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Barraclough TG. Does selection favour the maintenance of porous species boundaries? J Evol Biol 2024; 37:616-627. [PMID: 38599591 DOI: 10.1093/jeb/voae030] [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: 08/04/2023] [Revised: 03/01/2024] [Accepted: 03/05/2024] [Indexed: 04/12/2024]
Abstract
The endpoint of speciation has been viewed as complete isolation and the absence of gene flow between species. If the influx of genes from another species is maladaptive because species have different adaptations and genetic backgrounds, selection should favour the closing of species boundaries and zero gene flow, a process known as reinforcement. Recently, numerous cases of gene flow between species have been identified, many of which involved adaptive introgression of beneficial alleles. These cases could reflect transient states on the way to closed species boundaries or the result of declining strength or efficacy of selection for reinforcement as the level of gene flow approaches zero. An alternative hypothesis, however, is that selection favours porous species boundaries that allow beneficial alleles to cross, especially in changing environments. This perspective evaluates the conditions that would be needed for selection to favour porous species boundaries and the evidence for them. A contrast is made between hybridization in sexual eukaryotes and gene transfer via homologous recombination in bacteria. Current evidence is inconclusive on whether non-zero gene flow is favoured by selection. Studies are needed that quantify selection gradients on rates of gene flow and test for evolution towards intermediate values, especially experiments that manipulate conditions and track evolution for multiple generations. Estimation of gene flow networks for more clades and regional assemblages using emerging genome data will also allow the evolutionary determinants of interspecific gene flow to be better understood.
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Boom AF, Migliore J, Ojeda Alayon DI, Kaymak E, Hardy OJ. Phylogenomics of Brachystegia: Insights into the origin of African miombo woodlands. AMERICAN JOURNAL OF BOTANY 2024; 111:e16352. [PMID: 38853465 DOI: 10.1002/ajb2.16352] [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: 08/21/2023] [Revised: 03/29/2024] [Accepted: 04/01/2024] [Indexed: 06/11/2024]
Abstract
PREMISE Phylogenetic approaches can provide valuable insights on how and when a biome emerged and developed using its structuring species. In this context, Brachystegia Benth, a dominant genus of trees in miombo woodlands, appears as a key witness of the history of the largest woodland and savanna biome of Africa. METHODS We reconstructed the evolutionary history of the genus using targeted-enrichment sequencing on 60 Brachystegia specimens for a nearly complete species sampling. Phylogenomic inferences used supermatrix (RAxML-NG) and summary-method (ASTRAL-III) approaches. Conflicts between species and gene trees were assessed, and the phylogeny was time-calibrated in BEAST. Introgression between species was explored using Phylonet. RESULTS The phylogenies were globally congruent regardless of the method used. Most of the species were recovered as monophyletic, unlike previous plastid phylogenetic reconstructions where lineages were shared among geographically close individuals independently of species identity. Still, most of the individual gene trees had low levels of phylogenetic information and, when informative, were mostly in conflict with the reconstructed species trees. These results suggest incomplete lineage sorting and/or reticulate evolution, which was supported by network analyses. The BEAST analysis supported a Pliocene origin for current Brachystegia lineages, with most of the diversification events dated to the Pliocene-Pleistocene. CONCLUSIONS These results suggest a recent origin of species of the miombo, congruently with their spatial expansion documented from plastid data. Brachystegia species appear to behave potentially as a syngameon, a group of interfertile but still relatively well-delineated species, an aspect that deserves further investigations.
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Affiliation(s)
- Arthur F Boom
- Royal Museum for Central Africa, Biology Department, Section Vertebrates, Tervuren, Belgium
- Université Libre de Bruxelles, Faculté des Sciences, Service Evolution Biologique et Ecologie, Bruxelles, Belgium
| | - Jérémy Migliore
- Université Libre de Bruxelles, Faculté des Sciences, Service Evolution Biologique et Ecologie, Bruxelles, Belgium
- Muséum départemental du Var, Toulon, France
| | - Dario I Ojeda Alayon
- Muséum départemental du Var, Toulon, France
- Department of Forest Biodiversity, Norwegian Institute of Bioeconomy Research, Ås, Norway
| | - Esra Kaymak
- Université Libre de Bruxelles, Faculté des Sciences, Service Evolution Biologique et Ecologie, Bruxelles, Belgium
- Institute of Science and Technology (OIST), Okinawa, Japan
| | - Olivier J Hardy
- Université Libre de Bruxelles, Faculté des Sciences, Service Evolution Biologique et Ecologie, Bruxelles, Belgium
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Musher LJ, Del-Rio G, Marcondes RS, Brumfield RT, Bravo GA, Thom G. Geogenomic Predictors of Genetree Heterogeneity Explain Phylogeographic and Introgression History: A Case Study in an Amazonian Bird (Thamnophilus aethiops). Syst Biol 2024; 73:36-52. [PMID: 37804132 DOI: 10.1093/sysbio/syad061] [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] [Received: 12/20/2022] [Revised: 09/14/2023] [Accepted: 10/04/2023] [Indexed: 10/08/2023] Open
Abstract
Can knowledge about genome architecture inform biogeographic and phylogenetic inference? Selection, drift, recombination, and gene flow interact to produce a genomic landscape of divergence wherein patterns of differentiation and genealogy vary nonrandomly across the genomes of diverging populations. For instance, genealogical patterns that arise due to gene flow should be more likely to occur on smaller chromosomes, which experience high recombination, whereas those tracking histories of geographic isolation (reduced gene flow caused by a barrier) and divergence should be more likely to occur on larger and sex chromosomes. In Amazonia, populations of many bird species diverge and introgress across rivers, resulting in reticulated genomic signals. Herein, we used reduced representation genomic data to disentangle the evolutionary history of 4 populations of an Amazonian antbird, Thamnophilus aethiops, whose biogeographic history was associated with the dynamic evolution of the Madeira River Basin. Specifically, we evaluate whether a large river capture event ca. 200 Ka, gave rise to reticulated genealogies in the genome by making spatially explicit predictions about isolation and gene flow based on knowledge about genomic processes. We first estimated chromosome-level phylogenies and recovered 2 primary topologies across the genome. The first topology (T1) was most consistent with predictions about population divergence and was recovered for the Z-chromosome. The second (T2), was consistent with predictions about gene flow upon secondary contact. To evaluate support for these topologies, we trained a convolutional neural network to classify our data into alternative diversification models and estimate demographic parameters. The best-fit model was concordant with T1 and included gene flow between non-sister taxa. Finally, we modeled levels of divergence and introgression as functions of chromosome length and found that smaller chromosomes experienced higher gene flow. Given that (1) genetrees supporting T2 were more likely to occur on smaller chromosomes and (2) we found lower levels of introgression on larger chromosomes (and especially the Z-chromosome), we argue that T1 represents the history of population divergence across rivers and T2 the history of secondary contact due to barrier loss. Our results suggest that a significant portion of genomic heterogeneity arises due to extrinsic biogeographic processes such as river capture interacting with intrinsic processes associated with genome architecture. Future phylogeographic studies would benefit from accounting for genomic processes, as different parts of the genome reveal contrasting, albeit complementary histories, all of which are relevant for disentangling the intricate geogenomic mechanisms of biotic diversification. [Amazonia; biogeography; demographic modeling; gene flow; gene tree; genome architecture; geogenomics; introgression; linked selection; neural network; phylogenomic; phylogeography; reproductive isolation; speciation; species tree.].
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Affiliation(s)
- Lukas J Musher
- Department of Ornithology, The Academy of Natural Sciences of Drexel University, Philadelphia, PA 19103, USA
- Department of Ornithology, American Museum of Natural History, New York, NY 10024, USA
| | - Glaucia Del-Rio
- Cornell Laboratory of Ornithology and Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | - Rafael S Marcondes
- Department of Biology and Museum of Natural Science, Louisiana State University, Baton Rouge, LA 70803, USA
- Department of BioSciences, Rice University, Houston, TX 77005, USA
| | - Robb T Brumfield
- Department of Biology and Museum of Natural Science, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Gustavo A Bravo
- Sección de Ornitología, Colecciones Biológicas, Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, Claustro de San Agustín, Villa de Leyva, Boyacá 111311, Colombia
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Gregory Thom
- Department of Biology and Museum of Natural Science, Louisiana State University, Baton Rouge, LA 70803, USA
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Lajmi A, Glinka F, Privman E. Optimizing ddRAD sequencing for population genomic studies with ddgRADer. Mol Ecol Resour 2023. [PMID: 37732396 DOI: 10.1111/1755-0998.13870] [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: 10/27/2022] [Revised: 08/04/2023] [Accepted: 08/31/2023] [Indexed: 09/22/2023]
Abstract
Double-digest Restriction-site Associated DNA sequencing (ddRADseq) is widely used to generate genomic data for non-model organisms in evolutionary and ecological studies. Along with affordable paired-end sequencing, this method makes population genomic analyses more accessible. However, multiple factors should be considered when designing a ddRADseq experiment, which can be challenging for new users. The generated data often suffer from substantial read overlaps and adaptor contamination, severely reducing sequencing efficiency and affecting data quality. Here, we analyse diverse datasets from the literature and carry out controlled experiments to understand the effects of enzyme choice and size selection on sequencing efficiency. The empirical data reveal that size selection is imprecise and has limited efficacy. In certain scenarios, a substantial proportion of short fragments pass below the lower size-selection cut-off resulting in low sequencing efficiency. However, enzyme choice can considerably mitigate inadvertent inclusion of these shorter fragments. A simple model based on these experiments is implemented to predict the number of genomic fragments generated after digestion and size selection, number of SNPs genotyped, number of samples that can be multiplexed and the expected sequencing efficiency. We developed ddgRADer - http://ddgrader.haifa.ac.il/ - a user-friendly webtool and incorporated these calculations to aid in ddRADseq experimental design while optimizing sequencing efficiency. This tool can also be used for single enzyme protocols such as Genotyping-by-Sequencing. Given user-defined study goals, ddgRADer recommends enzyme pairs and allows users to compare and choose enzymes and size-selection criteria. ddgRADer improves the accessibility and ease of designing ddRADseq experiments and increases the probability of success of the first population genomic study conducted in labs with no prior experience in genomics.
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Affiliation(s)
- Aparna Lajmi
- Department of Evolutionary and Environmental Biology, Institute of Evolution, University of Haifa, Haifa, Israel
| | - Felix Glinka
- Department of Evolutionary and Environmental Biology, Institute of Evolution, University of Haifa, Haifa, Israel
| | - Eyal Privman
- Department of Evolutionary and Environmental Biology, Institute of Evolution, University of Haifa, Haifa, Israel
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Gardner EM. Phylogenomic analyses of the Neotropical Artocarpeae (Moraceae) reveal a history of introgression and support the reinstatement of Acanthinophyllum. Mol Phylogenet Evol 2023:107837. [PMID: 37270033 DOI: 10.1016/j.ympev.2023.107837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 05/24/2023] [Accepted: 05/27/2023] [Indexed: 06/05/2023]
Abstract
This molecular study of the Neotropical Artocarpeae, the closest living allies of the Asia-Pacific breadfruit genus, uses phylogenomic and network analyses to untangle the evolutionary history of this difficult group. Results paint a picture of a rapid radiation, with introgression, incomplete lineage sorting, and lack of gene tree resolution confounding attempts to reconstruct a well-supported bifurcating tree. While coalescent-based species trees were markedly at odds with morphology, multifurcating phylogenetic network analyses recovered multiple histories, with clearer traces of morphological alliances. The sole unambiguous finding is the sister relationship between Clarisia sect. Acanthinophyllum and the rest of the Neotropical Artocarpeae; as a result, the genus Acanthinophyllum is reinstated.
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Affiliation(s)
- Elliot M Gardner
- International Center for Tropical Botany at The Kampong, Institute of Environment, Florida International University, Miami, Florida, USA; National Tropical Botanical Garden, Kalaheo, Hawaii, USA.
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Soza VL, Kriebel R, Ramage E, Hall BD, Twyford AD. The symmetry spectrum in a hybridising, tropical group of rhododendrons. THE NEW PHYTOLOGIST 2022; 234:1491-1506. [PMID: 35274743 PMCID: PMC9313591 DOI: 10.1111/nph.18083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 01/23/2022] [Indexed: 06/14/2023]
Abstract
Many diverse plant clades possess bilaterally symmetrical flowers and specialised pollination syndromes, suggesting that these traits may promote diversification. We examined the evolution of diverse floral morphologies in a species-rich tropical radiation of Rhododendron. We used restriction-site associated DNA sequencing on 114 taxa from Rhododendron sect. Schistanthe to reconstruct phylogenetic relationships and examine hybridisation. We then captured and quantified floral variation using geometric morphometric analyses, which we interpreted in a phylogenetic context. We uncovered phylogenetic conflict and uncertainty caused by introgression within and between clades. Morphometric analyses revealed flower symmetry to be a morphological continuum without clear transitions between radial and bilateral symmetry. Tropical Rhododendron species that began diversifying into New Guinea c. 6 million years ago expanded into novel floral morphological space. Our results showed that the evolution of tropical Rhododendron is characterised by recent speciation, recurrent hybridisation and the origin of floral novelty. Floral variation evolved via changes to multiple components of the corolla that are only recognised in geometric morphometrics with both front and side views of flowers.
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Affiliation(s)
- Valerie L. Soza
- Department of BiologyUniversity of WashingtonSeattleWA98115USA
| | - Ricardo Kriebel
- Department of BotanyUniversity of Wisconsin‐MadisonMadisonWI53706USA
| | | | | | - Alex D. Twyford
- Institute of Evolutionary BiologySchool of Biological SciencesUniversity of EdinburghCharlotte Auerbach RoadEdinburghEH9 3FLUK
- Royal Botanic Garden Edinburgh20A Inverleith RowEdinburghEH3 5LRUK
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Choo LM, Loo AHB, Ang WF, Er KBH. A natural hybrid of Sindora (Fabaceae, Detarioideae) from Singapore. PHYTOKEYS 2022; 190:87-102. [PMID: 35437378 PMCID: PMC8891240 DOI: 10.3897/phytokeys.190.79185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
Sindora×changiensis L.M.Choo, Loo, W.F.Ang & K.Er is a new hybrid from the subfamily Detarioideae in Fabaceae. This is the first reported instance of natural hybridisation in Sindora. Based on population genetics analyses using ddRAD and morphological observations, this taxon represents a fertile hybrid between Sindoracoriacea and Sindoraechinocalyx. This new hybrid is so far only known to occur naturally from Changi at the north-eastern coast of Singapore. It has pods that are sparsely spiny. This is intermediate between the smooth, non-spiny pods of S.coriacea, and the densely spiny pods of S.echinocalyx. The calyx is smooth and unarmed, resembling S.coriacea. Last but not least, the ovary is entirely pubescent, different from S.coriacea and S.echinocalyx. The ovary of S.coriacea has a glabrous patch in the middle, while that of S.echinocalyx has minute spines protruding from the dense pubescence. A taxonomic description and an updated key to the Sindora of Singapore and Peninsular Malaysia are also provided.
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Affiliation(s)
- Le Min Choo
- National Parks Board, 1 Cluny Road, 259569, Singapore, SingaporeNational Parks BoardSingaporeSingapore
| | - Adrian Hock Beng Loo
- National Parks Board, 1 Cluny Road, 259569, Singapore, SingaporeNational Parks BoardSingaporeSingapore
| | - Wee Foong Ang
- National Parks Board, 1 Cluny Road, 259569, Singapore, SingaporeNational Parks BoardSingaporeSingapore
| | - Kenneth Boon Hwee Er
- National Parks Board, 1 Cluny Road, 259569, Singapore, SingaporeNational Parks BoardSingaporeSingapore
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Chen S, Milne R, Zhou R, Meng K, Yin Q, Guo W, Ma Y, Mao K, Xu K, Kim YD, Do TV, Liao W, Fan Q. When tropical and subtropical congeners met: Multiple ancient hybridization events within Eriobotrya in the Yunnan-Guizhou Plateau, a tropical-subtropical transition area in China. Mol Ecol 2021; 31:1543-1561. [PMID: 34910340 DOI: 10.1111/mec.16325] [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: 12/13/2020] [Revised: 11/25/2021] [Accepted: 11/29/2021] [Indexed: 01/09/2023]
Abstract
Global climate changes during the Miocene may have created ample opportunities for hybridization between members of tropical and subtropical biomes at the boundary between these zones. Yet, very few studies have explored this possibility. The Yunnan-Guizhou Plateau (YGP) in Southwest China is a biodiversity hotspot for vascular plants, located in a transitional area between the floristic regions of tropical Southeast Asia and subtropical East Asia. The genus Eriobotrya (Rosaceae) comprises both tropical and subtropical taxa, with 12 species recorded in the YGP, making it a suitable basis for testing the hypothesis of between-biome hybridization. Therefore, we surveyed the evolutionary history of Eriobotrya by examining three chloroplast regions and five nuclear genes for 817 individuals (47 populations) of 23 Eriobotrya species (including 19 populations of 12 species in the YGP), plus genome re-sequencing of 33 representative samples. We concluded that: (1) phylogenetic positions for 16 species exhibited strong cytonuclear conflicts, most probably due to ancient hybridization; (2) the YGP is a hotspot for hybridization, with 11 species showing clear evidence of chloroplast capture; and (3) Eriobotrya probably originated in tropical Asia during the Eocene. From the Miocene onwards, the intensification of the Eastern Asia monsoon and global cooling may have shifted the tropical-subtropical boundary and caused secondary contact between species, thus providing ample opportunity for hybridization and diversification of Eriobotrya, especially in the YGP. Our study highlights the significant role that paleoclimate changes probably played in driving hybridization and generating rich species diversity in climate transition zones.
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Affiliation(s)
- Sufang Chen
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Richard Milne
- Institute of Molecular Plant Sciences, University of Edinburgh, Edinburgh, UK
| | - Renchao Zhou
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Kaikai Meng
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Qianyi Yin
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Wei Guo
- Department of Horticulture and Landscape Architecture, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Yongpeng Ma
- Kunming Botanical Garden, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Kangshan Mao
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, China
| | - Kewang Xu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, China
| | - Young-Dong Kim
- Department of Life Science, Multidisciplinary Genome Institute, Hallym University, Chuncheon City, South Korea
| | - Truong Van Do
- Vietnam National Museum of Nature, Vietnam Academy of Science & Technology, Hanoi, Vietnam.,Graduate University of Science and Technology, Vietnam Academy of Science & Technology, Hanoi, Vietnam
| | - Wenbo Liao
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Qiang Fan
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
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Larson DA, Vargas OM, Vicentini A, Dick CW. Admixture may be extensive among hyperdominant Amazon rainforest tree species. THE NEW PHYTOLOGIST 2021; 232:2520-2534. [PMID: 34389989 PMCID: PMC9292926 DOI: 10.1111/nph.17675] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 08/04/2021] [Indexed: 05/25/2023]
Abstract
Admixture is a mechanism by which species of long-lived plants may acquire novel alleles. However, the potential role of admixture in the origin and maintenance of tropical plant diversity is unclear. We ask whether admixture occurs in an ecologically important clade of Eschweilera (Parvifolia clade, Lecythidaceae), which includes some of the most widespread and abundant tree species in Amazonian forests. Using target capture sequencing, we conducted a detailed phylogenomic investigation of 33 species in the Parvifolia clade and investigated specific hypotheses of admixture within a robust phylogenetic framework. We found strong evidence of admixture among three ecologically dominant species, E. coriacea, E. wachenheimii and E. parviflora, but a lack of evidence for admixture among other lineages. Accepted species were largely distinguishable from one another, as was geographic structure within species. We show that hybridization may play a role in the evolution of the most widespread and ecologically variable Amazonian tree species. While admixture occurs among some species of Eschweilera, it has not led to widespread erosion of most species' genetic or morphological identities. Therefore, current morphological based species circumscriptions appear to provide a useful characterization of the clade's lineage diversity.
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Affiliation(s)
- Drew A. Larson
- Department of Ecology & Evolutionary BiologyUniversity of MichiganAnn ArborMI48109USA
| | - Oscar M. Vargas
- Department of Biological SciencesHumboldt State UniversityArcataCA95521USA
| | - Alberto Vicentini
- Instituto Nacional de Pesquisas da Amazônia (INPA)ManausAMCEP 69067‐375Brazil
| | - Christopher W. Dick
- Department of Ecology & Evolutionary BiologyUniversity of MichiganAnn ArborMI48109USA
- Smithsonian Tropical Research InstitutePanama CityRepublic of Panama
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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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Ashton PS. Is introgression an increasing threat to tree species diversity in hyperdiverse rain forest communities? Biotropica 2021. [DOI: 10.1111/btp.12983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Peter S. Ashton
- Organismic and Evolutionary Biology Harvard University and Royal Botanic Gardens, Kew Cambridge MA USA
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12
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Pérez-Escobar OA, Dodsworth S, Bogarín D, Bellot S, Balbuena JA, Schley RJ, Kikuchi IA, Morris SK, Epitawalage N, Cowan R, Maurin O, Zuntini A, Arias T, Serna-Sánchez A, Gravendeel B, Torres Jimenez MF, Nargar K, Chomicki G, Chase MW, Leitch IJ, Forest F, Baker WJ. Hundreds of nuclear and plastid loci yield novel insights into orchid relationships. AMERICAN JOURNAL OF BOTANY 2021; 108:1166-1180. [PMID: 34250591 DOI: 10.1002/ajb2.1702] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 06/10/2021] [Indexed: 06/13/2023]
Abstract
PREMISE The inference of evolutionary relationships in the species-rich family Orchidaceae has hitherto relied heavily on plastid DNA sequences and limited taxon sampling. Previous studies have provided a robust plastid phylogenetic framework, which was used to classify orchids and investigate the drivers of orchid diversification. However, the extent to which phylogenetic inference based on the plastid genome is congruent with the nuclear genome has been only poorly assessed. METHODS We inferred higher-level phylogenetic relationships of orchids based on likelihood and ASTRAL analyses of 294 low-copy nuclear genes sequenced using the Angiosperms353 universal probe set for 75 species (representing 69 genera, 16 tribes, 24 subtribes) and a concatenated analysis of 78 plastid genes for 264 species (117 genera, 18 tribes, 28 subtribes). We compared phylogenetic informativeness and support for the nuclear and plastid phylogenetic hypotheses. RESULTS Phylogenetic inference using nuclear data sets provides well-supported orchid relationships that are highly congruent between analyses. Comparisons of nuclear gene trees and a plastid supermatrix tree showed that the trees are mostly congruent, but revealed instances of strongly supported phylogenetic incongruence in both shallow and deep time. The phylogenetic informativeness of individual Angiosperms353 genes is in general better than that of most plastid genes. CONCLUSIONS Our study provides the first robust nuclear phylogenomic framework for Orchidaceae and an assessment of intragenomic nuclear discordance, plastid-nuclear tree incongruence, and phylogenetic informativeness across the family. Our results also demonstrate what has long been known but rarely thoroughly documented: nuclear and plastid phylogenetic trees can contain strongly supported discordances, and this incongruence must be reconciled prior to interpretation in evolutionary studies, such as taxonomy, biogeography, and character evolution.
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Affiliation(s)
| | - Steven Dodsworth
- School of Biological Sciences, University of Portsmouth, Portsmouth, PO1 2UP, UK
| | - Diego Bogarín
- Lankester Botanic Garden, University of Costa Rica, Cartago, Costa Rica
| | | | | | | | | | | | | | - Robyn Cowan
- Royal Botanic Gardens Kew, Richmond, TW9 3AE, UK
| | | | | | | | | | | | | | - Katharina Nargar
- Australian Tropical Herbarium, James Cook University, Australia
- National Research Collections, Commonwealth Industrial and Scientific Research Organization, Australia
| | - Guillaume Chomicki
- Department of Animal and Plant Sciences, Alfred Denny Building, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Mark W Chase
- Royal Botanic Gardens Kew, Richmond, TW9 3AE, UK
- Department of Environment and Agriculture, Curtin University, Bentley, Western Australia, 6102, Australia
| | | | - Félix Forest
- Royal Botanic Gardens Kew, Richmond, TW9 3AE, UK
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Baker WJ, Dodsworth S, Forest F, Graham SW, Johnson MG, McDonnell A, Pokorny L, Tate JA, Wicke S, Wickett NJ. Exploring Angiosperms353: An open, community toolkit for collaborative phylogenomic research on flowering plants. AMERICAN JOURNAL OF BOTANY 2021; 108:1059-1065. [PMID: 34293179 DOI: 10.1002/ajb2.1703] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 05/14/2021] [Indexed: 06/13/2023]
Affiliation(s)
| | - Steven Dodsworth
- School of Life Sciences, University of Bedfordshire, University Square, Luton, LU1 3JU, UK
| | - Félix Forest
- Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AE, UK
| | - Sean W Graham
- Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, V6T 1Z4, Canada
| | - Matthew G Johnson
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
| | - Angela McDonnell
- Plant Science and Conservation, Chicago Botanic Garden, 1000 Lake Cook Road, Glencoe, IL, 60022, USA
| | - Lisa Pokorny
- Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AE, UK
| | - Jennifer A Tate
- School of Fundamental Sciences, Massey University, Palmerston North, 4442, New Zealand
| | - Susann Wicke
- Plant Evolutionary Biology, Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
- Plant Systematics and Biodiversity, Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Norman J Wickett
- Plant Science and Conservation, Chicago Botanic Garden, 1000 Lake Cook Road, Glencoe, IL, 60022, USA
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14
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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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15
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Comparative Analysis of SNP Discovery and Genotyping in Fagus sylvatica L. and Quercus robur L. Using RADseq, GBS, and ddRAD Methods. FORESTS 2021. [DOI: 10.3390/f12020222] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Next-generation sequencing of reduced representation genomic libraries (RRL) is capable of providing large numbers of genetic markers for population genetic studies at relatively low costs. However, one major concern of these types of markers is the precision of genotyping, which is related to the common problem of missing data, which appears to be particularly important in association and genomic selection studies. We evaluated three RRL approaches (GBS, RADseq, ddRAD) and different SNP identification methods (de novo or based on a reference genome) to find the best solutions for future population genomics studies in two economically and ecologically important broadleaved tree species, namely F. sylvatica and Q. robur. We found that the use of ddRAD method coupled with SNP calling based on reference genomes provided the largest numbers of markers (28 k and 36 k for beech and oak, respectively), given standard filtering criteria. Using technical replicates of samples, we demonstrated that more than 80% of SNP loci should be considered as reliable markers in GBS and ddRAD, but not in RADseq data. According to the reference genomes’ annotations, more than 30% of the identified ddRAD loci appeared to be related to genes. Our findings provide a solid support for using ddRAD-based SNPs for future population genomics studies in beech and oak.
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16
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Schneider JV, Paule J, Jungcurt T, Cardoso D, Amorim AM, Berberich T, Zizka G. Resolving Recalcitrant Clades in the Pantropical Ochnaceae: Insights From Comparative Phylogenomics of Plastome and Nuclear Genomic Data Derived From Targeted Sequencing. FRONTIERS IN PLANT SCIENCE 2021; 12:638650. [PMID: 33613613 PMCID: PMC7890083 DOI: 10.3389/fpls.2021.638650] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 01/15/2021] [Indexed: 05/13/2023]
Abstract
Plastid DNA sequence data have been traditionally widely used in plant phylogenetics because of the high copy number of plastids, their uniparental inheritance, and the blend of coding and non-coding regions with divergent substitution rates that allow the reconstruction of phylogenetic relationships at different taxonomic ranks. In the present study, we evaluate the utility of the plastome for the reconstruction of phylogenetic relationships in the pantropical plant family Ochnaceae (Malpighiales). We used the off-target sequence read fraction of a targeted sequencing study (targeting nuclear loci only) to recover more than 100 kb of the plastid genome from the majority of the more than 200 species of Ochnaceae and all but two genera using de novo and reference-based assembly strategies. Most of the recalcitrant nodes in the family's backbone were resolved by our plastome-based phylogenetic inference, corroborating the most recent classification system of Ochnaceae and findings from a phylogenomic study based on nuclear loci. Nonetheless, the phylogenetic relationships within the major clades of tribe Ochnineae, which comprise about two thirds of the family's species diversity, received mostly low support. Generally, the phylogenetic resolution was lowest at the infrageneric level. Overall there was little phylogenetic conflict compared to a recent analysis of nuclear loci. Effects of taxon sampling were invoked as the most likely reason for some of the few well-supported discords. Our study demonstrates the utility of the off-target fraction of a target enrichment study for assembling near-complete plastid genomes for a large proportion of samples.
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Affiliation(s)
- Julio V. Schneider
- Department of Botany and Molecular Evolution, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt am Main, Germany
- Entomology III, Department of Terrestrial Zoology, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt am Main, Germany
| | - Juraj Paule
- Department of Botany and Molecular Evolution, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt am Main, Germany
- Institute of Ecology, Evolution and Diversity, Goethe University, Frankfurt am Main, Germany
| | - Tanja Jungcurt
- Department of Botany and Molecular Evolution, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt am Main, Germany
- Institute of Ecology, Evolution and Diversity, Goethe University, Frankfurt am Main, Germany
| | - Domingos Cardoso
- Instituto de Biologia, Universidade Federal da Bahia (UFBA), Salvador, Brazil
| | - André Márcio Amorim
- Universidade Estadual de Santa Cruz (UESC), Ilhéus, Brazil
- Herbário André Maurício Vieira de Carvalho, CEPEC, CEPLAC, Itabuna, Brazil
| | - Thomas Berberich
- Senckenberg Biodiversity and Climate Research Center, Lab-Center, Frankfurt am Main, Germany
| | - Georg Zizka
- Department of Botany and Molecular Evolution, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt am Main, Germany
- Institute of Ecology, Evolution and Diversity, Goethe University, Frankfurt am Main, Germany
- *Correspondence: Georg Zizka, ;
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17
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Linan AG, Lowry PP, Miller AJ, Schatz GE, Sevathian JC, Edwards CE. RAD-sequencing reveals patterns of diversification and hybridization, and the accumulation of reproductive isolation in a clade of partially sympatric, tropical island trees. Mol Ecol 2020; 30:4520-4537. [PMID: 33210759 DOI: 10.1111/mec.15736] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/04/2020] [Accepted: 11/11/2020] [Indexed: 12/31/2022]
Abstract
A common pattern observed in temperate tree clades is that species are often morphologically distinct and partially interfertile but maintain species cohesion despite ongoing hybridization where ranges overlap. Although closely related species commonly occur in sympatry in tropical ecosystems, little is known about patterns of hybridization within a clade over time, and the implications of this hybridization for the maintenance of species boundaries. In this study, we focused on a clade of sympatric trees in the genus Diospyros in the Mascarene islands and investigated whether species are genetically distinct, whether they hybridize, and how patterns of hybridization are related to the time since divergence among species. We sampled multiple populations from each of 12 Mascarene Diospyros species, generated genome-wide single nucleotide polymorphism data using 2bRADseq, and conducted population genomic and phylogenomic analyses. We found that Mascarene Diospyros species diverged millions of years ago and are today largely genetically distinct from one another. Although hybridization was observed between closely related species belonging to the same subclade, more distantly related species showed little evidence of interspecific hybridization. Phylogenomic analyses also suggested that introgression has occurred during the evolutionary history of the clade. This suggests that, as diversification progressed, interspecific hybridization occurred among species, but became infrequent as lineages diverged from one another and evolved reproductive barriers. Species now coexist in partial sympatry, and experience limited hybridization between close relatives. Additional research is needed to better understand the role that introgression may have played in adaptation and diversification of Mascarene Diospyros, and its relevance for conservation.
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Affiliation(s)
- Alexander G Linan
- Department of Biology, Saint Louis University, St. Louis, MO, USA.,Center for Conservation and Sustainable Development, Missouri Botanical Garden, St. Louis, MO, USA
| | - Porter P Lowry
- Africa and Madagascar Program, Missouri Botanical Garden, St. Louis, MO, USA.,Institut de Systématique, Évolution et Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, Centre National de la Recherche Scientifique, Sorbonne Université, École Pratique des Hautes Études, Université des Antilles, Paris, France
| | - Allison J Miller
- Department of Biology, Saint Louis University, St. Louis, MO, USA.,Donald Danforth Plant Science Center, St. Louis, MO, USA
| | - George E Schatz
- Africa and Madagascar Program, Missouri Botanical Garden, St. Louis, MO, USA
| | - Jean-Claude Sevathian
- Botanist, Sustainability Consultant and Landscape Care and Maintenance Service, Beau Bassin-Rose Hill, Mauritius
| | - Christine E Edwards
- Center for Conservation and Sustainable Development, Missouri Botanical Garden, St. Louis, MO, USA
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