scholarly journals Placozoa and Cnidaria are sister taxa

2017 ◽  
Author(s):  
Christopher E. Laumer ◽  
Harald Gruber-Vodicka ◽  
Michael G. Hadfield ◽  
Vicki B. Pearse ◽  
Ana Riesgo ◽  
...  
Keyword(s):  
Strong Support ◽  
Sister Group ◽  
Sister Group Relationship ◽  
Large Dataset ◽  
Animal Evolution ◽  
Phylogenetic Placement ◽  
The Matrix ◽  
Show Evidence ◽  
Animal Phylogeny ◽  
Reduced Forms

AbstractThe phylogenetic placement of the morphologically simple placozoans is crucial to understanding the evolution of complex animal traits. Here, we examine the influence of adding new genomes from placozoans to a large dataset designed to study the deepest splits in the animal phylogeny. Using site-heterogeneous substitution models, we show that it is possible to obtain strong support, in both amino acid and reduced-alphabet matrices, for either a sister-group relationship between Cnidaria and Placozoa, or for Cnidaria and Bilateria (=Planulozoa), also seen in most published work to date, depending on the orthologues selected to construct the matrix. We demonstrate that a majority of genes show evidence of compositional heterogeneity, and that the support for Planulozoa can be assigned to this source of systematic error. In interpreting this placozoan-cnidarian clade, we caution against a peremptory reading of placozoans as secondarily reduced forms of little relevance to broader discussions of early animal evolution.

scholarly journals Support for a clade of Placozoa and Cnidaria in genes with minimal compositional bias

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Christopher E Laumer ◽  
Harald Gruber-Vodicka ◽  
Michael G Hadfield ◽  
Vicki B Pearse ◽  
Ana Riesgo ◽  
...  
Keyword(s):  
Strong Support ◽  
Sister Group ◽  
Compositional Bias ◽  
Sister Group Relationship ◽  
Large Dataset ◽  
Animal Evolution ◽  
The Matrix ◽  
Show Evidence ◽  
Animal Phylogeny ◽  
Reduced Forms

The phylogenetic placement of the morphologically simple placozoans is crucial to understanding the evolution of complex animal traits. Here, we examine the influence of adding new genomes from placozoans to a large dataset designed to study the deepest splits in the animal phylogeny. Using site-heterogeneous substitution models, we show that it is possible to obtain strong support, in both amino acid and reduced-alphabet matrices, for either a sister-group relationship between Cnidaria and Placozoa, or for Cnidaria and Bilateria as seen in most published work to date, depending on the orthologues selected to construct the matrix. We demonstrate that a majority of genes show evidence of compositional heterogeneity, and that support for the Cnidaria + Bilateria clade can be assigned to this source of systematic error. In interpreting these results, we caution against a peremptory reading of placozoans as secondarily reduced forms of little relevance to broader discussions of early animal evolution.

scholarly journals Revisiting metazoan phylogeny with genomic sampling of all phyla

2019 ◽  
Vol 286 (1906) ◽  
pp. 20190831 ◽  
Author(s):  
Christopher E. Laumer ◽  
Rosa Fernández ◽  
Sarah Lemer ◽  
David Combosch ◽  
Kevin M. Kocot ◽  
...  
Keyword(s):  
Sister Group ◽  
Sister Group Relationship ◽  
The Matrix ◽  
Biological Interpretation ◽  
Animal Phylogeny ◽  
Inference Methods ◽  
Matrix Construction ◽  
Genome Scale ◽  
Future Work ◽  
Metazoan Phylogeny

Proper biological interpretation of a phylogeny can sometimes hinge on the placement of key taxa—or fail when such key taxa are not sampled. In this light, we here present the first attempt to investigate (though not conclusively resolve) animal relationships using genome-scale data from all phyla. Results from the site-heterogeneous CAT + GTR model recapitulate many established major clades, and strongly confirm some recent discoveries, such as a monophyletic Lophophorata, and a sister group relationship between Gnathifera and Chaetognatha, raising continued questions on the nature of the spiralian ancestor. We also explore matrix construction with an eye towards testing specific relationships; this approach uniquely recovers support for Panarthropoda, and shows that Lophotrochozoa (a subclade of Spiralia) can be constructed in strongly conflicting ways using different taxon- and/or orthologue sets. Dayhoff-6 recoding sacrifices information, but can also reveal surprising outcomes, e.g. full support for a clade of Lophophorata and Entoprocta + Cycliophora, a clade of Placozoa + Cnidaria, and raising support for Ctenophora as sister group to the remaining Metazoa, in a manner dependent on the gene and/or taxon sampling of the matrix in question. Future work should test the hypothesis that the few remaining uncertainties in animal phylogeny might reflect violations of the various stationarity assumptions used in contemporary inference methods.

scholarly journals On a remarkable new species of <i>Tharsis</i>, a Late Jurassic teleostean fish from southern Germany: its morphology and phylogenetic relationships

Fossil Record ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 1-23 ◽  
Author(s):  
Gloria Arratia ◽  
Hans-Peter Schultze ◽  
Helmut Tischlinger
Keyword(s):  
New Species ◽  
Late Jurassic ◽  
Strong Support ◽  
Sister Group ◽  
Common Species ◽  
Upper Jurassic ◽  
Morphological Characters ◽  
Morphological Description ◽  
Sister Group Relationship ◽  
Southern Germany

Abstract. A complete morphological description, as preservation permits, is provided for a new Late Jurassic fish species (Tharsis elleri) together with a revision and comparison of some morphological features of Tharsis dubius, one of the most common species from the Solnhofen limestone, southern Germany. An emended diagnosis of the genus Tharsis – now including two species – is presented. The new species is characterized by a combination of morphological characters, such as the presence of a complete sclerotic ring formed by two bones placed anterior and posterior to the eye, a moderately short lower jaw with quadrate-mandibular articulation below the anterior half of the orbit, caudal vertebrae with neural and haemal arches fused to their respective vertebral centrum, and parapophyses fused to their respective centrum. A phylogenetic analysis based on 198 characters and 43 taxa is performed. Following the phylogenetic hypothesis, the sister-group relationship Ascalaboidae plus more advanced teleosts stands above the node of Leptolepis coryphaenoides. Both nodes have strong support among teleosts. The results confirm the inclusion of Ascalabos, Ebertichthys and Tharsis as members of this extinct family. Tharsis elleri n. sp. (LSID urn:lsid:zoobank.org:act:6434E6F5-2DDD-48CF-A2B1-827495FE46E6, date: 13 December 2018) is so far restricted to one Upper Jurassic German locality – Wegscheid Quarry near Schernfeld, Eichstätt – whereas Tharsis dubius is known not only from Wegscheid Quarry, but also from different localities in the Upper Jurassic of Bavaria, Germany, and Cerin in France.

On Putaoa, a new genus of the spider family Pimoidae (Araneae) from China, with a cladistic test of its monophyly and phylogenetic placement

Zootaxa ◽  
2008 ◽  
Vol 1792 (1) ◽  
pp. 1 ◽  
Author(s):  
GUSTAVO HORMIGA ◽  
LIHONG TU
Keyword(s):  
New Species ◽  
Type Species ◽  
New Genus ◽  
Sister Group ◽  
Morphological Characters ◽  
New Combination ◽  
Sister Group Relationship ◽  
Parsimony Analysis ◽  
Phylogenetic Placement

The spider genus Putaoa new genus (Araneae, Pimoidae) is described to place two species of pimoids from China, Putaoa huaping new species (the type species) and P. megacantha (Xu & Li, 2007) new combination. Parsimony analysis of morphological characters provides support for the monophyly of Putaoa and for its sister group relationship to the genus Weintrauboa Hormiga, 2003 and corroborates the monophyly of Pimoidae.

A Phylogenetic Analysis and Taxonomic Revision of Bartonia (Gentianaceae: Gentianeae), Based on Molecular and Morphological Evidence

2009 ◽  
Vol 34 (1) ◽  
pp. 162-172 ◽  
Author(s):  
Katherine G. Mathews ◽  
Niall Dunne ◽  
Emily York ◽  
Lena Struwe
Keyword(s):  
Phylogenetic Analyses ◽  
Strong Support ◽  
Taxonomic Revision ◽  
Sister Group ◽  
Species Boundaries ◽  
Morphological Evidence ◽  
Phylogenetic Study ◽  
Sister Group Relationship ◽  
Internal Transcribed Spacer Region ◽  
Test Species

A phylogenetic study and taxonomic revision of the four currently accepted species of Bartonia (Gentianaceae, subtribe Swertiinae) were conducted in order to test species boundaries and interspecific relationships. Species boundaries were examined based on measurements of key quantitative and qualitative morphological characters as given in the original descriptions. Phylogenetic analyses were performed using molecular data from the nuclear internal transcribed spacer region and chloroplast DNA (trnL intron through the trnL-F spacer), separately and combined using parsimony and Bayesian methodologies, incorporating outgroups from subtribes Swertiinae and Gentianinae. The morphological study revealed that characters of one species, B. texana, represent a subset of the morphological variation found within B. paniculata, but that B. paniculata, B. verna, and B. virginica could all be separated from one another. The molecular phylogenetic analyses all found B. texana to nest in a clade with the two recognized subspecies of B. paniculata (subsp. paniculata and subsp. iodandra), making the latter paraphyletic. Bartonia texana is here reduced to subspecific rank, as Bartonia paniculata subsp. texana. Also, the phylogenetic analyses showed strong support for a sister group relationship between B. verna and B. virginica, as opposed to between B. paniculata and B. virginica as has been previously suggested.

Inference of higher-order conifer relationships from a multi-locus plastid data setThis paper is one of a selection of papers published in the Special Issue on Systematics Research.

Botany ◽  
2008 ◽  
Vol 86 (7) ◽  
pp. 658-669 ◽  
Author(s):  
Hardeep S. Rai ◽  
Patrick A. Reeves ◽  
Rod Peakall ◽  
Richard G. Olmstead ◽  
Sean W. Graham
Keyword(s):  
Strong Support ◽  
Sister Group ◽  
Higher Order ◽  
Bootstrap Support ◽  
Sister Group Relationship ◽  
Ribosomal Protein Genes ◽  
Conifer Species ◽  
Noncoding Regions ◽  
Selection Of

We reconstructed the broad backbone of conifer phylogeny from a survey of 15–17 plastid loci and associated noncoding regions from exemplar conifer species. Parsimony and likelihood analyses recover the same higher-order relationships, and we find strong support for most of the deep splits in conifer phylogeny, including those within our two most heavily sampled families, Araucariaceae and Cupressaceae. Our findings are broadly congruent with other recent studies, and are inferred with comparable or improved bootstrap support. The deepest phylogenetic split in conifers is inferred to be between Pinaceae and all other conifers (Cupressophyta). Our current gene and taxon sampling does not support a relationship between Pinaceae and Gnetales, observed in some published studies. Within the Cupressophyta clade, we infer well-supported relationships among Cephalotaxaceae, Cupressaceae, Sciadopityaceae, and Taxaceae. Our data support recent moves to recognize Cephalotaxus under Taxaceae, and we find strong support for a sister-group relationship between the two predominantly southern hemisphere conifer families, Araucariaceae and Podocarpaceae. A local hotspot of indel evolution shared by the latter two conifer families is identified in the coding portion of one of the plastid ribosomal protein genes. The removal of the most rapidly evolving plastid characters, as defined using a likelihood-based classification of substitution rates for the taxa considered here, is shown to have little to no effect on our inferences of higher-order conifer relationships.

scholarly journals Phylogenetic evidence suggests a later origin of the DRD2l and DRD4rs dopamine receptor gene lineages

2018 ◽  
Author(s):  
Juan C Opazo ◽  
Kattina Zavala ◽  
Soledad Miranda-Rottmann ◽  
Roberto Araya
Keyword(s):  
Dopamine Receptors ◽  
Phylogenetic Relationships ◽  
Receptor Gene ◽  
Strong Support ◽  
Sister Group ◽  
Sister Group Relationship ◽  
Dopaminergic Neurotransmission ◽  
Tree Topologies ◽  
The Central Nervous System ◽  
Time Of Origin

Dopamine receptors are integral membrane proteins whose endogenous ligand is dopamine. They play a fundamental role in the central nervous system and dysfunction of dopaminergic neurotransmission is responsible for the generation of a variety of neuropsychiatric disorders. From an evolutionary standpoint, phylogenetic relationships among the DRD1 class of dopamine receptors are still a matter of debate as in the literature different tree topologies have been proposed. In contrast, phylogenetic relationships among the DRD2 group of receptors are well understood. Understanding the time of origin of the different dopamine receptors is also an issue that needs further study, especially for the genes that have restricted phyletic distributions (e.g. DRD2l and DRD4rs). Thus, the goal of this study was to investigate the evolution of dopamine receptors, with emphasis on shedding light on the phylogenetic relationships among the D1 class of dopamine receptors and the time of origin of the DRD2l and DRD4rs gene lineages. Our results recovered the monophyly of the two groups of dopamine receptors. Within the DRD1 group the monophyly of each paralog was recovered with strong support, and phylogenetic relationships among them were well resolved. Within the DRD1 class of dopamine receptors we recovered the sister group relationship between the DRD1C and DRD1E, and this clade was recovered sister to a cyclostome sequence. The DRD1 clade was recovered sister to the aforementioned clade, and the group containing DRD5 receptors was sister to all other DRD1 paralogs. In agreement with the literature, among the DRD2 class of receptors, DRD2 was recovered sister to DRD3, whereas DRD4 was sister to the DRD2/DRD3 clade. According to our phylogenetic tree, the DRD2l and DRD4rs gene lineages would have originated in the ancestor of gnathostomes between 615 and 473 mya. Conservation of sequences required for dopaminergic neurotransmission and small changes in regulatory regions suggest a functional refinement of the dopaminergic pathways along evolution.

scholarly journals Early animal evolution: a morphologist's view

2019 ◽  
Vol 6 (7) ◽  
pp. 190638 ◽  
Author(s):  
Claus Nielsen
Keyword(s):  
Digestive System ◽  
Strong Support ◽  
Sister Group ◽  
Morphological Characters ◽  
Animal Evolution ◽  
Nervous Systems ◽  
Independent Evolution ◽  
Subsequent Loss ◽  
Early Radiation

Two hypotheses for the early radiation of the metazoans are vividly discussed in recent phylogenomic studies, the ‘Porifera-first’ hypothesis, which places the poriferans as the sister group of all other metazoans, and the ‘Ctenophora-first’ hypothesis, which places the ctenophores as the sister group to all other metazoans. It has been suggested that an analysis of morphological characters (including specific molecules) could throw additional light on the controversy, and this is the aim of this paper. Both hypotheses imply independent evolution of nervous systems in Planulozoa and Ctenophora. The Porifera-first hypothesis implies no homoplasies or losses of major characters. The Ctenophora-first hypothesis shows no important synapomorphies of Porifera, Planulozoa and Placozoa. It implies either independent evolution, in Planulozoa and Ctenophora, of a new digestive system with a gut with extracellular digestion, which enables feeding on larger organisms, or the subsequent loss of this new gut in the Poriferans (and the re-evolution of the collar complex). The major losses implied in the Ctenophora-first theory show absolutely no adaptational advantages. Thus, morphology gives very strong support for the Porifera-first hypothesis.

On the spider genus Weintrauboa (Araneae, Pimoidae), with a description of a new species from China and comments on its phylogenetic relationships

Zootaxa ◽  
2008 ◽  
Vol 1814 (1) ◽  
pp. 1 ◽  
Author(s):  
GUSTAVO HORMIGA
Keyword(s):  
New Species ◽  
Phylogenetic Relationships ◽  
Taxonomic Status ◽  
Sister Group ◽  
Morphological Characters ◽  
New Combination ◽  
Sister Group Relationship ◽  
Parsimony Analysis ◽  
Phylogenetic Placement ◽  
A New Species

Weintrauboa yele new species (Pimoidae) is described and illustrated based on specimens collected in China. The taxonomic status and distribution of Weintrauboa insularis (Saito, 1935) new combination and of W. chikunii (Oi, 1979) are discussed and the former species is illustrated based on specimens from the Sakhalin islands. Parsimony analysis of morphological characters provides support for the monophyly of Weintrauboa and for its sister group relationship to the genus Putaoa Hormiga and Tu, 2008. Some comments on the phylogenetic placement of the recently erected family “Sinopimoidae” are provided.

scholarly journals Evolution of dopamine receptors: phylogenetic evidence suggests a later origin of the DRD2l and DRD4rs dopamine receptor gene lineages

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4593 ◽  
Author(s):  
Juan C. Opazo ◽  
Kattina Zavala ◽  
Soledad Miranda-Rottmann ◽  
Roberto Araya
Keyword(s):  
Dopamine Receptors ◽  
Phylogenetic Relationships ◽  
Receptor Gene ◽  
Strong Support ◽  
Sister Group ◽  
Sister Group Relationship ◽  
Dopaminergic Neurotransmission ◽  
Tree Topologies ◽  
The Central Nervous System ◽  
Time Of Origin

Dopamine receptors are integral membrane proteins whose endogenous ligand is dopamine. They play a fundamental role in the central nervous system and dysfunction of dopaminergic neurotransmission is responsible for the generation of a variety of neuropsychiatric disorders. From an evolutionary standpoint, phylogenetic relationships among the DRD1 class of dopamine receptors are still a matter of debate as in the literature different tree topologies have been proposed. In contrast, phylogenetic relationships among the DRD2 group of receptors are well understood. Understanding the time of origin of the different dopamine receptors is also an issue that needs further study, especially for the genes that have restricted phyletic distributions (e.g., DRD2l and DRD4rs). Thus, the goal of this study was to investigate the evolution of dopamine receptors, with emphasis on shedding light on the phylogenetic relationships among the D1 class of dopamine receptors and the time of origin of the DRD2l and DRD4rs gene lineages. Our results recovered the monophyly of the two groups of dopamine receptors. Within the DRD1 group the monophyly of each paralog was recovered with strong support, and phylogenetic relationships among them were well resolved. Within the DRD1 class of dopamine receptors we recovered the sister group relationship between the DRD1C and DRD1E, and this clade was recovered sister to a cyclostome sequence. The DRD1 clade was recovered sister to the aforementioned clade, and the group containing DRD5 receptors was sister to all other DRD1 paralogs. In agreement with the literature, among the DRD2 class of receptors, DRD2 was recovered sister to DRD3, whereas DRD4 was sister to the DRD2/DRD3 clade. According to our phylogenetic tree, the DRD2l and DRD4rs gene lineages would have originated in the ancestor of gnathostomes between 615 and 473 mya. Conservation of sequences required for dopaminergic neurotransmission and small changes in regulatory regions suggest a functional refinement of the dopaminergic pathways along evolution.

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