scholarly journals Dental characters used in phylogenetic analyses of mammals show higher rates of evolution, but not reduced independence

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8744 ◽  
Author(s):  
Neil Brocklehurst ◽  
Gemma Louise Benevento

Accurate reconstructions of phylogeny are essential for studying the evolution of a clade, and morphological characters are necessarily used for the reconstruction of the relationships of fossil organisms. However, variation in their evolutionary modes (for example rate variation and character non-independence) not accounted for in analyses may be leading to unreliable phylogenies. A recent study suggested that phylogenetic analyses of mammals may be suffering from a dominance of dental characters, which were shown to have lower phylogenetic signal than osteological characters and produced phylogenies less congruent with molecularly-derived benchmarks. Here we build on this previous work by testing five additional morphological partitions for phylogenetic signal and examining what aspects of dental and other character evolution may be affecting this, by fitting models of discrete character evolution to phylogenies inferred and time calibrated using molecular data. Results indicate that the phylogenetic signal of discrete characters correlate most strongly with rates of evolution, with increased rates driving increased homoplasy. In a dataset covering all Mammalia, dental characters have higher rates of evolution than other partitions. They do not, however, fit a model of independent character evolution any worse than other regions. Primates and marsupials show different patterns to other mammal clades, with dental characters evolving at slower rates and being more heavily integrated (less independent). While the dominance of dental characters in analyses of mammals could be leading to inaccurate phylogenies, the issue is not unique to dental characters and the results are not consistent across datasets. Molecular benchmarks (being entirely independent of the character data) provide a framework for examining each dataset individually to assess the evolution of the characters used.

2021 ◽  
Vol 307 (2) ◽  
Author(s):  
Pau Carnicero ◽  
Núria Garcia-Jacas ◽  
Llorenç Sáez ◽  
Theophanis Constantinidis ◽  
Mercè Galbany-Casals

AbstractThe eastern Mediterranean basin hosts a remarkably high plant diversity. Historical connections between currently isolated areas across the Aegean region and long-distance dispersal events have been invoked to explain current distribution patterns of species. According to most recent treatments, at least two Cymbalaria species occur in this area, Cymbalaria microcalyx and C. longipes. The former comprises several intraspecific taxa, treated at different ranks by different authors based on morphological data, evidencing the need of a taxonomic revision. Additionally, some populations of C. microcalyx show exclusive morphological characters that do not match any described taxon. Here, we aim to shed light on the systematics of eastern Mediterranean Cymbalaria and to propose a classification informed by various sources of evidence. We performed molecular phylogenetic analyses using ITS, 3’ETS, ndhF and rpl32-trnL sequences and estimated the ploidy level of some taxa performing relative genome size measures. Molecular data combined with morphology support the division of traditionally delimited C. microcalyx into C. acutiloba, C. microcalyx and C. minor, corresponding to well-delimited nrDNA lineages. Furthermore, we propose to combine C. microcalyx subsp. paradoxa at the species level. A group of specimens previously thought to belong to Cymbalaria microcalyx constitute a well-defined phylogenetic and morphological entity and are described here as a new species, Cymbalaria spetae. Cymbalaria longipes is non-monophyletic, but characterized by being glabrous and diploid, unlike other eastern species. The nrDNA data suggest at least two dispersals from the mainland to the Aegean Islands, potentially facilitated by marine regressions.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10364
Author(s):  
Natalia I. Abramson ◽  
Fedor N. Golenishchev ◽  
Semen Yu. Bodrov ◽  
Olga V. Bondareva ◽  
Evgeny A. Genelt-Yanovskiy ◽  
...  

In this article, we present the nearly complete mitochondrial genome of the Subalpine Kashmir vole Hyperacrius fertilis (Arvicolinae, Cricetidae, Rodentia), assembled using data from Illumina next-generation sequencing (NGS) of the DNA from a century-old museum specimen. De novo assembly consisted of 16,341 bp and included all mitogenome protein-coding genes as well as 12S and 16S RNAs, tRNAs and D-loop. Using the alignment of protein-coding genes of 14 previously published Arvicolini tribe mitogenomes, seven Clethrionomyini mitogenomes, and also Ondatra and Dicrostonyx outgroups, we conducted phylogenetic reconstructions based on a dataset of 13 protein-coding genes (PCGs) under maximum likelihood and Bayesian inference. Phylogenetic analyses robustly supported the phylogenetic position of this species within the tribe Arvicolini. Among the Arvicolini, Hyperacrius represents one of the early-diverged lineages. This result of phylogenetic analysis altered the conventional view on phylogenetic relatedness between Hyperacrius and Alticola and prompted the revision of morphological characters underlying the former assumption. Morphological analysis performed here confirmed molecular data and provided additional evidence for taxonomic replacement of the genus Hyperacrius from the tribe Clethrionomyini to the tribe Arvicolini.


2021 ◽  
Vol 99 (2) ◽  
pp. 398-412
Author(s):  
Marcelo R. Pace ◽  
Brenda Hernández-Hernández ◽  
Esteban M. Martínez Salas ◽  
Lúcia G. Lohmann ◽  
N. Ivalu Cacho

Background: Astianthus is a monospecific arborescent genus of Bignoniaceae that occur in the Pacific Coast of central Mexico and northern Central America, where it grows in dense populations along riversides. Its phylogenetic placement has remained controversial since Astianthus has unusual morphological characters such as a four-loculed ovary, and simple, pulvinate, verticillate leaves. Methods: Here we used three plastid markers ndhF, rbcL, and trnL-F, wood, and bark anatomical data to investigate the phylogenetic placement of Astianthus and assign it to one of Bignoniaceae’s main clades. Results: Our molecular phylogenetic analyses indicated that Astianthus belongs in tribe Tecomeae s.s., where other charismatic Neotropical Bignoniaceae genera such as Campsis and Tecoma are currently placed. Wood and bark anatomy support this placement, as Astianthus reunites a unique combination of features only known from members of Tecomeae s.s., such as storied axial parenchyma, the co-occurrence of homo- and heterocellular rays, septate fibers, and scattered phloem fibers in the bark. Conclusions: The placement of Astianthus within Tecomeae s.s. provides further support to previous proposals for the Neotropical origin of this Pantropical tribe.


2019 ◽  
Vol 69 (3) ◽  
pp. 530-544 ◽  
Author(s):  
Michael R May ◽  
Brian R Moore

Abstract Understanding how and why rates of character evolution vary across the Tree of Life is central to many evolutionary questions; for example, does the trophic apparatus (a set of continuous characters) evolve at a higher rate in fish lineages that dwell in reef versus nonreef habitats (a discrete character)? Existing approaches for inferring the relationship between a discrete character and rates of continuous-character evolution rely on comparing a null model (in which rates of continuous-character evolution are constant across lineages) to an alternative model (in which rates of continuous-character evolution depend on the state of the discrete character under consideration). However, these approaches are susceptible to a “straw-man” effect: the influence of the discrete character is inflated because the null model is extremely unrealistic. Here, we describe MuSSCRat, a Bayesian approach for inferring the impact of a discrete trait on rates of continuous-character evolution in the presence of alternative sources of rate variation (“background-rate variation”). We demonstrate by simulation that our method is able to reliably infer the degree of state-dependent rate variation, and show that ignoring background-rate variation leads to biased inferences regarding the degree of state-dependent rate variation in grunts (the fish group Haemulidae). [Bayesian phylogenetic comparative methods; continuous-character evolution; data augmentation; discrete-character evolution.]


Phytotaxa ◽  
2015 ◽  
Vol 239 (3) ◽  
pp. 223 ◽  
Author(s):  
Osman Erol ◽  
Doerte Harpke ◽  
Hasan Yıldırım

Crocus musagecitii is described as a new species. Diagnostic morphological characters, a full description and detailed illustrations are provided on the basis of the type specimen and wild specimens. Morphologically, C. musagecitii is close to Crocus biflorus subsp. pseudonubigena. Crocus musagecitii differs from C. biflorus subsp. pseudonubigena by the lack of stripes or narrow purplish tongue on outside of outer tepals, wider tepals, and homogenously yellow anthers. In order to clarify the phylogenetic position of this species within the Crocus adamii species complex, we sequenced the internal transcribed spacer region (ITS: ITS1 + 5.8SrDNA + ITS2) and 5’ external transcribed spacer (ETS) of the nuclear ribosomal DNA (rDNA). A phylogenetic tree obtained by Bayesian phylogenetic inference is given. Phylogenetic analyses revealed that the new taxon is close to C. munzurensis. Crocus musagecitii differs from its phylogenetically closest relative C. munzurensis by the corm tunics (C. musagecitii: coriaceus; C. munzurensis: membranous), the number of leaves (C. musagecitii: up to 8; C. munzurensis: up to 4) and non-hairy leaf margins.


Phytotaxa ◽  
2019 ◽  
Vol 415 (4) ◽  
pp. 179-188
Author(s):  
XIANG-NYU CHEN ◽  
MING ZHANG ◽  
TAI-HUI LI ◽  
NIAN-KAI ZENG

Heimioporus sinensis, collected from tropical and subtropical areas of China, is introduced as a new species based on both morphological characters and molecular data. The species is characterized by the purplish red to deep magenta pileus, the reticulated stipe, the irregularly reticulate to reticulate-alveolate basidiospores 11.5–13.5 × 8–9.5 μm, and a trichodermal to intricately trichodermal pileipellis. Phylogenetic analyses based on the nuc 28S rDNA D1-D2 domains (28S) and the translation elongation factor 1-α gene (tef1-α) showed that H. sinensis is a distinct member of the genus Heimioporus in the subfamily Xerocomoideae.


Zootaxa ◽  
2007 ◽  
Vol 1423 (1) ◽  
pp. 1-26 ◽  
Author(s):  
JEFFREY H. SKEVINGTON ◽  
CHRISTIAN KEHLMAIER ◽  
GUNILLA STÅHLS

Sequence data from 658 base pairs of mitochondrial cytochrome c oxidase I (cox1) were analysed for 28 described species of Pipunculidae (Diptera) in an effort to test the concept of DNA Barcoding on this family. Two recently revised but distantly related pipunculid lineages with presumed different evolutionary histories were used for the test (Clistoabdominalis Skevington, 2001 and Nephrocerus Zetterstedt, 1838). An effort was made to test the concept using sister taxa and morphologically similar sibling species swarms in these two genera. Morphological species concepts for Clistoabdominalis taxa were either supported by cox1 data or found to be too broad. Most of the discordance could be accounted for after reassessing morphological characters. In these cases, the molecular data were invaluable in assisting taxonomic decision-making. The radiation of Nearctic species of Nephrocerus could not be diagnosed using cox1. The ability of cox1 to recover phylogenetic signal was also tested on Clistoabdominalis. Morphological data for Clistoabdominalis were combined with the molecular data set. The pipunculid phylogeny from molecular data closely resembles the published phylogeny based on morphology. Partitioned Bremer support is used to localize areas of conflict between the datasets.


2015 ◽  
Vol 46 (3) ◽  
pp. 269-290 ◽  
Author(s):  
Ian J. Kitching ◽  
C. Lorna Culverwell ◽  
Ralph E. Harbach

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.


2017 ◽  
Vol 31 (3) ◽  
pp. 317 ◽  
Author(s):  
Jesús A. Cruz-López ◽  
Oscar F. Francke

Systematic relationships among Laniatores have received considerable attention during the past few years. Many significant taxonomic changes have been proposed, particularly in the superfamily Gonyleptoidea. As part of this superfamily, the basalmost Stygnopsidae is the least known family. In order to propose the first total evidence phylogeny of the family, we produced four datasets: three molecular markers – partial nuclear 28S, mitochondrial ribosomal 16S, mitochondrial protein-encoding cytochrome c oxidase subunit I; and 72 morphological characters. With these data, we performed three different phylogenetic analyses: (1) Bayesian Inference with molecular data, and (2) Bayesian Inference and (3) Maximum Likelihood using combined data. Our results are congruent: a monophyletic Stygnopsidae subdivided into two major clades: Stygnopsinae and Karosinae, subfam. nov. The following genera are redefined: Stygnopsis, Hoplobunus and Serrobunus stat. rev. The following taxa are described: Iztlina venefica, gen. nov., sp. nov. and Tonalteca, gen. nov. Additionally, the following changes are proposed: Serrobunus queretarius (Šilhavý, 1974), comb. nov., Stygnopsis apoalensis (Goodnight & Goodnight, 1973), comb. nov., Stygnopsis mexicana (Roewer, 1915), comb. nov., Stygnopsis oaxacensis (Goodnight & Goodnight, 1973), comb. nov., and Tonalteca spinooculorum (Goodnight & Goodnight, 1973), comb. nov. We also discuss the status of the genera Isaeus stat. rev. and Mexotroglinus. Finally, we discuss the evolution of male genitalia and convergence of selected homoplastic diagnostic characters.


2014 ◽  
Vol 62 (8) ◽  
pp. 638 ◽  
Author(s):  
Farrokh Ghahremaninejad ◽  
Mehrshid Riahi ◽  
Melina Babaei ◽  
Faride Attar ◽  
Lütfi Behçet ◽  
...  

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.


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