Molecular systematics and phylogenetic reconstruction of iSteinernema/i and iHeterorhabditis/i.

2017 ◽  
pp. 143-153
Author(s):  
F. de Luca ◽  
M. M. M. Abd-Elgawad
Keyword(s):  
Molecular Systematics ◽  
Phylogenetic Reconstruction

scholarly journals Systematic implications from a robust phylogenetic reconstruction of the genus Helianthemum (Cistaceae) based on genotyping-by-sequencing (GBS) data

2021 ◽  
Vol 78 (2) ◽  
pp. e113
Author(s):  
Sara Martín-Hernanz ◽  
Mauricio Velayos ◽  
Rafael G. Albaladejo ◽  
Abelardo Aparicio
Keyword(s):  
Maximum Likelihood ◽  
Molecular Systematics ◽  
Phylogenetic Trees ◽  
Phylogenetic Reconstruction ◽  
Genotyping By Sequencing ◽  
New Combinations ◽  
Bayesian Analyses ◽  
Taxonomic Sampling ◽  
New Subgenus ◽  
Phylogenetic Framework

Molecular systematics requires the establishment of a robust phylogenetic framework including extensive geographical and taxonomic sampling. In this work, we proposed systematic changes in the genus Helianthemum based on phylogenetic trees obtained by both maximum likelihood and Bayesian analyses of GBS data. The implications of these phylogenetic results for the systematics of Helianthemum entail the establishment of a new subgenus and novel re-ascriptions of sections and species along with some nomenclatural novelties. The following new combinations are proposed: Helianthemum subg. Eriocarpum (Dunal) Martín-Hernanz, Velayos, Albaladejo & Aparicio; H. oelandicum subsp. conquense (Borja & Rivas Goday ex G.López) Martín-Hernanz, Velayos, Albaladejo & Aparicio; H. nummularium subsp. cantabricum (M.Laínz) Martín-Hernanz, Velayos, Albaladejo & Aparicio; H. nummularium subsp. tinetense (M.Mayor & Fern.Benito) Martín-Hernanz, Velayos, Albaladejo & Aparicio.

A new species of Contomastix (Squamata, Teiidae) supported by total evidence, with remarks on diagnostic characters defining the genus

2019 ◽  
pp. 23-36
Author(s):  
Mario. R. Cabrera
Keyword(s):  
New Species ◽  
Geographic Distribution ◽  
Phylogenetic Reconstruction ◽  
Total Evidence ◽  
Molecular Evidence ◽  
Proximal Margin ◽  
Diagnostic Characters ◽  
Morphological Differences ◽  
A New Species ◽  
Molecular Characters

Formerly Cnemidophorus was thought to be the most speciose genus of Teiidae. This genus comprised four morphological groups that were later defined as four different genera, Ameivula, Aurivela, Cnemidophorus and Contomastix. The last appears as paraphyletic in a recent phylogenetic reconstruction based on morphology, but monophyletic in a reconstruction using molecular characters. Six species are allocated to Contomastix. One of them, C. lacertoides, having an extensive and disjunct geographic distribution in Argentina, Uruguay and Brazil. Preliminary analyses revealed morphological differences among its populations, suggesting that it is actually a complex of species. Here, we describe a new species corresponding to the Argentinian populations hitherto regarded as C. lacertoides, by integrating morphological and molecular evidence. Furthermore, we demonstrate that the presence of notched proximal margin of the tongue is a character that defines the genus Contomastix.

Evolution of carnivory in angiosperms

2018 ◽  
Author(s):  
Andreas Fleischmann ◽  
Jan Schlauer ◽  
Stephen A. Smith ◽  
Thomas J. Givnish
Keyword(s):  
Molecular Systematics ◽  
Carnivorous Plants ◽  
Carnivorous Species ◽  
Ecological Differences

Molecular systematics demonstrate that carnivorous plants have evolved at least ten times independently, in five orders, 12 families, and 19 genera of angiosperms. Carnivory has arisen once in Nepenthales (a segregate of Caryophyllales), once in Oxalidales, twice in Ericales, and three times each in Lamiales and Poales. Estimated crown ages of these ten lineages range from 1.9 to 81 million years (Mya), with the youngest three lineages (1.9 – 2.6 Mya) being all single genera of Poales, and all involving one or two carnivorous species in an otherwise noncarnivorous group. We now understand the evolution of carnivorous plants based on knowing when and (often) where they diverged from specific noncarnivorous ancestors; inferring which traits were gained, which were retained, and which of the latter may have been crucial preadaptations for carnivory; and identifying the evolutionary drivers of carnivory by evaluating the ecological differences between carnivorous plants and their noncarnivorous relatives.

Molecular systematics and taxonomic overview of the bird’s nest fungi (Nidulariaceae)

2021 ◽  
Author(s):  
Nattapol Kraisitudomsook ◽  
Rosanne A. Healy ◽  
Matthew E. Smith
Keyword(s):  
Molecular Systematics

scholarly journals Phylogeography in an “oyster” shell provides first insights into the genetic structure of an extinct Ostrea edulis population

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarah Hayer ◽  
Dirk Brandis ◽  
Alexander Immel ◽  
Julian Susat ◽  
Montserrat Torres-Oliva ◽  
...  
Keyword(s):  
Large Scale ◽  
Wadden Sea ◽  
Atlantic Coast ◽  
Phylogenetic Reconstruction ◽  
Oyster Shell ◽  
Glacial Refugia ◽  
Late Nineteenth Century ◽  
Ostrea Edulis ◽  
Geographic Ranges ◽  
The North

AbstractThe historical phylogeography of Ostrea edulis was successfully depicted in its native range for the first time using ancient DNA methods on dry shells from museum collections. This research reconstructed the historical population structure of the European flat oyster across Europe in the 1870s—including the now extinct population in the Wadden Sea. In total, four haplogroups were identified with one haplogroup having a patchy distribution from the North Sea to the Atlantic coast of France. This irregular distribution could be the result of translocations. The other three haplogroups are restricted to narrow geographic ranges, which may indicate adaptation to local environmental conditions or geographical barriers to gene flow. The phylogenetic reconstruction of the four haplogroups suggests the signatures of glacial refugia and postglacial expansion. The comparison with present-day O. edulis populations revealed a temporally stable population genetic pattern over the past 150 years despite large-scale translocations. This historical phylogeographic reconstruction was able to discover an autochthonous population in the German and Danish Wadden Sea in the late nineteenth century, where O. edulis is extinct today. The genetic distinctiveness of a now-extinct population hints at a connection between the genetic background of O. edulis in the Wadden Sea and for its absence until today.

scholarly journals An evaluation of genetic distances for use with microsatellite loci.

Genetics ◽  
1995 ◽  
Vol 139 (1) ◽  
pp. 463-471 ◽  
Author(s):  
D B Goldstein ◽  
A Ruiz Linares ◽  
L L Cavalli-Sforza ◽  
M W Feldman
Keyword(s):  
Microsatellite Loci ◽  
Phylogenetic Reconstruction ◽  
Genetic Distances ◽  
Stepwise Mutation Model ◽  
Mutation Model ◽  
Stepwise Mutation ◽  
The Difference ◽  
Nei's Distance ◽  
Infinite Alleles Model ◽  
Overall Reliability

Abstract Mutations of alleles at microsatellite loci tend to result in alleles with repeat scores similar to those of the alleles from which they were derived. Therefore the difference in repeat score between alleles carries information about the amount of time that has passed since they shared a common ancestral allele. This information is ignored by genetic distances based on the infinite alleles model. Here we develop a genetic distance based on the stepwise mutation model that includes allelic repeat score. We adapt earlier treatments of the stepwise mutation model to show analytically that the expectation of this distance is a linear function of time. We then use computer simulations to evaluate the overall reliability of this distance and to compare it with allele sharing and Nei's distance. We find that no distance is uniformly superior for all purposes, but that for phylogenetic reconstruction of taxa that are sufficiently diverged, our new distance is preferable.

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