkleberry and flowering dogwood flies. Thus, divergent phenological adaptation can drive the initiation of reproductive isolation, while also enhancing genetic exchange across broader adaptive radiations, potentially serving as a source of novel genotypic variation and accentuating further diversification.
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Affiliation(s)
- Katherine A Inskeep
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Meredith M Doellman
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Thomas H Q Powell
- Department of Biological Sciences, Binghamton University (State University of New York), Binghamton, NY, USA
| | - Stewart H Berlocher
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Nicholas R Seifert
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Glen R Hood
- Department of Biological Sciences, Wayne State University, Detroit, MI, USA
| | - Gregory J Ragland
- Department of Integrative Biology, University of Colorado Denver, Denver, CO, USA
| | - Peter J Meyers
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Jeffrey L Feder
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
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44
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Hausmann AE, Kuo CY, Freire M, Rueda-M N, Linares M, Pardo-Diaz C, Salazar C, Merrill RM. Light environment influences mating behaviours during the early stages of divergence in tropical butterflies. Proc Biol Sci 2021; 288:20210157. [PMID: 33757348 PMCID: PMC8059652 DOI: 10.1098/rspb.2021.0157] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 02/23/2021] [Indexed: 12/31/2022] Open
Abstract
Speciation is facilitated when traits under divergent selection also act as mating cues. Fluctuations in sensory conditions can alter signal perception independently of adaptation to the broader sensory environment, but how this fine-scale variation may constrain or promote behavioural isolation has received little attention. The warning patterns of Heliconius butterflies are under selection for aposematism and act as mating cues. Using computer vision, we extracted behavioural data from 1481 h of video footage, for 387 individuals. We show that the putative hybrid species H. heurippa and its close relative H. timareta linaresi differ in their response to divergent warning patterns, but that these differences are strengthened with increased local illuminance. Trials with live individuals reveal low-level assortative mating that is sufficiently explained by differences in visual attraction. Finally, results from hybrid butterflies are consistent with linkage between a major warning pattern gene and the corresponding behaviour, though the differences in behaviour we observe are unlikely to cause rapid reproductive isolation as predicted under a model of hybrid trait speciation. Overall, our results reveal that the contribution of ecological mating cues to reproductive isolation may depend on the immediate sensory conditions during which they are displayed to conspecifics.
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Affiliation(s)
- Alexander E. Hausmann
- Division of Evolutionary Biology, Ludwig-Maximilians-Universität München, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Chi-Yun Kuo
- Division of Evolutionary Biology, Ludwig-Maximilians-Universität München, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
- Smithsonian Tropical Research Institute, Gamboa 0843-03092, Panama
| | - Marília Freire
- Division of Evolutionary Biology, Ludwig-Maximilians-Universität München, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Nicol Rueda-M
- Department of Biology, Faculty of Natural Sciences, Universidad del Rosario, Carrera 24 No 63C-69, Bogotá 111221, Colombia
| | - Mauricio Linares
- Department of Biology, Faculty of Natural Sciences, Universidad del Rosario, Carrera 24 No 63C-69, Bogotá 111221, Colombia
| | - Carolina Pardo-Diaz
- Department of Biology, Faculty of Natural Sciences, Universidad del Rosario, Carrera 24 No 63C-69, Bogotá 111221, Colombia
| | - Camilo Salazar
- Department of Biology, Faculty of Natural Sciences, Universidad del Rosario, Carrera 24 No 63C-69, Bogotá 111221, Colombia
| | - Richard M. Merrill
- Division of Evolutionary Biology, Ludwig-Maximilians-Universität München, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
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45
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Maltseva AL, Varfolomeeva MA, Lobov AA, Tikanova PO, Repkin EA, Babkina IY, Panova M, Mikhailova NA, Granovitch AI. Premating barriers in young sympatric snail species. Sci Rep 2021; 11:5720. [PMID: 33707514 PMCID: PMC7952697 DOI: 10.1038/s41598-021-84407-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 02/15/2021] [Indexed: 01/04/2023] Open
Abstract
Sympatric coexistence of recently diverged species raises the question of barriers restricting the gene flow between them. Reproductive isolation may be implemented at several levels, and the weakening of some, e.g. premating, barriers may require the strengthening of the others, e.g. postcopulatory ones. We analysed mating patterns and shell size of mates in recently diverged closely related species of the subgenus Littorina Neritrema (Littorinidae, Caenogastropoda) in order to assess the role of premating reproductive barriers between them. We compared mating frequencies observed in the wild with those expected based on relative densities using partial canonical correspondence analysis. We introduced the fidelity index (FI) to estimate the relative accuracy of mating with conspecific females and precopulatory isolation index (IPC) to characterize the strength of premating barriers. The species under study, with the exception of L. arcana, clearly demonstrated preferential mating with conspecifics. According to FI and IPC, L. fabalis and L. compressa appeared reliably isolated from their closest relatives within Neritrema. Individuals of these two species tend to be smaller than those of the others, highlighting the importance of shell size changes in gastropod species divergence. L. arcana males were often found in pairs with L. saxatilis females, and no interspecific size differences were revealed in this sibling species pair. We discuss the lack of discriminative mate choice in the sympatric populations of L. arcana and L. saxatilis, and possible additional mechanisms restricting gene flow between them.
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Affiliation(s)
- Arina L Maltseva
- Department of Invertebrate Zoology, St Petersburg State University, St Petersburg, Russia.
| | - Marina A Varfolomeeva
- Department of Invertebrate Zoology, St Petersburg State University, St Petersburg, Russia
| | - Arseniy A Lobov
- Department of Invertebrate Zoology, St Petersburg State University, St Petersburg, Russia.,Laboratory of Regenerative Biomedicine, Institute of Cytology Russian Academy of Sciences, St Petersburg, Russia
| | - Polina O Tikanova
- Department of Invertebrate Zoology, St Petersburg State University, St Petersburg, Russia.,Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna, Austria
| | - Egor A Repkin
- Department of Invertebrate Zoology, St Petersburg State University, St Petersburg, Russia
| | - Irina Y Babkina
- Department of Invertebrate Zoology, St Petersburg State University, St Petersburg, Russia
| | - Marina Panova
- Department of Invertebrate Zoology, St Petersburg State University, St Petersburg, Russia.,Department of Marine Sciences - Tjärnö, University of Gothenburg, Gothenburg, Sweden
| | - Natalia A Mikhailova
- Department of Invertebrate Zoology, St Petersburg State University, St Petersburg, Russia.,Centre of Cell Technologies, Institute of Cytology Russian Academy of Sciences, St Petersburg, Russia
| | - Andrei I Granovitch
- Department of Invertebrate Zoology, St Petersburg State University, St Petersburg, Russia
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46
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Tusso S, Nieuwenhuis BPS, Weissensteiner B, Immler S, Wolf JBW. Experimental evolution of adaptive divergence under varying degrees of gene flow. Nat Ecol Evol 2021; 5:338-349. [PMID: 33432131 DOI: 10.1038/s41559-020-01363-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 11/12/2020] [Indexed: 01/28/2023]
Abstract
Adaptive divergence is the key evolutionary process generating biodiversity by means of natural selection. Yet, the conditions under which it can arise in the presence of gene flow remain contentious. To address this question, we subjected 132 sexually reproducing fission yeast populations, sourced from two independent genetic backgrounds, to disruptive ecological selection and manipulated the level of migration between environments. Contrary to theoretical expectations, adaptive divergence was most pronounced when migration was either absent (allopatry) or maximal (sympatry), but was much reduced at intermediate rates (parapatry and local mating). This effect was apparent across central life-history components (survival, asexual growth and mating) but differed in magnitude between ancestral genetic backgrounds. The evolution of some fitness components was constrained by pervasive negative correlations (trade-off between asexual growth and mating), while others changed direction under the influence of migration (for example, survival and mating). In allopatry, adaptive divergence was mainly conferred by standing genetic variation and resulted in ecological specialization. In sympatry, divergence was mainly mediated by novel mutations enriched in a subset of genes and was characterized by the repeated emergence of two strategies: an ecological generalist and an asexual growth specialist. Multiple loci showed consistent evidence for antagonistic pleiotropy across migration treatments providing a conceptual link between adaptation and divergence. This evolve-and-resequence experiment shows that rapid ecological differentiation can arise even under high rates of gene flow. It further highlights that adaptive trajectories are governed by complex interactions of gene flow, ancestral variation and genetic correlations.
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Affiliation(s)
- Sergio Tusso
- Division of Evolutionary Biology, Faculty of Biology, Ludwig-Maximilians-Universität Munich, Munich, Germany. .,Science for Life Laboratory, Uppsala University, Uppsala, Sweden. .,Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden.
| | - Bart P S Nieuwenhuis
- Division of Evolutionary Biology, Faculty of Biology, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Bernadette Weissensteiner
- Division of Evolutionary Biology, Faculty of Biology, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Simone Immler
- Science for Life Laboratory, Uppsala University, Uppsala, Sweden.,Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden.,School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Jochen B W Wolf
- Division of Evolutionary Biology, Faculty of Biology, Ludwig-Maximilians-Universität Munich, Munich, Germany. .,Science for Life Laboratory, Uppsala University, Uppsala, Sweden. .,Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden.
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47
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Orsucci M, Sicard A. Flower evolution in the presence of heterospecific gene flow and its contribution to lineage divergence. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:971-989. [PMID: 33537708 DOI: 10.1093/jxb/eraa549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/16/2020] [Indexed: 06/12/2023]
Abstract
The success of species depends on their ability to exploit ecological resources in order to optimize their reproduction. However, species are not usually found within single-species ecosystems but in complex communities. Because of their genetic relatedness, closely related lineages tend to cluster within the same ecosystem, rely on the same resources, and be phenotypically similar. In sympatry, they will therefore compete for the same resources and, in the case of flowering plants, exchange their genes through heterospecific pollen transfer. These interactions, nevertheless, pose significant challenges to species co-existence because they can lead to resource limitation and reproductive interference. In such cases, divergent selective pressures on floral traits will favour genotypes that isolate or desynchronize the reproduction of sympatric lineages. The resulting displacement of reproductive characters will, in turn, lead to pre-mating isolation and promote intraspecific divergence, thus initiating or reinforcing the speciation process. In this review, we discuss the current theoretical and empirical knowledge on the influence of heterospecific pollen transfer on flower evolution, highlighting its potential to uncover the ecological and genomic constraints shaping the speciation process.
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Affiliation(s)
- Marion Orsucci
- Department of Plant Biology, Swedish University of Agricultural, Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
| | - Adrien Sicard
- Department of Plant Biology, Swedish University of Agricultural, Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
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48
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Kaiser TS, von Haeseler A, Tessmar-Raible K, Heckel DG. Timing strains of the marine insect Clunio marinus diverged and persist with gene flow. Mol Ecol 2021; 30:1264-1280. [PMID: 33410230 DOI: 10.1111/mec.15791] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 12/17/2020] [Accepted: 01/04/2021] [Indexed: 02/06/2023]
Abstract
Genetic divergence of populations in the presence of gene flow is a central theme in speciation research. Theory predicts that divergence can happen with full range overlap - in sympatry - driven by ecological factors, but there are few empirical examples of how ecologically divergent selection can overcome gene flow and lead to reproductive isolation. In the marine midge Clunio marinus (Diptera: Chironomidae) reproduction is ecologically restricted to the time of the lowest tides, which is ensured through accurate control of development and adult emergence by circalunar and circadian clocks. As tidal regimes differ along the coastline, locally adapted timing strains of C. marinus are found in different sites across Europe. At the same time, ecologically suitable low tides occur at both full and new moon and twice a day, providing C. marinus with four nonoverlapping temporal niches at every geographic location. Along the coast of Brittany, which is characterized by a steep gradient in timing of the tides, we found an unusually large number of differentially adapted timing strains, and the first known instances of sympatric C. marinus strains occupying divergent temporal niches. Analysis of mitochondrial genotypes suggests that these timing strains originated from a single recent colonization event. Nuclear genotypes show strong gene flow, sympatric timing strains being the least differentiated. Even when sympatric strains exist in nonoverlapping temporal niches, timing adaptations do not result in genome-wide genetic divergence, suggesting timing adaptations are maintained by permanent ecological selection. This constitutes a model case for incipient ecological divergence with gene flow.
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Affiliation(s)
- Tobias S Kaiser
- Max Planck Research Group Biological Clocks, Max Planck Institute for Evolutionary Biology, Plön, Germany.,Center for Integrative Bioinformatics Vienna, Max Perutz Laboratories, University of Vienna and Medical University of Vienna, Vienna, Austria.,Max Perutz Laboratories, University of Vienna, Vienna, Austria.,Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Arndt von Haeseler
- Center for Integrative Bioinformatics Vienna, Max Perutz Laboratories, University of Vienna and Medical University of Vienna, Vienna, Austria.,Bioinformatics and Computational Biology, Faculty of Computer Science, University of Vienna, Vienna, Austria
| | | | - David G Heckel
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
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Lin Z, Wang S, Neumann P, Chen G, Page P, Li L, Hu F, Zheng H, Dietemann V. Population genetics and host specificity of Varroa destructor mites infesting eastern and western honeybees. JOURNAL OF PEST SCIENCE 2021; 94:1487-1504. [PMID: 34720788 PMCID: PMC8549952 DOI: 10.1007/s10340-020-01322-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 11/20/2020] [Accepted: 12/17/2020] [Indexed: 06/13/2023]
Abstract
In a globalized world, parasites are often brought in contact with new potential hosts. When parasites successfully shift host, severe diseases can emerge at a large cost to society. However, the evolutionary processes leading to successful shifts are rarely understood, hindering risk assessment, prevention, or mitigation of their effects. Here, we screened populations of Varroa destructor, an ectoparasitic mite of the honeybee genus Apis, to investigate their genetic structure and reproductive potential on new and original hosts. From the patterns identified, we deduce the factors that influenced the macro- and microevolutionary processes that led to the structure observed. Among the mite variants identified, we found two genetically similar populations that differed in their reproductive abilities and thus in their host specificity. These lineages could interbreed, which represents a threat due to the possible increased virulence of the parasite on its original host. However, interbreeding was unidirectional from the host-shifted to the nonshifted native mites and could thus lead to speciation of the former. The results improve our understanding of the processes affecting the population structure and evolution of this economically important mite genus and suggest that introgression between shifted and nonshifted lineages may endanger the original host. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s10340-020-01322-7.
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Affiliation(s)
- Zheguang Lin
- College of Animal Sciences, Zhejiang University, Hangzhou, China
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Shuai Wang
- College of Animal Sciences, Zhejiang University, Hangzhou, China
| | - Peter Neumann
- Swiss Bee Research Center, Agroscope, Bern, Switzerland
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Gongwen Chen
- College of Animal Sciences, Zhejiang University, Hangzhou, China
| | - Paul Page
- Swiss Bee Research Center, Agroscope, Bern, Switzerland
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Li Li
- College of Animal Sciences, Zhejiang University, Hangzhou, China
| | - Fuliang Hu
- College of Animal Sciences, Zhejiang University, Hangzhou, China
| | - Huoqing Zheng
- College of Animal Sciences, Zhejiang University, Hangzhou, China
| | - Vincent Dietemann
- Swiss Bee Research Center, Agroscope, Bern, Switzerland
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
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50
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Silva CNS, Murphy NP, Bell JJ, Green BS, Duhamel G, Cockcroft AC, Hernández CE, Strugnell JM. Global drivers of recent diversification in a marine species complex. Mol Ecol 2021; 30:1223-1236. [PMID: 33342039 DOI: 10.1111/mec.15780] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 11/03/2020] [Accepted: 12/14/2020] [Indexed: 02/06/2023]
Abstract
Investigating historical gene flow in species complexes can indicate how environmental and reproductive barriers shape genome divergence during speciation. The processes influencing species diversification under environmental change remain one of the central focal points of evolutionary biology, particularly for marine organisms with high dispersal potential. We investigated genome-wide divergence, introgression patterns and inferred demographic history between species pairs of all six extant rock lobster species (Jasus spp.), which have a long larval duration of up to two years and have populated continental shelf and seamount habitats around the globe at approximately 40o S. Genetic differentiation patterns reflected geographic isolation and the environment (i.e. habitat structure). Eastern Pacific species (J. caveorum and J. frontalis) were geographically more distant and genetically more differentiated from the remaining four species. Species associated with continental shelf habitats shared a common ancestry, but are geographically distant from one another. Similarly, species associated with island/seamount habitats in the Atlantic and Indian Oceans shared a common ancestry, but are also geographically distant. Benthic temperature was the environmental variable that explained most of the genetic differentiation (FST ), while controlling for the effects of geographic distance. Eastern Pacific species retained a signal of strict isolation following ancient migration, whereas species pairs from Australia and Africa, and seamounts in the Indian and Atlantic oceans, included events of introgression after secondary contact. Our results reveal important effects of habitat and demographic processes on the recent divergence of species within the genus Jasus, providing one of the first empirical studies of genome-wide drivers of diversification that incorporates all extant species in a marine genus with long pelagic larval duration.
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Affiliation(s)
- Catarina N S Silva
- Centre for Sustainable Tropical Fisheries and Aquaculture and College of Science and Engineering, James Cook University, Townsville, QLD, Australia
| | - Nicholas P Murphy
- Department of Ecology, Environment & Evolution, La Trobe University, Melbourne, Vic, Australia
| | - James J Bell
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Bridget S Green
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Guy Duhamel
- Département Adaptations du Vivant, BOREA, MNHN, Paris, France
| | - Andrew C Cockcroft
- Department of Agriculture, Forestry and Fisheries, Cape Town, South Africa
| | - Cristián E Hernández
- Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile.,Universidad Católica de Santa María, Arequipa, Perú
| | - Jan M Strugnell
- Centre for Sustainable Tropical Fisheries and Aquaculture and College of Science and Engineering, James Cook University, Townsville, QLD, Australia.,Department of Ecology, Environment & Evolution, La Trobe University, Melbourne, Vic, Australia
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