scholarly journals A conservative approach for species delimitation based on multi-locus DNA sequences: a case study of the genus Giraffa (Mammalia, Cetartiodactyla)

2019 ◽  
Author(s):  
Alice Petzold ◽  
Alexandre Hassanin
Keyword(s):  
Dna Sequences ◽  
Population Genetic ◽  
Phylogenetic Analyses ◽  
Single Species ◽  
Haplotype Network ◽  
Molecular Data ◽  
Sensu Stricto ◽  
Nuclear Introns ◽  
Multispecies Coalescent ◽  
Nucleotide Divergence

AbstractMolecular data are now commonly used in taxonomy for delimiting cryptic species. In the case of giraffes, which were treated as a single species (Giraffa camelopardalis) during half of a century, several molecular studies have suggested a splitting into four to seven species, but the criteria applied for taxonomic delimitation were not fully described.In this study, we have analysed all multi-locus DNA sequences available for giraffes using multispecies coalescent (MSC: *BEAST, BPP and STACEY), population genetic (STRUCTURE, allelic networks, haplotype network and bootstrapping) and phylogenetic (MrBayes, PhyML, SuperTRI) methods to identify the number of species. Our results show that depending on the method chosen, different taxonomic hypotheses, recognizing from two to six species, can be considered for the genus Giraffa. Our results confirm that MSC methods can lead to taxonomic over-splitting, as they delimit geographic structure rather than species. The 3-species hypothesis, which recognizes G. camelopardalis sensu strico, G. giraffa, and G. tippelskirchi, is highly supported by phylogenetic analyses and also corroborated by most population genetic and MSC analyses. The three species show high levels of nucleotide divergence in both nuclear (0.35-0.51 %) and mitochondrial sequences (3-4 %), and they are characterised by 7 to 12 exclusive synapomorphies (ES) detected in nine of the 21 nuclear introns analysed for this study. By contrast, other putative species, such as G. peralta, G. reticulata, G. thornicrofti or G. tippelskirchi sensu stricto, do not exhibit any ES in nuclear genes.A robust mito-nuclear conflict was found for the position and monophyly of G. giraffa and G. tippelskirchi, which is explained firstly by a mitochondrial introgression from Masai giraffe to southeastern giraffe during the Pleistocene, and secondly, by gene flow mediated by male dispersal between southern populations (subspecies G.g. giraffa and G.g. angolensis).

scholarly journals Evaluating methodologies for species delimitation: the mismatch between phenotypes and genotypes in lichenized fungi (Bryoria sect. Implexae, Parmeliaceae)

2019 ◽  
Vol 42 (1) ◽  
pp. 75-100 ◽  
Author(s):  
C.G. Boluda ◽  
V.J. Rico ◽  
P.K. Divakar ◽  
O. Nadyeina ◽  
L. Myllys ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Species Delimitation ◽  
Sequence Data ◽  
Species Recognition ◽  
Phylogenetic Analyses ◽  
Phylogenetic Reconstruction ◽  
Haplotype Network ◽  
Molecular Data ◽  
Integrative Taxonomy ◽  
Molecular Sequence Data

In many lichen-forming fungi, molecular phylogenetic analyses lead to the discovery of cryptic species within traditional morphospecies. However, in some cases, molecular sequence data also questions the separation of phenotypically characterised species. Here we apply an integrative taxonomy approach – including morphological, chemical, molecular, and distributional characters – to re-assess species boundaries in a traditionally speciose group of hair lichens, Bryoria sect. Implexae. We sampled multilocus sequence and microsatellite data from 142 specimens from a broad intercontinental distribution. Molecular data included DNA sequences of the standard fungal markers ITS, IGS, GAPDH, two newly tested loci (FRBi15 and FRBi16), and SSR frequencies from 18 microsatellite markers. Datasets were analysed with Bayesian and maximum likelihood phylogenetic reconstruction, phenogram reconstruction, STRUCTURE Bayesian clustering, principal coordinate analysis, haplotype network, and several different species delimitation analyses (ABGD, PTP, GMYC, and DISSECT). Additionally, past population demography and divergence times are estimated. The different approaches to species recognition do not support the monophyly of the 11 currently accepted morphospecies, and rather suggest the reduction of these to four phylogenetic species. Moreover, three of these are relatively recent in origin and cryptic, including phenotypically and chemically variable specimens. Issues regarding the integration of an evolutionary perspective into taxonomic conclusions in species complexes, which have undergone recent diversification, are discussed. The four accepted species, all epitypified by sequenced material, are Bryoria fuscescens, B. glabra, B. kockiana, and B. pseudofuscescens. Ten species rank names are reduced to synonymy. In the absence of molecular data, they can be recorded as the B. fuscescens complex. Intraspecific phenotype plasticity and factors affecting the speciation of different morphospecies in this group of Bryoria are outlined.

scholarly journals Linking morphological and molecular sources to disentangle the case of Xylodon australis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Javier Fernández-López ◽  
M. Teresa Telleria ◽  
Margarita Dueñas ◽  
Mara Laguna-Castro ◽  
Klaus Schliep ◽  
...  
Keyword(s):  
New Zealand ◽  
Phylogenetic Analyses ◽  
Single Species ◽  
R Package ◽  
Molecular Data ◽  
Historical Collections ◽  
Close Relationship ◽  
Kinship Relations ◽  
History Of ◽  
Different Sources

AbstractThe use of different sources of evidence has been recommended in order to conduct species delimitation analyses to solve taxonomic issues. In this study, we use a maximum likelihood framework to combine morphological and molecular traits to study the case of Xylodon australis (Hymenochaetales, Basidiomycota) using the locate.yeti function from the phytools R package. Xylodon australis has been considered a single species distributed across Australia, New Zealand and Patagonia. Multi-locus phylogenetic analyses were conducted to unmask the actual diversity under X. australis as well as the kinship relations respect their relatives. To assess the taxonomic position of each clade, locate.yeti function was used to locate in a molecular phylogeny the X. australis type material for which no molecular data was available using morphological continuous traits. Two different species were distinguished under the X. australis name, one from Australia–New Zealand and other from Patagonia. In addition, a close relationship with Xylodon lenis, a species from the South East of Asia, was confirmed for the Patagonian clade. We discuss the implications of our results for the biogeographical history of this genus and we evaluate the potential of this method to be used with historical collections for which molecular data is not available.

scholarly journals Morphological and Genetic Structure of Two Equivalent Astyanax Species (Characiformes: Characidae) in the Region of Paranaíba Arc

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Renan Rodrigues Rocha ◽  
Rosana de Mesquita Alves ◽  
Rubens Pasa ◽  
Karine Frehner Kavalco
Keyword(s):  
Geometric Morphometrics ◽  
River Basin ◽  
Dna Sequences ◽  
Haplotype Network ◽  
River Basins ◽  
Molecular Data ◽  
The Body ◽  
Present Species ◽  
Body Depth ◽  
Geometric Morphometric

The Astyanax scabripinnis complex is composed of a large number of almost morphological indistinguishable species, including Astyanax paranae and Astyanax rivularis, which exist in the Paraná and São Francisco Basins, respectively, and sometimes are considered subspecies of the A. scabripinnis group or even are cited just as A. scabripinnis. The two river basins are separated by the Upper Paranaíba Arc, likely the main cause of the isolation of these species. We used geometric morphometric tools and DNA analyses of populations of both species to identify the differences between them. Geometric morphometrics separated the two species into distinct groups, whose main difference was the body depth. This is generally related to the speed of the water flow in the river basins. The maximum likelihood phylogram based on mitochondrial DNA sequences formed two main clades: one composed of the population of A. rivularis and the other, of A. paranae. In the haplotype network, the species were similarly separated into two groups from the same ancestral haplotype, with A. rivularis dispersing into two lineages in the São Francisco River Basin. The distribution of A. paranae is a consequence of a secondary dispersion event in the Paraná River Basin. It forms two lineages from a haplotype derived from the ancestor. The vicariant effect of separate basins, through the elevation of the Upper Paranaíba Arc, led to the allopatric speciation of the populations originating the present species. The results of geometric morphometrics and molecular data of the fish show the importance of this geological event in the biogeography and evolutionary history of the ichthyofauna of the region and indicate that the isolation of these species seems to be effective.

scholarly journals Phylogenetics of Taxus Using the Internal Transcribed Spacers of Nuclear Ribosomal DNA and Plastid trnL-F Regions

Horticulturae ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 19
Author(s):  
Patricia Coughlan ◽  
James C. Carolan ◽  
Ingrid L. I. Hook ◽  
Lisa Kilmartin ◽  
Trevor R. Hodkinson
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Analyses ◽  
Intergenic Spacer ◽  
Its Region ◽  
Single Species ◽  
Internal Transcribed Spacers ◽  
Nuclear Ribosomal Dna ◽  
Trnl Intron ◽  
Group Status ◽  
Haplotype Networks

Taxus is a genus of trees and shrubs with high value in horticulture and medicine as a source of the anticancer drug paclitaxel. The taxonomy of the group is complex due to the lack of diagnostic morphological characters and the high degree of similarity among species. Taxus has a wide global geographic distribution and some taxonomists recognize only a single species with geographically defined subgroups, whereas others have described several species. To address these differences in taxonomic circumscription, phylogenetic analyses were conducted on DNA sequences using Maximum Likelihood, Bayesian Inference and TCS haplotype networks on single and combined gene regions obtained for the nuclear ribosomal ITS region and the plastid trnL intron and trnL-F intergenic spacer. Evidence is presented for the sister group status of Pseudotaxus to Taxus and the inclusion of Amentotaxus, Austrotaxus, Cephalotaxus and Torreya within Taxaceae. Results are consistent with the taxonomic recognition of nine species: T. baccata, T. brevifolia, T. canadensis, T. cuspidata, T. floridana, T. fuana, T. globosa, T. sumatrana and T. wallichiana, but evidence is found for less species distinction and considerable reticulation within the T. baccata, T. canadensis and T. cuspidata group. We compare the results to known taxonomy, biogeography, present new leaf anatomical data and discuss the origins of the hybrids T. ×media and T. ×hunnewelliana.

Cryptic species complexes in manipulative echinostomatid trematodes: when two become six

Parasitology ◽  
2008 ◽  
Vol 136 (2) ◽  
pp. 241-252 ◽  
Author(s):  
T. L. F. LEUNG ◽  
D. B. KEENEY ◽  
R. POULIN
Keyword(s):  
Cryptic Species ◽  
Phylogenetic Analyses ◽  
Morphological Characteristics ◽  
Single Species ◽  
Distinct Species ◽  
Molecular Data ◽  
Spatial Segregation ◽  
Small Scale ◽  
Intermediate Hosts ◽  
Species Complexes

SUMMARYRecent studies have shown that some digenean trematodes previously identified as single species due to the lack of distinguishing morphological characteristics actually consist of a number of genetically distinct cryptic species. We obtained mitochondrial 16S and nuclear ITS1 sequences for the redial stages of Acanthoparyphium sp. and Curtuteria australis collected from snails and whelks at various locations around Otago Peninsula, New Zealand. These two echinostomes are well-known host manipulators whose impact extends to the entire intertidal community. Using phylogenetic analyses, we found that Acanthoparyphium sp. is actually composed of at least 4 genetically distinct species, and that a cryptic species of Curtuteria occurs in addition to C. australis. Molecular data obtained for metacercariae dissected from cockle second intermediate hosts matched sequences obtained for Acanthoparyphium sp. A and C. australis rediae, respectively, but no other species. The various cryptic species of both Acanthoparyphium and Curtuteria also showed an extremely localized pattern of distribution: some species were either absent or very rare in Otago Harbour, but reached far higher prevalence in nearby sheltered inlets. This small-scale spatial segregation is unexpected as shorebird definitive hosts can disperse trematode eggs across wide geographical areas, which should result in a homogeneous mixing of the species on small geographical scales. Possible explanations for this spatial segregation of the species include sampling artefacts, local adaptation by first intermediate hosts, environmental conditions, and site fidelity of the definitive hosts.

Global classification and evolution of brushlegged mayflies (Insecta: Ephemeroptera: Oligoneuriidae): phylogenetic analyses of morphological and molecular data and dated historical biogeography

2019 ◽  
Vol 187 (2) ◽  
pp. 378-412 ◽  
Author(s):  
Fabiana Criste Massariol ◽  
Daniela Maeda Takiya ◽  
Frederico Falcão Salles
Keyword(s):  
Phylogenetic Analyses ◽  
Divergence Time ◽  
Time Estimation ◽  
Single Species ◽  
Molecular Data ◽  
Neotropical Region ◽  
Fossil Species ◽  
Divergence Time Estimation ◽  
The Family ◽  
Family Based

AbstractOligoneuriidae is a Pantropical family of Ephemeroptera, with 68 species described in 12 genera. Three subfamilies are recognized: Chromarcyinae, with a single species from East Asia; Colocrurinae, with two fossil species from Brazil; and Oligoneuriinae, with the remaining species distributed in the Neotropical, Nearctic, Afrotropical and Palaearctic regions. Phylogenetic and biogeographical analyses were performed for the family based on 2762 characters [73 morphological and 2689 molecular (COI, 16S, 18S and 28S)]. Four major groups were recovered in all analyses (parsimony, maximum likelihood and Bayesian inference), and they were assigned to tribal level, namely Oligoneuriini, Homoeoneuriini trib. nov., Oligoneuriellini trib. nov. and Elassoneuriini trib. nov. In addition, Yawari and Madeconeuria were elevated to genus level. According to Statistical Dispersal-Vicariance (S-DIVA), Dispersal Extinction Cladogenesis (DEC) and divergence time estimation analyses, Oligoneuriidae originated ~150 Mya in the Gondwanan supercontinent, but was probably restricted to the currently delimited Neotropical region. The initial divergence of Oligoneuriidae involved a range expansion to Oriental and Afrotropical areas, sometime between 150 and 118 Mya. At ~118 Mya, the family started its diversification, reaching the Nearctic through dispersal from the Neotropical region and the Palaearctic and Madagascar from the Afrotropical region.

scholarly journals The phylogenetic conundrum of Lutzia (Diptera: Culicidae: Culicini): a cautionary account of conflict and support

2015 ◽  
Vol 46 (3) ◽  
pp. 269-290 ◽  
Author(s):  
Ian J. Kitching ◽  
C. Lorna Culverwell ◽  
Ralph E. Harbach
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Analyses ◽  
Morphological Characters ◽  
Molecular Data ◽  
Morphological Data ◽  
Data Set ◽  
Generic Status ◽  
Strong Signal ◽  
Phylogenetic Studies ◽  
Data Support

Lutzia Theobald was reduced to a subgenus of Culex in 1932 and was treated as such until it was restored to its original generic status in 2003, based mainly on modifications of the larvae for predation. Previous phylogenetic studies based on morphological and molecular data have provided conflicting support for the generic status of Lutzia: analyses of morphological data support the generic status whereas analyses based on DNA sequences do not. Our previous phylogenetic analyses of Culicini (based on 169 morphological characters and 86 species representing the four genera and 26 subgenera of Culicini, most informal group taxa of subgenus Culex and five outgroup species from other tribes) seemed to indicate a conflict between adult and larval morphological data. Hence, we conducted a series of comparative and data exclusion analyses to determine whether the alternative positions of Lutzia are due to conflicting signal or to a lack of strong signal. We found that separate and combined analyses of adult and larval data support different patterns of relationships between Lutzia and other Culicini. However, the majority of conflicting clades are poorly supported and once these are removed from consideration, most of the topological disparity disappears, along with much of the resolution, suggesting that morphology alone does not have sufficiently strong signal to resolve the position of Lutzia. We critically examine the results of other phylogenetic studies of culicinine relationships and conclude that no morphological or molecular data set analysed in any study conducted to date has adequate signal to place Lutzia unequivocally with regard to other taxa in Culicini. Phylogenetic relationships observed thus far suggest that Lutzia is placed within Culex but further data and extended taxon sampling are required to confirm its position relative to Culex.

Monophyly of Verbascum (Scrophularieae : Scrophulariaceae): evidence from nuclear and plastid phylogenetic analyses

2014 ◽  
Vol 62 (8) ◽  
pp. 638 ◽  
Author(s):  
Farrokh Ghahremaninejad ◽  
Mehrshid Riahi ◽  
Melina Babaei ◽  
Faride Attar ◽  
Lütfi Behçet ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Dna Sequences ◽  
Phylogenetic Relationships ◽  
Phylogenetic Analyses ◽  
Morphological Characters ◽  
Molecular Data ◽  
Nrdna Its ◽  
Starting Point ◽  
High Species Diversity ◽  
Phylogenetic Estimation

Verbascum is one of the main genera of Scrophulariaceae, but delimitation and phylogenetic relationships of this genus are unclear and have not yet been studied using DNA sequences. Here, using four selected molecular markers (nrDNA ITS and the plastid spacers trnS/G, psbA-trnH and trnY/T), we present a phylogeny of Verbascum and test previous infrageneric taxonomic hypotheses as well as its monophyly with respect to Scrophularia. We additionally discuss morphological variation and the utility of morphological characters as predictors of phylogenetic relationships. Our results show that while molecular data unambiguously support the circumscription of Verbascum inferred from morphology, they prove to be of limited utility in resolving infrageneric relationships, suggesting that Verbascum ‘s high species diversity is due to rapid and recent radiation. Our work provides phylogenetic estimation of the genus Verbascum using molecular data and can serve as a starting point for future investigations of Verbascum and relatives.

Morphological and molecular identification of a new species of Perenniporia (Polyporales, Basidiomycota) in North America

Phytotaxa ◽  
2018 ◽  
Vol 351 (1) ◽  
pp. 63
Author(s):  
SHAN SHEN ◽  
TAI-MIN XU ◽  
JASON KARAKEHIAN ◽  
CHANG-LIN ZHAO
Keyword(s):  
New Species ◽  
Phylogenetic Analyses ◽  
Large Subunit ◽  
Strong Support ◽  
Molecular Data ◽  
Sensu Stricto ◽  
Fungal Species ◽  
Monophyletic Lineage ◽  
Inference Methods ◽  
Molecular Characters

A new poroid wood-inhabiting fungal species, Perenniporia bostonensis sp. nov., is proposed based on morphological and molecular characters. The species is characterized by resupinate, cream to buff pore surface; a dimitic hyphal system with skeletal hyphae strongly dextrinoid, unbranched, interwoven and a distinct wide lumen; ovoid to broad ellipsoid, non-truncate, hyaline, distinct thick-walled, smooth, dextrinoid basidiospores, 3.5–4.5 × 3–4 µm. The internal transcribed spacer (ITS) and the large subunit (LSU) regions of nuclear ribosomal RNA gene sequences of the studied samples were generated, and phylogenetic analyses were performed with maximum likelihood, maximum parsimony and bayesian inference methods. The phylogenetic analysis based on molecular data of ITS+nLSU sequences showed that P. bostonensis recognized in Perenniporia sensu stricto. The new species formed a monophyletic lineage with a strong support (100% BS, 100% BP, 1.00 BPP) and was closely related to P. bannaensis and P. koreana. Both morphological and molecular characters confirmed the placement of the new species in Perenniporia.

Phylogeny of the Micareaceae inferred from nrSSU DNA sequences

2004 ◽  
Vol 36 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Heidi L. ANDERSEN ◽  
Stefan EKMAN
Keyword(s):  
Bayesian Inference ◽  
Maximum Likelihood ◽  
Dna Sequences ◽  
Phylogenetic Analyses ◽  
Sister Group ◽  
Small Subunit ◽  
Sensu Stricto ◽  
Confidence Set ◽  
Tree Topologies ◽  
Small Subunit Ribosomal Dna

The phylogeny of the Micareaceae and the genus Micarea Fr. was studied using 39 nuclear small subunit ribosomal DNA sequences. Phylogenetic analyses were carried out using maximum parsimony, maximum likelihood, and Bayesian inference. A confidence set of trees was estimated using expected likelihood weights to investigate a series of hypotheses of monophyly. Tree topologies were very similar between methods and differed only in the placement of a few poorly supported branches. The results indicate that the Micareaceae in its current circumscription belongs in the Lecanorales, but that it is not monophyletic. Psilolechia, Micarea with a ‘non-micareoid’ photobiont, Micarea sensu stricto and Byssoloma form a paraphyletic grade in this study. Micarea sensu stricto and Byssoloma (Pilocarpaceae) form a strongly supported monophyletic group, which constitutes the sister group to the Bacidiaceae. Scoliciosporum A. Massal has sometimes been considered close to Micarea, but no support was found for that hypothesis.

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