scholarly journals Sea lettuce systematics: lumping or splitting?

2018 ◽  
Author(s):  
Manuela Bernardes Batista ◽  
Regina L. Cunha ◽  
Rita Castilho ◽  
Paulo Antunes Horta
Keyword(s):  
Phylogenetic Relationships ◽  
Upper Cretaceous ◽  
Phylogenetic Analyses ◽  
Brazilian Coast ◽  
Nominal Species ◽  
Bayesian Analyses ◽  
The Pacific ◽  
Phylogenetic Framework ◽  
Flow Through ◽  
Daunting Challenge

AbstractPhylogenetic relationships within sea lettuce species belonging to the genus Ulva is a daunting challenge given the scarcity of diagnostic morphological features and the pervasive phenotypic plasticity. With more than 100 species described on a morphological basis, an accurate evaluation of its diversity is still missing. Here we analysed 277 chloroplast-encoded gene sequences (43 from this study), representing 35 nominal species of Ulva from the Pacific, Indian Ocean, and Atlantic (with a particular emphasis on the Brazilian coast) in an attempt to solve the complex phylogenetic relationships within this widespread genus. Maximum likelihood, Bayesian analyses and species delimitation tests support the existence of 22 evolutionary significant units (ESUs), lumping the currently recognized number of species. All individuals sampled throughout an extensive area of the Brazilian coast were included within two distinct ESUs. Most of the clades retrieved in the phylogenetic analyses do not correspond to a single nominal species. Geographic range evolution indicated that the ancestor of Ulva had a distribution restricted to the temperate North Pacific. The dating analysis estimated its origin during the Upper Cretaceous at 75.8 million years (myr) ago but most of the cladogenetic events within the genus occurred in the last ten myr. Pervasive human-mediated gene flow through ballast water and widespread morphologic plasticity are the most likely explanations for the difficulty in establishing a reliable phylogenetic framework for this conspicuous, widespred and many times abundant green algae morphotype.

scholarly journals Phylogeny and morphologic evolution of the Ordovician Camerata (Class Crinoidea, Phylum Echinodermata)

2017 ◽  
Vol 91 (4) ◽  
pp. 815-828 ◽  
Author(s):  
Selina R. Cole
Keyword(s):  
Phylogenetic Analysis ◽  
Phylogenetic Relationships ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Major Group ◽  
Higher Taxa ◽  
Morphologic Evolution ◽  
Phylogenetic Framework ◽  
Selection For

AbstractThe subclass Camerata (Crinoidea, Echinodermata) is a major group of Paleozoic crinoids that represents an early divergence in the evolutionary history and morphologic diversification of class Crinoidea, yet phylogenetic relationships among early camerates remain unresolved. This study conducted a series of quantitative phylogenetic analyses using parsimony methods to infer relationships of all well-preserved Ordovician camerate genera (52 taxa), establish the branching sequence of early camerates, and test the monophyly of traditionally recognized higher taxa, including orders Monobathrida and Diplobathrida. The first phylogenetic analysis identified a suitable outroup for rooting the Ordovician camerate tree and assessed affinities of the atypical dicyclic family Reteocrinidae. The second analysis inferred the phylogeny of all well-preserved Ordovician camerate genera. Inferred phylogenies confirm: (1) the Tremadocian genera Cnemecrinus and Eknomocrinus are sister to the Camerata; (2) as historically defined, orders Monobathrida and Diplobathrida do not represent monophyletic groups; (3) with minimal revision, Monobathrida and Diplobathrida can be re-diagnosed to represent monophyletic clades; (4) family Reteocrinidae is more closely related to camerates than to other crinoid groups currently recognized at the subclass level; and (5) several genera in subclass Camerata represent stem taxa that cannot be classified as either true monobathrids or true diplobathrids. The clade containing Monobathrida and Diplobathrida, as recognized herein, is termed Eucamerata to distinguish its constituent taxa from more basally positioned taxa, termed stem eucamerates. The results of this study provide a phylogenetic framework for revising camerate classification, elucidating patterns of morphologic evolution, and informing outgroup selection for future phylogenetic analyses of post-Ordovician camerates.

Morphological reassessment and molecular assessment of Sargassum (Fucales: Phaeophyceae) species from the Gulf of California, Mexico

Phytotaxa ◽  
2014 ◽  
Vol 183 (4) ◽  
pp. 201 ◽  
Author(s):  
GABRIELA ANDRADE-SORCIA ◽  
RAFAEL RIOSMENA-RODRIGUEZ ◽  
RAQUEL MUÑIZ-SALAZAR ◽  
JUAN MANUEL LÓPEZ-VIVAS ◽  
GA HUN BOO ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Phylogenetic Relationships ◽  
Brown Algae ◽  
Gulf Of California ◽  
Phylogenetic Analyses ◽  
The Pacific ◽  
Pacific Side ◽  
Molecular Studies ◽  
Molecular Assessment ◽  
The Individual

Systematic molecular studies have not been performed on ecologically important brown algae (Sargassum) in the Gulf of California, Mexico, where 42 specific and infraspecific names have been recorded within this genus. We conducted phylogenetic analyses of nuclear ribosomal ITS and mitochondrial cox1 and cox3 sequences, along with detailed morphological observations of Sargassum collected in the Gulf of California. We confirmed the presence of six species, five previously described—S. herporhizum, S. horridum, S. johnstonii, S. lapazeanum, and S. sinicola, as well as the newly described Sargassum ulixei sp. nov. which is characterized by terete primary axes arising from the stipe, lanceolate to elliptical sessile ecostate blades with smooth margins, cryptostomata, ellipsoidal vesicles with a short mucron, and cylindrical to ellipsoidal receptacles. The individual analyses and subsequent phylogenetic analysis recognized two groups previously described by Dawson, one as Sargassum and other as Horridum. Our studies suggest that the Gulf of California is a region with endemic Sargassum species, and is clearly distinguished from the Pacific side of Baja California, where recently introduced species are common. Based on phylogenetic relationships, we propose two geographical origins for the Sargassum from the Gulf of California: a first group originating from the proto-Gulf, related to species from the northern hemisphere (including five species); and a second group, containing S. sinicola, introduced when the southern end opened at a later stage. 

Sineoamphisbaena hexatabularis, an amphisbaenian (Diapsida: Squamata) from the Upper Cretaceous redbeds at Bayan Mandahu (Inner Mongolia, People's Republic of China), and comments on the phylogenetic relationships of the Amphisbaenia

1996 ◽  
Vol 33 (4) ◽  
pp. 541-577 ◽  
Author(s):  
Xiao-Chun Wu ◽  
Donald B. Brinkman ◽  
Anthony P. Russell
Keyword(s):  
Central Asia ◽  
Phylogenetic Relationships ◽  
Inner Mongolia ◽  
Upper Cretaceous ◽  
Phylogenetic Analyses ◽  
Temporal Region ◽  
People's Republic Of China ◽  
Way Of Life ◽  
Lacustrine Environment ◽  
Republic Of China

Sineoamphisbaena hexatabularis Wu et al., 1993 is the earliest known amphisbaenian represented by well-preserved cranial and postcranial material. It reveals a mosaic of generalized lizard-like features and amphisbaenian characters. Most distinctive of the latter are features of cranial consolidation adaptive for a fossorial way of life. Phylogenetic analyses strongly confirm the monophyly of the Amphisbaenia inclusive of S. hexatabularis. The Amphisbaenia is diagnosed by a suite of apomorphic characters. The available evidence suggests a probable Amphisbaenia–Macrocephalosauridae relationship within the Scincomorpha. This is supported primarily by the unique modifications of the palate and temporal region of the skull. It is argued here that the Amphisbaenia evolved in Central Asia during the Cretaceous, in response to the transition from a perennial lacustrine environment to a dry, semiarid eolian environment. The relatively primitive morphology indicates that S. hexatabularis was not permanently subterranean. The further derived modifications of later forms are associated with tunneling in an environment of more compact soils.

Molecular phylogeny of the genus Hylodesmum (Fabaceae)

Phytotaxa ◽  
2019 ◽  
Vol 403 (3) ◽  
pp. 221
Author(s):  
HUAI-CHENG LI ◽  
XUE-LI ZHAO ◽  
XIN-FEN GAO ◽  
BO XU
Keyword(s):  
Maximum Likelihood ◽  
Molecular Phylogeny ◽  
Phylogenetic Relationships ◽  
Maximum Parsimony ◽  
Internal Transcribed Spacer ◽  
Phylogenetic Analyses ◽  
Nuclear Marker ◽  
Bayesian Analyses ◽  
Chloroplast Dna Regions ◽  
Taxonomic System

The phylogenetic relationships of 12 Hylodesmum species and closely related genera were reconstructed using maximum parsimony, maximum likelihood, and Bayesian analyses based on two chloroplast DNA regions (rps16-trnQ and trnL-F) and one nuclear marker (internal transcribed spacer, ITS). All analyses yielded reliable relationships among the major lineages within Hylodesmum, suggesting that Hylodesmum is monophyletic. Neither the traditionally defined Desmodium sect. Podocarpium nor D. sect. Repanda within the genus was supported as being monophyletic based on the ITS analyses and the combined ITS and chloroplast dataset analyses. The phylogenetic topologies indicated that the three species included in D. sect. Repanda were separated into different clades, which suggested that D. sect. Repanda is paraphyletic. Generally, the clades retrieved by phylogenetic analyses within D. sect. Podocarpium were consistent with traditionally defined groups except for the American group. The molecular analysis provides information regarding the revision of the traditional taxonomic system of Hylodesmum and for the evaluation of the systematic positions of each species within the genus Hylodesmum.

Phylogenetic Relationships and the Description of a New Species of Enriquebeltrania (Euphorbiaceae s.s.): An Enigmatic Genus Endemic to Mexico

2006 ◽  
Vol 31 (3) ◽  
pp. 533-546 ◽  
Author(s):  
Jose Arturo De-Nova ◽  
Victoria Sosa ◽  
Kenneth J. Wurdack
Keyword(s):  
New Species ◽  
Dna Sequences ◽  
Phylogenetic Relationships ◽  
Pacific Coast ◽  
Phylogenetic Analyses ◽  
Disjunct Distribution ◽  
The Pacific ◽  
Trees And Shrubs ◽  
A New Species ◽  
Molecular Characters

Enriquebeltrania, a genus of trees and shrubs endemic to Mexico, traditionally has been included in Euphorbiaceae (tribe Adelieae, subfamily Acalyphoideae). It was previously thought to be monotypic with a disjunct distribution on the Yucatan Peninsula and along the Pacific coast in Jalisco and Sinaloa. There is some question about whether Enriquebeltrania should be treated as distinct from Adelia. Morphological and molecular characters (trnL-F spacer and rbcL DNA sequences) were utilized in phylogenetic analyses to determine if Enriquebeltrania belongs to the tribe Adelieae, to test whether it should be recognized as a genus separate from Adelia, and to determine the number of species that should be recognized. Results indicate that Enriquebeltrania does not belong to tribe Adelieae, that it should be recognized as a genus separate from Adelia, and that it consists of two species. The second species, Enriquebeltrania disjuncta, is named and described here.

scholarly journals Phylogenomics resolves deep subfamilial relationships in Malvaceae s.l.

2021 ◽  
Author(s):  
Tijana Cvetković ◽  
Fabiola Areces-Berazain ◽  
Damien D Hinsinger ◽  
Daniel C Thomas ◽  
Jan J Wieringa ◽  
...  
Keyword(s):  
Maximum Likelihood ◽  
Phylogenetic Analyses ◽  
Economic Importance ◽  
Plant Family ◽  
Bayesian Analyses ◽  
Plastid Genomes ◽  
Great Economic Importance ◽  
The Family ◽  
Evolutionary Studies ◽  
Phylogenetic Framework

Abstract Malvaceae s.l., the most diverse family within Malvales, includes well-known species of great economic importance like cotton, cacao, and durian. Despite numerous phylogenetic analyses employing multiple markers, relationships between several of its nine subfamilies, particularly within the largest lineage/Malvadendrina, remain unclear. In this study, we attempted to resolve the relationships within the major clades of Malvaceae s.l. using plastid genomes of 48 accessions representing all subfamilies. Maximum likelihood and Bayesian analyses recovered a fully resolved and well-supported topology confirming the split of the family into/Byttneriina (/Grewioideae +/Byttnerioideae) and/Malvadendrina. Within/Malvadendrina,/Helicteroideae occupied the earliest branching position, followed by/Sterculioideae./Brownlowioideae,/Tiliodeae, and/Dombeyoideae formed a clade sister to/Malvatheca (/Malvoideae +/Bombacoideae), a grouping morphologically supported by the lack of androgynophore. Results from dating analyses suggest that all subfamilies originated during hot or warm phases in the Late Cretaceous to Paleocene. This study presents a well-supported phylogenetic framework for Malvaceae s.l. that will aid downstream revisions and evolutionary studies of this economically important plant family.

scholarly journals An updated tribal classification of Lamiaceae based on plastome phylogenomics

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Fei Zhao ◽  
Ya-Ping Chen ◽  
Yasaman Salmaki ◽  
Bryan T. Drew ◽  
Trevor C. Wilson ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Character Evolution ◽  
Bayesian Analyses ◽  
Protein Coding ◽  
Future Studies ◽  
The Past ◽  
Phylogenetic Framework ◽  
Tribal Classification ◽  
Stable Classification

Abstract Background A robust molecular phylogeny is fundamental for developing a stable classification and providing a solid framework to understand patterns of diversification, historical biogeography, and character evolution. As the sixth largest angiosperm family, Lamiaceae, or the mint family, consitutes a major source of aromatic oil, wood, ornamentals, and culinary and medicinal herbs, making it an exceptionally important group ecologically, ethnobotanically, and floristically. The lack of a reliable phylogenetic framework for this family has thus far hindered broad-scale biogeographic studies and our comprehension of diversification. Although significant progress has been made towards clarifying Lamiaceae relationships during the past three decades, the resolution of a phylogenetic backbone at the tribal level has remained one of the greatest challenges due to limited availability of genetic data. Results We performed phylogenetic analyses of Lamiaceae to infer relationships at the tribal level using 79 protein-coding plastid genes from 175 accessions representing 170 taxa, 79 genera, and all 12 subfamilies. Both maximum likelihood and Bayesian analyses yielded a more robust phylogenetic hypothesis relative to previous studies and supported the monophyly of all 12 subfamilies, and a classification for 22 tribes, three of which are newly recognized in this study. As a consequence, we propose an updated phylogenetically informed tribal classification for Lamiaceae that is supplemented with a detailed summary of taxonomic history, generic and species diversity, morphology, synapomorphies, and distribution for each subfamily and tribe. Conclusions Increased taxon sampling conjoined with phylogenetic analyses based on plastome sequences has provided robust support at both deep and shallow nodes and offers new insights into the phylogenetic relationships among tribes and subfamilies of Lamiaceae. This robust phylogenetic backbone of Lamiaceae will serve as a framework for future studies on mint classification, biogeography, character evolution, and diversification. Graphical abstract

scholarly journals Justicieae II: Resolved Placement of Many Genera and Recognition of a New Lineage Sister to Isoglossinae

Aliso ◽  
2021 ◽  
Vol 38 (1) ◽  
pp. 1-31
Author(s):  
Lucinda McDade ◽  
Carrie Kiel ◽  
Thomas Daniel ◽  
Iain Darbyshire
Keyword(s):  
Phylogenetic Relationships ◽  
Pollen Morphology ◽  
Sequence Data ◽  
Molecular Data ◽  
Long Distance Dispersal ◽  
Taxonomic Assignment ◽  
Long Distance ◽  
The Pacific ◽  
Rapid Diversification ◽  
Phylogenetic Framework

We present phylogenetic results for Justicieae, the largest of the major lineages of Acanthaceae. With 300% more sequence data and a similarly increased but also more geographically representative taxon sample compared to the only previous study of the lineage as a whole, we confirm the existence of the Pseuderanthemum Lineage, Isoglossinae, the Tetramerium Lineage and the Justicioid Lineage. To the last three lineages, we add a number of taxa with the goal of advancing our knowledge of genera (e.g., Isoglossa, Rhinacanthus) and of geographic areas (e.g., Malagasy and Asian Acanthaceae). These added taxa are accommodated within the phylogenetic framework for the lineages established in our earlier work with one exception. The monospecific genus Ichthyostoma is not placed in any of the established lineages but is instead sister to (Tetramerium Lineage + Justicioid Lineage). As this result is unexpected, we examined topologies both including and excluding this plant which revealed that other aspects of relationships remain stable whether Ichthyostoma is included or not. We point to Ichthyostoma as one of several Justicieae that will benefit from additional study. One species of Isoglossa is placed in the Tetramerium Lineage instead of with all other sampled members of the genus in Isoglossinae. Pollen morphology of I. variegata is more consistent with its phylogenetic placement here than with its taxonomic assignment to Isoglossa. As suggested in our earlier work, pollen morphology can be a powerful signal of phylogenetic relationships in Justicieae. With our increased sampling, we show that the Ptyssiglottis Lineage, a relatively small group of African and Asian plants, warrants recognition separate from Isoglossinae. With the addition of the Ptyssiglottis Lineage and excluding Ichthyostoma for now, the lineages of Justicieae are related as follows: (Pseuderanthemum Lineage ((Isoglossinae + Ptyssiglottis Lineage) (Tetramerium Lineage + Justicioid Lineage))). The Pseuderanthemum Lineage has been understudied to date and we here attempt to include representatives of all genera that are putatively part of this lineage and also to test monophyly of the larger genera. We identify a number of strongly supported clades but some aspects of relationship remain unresolved. Asystasia, Graptophyllum, Oplonia, and Pseuderanthemum are not monophyletic although, with a small number of nomenclatural changes, the first and second can be rendered monophyletic. With a range essentially as extensive as that of Justicieae as a whole, the Pseuderanthemum Lineage is biogeographically complex with patterns of distribution suggestive of multiple shifts between continents including Australia and parts of the Pacific basin. The calibrated phylogeny confirms that intercontinental shifts in distribution across Justicieae must have been by long-distance dispersal rather than by vicariance or stepwise dispersal over land bridges and also points to a number of groups that have potentially undergone rapid diversification. The Pseuderanthemum Lineage, in particular, requires considerable additional research to both understand relationships and achieve an informative taxonomy for the group. Although we here establish a phylogenetic framework across Justicieae, Next Generation Sequence data will be necessary to elucidate details of relationships in most lineages. Additional study of structural characters is also warranted as we continue to be unable to identify structural synapomorphies for a number of aspects of phylogenetic relationships that are very strongly supported by molecular data.

scholarly journals Evolution of African barbs from the Lake Victoria drainage system, Kenya

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5762 ◽  
Author(s):  
Violet M. Ndeda ◽  
Mariana Mateos ◽  
Luis A. Hurtado
Keyword(s):  
Cytochrome B ◽  
Phylogenetic Relationships ◽  
Drainage Basin ◽  
Lake Victoria ◽  
Phylogenetic Analyses ◽  
Drainage System ◽  
Nominal Species ◽  
Sister Relationship ◽  
Mitochondrial Cytochrome B ◽  
Sister Relationships

The Lake Victoria drainage basin (LVD) in Kenya is home to ten nominal species of small barbs (Enteromius) and one of large barbs (Labeobarbus altianalis). A recent molecular study genetically characterized small barbs in this region and found evidence of introgression between certain species, complicating the taxonomy and species identification of these fishes. This study aimed to extend our understanding on the evolution of these fishes by: (1) determining whether putatively pure individuals of Enteromius cercops are found in the Kenyan LVD, as the previous study only found hybrid individuals of this species in this region; (2) testing the sister relationship between Enteromius profundus, endemic to Lake Victoria, and Enteromius radiatus, also found in Lake Victoria, which had been previously synonymized; (3) examining the phylogenetic relationships of small barbs of the Kenyan LVD with those reported from other ichthyological provinces of Africa; and (4) examining the phylogenetic relationships of Labeobarbus altianalis with other Labeobarbus species. To this end, we obtained mitochondrial Cytochrome b and nuclear Growth Hormone (GH) intron 2 gene sequences of nine Enteromius species from the LVD in Kenya, as well as cytochrome b sequences for L. altianalis. We conducted Maximum likelihood and Bayesian phylogenetic analyses to establish their evolutionary relationships in relation to many other barbs specimens from Africa. Phylogenetic analyses did not reveal instances of hybridization/introgression among the individuals sequenced by us. A sister relationship between E. profundus and E. radiatus was not found. This latter species shows instead a sister relationship with a lineage comprised of two species from West Africa. Other sister relationships between taxa from the East coast and other ecoregions from Africa are observed, suggesting that past drainage connections and vicariant events contributed to the diversification of Enteromius. Finally, only a single haplotype was recovered among the L. altianalis individuals examined, which is most similar to a specimen from Lake Edward in Uganda.

scholarly journals Evolution of African barbs from the Lake Victoria drainage system, Kenya

2018 ◽  
Author(s):  
Violet M Ndeda ◽  
Mariana Mateos ◽  
Luis A Hurtado
Keyword(s):  
Cytochrome B ◽  
Phylogenetic Relationships ◽  
Drainage Basin ◽  
Lake Victoria ◽  
Phylogenetic Analyses ◽  
Drainage System ◽  
Nominal Species ◽  
Sister Relationship ◽  
Mitochondrial Cytochrome B ◽  
Sister Relationships

The Lake Victoria drainage basin (LVD) in Kenya is home to ten nominal species of small barbs (‘Barbus’) and one of large barbs (Labeobarbus altianalis). A recent molecular study genetically characterized small barbs in this region and found evidence of introgression between certain species, further complicating the taxonomy and species identification of these fishes. This study aimed to extend our understanding on the evolution of these fishes by: (1) examining the phylogenetic relationships of small barbs of the Kenyan LVD with those reported from other ichthyological provinces of Africa; (2) testing the sister relationship between ‘Barbus’ profundus, endemic to Lake Victoria, and ‘Barbus’ radiatus, also found in Lake Victoria, which had been previously synonymized; (3) determining whether putatively pure individuals of ‘Barbus’ cercops are found in the Kenyan LVD, as a previous study only found hybrid individuals of this species in this region; and (4) examining the phylogenetic relationships of Labeobarbus altianalis with other Labeobarbus species. To this end, we obtained mitochondrial Cytochrome b and nuclear Growth Hormone (GH) intron 2 gene sequences of nine ‘Barbus’ species from the LVD in Kenya, as well as cytochrome b sequences for L. altianalis. We conducted Maximum likelihood and Bayesian phylogenetic analyses to establish their evolutionary relationships in relation to many other barbs specimens from Africa. Phylogenetic analyses did not reveal instances of hybridization/introgression among the individuals sequenced by us. A sister relationship between ‘B’. profundus and ‘B’. radiatus was not found. This latter species shows instead a sister relationship with a lineage comprised of two species from West Africa. Other sister relationships between taxa from the East coast and other ecoregions from Africa are observed, suggesting that past drainage connections and vicariant events contributed to the diversification of this group. Finally, only a single haplotype was recovered among the L. altianalis individuals examined, which is most similar to a specimen from Lake Edward in Uganda.

Sign in / Sign up

Export Citation Format

Share Document