Molecular phylogeny and divergence time estimates in pennatulaceans (Cnidaria: Octocorallia: Pennatulacea)

2020 ◽  
Vol 84 (4) ◽  
pp. 317-330
Author(s):  
Francisco J. García-Cárdenas ◽  
Mónica Núñez-Flores ◽  
Pablo J. López-González

Pennatulaceans are an important component of benthic marine communities usually related to soft bottoms. Despite their important ecological role, as yet little is known about their origin and divergence time. The first attempts to establish phylogenetic relationships among genera date from the early 20th century, when only morphological characters were available. In the last decade, phylogenetic analyses based on mitochondrial DNA sequences from a selected number of species have proposed a different hypothetical ancestor for this group, but their intergeneric relationships remain obscure. The present study is based on a combination of mitochondrial and nuclear markers (mtMutS, Cox1 and 28S rDNA), adding new molecular information about the phylogenetic relationships among the pennatulacean genera, including 38 new sequences belonging to 13 different species. Some of the phylogenetic relationships inferred in the present study question the current classification of sea pens based on morphology (at different taxonomic levels), clearly indicating that the two main groups Sessiliflorae and Subselliflorae, some of their main families (e.g. Pennatulidae, Umbellulidae, Virgulariidae) and some genera (e.g. Umbellula, Veretillum) are non-monophyletic. In addition, the veretillids, traditionally considered the most primitive pennatulaceans, are not shown as the earliest-diverging taxon. Moreover, an analysis of divergence time performed here suggested that the origin of the pennatulaceans dates from the Lower Cretaceous (Berriasian, ~144 Ma), in agreement with their sparsely known fossil record, while the initial divergence of most extant genera occurred in the Oligocene and Miocene times.

2021 ◽  
pp. 1-28
Author(s):  
Yoshimasa Kumekawa ◽  
Haruka Fujimoto ◽  
Osamu Miura ◽  
Ryo Arakawa ◽  
Jun Yokoyama ◽  
...  

Abstract Harvestmen (Arachnida: Opiliones) are soil animals with extremely low dispersal abilities that experienced allopatric differentiation. To clarify the morphological and phylogenetic differentiation of the endemic harvestman Zepedanulus ishikawai (Suzuki, 1971) (Laniatores: Epedanidae) in the southern part of the Ryukyu Archipelago, we conducted molecular phylogenetic analyses and divergence time estimates based on CO1 and 16S rRNA sequences of mtDNA, the 28S rRNA sequence of nrDNA, and the external morphology. A phylogenetic tree based on mtDNA sequences indicated that individuals of Z. ishikawai were monophyletic and were divided into clade I and clade II. This was supported by the nrDNA phylogenetic tree. Although clades I and II were distributed sympatrically on all three islands examined (Ishigaki, Iriomote, and Yonaguni), heterogeneity could not be detected by polymerase chain reaction–restriction fragment length polymorphism of nrDNA, indicating that clades I and II do not have a history of hybridisation. Also, several morphological characters differed significantly between individuals of clade I and clade II. The longstanding isolation of the southern Ryukyus from the surrounding islands enabled estimation of the original morphological characters of both clades of Z. ishikawai.


2021 ◽  
Author(s):  
◽  
Whitney L M Bouma

<p>The fern family Pteridaceae is among the largest fern families in New Zealand. It comprises 17 native species among five genera. Traditionally the classification of Pteridaceae was based on morphological characters. The advent of molecular technology, now makes is possible to test these morphology-based classifications. The Pteridaceae has previously been subjected to phylogenetic analyses; however representatives from New Zealand and the South Pacific have never been well represented in these studies. This thesis research aimed to investigate the phylogenetic relationships of the New Zealand Pteridaceae, as well as, the phylogenetic relationships of the New Zealand species to their overseas relatives. The DNA sequences of several Chloroplast loci (e.g. trnL-trnF locus, rps4 and rps4-trnS IGS, atpB, and rbcL) were determined and the phylogenetic relationships of the New Zealand Pteridaceae and several species-specific question within the genus Pellaea and Adiantum were investigated. Results presented in this thesis confirm previously published phylogenetics of the Pteridaceae, which show the resolution of five major clades, i.e.,cryptogrammoids, ceratopteridoids, pteridoids, cheilanthoids, and the adiantoids. The addition of the New Zealand species revealed a possible South West Pacific groups formed by the respective genera, where New Zealand species were generally more related to one another than to overseas relatives. Within the New Zealand Pellaea, the analysis of the trnL-trnF locus sequence data showed that the morphologically-intermediate plants P. aff. falcata, responsible for taxonomic confusion, were more closely related to P. rotundifolia than to P. falcata. Furthermore, the species collected on the Kermadec Islands, previously thought to be P. falcata, are genetically distinct from the Australian P. falcata and they could constitute a new species. Adiantum hispidulum, which is polymorphic for two different hair types being used to distinguish them as different species, was also reinvestigated morphologically and molecularly. Morphological inspection of hairs revealed three hair types as opposed to the previous thought two, and furthermore, they correspond to three different trnL-trnF sequences haplotypes.</p>


2021 ◽  
Author(s):  
◽  
Whitney L M Bouma

<p>The fern family Pteridaceae is among the largest fern families in New Zealand. It comprises 17 native species among five genera. Traditionally the classification of Pteridaceae was based on morphological characters. The advent of molecular technology, now makes is possible to test these morphology-based classifications. The Pteridaceae has previously been subjected to phylogenetic analyses; however representatives from New Zealand and the South Pacific have never been well represented in these studies. This thesis research aimed to investigate the phylogenetic relationships of the New Zealand Pteridaceae, as well as, the phylogenetic relationships of the New Zealand species to their overseas relatives. The DNA sequences of several Chloroplast loci (e.g. trnL-trnF locus, rps4 and rps4-trnS IGS, atpB, and rbcL) were determined and the phylogenetic relationships of the New Zealand Pteridaceae and several species-specific question within the genus Pellaea and Adiantum were investigated. Results presented in this thesis confirm previously published phylogenetics of the Pteridaceae, which show the resolution of five major clades, i.e.,cryptogrammoids, ceratopteridoids, pteridoids, cheilanthoids, and the adiantoids. The addition of the New Zealand species revealed a possible South West Pacific groups formed by the respective genera, where New Zealand species were generally more related to one another than to overseas relatives. Within the New Zealand Pellaea, the analysis of the trnL-trnF locus sequence data showed that the morphologically-intermediate plants P. aff. falcata, responsible for taxonomic confusion, were more closely related to P. rotundifolia than to P. falcata. Furthermore, the species collected on the Kermadec Islands, previously thought to be P. falcata, are genetically distinct from the Australian P. falcata and they could constitute a new species. Adiantum hispidulum, which is polymorphic for two different hair types being used to distinguish them as different species, was also reinvestigated morphologically and molecularly. Morphological inspection of hairs revealed three hair types as opposed to the previous thought two, and furthermore, they correspond to three different trnL-trnF sequences haplotypes.</p>


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.


2020 ◽  
Vol 42 (3) ◽  
pp. 266 ◽  
Author(s):  
Shimona Kealy ◽  
Stephen C. Donnellan ◽  
Kieren J. Mitchell ◽  
Michael Herrera ◽  
Ken Aplin ◽  
...  

The species-level systematics of the marsupial family Phalangeridae, particularly Phalanger, are poorly understood, due partly to the family’s wide distribution across Australia, New Guinea, eastern Indonesia, and surrounding islands. In order to refine the species-level systematics of Phalangeridae, and improve our understanding of their evolution, we generated 36 mitochondrial ND2 DNA sequences from multiple species and sample localities. We combined our new data with available sequences and produced the most comprehensive molecular phylogeny for Phalangeridae to date. Our analyses (1) strongly support the monophyly of the three phalangerid subfamilies (Trichosurinae, Ailuropinae, Phalangerinae); (2) reveal the need to re-examine all specimens currently identified as ‘Phalanger orientalis’; and (3) suggest the elevation of the Solomon Island P. orientalis subspecies to species level (P. breviceps Thomas, 1888). In addition, samples of P. orientalis from Timor formed a clade, consistent with an introduction by humans from a single source population. However, further research on east Indonesian P. orientalis populations will be required to test this hypothesis, resolve inconsistencies in divergence time estimates, and locate the source population and taxonomic status of the Timor P. orientalis.


2019 ◽  
Vol 99 (1) ◽  
pp. 105-367 ◽  
Author(s):  
Mao-Qiang He ◽  
Rui-Lin Zhao ◽  
Kevin D. Hyde ◽  
Dominik Begerow ◽  
Martin Kemler ◽  
...  

AbstractThe Basidiomycota constitutes a major phylum of the kingdom Fungi and is second in species numbers to the Ascomycota. The present work provides an overview of all validly published, currently used basidiomycete genera to date in a single document. An outline of all genera of Basidiomycota is provided, which includes 1928 currently used genera names, with 1263 synonyms, which are distributed in 241 families, 68 orders, 18 classes and four subphyla. We provide brief notes for each accepted genus including information on classification, number of accepted species, type species, life mode, habitat, distribution, and sequence information. Furthermore, three phylogenetic analyses with combined LSU, SSU, 5.8s, rpb1, rpb2, and ef1 datasets for the subphyla Agaricomycotina, Pucciniomycotina and Ustilaginomycotina are conducted, respectively. Divergence time estimates are provided to the family level with 632 species from 62 orders, 168 families and 605 genera. Our study indicates that the divergence times of the subphyla in Basidiomycota are 406–430 Mya, classes are 211–383 Mya, and orders are 99–323 Mya, which are largely consistent with previous studies. In this study, all phylogenetically supported families were dated, with the families of Agaricomycotina diverging from 27–178 Mya, Pucciniomycotina from 85–222 Mya, and Ustilaginomycotina from 79–177 Mya. Divergence times as additional criterion in ranking provide additional evidence to resolve taxonomic problems in the Basidiomycota taxonomic system, and also provide a better understanding of their phylogeny and evolution.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Joanna Malukiewicz ◽  
Reed A. Cartwright ◽  
Nelson H. A. Curi ◽  
Jorge A. Dergam ◽  
Claudia S. Igayara ◽  
...  

Abstract Background Callithrix marmosets are a relatively young primate radiation, whose phylogeny is not yet fully resolved. These primates are naturally para- and allopatric, but three species with highly invasive potential have been introduced into the southeastern Brazilian Atlantic Forest by the pet trade. There, these species hybridize with each other and endangered, native congeners. We aimed here to reconstruct a robust Callithrix phylogeny and divergence time estimates, and identify the biogeographic origins of autochthonous and allochthonous Callithrix mitogenome lineages. We sequenced 49 mitogenomes from four species (C. aurita, C. geoffroyi, C. jacchus, C. penicillata) and anthropogenic hybrids (C. aurita x Callithrix sp., C. penicillata x C. jacchus, Callithrix sp. x Callithrix sp., C. penicillata x C. geoffroyi) via Sanger and whole genome sequencing. We combined these data with previously published Callithrix mitogenomes to analyze five Callithrix species in total. Results We report the complete sequence and organization of the C. aurita mitogenome. Phylogenetic analyses showed that C. aurita was the first to diverge within Callithrix 3.54 million years ago (Ma), while C. jacchus and C. penicillata lineages diverged most recently 0.5 Ma as sister clades. MtDNA clades of C. aurita, C. geoffroyi, and C. penicillata show intraspecific geographic structure, but C. penicillata clades appear polyphyletic. Hybrids, which were identified by phenotype, possessed mainly C. penicillata or C. jacchus mtDNA haplotypes. The biogeographic origins of mtDNA haplotypes from hybrid and allochthonous Callithrix were broadly distributed across natural Callithrix ranges. Our phylogenetic results also evidence introgression of C. jacchus mtDNA into C. aurita. Conclusion Our robust Callithrix mitogenome phylogeny shows C. aurita lineages as basal and C. jacchus lineages among the most recent within Callithrix. We provide the first evidence that parental mtDNA lineages of anthropogenic hybrid and allochthonous marmosets are broadly distributed inside and outside of the Atlantic Forest. We also show evidence of cryptic hybridization between allochthonous Callithrix and autochthonous C. aurita. Our results encouragingly show that further development of genomic resources will allow to more clearly elucidate Callithrix evolutionary relationships and understand the dynamics of Callithrix anthropogenic introductions into the Brazilian Atlantic Forest.


2020 ◽  
Author(s):  
Sebastián Escobar ◽  
Andrew J. Helmstetter ◽  
Rommel Montúfar ◽  
Thomas L. P. Couvreur ◽  
Henrik Balslev

AbstractThe vegetable ivory palms (Phytelepheae) form a small group of Neotropical palms whose phylogenetic relationships are not fully understood. Three genera and eight species are currently recognized; however, it has been suggested that Phytelephas macrocarpa could include the species Phytelephas seemannii and Phytelephas schottii because of supposed phylogenetic relatedness and similar morphology. We inferred their phylogenetic relationships and divergence time estimates using the 32 most clock-like loci of a custom palm bait-kit formed by 176 genes and four fossils for time calibration. We additionally explored the historical biogeography of the tribe under the recovered phylogenetic relationships. Our fossil-dated tree showed the eight species previously recognized, and that P. macrocarpa is not closely related to P. seemanii and P. schottii, which, as a consequence, should not be included in P. macrocarpa. The ancestor of the vegetable ivory palms was widely-distributed in the Chocó, the inter-Andean valley of the Magdalena River, and the Amazonia during the Miocene at 19.25 Ma. Early diversification in Phytelephas at 5.27 Ma can be attributed to trans-Andean vicariance between the Chocó/Magdalena and the Amazonia. Our results support the role of Andean uplift in the early diversification of Phytelephas under new phylogenetic relationships inferred from genomic data.


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