scholarly journals Threatened gastropods under the evolutionary genetic species concept: redescription and new species of the genusAylacostoma(Gastropoda: Thiaridae) from High Paraná River (Argentina-Paraguay)

2014 ◽  
Vol 172 (3) ◽  
pp. 501-520 ◽  
Author(s):  
Roberto E. Vogler ◽  
Ariel A. Beltramino ◽  
Juana G. Peso ◽  
Alejandra Rumi
Keyword(s):  
New Species ◽  
Species Concept ◽  
Paraná River ◽  
Parana River ◽  
Evolutionary Genetic ◽  
Genetic Species Concept ◽  
Genetic Species

scholarly journals Evolutionary Genetic Species Detected in Prokaryotes by Applying the K/θ Ratio to DNA Sequences

2020 ◽  
Author(s):  
C. William Birky
Keyword(s):  
Dna Sequences ◽  
Core Genome ◽  
Species Concept ◽  
Single Gene ◽  
Species Boundaries ◽  
Genetic Theory ◽  
Evolutionary Genetic ◽  
Genetic Species Concept ◽  
Genetic Species ◽  
General Method

AbstractIn previous papers in this series, I described the “evolutionary genetic species concept” which is based on population genetic theory and should be applicable to any organism. I also described a species criterion, the K/θ ratio, that delimits independently evolving evolutionary species based on single-gene sequences. I then illustrated its application to sexual and asexual eukaryotes. Here, I show how the evolutionary genetic species concept and the K/θ ratio can be applied to bacteria, using the sequences from some genes of the core genome that are rarely, if ever, transferred horizontally between different species. This completes the demonstration that K/θ is a general method for species delimitation, applicable to all organisms. Also, it adds to the evidence that bacteria have species in the most general sense, even though they have the ability to exchange genes across species boundaries. Finally, I show that a published critique of the use of K/θ ≥ 4 as a criterion for independently evolving species rests on two errors in the application of population/evolutionary genetic theory.

The genetic species concept and its versatility

2021 ◽  
pp. 60-68
Author(s):  
Sergey Mezhzherin
Keyword(s):  
Gene Pool ◽  
Species Concept ◽  
Biological Species ◽  
Species Concepts ◽  
Structural Genes ◽  
Evolutionary Genetic ◽  
Genetic Species Concept ◽  
Genetic Species

A review of the species criteria of the four most popular species concepts (typological, genetic, bio-logical, and evolutionary-phylogenetic) shows that they are essentially the same. In each of them, the fact of fixing alternative alleles in diverging populations is a key circumstance in one form or another. Such groups of populations should be considered as a kind of evolutionary genetic dis-creteness supported by a protected gene pool. Therefore, a biological species should be understood as a set of populations, individuals of which have the fixation of common unique alleles for a num-ber of structural genes. Differences between the concepts are secondary and are due to the emphasis on different sides of the same phenomenon or the use of different methods for determining the ge-netic structure. It is indicated that there are subjective difficulties in the application of the genetic concept (the reluctance of traditional taxonomists to lose their monopoly) and objective problems caused by the unequal period of divergence of taxa of the species rank and different ways of form-ing genetically discrete entities.

Origin of species diversity in the catfish genus Hypostomus (Siluriformes: Loricariidae) inhabiting the Paraná river basin, with the description of a new species

Zootaxa ◽  
2012 ◽  
Vol 3453 (1) ◽  
pp. 69 ◽  
Author(s):  
YAMILA P. CARDOSO ◽  
ADRIANA ALMIRÓN ◽  
JORGE CASCIOTTA ◽  
DANILO AICHINO ◽  
MARTA S. LIZARRALDE ◽  
...  
Keyword(s):  
New Species ◽  
Species Diversity ◽  
River Basin ◽  
Mitochondrial Control Region ◽  
Paraná River ◽  
Sea Level Changes ◽  
Parana River ◽  
D Loop ◽  
A New Species ◽  
Paraná River Basin

Within the Loricariidae, the genus Hypostomus is one of the most diversified freshwater catfish groups. Using new se-quence data from the mitochondrial Control Region (D-loop) we examined the phylogeny of this genus. Our phylogeneticanalyses suggest that, in the Paraná river basin, species diversity in the genus Hypostomus has been shaped by two proc-esses: 1) by inter-basin diversification, generating groups of species that inhabit different basins, as a result of dispersalevents; and 2) via intra-basin speciation as a result of basin fragmentation due to past marine transgressions, which pro-duced groups of species within a basin. Using the D-loop as a molecular clock, each event of diversification was datedand linked with documented hydrological events or sea level changes. We also assessed the possible dispersal routes be-tween the Paraná and Uruguay rivers, in addition to the obvious dispersal route via the Río de la Plata estuary. Finally, wedescribe a new species of Hypostomus inhabiting Middle Paraná river, Hypostomus arecuta n. sp. This species can be sep-arated from all other Hypostomus by having light roundish dots on a darker background and by number of premaxillary/ dentary teeth.

New species and records of Arrenurus from the Paraná river, Argentina (Acari: Parasitengona: Arrenuridae)

Zootaxa ◽  
2006 ◽  
Vol 1208 (1) ◽  
pp. 25
Author(s):  
ROSSO De FERRADÁS BEATRIZ
Keyword(s):  
New Species ◽  
River Basin ◽  
Geographic Distribution ◽  
Paraná River ◽  
Morphometric Characteristics ◽  
Parana River ◽  
Brazilian Species ◽  
First Time ◽  
Paraná River Basin

Arrenuridae inhabiting the Paraná river basin show great diversity relative to that of this family in Argentina and other Neotropical regions, with 38 species (35 studied by the author). In this new contribution Arrenurus mocovi n.sp. is described and A. (Arrenurus) trichophorus Daday is recorded for the first time. The female of this latter species is redescribed and data for the males are added, as well as the geographic distribution of the species. For Arrenurus imperator imperator Lundblad, a Brazilian species, morphometric characteristics are given. The recently created subgenus A. (Brevicaudaturus) is analyzed, within which the last species plus three other neotropical taxa are placed.

On the Strandesia obtusata/elliptica lineage (Ostracoda, Cyprididae) in the alluvial valley of the upper Paraná River (Brazil), with the description of three new species

Crustaceana ◽  
2013 ◽  
Vol 86 (2) ◽  
pp. 182-211 ◽  
Author(s):  
Janet Higuti ◽  
Isa Schön ◽  
Leen Audenaert ◽  
Koen Martens
Keyword(s):  
New Species ◽  
Genetic Network ◽  
Genetic Distances ◽  
Paraná River ◽  
Coi Gene ◽  
Alluvial Valley ◽  
Mitochondrial Coi ◽  
Parana River ◽  
Upper Paraná River ◽  
Three New Species

We redescribe Strandesia tolimensis Roessler, 1990, originally described from Colombia, and describe three new species, Strandesia lansactohai n. sp., S. velhoi n. sp. and S. nupelia n. sp. from lakes, channels and rivers in the alluvial valley of the upper Paraná River. Mainly valve morphology and shape and size of the attachment of the caudal ramus are used to characterize these species, as other soft parts are uninformative. All populations studied here are parthenogenetic, so male morphologies are not available. Sequences of the mitochondrial COI-gene are used to construct a phylogeny, as well as a genetic network of specimens, and in both analyses the four species are well-supported. In addition, we also delimit the four species with genetic distances using Birky’s K/θ method and conclude that it supports the identity of the species under consideration.

scholarly journals On the Bennelongia barangaroo lineage (Crustacea, Ostracoda) in Western Australia, with the description of seven new species

2013 ◽  
Author(s):  
Koen Martens ◽  
Stuart Halse ◽  
Isa Schön
Keyword(s):  
New Species ◽  
Western Australia ◽  
Molecular Evidence ◽  
Nominal Species ◽  
Rock Pools ◽  
Additional Species ◽  
Coi Sequences ◽  
The Right ◽  
Genetic Species Concept ◽  
Genetic Species

The ostracod genus Bennelongia De Deckker & McKenzie, 1981 is endemic to Australia and New Zealand. Extensive sampling in Western Australia (WA) revealed a high specific and largely undescribed diversity. Here, we describe seven new species belonging to the B. barangaroo lineage: B. timmsi sp. nov., B. gnamma sp. nov., B. hirsuta sp. nov., B. ivanae sp. nov., B. mcraeae sp. nov., B. scanloni sp. nov. and B. calei sp. nov., and confirm the presence of an additional species, B. dedeckkeri, in WA. For five of these eight species, we could construct molecular phylogenies and parsimonious networks based on COI sequences. We also tested for cryptic diversity and specific status of clusters with a statistical method based on the evolutionary genetic species concept, namely Birky’s 4 theta rule. The analyses support the existence of these five species and a further three cryptic species in the WA B. barangaroo lineage. The molecular evidence was particularly relevant because most species described herein have very similar morphologies and can be distinguished from each other only by the shape, size and position of the antero-ventral lapel on the right valve, and, in sexual populations, by the small differences in shape of the hemipenes and the prehensile palps in males. Four species of the WA B. barangaroo lineage occur in small temporary rock pools (gnammas) on rocky outcrops. The other four species are mainly found in soft bottomed seasonal water bodies. One of the latter species, B. scanloni sp. nov., occurs in both claypans and deeper rock pools (pit gnammas). All species, except for B. dedeckkeri, originally described from Queensland, have quite clearly delimited distributions in WA. With the seven new species described here, the genus Bennelongia now comprises 25 nominal species but several more await formal description.

scholarly journals “Genetic Species” Concept in Xanthomonas

1965 ◽  
Vol 89 (1) ◽  
pp. 95-100
Author(s):  
S. Friedman ◽  
J. De Ley
Keyword(s):  
Species Concept ◽  
Genetic Species Concept ◽  
Genetic Species
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