scholarly journals A consensus phylogenomic approach highlights paleopolyploid and rapid radiation in the history of Ericales

2019 ◽  
Author(s):  
Drew A. Larson ◽  
Joseph F. Walker ◽  
Oscar M. Vargas ◽  
Stephen A. Smith

ABSTRACTPremise of studyLarge genomic datasets offer the promise of resolving historically recalcitrant species relationships. However, different methodologies can yield conflicting results, especially when clades have experienced ancient, rapid diversification. Here, we analyzed the ancient radiation of Ericales and explored sources of uncertainty related to species tree inference, conflicting gene tree signal, and the inferred placement of gene and genome duplications.MethodsWe used a hierarchical clustering approach, with tree-based homology and orthology detection, to generate six filtered phylogenomic matrices consisting of data from 97 transcriptomes and genomes. Support for species relationships was inferred from multiple lines of evidence including shared gene duplications, gene tree conflict, gene-wise edge-based analyses, concatenation, and coalescent-based methods and is summarized in a consensus framework.Key ResultsOur consensus approach supported a topology largely concordant with previous studies, but suggests that the data are not capable of resolving several ancient relationships due to lack of informative characters, sensitivity to methodology, and extensive gene tree conflict correlated with paleopolyploidy. We found evidence of a whole genome duplication before the radiation of all or most ericalean families and demonstrate that tree topology and heterogeneous evolutionary rates impact the inferred placement of genome duplications.ConclusionsOur approach provides a novel hypothesis regarding the history of Ericales and confidently resolves most nodes. We demonstrate that a series of ancient divergences are unresolvable with these data. Whether paleopolyploidy is a major source of the observed phylogenetic conflict warrants further investigation.

2017 ◽  
Vol 66 (6) ◽  
pp. 1007-1018 ◽  
Author(s):  
Gregg W C Thomas ◽  
S Hussain Ather ◽  
Matthew W Hahn

Abstract Polyploidy can have a huge impact on the evolution of species, and it is a common occurrence, especially in plants. The two types of polyploids—autopolyploids and allopolyploids—differ in the level of divergence between the genes that are brought together in the new polyploid lineage. Because allopolyploids are formed via hybridization, the homoeologous copies of genes within them are at least as divergent as orthologs in the parental species that came together to form them. This means that common methods for estimating the parental lineages of allopolyploidy events are not accurate, and can lead to incorrect inferences about the number of gene duplications and losses. Here, we have adapted an algorithm for topology-based gene-tree reconciliation to work with multi-labeled trees (MUL-trees). By definition, MUL-trees have some tips with identical labels, which makes them a natural representation of the genomes of polyploids. Using this new reconciliation algorithm we can: accurately place allopolyploidy events on a phylogeny, identify the parental lineages that hybridized to form allopolyploids, distinguish between allo-, auto-, and (in most cases) no polyploidy, and correctly count the number of duplications and losses in a set of gene trees. We validate our method using gene trees simulated with and without polyploidy, and revisit the history of polyploidy in data from the clades including both baker’s yeast and bread wheat. Our re-analysis of the yeast data confirms the allopolyploid origin and parental lineages previously identified for this group. The method presented here should find wide use in the growing number of genomes from species with a history of polyploidy. [Polyploidy; reconciliation; whole-genome duplication.]


2021 ◽  
Author(s):  
Gil Yardeni ◽  
Juan Viruel ◽  
Margot Paris ◽  
Jaqueline Hess ◽  
Clara Groot Crego ◽  
...  

Target capture emerged as an important tool for phylogenetics and population genetics in non-model taxa. Whereas developing taxon-specific capture probes requires sustained efforts, available universal kits may have a lower power to reconstruct relationships at shallow phylogenetic scales and within rapidly radiating clades. We present here a newly-developed target capture set for Bromeliaceae, a large and ecologically-diverse plant family with highly variable diversification rates. The set targets 1,776 coding regions, including genes putatively involved in key innovations, with the aim to empower testing of a wide range of evolutionary hypotheses. We compare the relative power of this taxon-specific set, Bromeliad1776, to the universal Angiosperms353 kit. The taxon-specific set results in higher enrichment success across the entire family. However, the overall performance of both kits to reconstruct phylogenetic trees is relatively comparable, highlighting the vast potential of universal kits for resolving evolutionary relationships. For more detailed phylogenetic or population genetic analyses, e.g. the exploration of gene tree concordance, nucleotide diversity or population structure, the taxon-specific capture set presents clear benefits. We discuss the potential lessons that this comparative study provides for future phylogenetic and population genetic investigations, in particular for the study of evolutionary radiations.


2021 ◽  
Author(s):  
Zuzana Musilova ◽  
Fabio Cortesi

Vertebrates have four visual cone opsin classes that, together with a light-sensitive chromophore, provide sensitivity from the ultraviolet to the red wavelengths of light. The rhodopsin-like 2 (RH2) opsin is sensitive to the centre blue-green part of the spectrum, which is the most prevalent light underwater. While various vertebrate groups such as mammals and sharks have lost the RH2 gene, in teleost fishes this opsin has continued to proliferate. By investigating the genomes of 115 teleost species, we find that RH2 shows an extremely dynamic evolutionary history with repeated gene duplications, gene losses and gene conversion affecting entire orders, families and species. At least four ancestral duplications provided the substrate for todays RH2 diversity with duplications occurring in the common ancestors of Clupeocephala, Neoteleostei, and Acanthopterygii. Following these events, RH2 has continued to duplicate both in tandem and during lineage specific genome duplications. However, it has also been lost many times over so that in the genomes of extant teleosts, we find between zero to eight RH2 copies. Using retinal transcriptomes in a phylogenetic representative dataset of 30 species, we show that RH2 is expressed as the dominant green-sensitive opsin in almost all fish lineages. The exceptions are the Osteoglossomorpha (bony tongues and mooneyes) and several characin species that have lost RH2, and tarpons, other characins and gobies which do not or only lowly express the gene. These fishes instead express a green-shifted long-wavelength-sensitive LWS opsin. Our study highlights the strength of using modern genomic tools within a comparative framework to elucidate the detailed evolutionary history of gene families.


2021 ◽  
Author(s):  
Jesus A Ballesteros ◽  
Carlos Eduardo Santibanez-Lopez ◽  
Caitlin M Baker ◽  
Ligia R Benavides ◽  
Tauana J Cunha ◽  
...  

Deciphering the evolutionary relationships of Chelicerata (arachnids, horseshoe crabs, and allied taxa) has proven notoriously difficult, due to their ancient rapid radiation and the incidence of elevated evolutionary rates in several lineages. While conflicting hypotheses prevail in morphological and molecular datasets alike, the monophyly of Arachnida is nearly universally accepted. Though a small number of phylotranscriptomic analyses have recovered arachnid monophyly, these did not sample all living chelicerate orders. We generated a dataset of 506 high-quality genomes and transcriptomes, sampling all living orders of Chelicerata with high occupancy and rigorous approaches to orthology inference. Our analyses consistently recovered the nested placement of horseshoe crabs within a paraphyletic Arachnida. This result was insensitive to variation in evolutionary rates of genes, complexity of the substitution models, and alternatives algorithmic approaches to species tree inference. Investigation of systematic bias showed that genes and sites that recover arachnid monophyly are enriched in noise and exhibit low information content. To test the effect of morphological data, we generated a 514-taxon morphological data matrix of extant and fossil Chelicerata, analyzed in tandem with the molecular matrix. Combined analyses recovered the clade Merostomata (the marine orders Xiphosura, Eurypterida, and Chasmataspidida), but nested within Arachnida. Our results suggest that morphological convergence resulting from adaptations to life in terrestrial habitats has driven the historical perception of arachnid monophyly, paralleling the history of numerous other invertebrate terrestrial groups.


2016 ◽  
Author(s):  
Gregg W.C. Thomas ◽  
S. Hussain Ather ◽  
Matthew W. Hahn

AbstractPolyploidy can have a huge impact on the evolution of species, and it is a common occurrence, especially in plants. The two types of polyploids - autopolyploids and allopolyploids - differ in the level of divergence between the genes that are brought together in the new polyploid lineage. Because allopolyploids are formed via hybridization, the homoeologous copies of genes within them are at least as divergent as orthologs in the parental species that came together to form them. This means that common methods for estimating the parental lineages of allopolyploidy events are not accurate, and can lead to incorrect inferences about the number of gene duplications and losses. Here, we have adapted an algorithm for topology-based gene-tree reconciliation to work with multi-labeled trees (MUL-trees). By definition, MUL-trees have some tips with identical labels, which makes them a natural representation of the genomes of polyploids. Using this new reconciliation algorithm we can: accurately place allopolyploidy events on a phylogeny, identify the parental lineages that hybridized to form allopolyploids, distinguish between allo-, auto-, and (in most cases) no polyploidy, and correctly count the number of duplications and losses in a set of gene trees. We validate our method using gene trees simulated with and without polyploidy, and revisit the history of polyploidy in data from the clades including both baker’s yeast and bread wheat. Our re-analysis of the yeast data confirms the allopolyploid origin and parental lineages previously identified for this group. The method presented here should find wide use in the growing number of genomes from species with a history of polyploidy.


2019 ◽  
Author(s):  
Dominic A. Evangelista ◽  
Michael A. Gilchrist ◽  
Frédéric Legendre ◽  
Brian O’Meara

AbstractPatterns of discordance between gene trees and the species trees they reside in are crucial to the debate over the superiority of coalescent or concatenation approaches to tree inference. However, errors in estimating gene tree topologies obfuscate the issue by making gene trees appear erroneously discordant with the species tree. We thus test the prevalence of discordance between gene trees and their species tree using an empirical dataset for a clade with a rapid radiation (Blaberidae). We find that one model of codon evolution (FMutSel0) prefers gene trees that are less discordant, while another (SelAC) shows no such preference. We compare the species trees resulting from the selected sets of gene trees on the basis of internal consistency, predictive ability, and congruence with independent data. The species tree resulting from gene trees those chosen by FMutSel0, a set with low discordance, is the most robust and biologically plausible. Thus, we conclude that the results from FMutSel0 are better supported: simple models (i.e., GTR and ECM) infer trees with erroneously high levels of gene tree discordance. Furthermore, the amount of discordance in the set of gene trees has a large effect on the downstream phylogeny. Thus, decreasing gene tree error by lessening erroneous discordance can result in higher quality species trees. These results allow us to support relationships among blaberid cockroaches that were previously in flux as they now demonstrate molecular and morphological congruence.


AoB Plants ◽  
2021 ◽  
Author(s):  
Min-Jie Li ◽  
Huan-Xi Yu ◽  
Xian-Lin Guo ◽  
Xing-Jin He

Abstract The disjunctive distribution (Europe-Caucasus-Asia) and species diversification across Eurasia for the genus Allium sect. Daghestanica has fascinating attractions for researchers aiming to understanding the development and history of the modern Eurasia flora. However, no any studies have been carried out to address the evolutionary history of this section. Based on the nrITS and cpDNA fragments (trnL-trnF and rpl32-trnL), the evolutionary history of the third evolutionary line (EL3) of the genus Allium was reconstructed and we further elucidate the evolutionary line of sect. Daghestanica under this background. Our molecular phylogeny recovered two highly supported clades in sect. Daghestanica: the Clade I includes Caucasian-European species and Asian A. maowenense, A. xinlongense and A. carolinianum collected in Qinghai; the Clade II comprises Asian yellowish tepal species, A. chrysanthum, A. chrysocephalum, A. herderianum, A. rude and A. xichuanense. The divergence time estimation and biogeography inference indicated that Asian ancestor located in the QTP and the adjacent region could have migrated to Caucasus and Europe distributions around the Late Miocene and resulted in further divergence and speciation; Asian ancestor underwent the rapid radiation in the QTP and the adjacent region most likely due to the heterogeneous ecology of the QTP resulted from the orogeneses around 4–3 Mya. Our study provides a picture to understand the origin and species diversification across Eurasia for sect. Daghestanica.


2021 ◽  
pp. 162-169
Author(s):  
Kyle E. Jaynes

The Príncipe giant tree frog Leptopelis palmatus is endemic to the small oceanic island of Príncipe in the Gulf of Guinea. For several decades, this charismatic but poorly known species was confused with another large tree frog species from continental Africa, L. rufus. Phylogenetic relationships within the African genus Leptopelis are poorly understood and consequently the evolutionary history of L. palmatus and its affinity to L. rufus remain unclear. In this study, we combined mitochondrial DNA (mtDNA), morphological, and acoustic data for L. palmatus and L. rufus to assess different axes of divergence between the species. Our mtDNA gene tree for the genus Leptopelis indicated that L. palmatus is not closely related to L. rufus or other large species of Leptopelis. Additionally, we found low mtDNA diversity in L. palmatus across its range on Príncipe. We found significant morphological differences between females of L. rufus and L. palmatus, but not between males. We characterised the advertisement call of L. palmatus for the first time, which is markedly distinct from L. rufus. Finally, we summarised our observations of L. palmatus habitats and additional notes on phenotypic variation and behaviour. Our study reinforces the distinctiveness of L. palmatus and provides information important for the conservation of this endangered species. A rã gigante de Príncipe, Leptopelis palmatus, é endêmica da pequena ilha oceânica de Príncipe no Golfo da Guiné. Por várias décadas, esta espécie carismática mas pouco conhecida foi confundida com outra espécie grande de rã da África continental, L. rufus. As relações filogenéticas dentro do gênero africano Leptopelis são mal compreendidas e, conseqüentemente, a história evolutiva de L. palmatus e sua afinidade com L. rufus permanecem obscuras. Neste estudo, combinamos dados de DNA mitocondrial (mtDNA), morfológicos e acústicos de L. palmatus e L. rufus para avaliar diferentes eixos de divergência entre as espécies. Nossa árvore de genes de mtDNA para o gênero Leptopelis indicou que L. palmatus não está proximamente relacionada a L. rufus ou outras espécies grandes de Leptopelis, e encontramos baixa diversidade de mtDNA em L. palmatus em toda a sua distribuição em Príncipe. Encontramos diferenças morfológicas significativas entre as fêmeas de L. rufus e L. palmatus, mas não entre os machos. Caracterizamos o canto reprodutor de L. palmatus pela primeira vez, que é marcadamente distinto do de L. rufus. Finalmente, resumimos nossas observações dos habitats de L. palmatus e notas adicionais sobre variação fenotípica e comportamento. Nosso estudo fornece informações importantes para a conservação dessa espécie ameaçada de extinção


F1000Research ◽  
2014 ◽  
Vol 3 ◽  
pp. 49 ◽  
Author(s):  
Fabian Schreiber

Summary: Phylogenetic trees are widely used to represent the evolution of gene families. As the history of gene families can be complex (including lots of gene duplications), its visualisation can become a difficult task. A good/accurate visualisation of phylogenetic trees - especially on the web - allows easier understanding and interpretation of trees to help to reveal the mechanisms that shape the evolution of a specific set of gene/species. Here, I present treeWidget, a modular BioJS component to visualise phylogenetic trees on the web. Through its modularity, treeWidget can be easily customized to allow the display of sequence information, e.g. protein domains and alignment conservation patterns.Availability: http://github.com/biojs/biojs; http://dx.doi.org/10.5281/zenodo.7707


1993 ◽  
Vol 67 (4) ◽  
pp. 549-570 ◽  
Author(s):  
Bruce S. Lieberman

Phylogenetic parsimony analysis was used to classify the Siegenian–Eifelian “Metacryphaeus group” of the family Calmoniidae. Thirty-eight exoskeletal characters for 16 taxa produced a shortest-length cladogram with a consistency index of 0.49. A classification based on retrieving the structure of this cladogram recognizes nine genera: Typhloniscus Salter, Plesioconvexa n. gen., Punillaspis Baldis and Longobucco, Eldredgeia n. gen., Clarkeaspis n. gen., Malvinocooperella n. gen., Wolfartaspis Cooper, Plesiomalvinella Lieberman, Edgecombe, and Eldredge (used to represent the malvinellid clade), and Metacryphaeus Reed. The malvinellid clade is most closely related to a revised monophyletic Metacryphaeus. Typhloniscus is the basal member of the “Metacryphaeus group,” and the monotypic Wolfartaspis is sister to the clade containing the malvinellids and Metacryphaeus. Six new species are diagnosed: Punillaspis n. sp. A, “Clarkeaspis” gouldi, Clarkeaspis padillaensis, Malvinocooperella pregiganteus, Metacryphaeus curvigena, and Metacryphaeus branisai. Primitively, this group has South African and Andean affinities, and its evolutionary history suggests rapid diversification. In addition, evolutionary patterns in this group, and the distribution of character reversals, call into question certain notions about the nature of adaptive radiations. The distributions of taxa may answer questions about the number of marine transgressive/regressive cycles in the Emsian–Eifelian of the Malvinokaffric Realm.


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