Evolution and hybridization in the radiolarian genera Theocorythium and Lamprocyclas

Paleobiology ◽  
1983 ◽  
Vol 9 (4) ◽  
pp. 341-354 ◽  
Author(s):  
Colin Baker
Keyword(s):  
Morphological Change ◽  
Genetic Information ◽  
Phylogenetic Analyses ◽  
Morphological Variability ◽  
Single Species ◽  
Core Material ◽  
Evolutionary Models ◽  
Insight Into ◽  
Hybridization And Introgression

Changes in morphological variability within fossil populations of planktonic protists provide insight into the processes responsible for morphological change. Evolution in the radiolarian genera Theocorythium and Lamprocyclas is documented biometrically in Pliocene and Pleistocene core material from the equatorial Pacific and Indian Oceans. The patterns of morphological change in Theocorythium within a single Pacific core could be interpreted as indicating the in situ evolution of T. trachelium trachelium from T. vetulum via intermediate forms during the Pleistocene. However, consideration of biogeographic data shows that this is not the case and supports instead two alternate interpretations: (1) immigration coupled with extensive hybridization and introgression, or (2) multiple polymorphs of a single species changing in frequency along a cline. Analyses of evolutionary change in Theocorythium and the closely related genus Lamprocyclas during the Pliocene suggest that hybridization may be a significant factor in the production of new species. Evolutionary models and phylogenetic analyses should consider that barriers to gene flow may vary significantly with time and permit the exchange of genetic information between populations previously reproductively isolated.

The STIMTEC experiment at the Reiche Zeche ULab

2020 ◽  
Author(s):  
Carolin Boese ◽  
joerg Renner ◽  
Georg Dresen ◽  
Keyword(s):  
Crystalline Rock ◽  
Hydraulic Testing ◽  
Core Material ◽  
Hydraulic Stimulation ◽  
In Situ Conditions ◽  
First Results ◽  
Passive Seismic ◽  
Velocity Calibration ◽  
Insight Into

<p><span>Between early 2018 and late 2019 the STIMTEC hydraulic stimulation experiment was performed at ca.~130 m below surface at the Reiche Zeche research mine in Freiberg, Saxony/Germany. The project aims at gaining insight into the creation and growth of fractures in anisotropic and heterogeneous crystalline rock units, to develop and optimise hydraulic stimulation techniques and to control the associated induced seismicity under in situ conditions at the mine-scale. These aspects of failure and associated seismicity are important for the development of enhanced geothermal energy systems. We present the infrastructure developed for the STIMTEC experiment and provide an overview of the obtained data, including 295 m of core material retrieved from 17 boreholes, 225 m of acoustic TV log, >50 TB of continuous passive seismic data from four field stimulation and hydraulic testing campaigns, as well as ~300 active velocity calibration measurements. </span></p><p><span>W</span><span>e highlight some of the first results regarding the hydro-mechanical and seismic response to the stimulation, the rock mass characterisation in-situ and in the laboratory, as well as 3-D numerical modelling of the stress state and fracturing. The heterogeneity and anisotropy of the strongly foliated metamorphic gneiss significantly affects fracture creation and propagation </span><span>in the experiment.</span></p>

scholarly journals A multilocus assessment reveals two new synonymies for East Asian Cyclommatus stag beetles (Coleoptera, Lucanidae)

ZooKeys ◽  
2021 ◽  
Vol 1021 ◽  
pp. 65-79
Author(s):  
Jiao Jiao Yuan ◽  
Dan Chen ◽  
Xia Wan
Keyword(s):  
Phylogenetic Analyses ◽  
East Asian ◽  
Morphological Variability ◽  
Single Species ◽  
Molecular Data ◽  
Mean Value ◽  
Distance Analysis ◽  
Taiwan Island ◽  
Different Populations ◽  
Stag Beetles

Cyclommatus scutellaris Möllenkamp, 1912, Cyclommatus elsae Kriesche, 1921 and Cyclommatus tamdaoensis Fujita, 2010 are East Asian stag beetle species with long-debated taxonomic relationships due to high intraspecific morphological variability. In this study, we applied multilocus phylogenetic analyses to reassess their relationships. Two mitochondrial genes (16S rDNA, COI) and two nuclear genes (28S rDNA, Wingless) were used to reconstruct the phylogeny through the Bayesian inference (BI) and Maximum Likelihood (ML) methods. Both topologies supported two clades: the clade C. scutellaris was sister to the clade (C. elsae + C. tamdaoensis) with the subclade C. tamdaoensis embedded in the subclade C. elsae. The Kimura 2-parameter (K2P) genetic distance analysis yielded a low mean value (≤0.035) among the three taxa, which was well below the minimum mean value between other Cyclommatus species (≥0.122). We also compared the accuracy and efficiency of two approaches, GMYC and ABGD, in delimitating the three lineages. The result shows that ABGD is a better approach than GMYC. Our molecular data recognizes the three species as different populations of a single species, ranging from Taiwan Island to the continent. Therefore, we propose two new junior synonyms for C. scutellaris: C. tamdaoensis, syn. nov. and C. elsaesyn. nov.

scholarly journals Molecular studies (ISSR, cpDNA) in Tragopogon buphthalmoides (Asteraceae): Population genetics and taxonomic implication

Genetika ◽  
2017 ◽  
Vol 49 (3) ◽  
pp. 775-789
Author(s):  
Hejraneh Azizi ◽  
Masoud Sheidai ◽  
Valiollah Mozaffarian ◽  
Zahra Noormohammadi
Keyword(s):  
Population Genetics ◽  
Phylogenetic Analyses ◽  
Morphological Variability ◽  
Single Species ◽  
Morphological Data ◽  
Assignment Test ◽  
Perennial Herb ◽  
Population Genetic Study ◽  
Complex Species ◽  
Morphological Criteria

The genus Tragopogon L. with about 110-150 species is distributed in Asia and Europe, while it is represented by 26 species in Iran. Hybridization and polyploidy occurs in the genus Tragopogon that bring about extensive morphological variation in its species. Tragopogon buphthalmoides (Asteraceae) is a perennial herb with common Persian name "Sheng e Iran" and "Sheng e cheshmgaavi" and is used as traditional medicine. Two varieties have been cited for this species in the country, but due to extensive morphological variability, it is difficult to delimit the two varieties. Therefore, the present study was performed to delimit these varieties by using both morphological and molecular markers (cpDNA and ISSRs). We also aimed to provide data on population genetics of the studied species due to its medicinal importance. In total 134 plant specimens of T. buphthalmoides were randomly collected from 16 geographical populations in 7 provinces. The studied plants were considered as two different varieties based on morphological criteria and were subjected to numerical and phylogenetic analyses. PCOA plot of morphological data, identified some plants with intermediate characters. Moreover, MDS plot of ISSR data and ML tree of cpDNA sequences, did not separate plants of the two varieties and the plants were placed intermixed. Therefore, we consider T. buphthalmoides as a single species with extensive morphological variability and it is complex species. Population genetic study identified four genetic groups in the country, while, STRUCTURE analysis based on admixture model as well as population assignment test revealed some degree of gene flow in the studied populations.

scholarly journals A Microbial Metagenome (Leucobacter sp.) in Caenorhabditis Whole Genome Sequences

2013 ◽  
Vol 7 ◽  
pp. BBI.S11064 ◽  
Author(s):  
Riccardo Percudani
Keyword(s):  
Genetic Information ◽  
Bacterial Species ◽  
Draft Genome ◽  
Single Species ◽  
Public Database ◽  
Genome Sequences ◽  
The Public ◽  
Caenorhabditis Remanei ◽  
Insight Into ◽  
Annotation Errors

DNA of apparently recent bacterial origin is found in the genomic sequences of Caenorhabditis angaria and Caenorhabditis remanei. Here we present evidence that the DNA belongs to a single species of the genus Leucobacter (high-GC Gram+Actinobacteria). Metagenomic tools enabled the assembly of the contaminating sequences in a draft genome of 3.2 Mb harboring 2,826 genes. This information provides insight into a microbial organism intimately associated with Caenorhabditis as well as a solid basis for the reassignment of 3,373 metazoan entries of the public database to a novel bacterial species ( Leucobacter sp. AEAR). The application of metagenomic techniques can thus prevent annotation errors and reveal unexpected genetic information in data obtained by conventional genomics.

scholarly journals Cell-free protein synthesis and in situ immobilization of deGFP-MatB in polymer microgels for malonate-to-malonyl CoA conversion

RSC Advances ◽  
2020 ◽  
Vol 10 (66) ◽  
pp. 40588-40596
Author(s):  
Tony Köhler ◽  
Thomas Heida ◽  
Sandra Hoefgen ◽  
Niclas Weigel ◽  
Vito Valiante ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Genetic Information ◽  
In Situ Immobilization ◽  
Bottom Up ◽  
Free Protein ◽  
Malonyl Coa ◽  
Cell Free Protein Synthesis

We describe a bottom-up approach towards functional enzymes utilizing microgels as carriers for genetic information that enable cell-free protein synthesis, in situ immobilization, and utilization of functional deGFP-MatB.

scholarly journals Development of Fragility Curves for Piping and Slope Stability of River Levees

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 738
Author(s):  
Nicola Rossi ◽  
Mario Bačić ◽  
Meho Saša Kovačević ◽  
Lovorka Librić
Keyword(s):  
Slope Stability ◽  
Fragility Curves ◽  
Safety Margin ◽  
Water Levels ◽  
Flood Event ◽  
Soil Parameters ◽  
Design Code ◽  
A Site ◽  
Insight Into

The design code Eurocode 7 relies on semi-probabilistic calculation procedures, through utilization of the soil parameters obtained by in situ and laboratory tests, or by the means of transformation models. To reach a prescribed safety margin, the inherent soil parameter variability is accounted for through the application of partial factors to either soil parameters directly or to the resistance. However, considering several sources of geotechnical uncertainty, including the inherent soil variability, measurement error and transformation uncertainty, full probabilistic analyses should be implemented to directly consider the site-specific variability. This paper presents the procedure of developing fragility curves for levee slope stability and piping as failure mechanisms that lead to larger breaches, where a direct influence of the flood event intensity on the probability of failure is calculated. A range of fragility curve sets is presented, considering the variability of levee material properties and varying durations of the flood event, thus providing crucial insight into the vulnerability of the levee exposed to rising water levels. The procedure is applied to the River Drava levee, a site which has shown a continuous trend of increased water levels in recent years.

scholarly journals Linking morphological and molecular sources to disentangle the case of Xylodon australis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Javier Fernández-López ◽  
M. Teresa Telleria ◽  
Margarita Dueñas ◽  
Mara Laguna-Castro ◽  
Klaus Schliep ◽  
...  
Keyword(s):  
New Zealand ◽  
Phylogenetic Analyses ◽  
Single Species ◽  
R Package ◽  
Molecular Data ◽  
Historical Collections ◽  
Close Relationship ◽  
Kinship Relations ◽  
History Of ◽  
Different Sources

AbstractThe use of different sources of evidence has been recommended in order to conduct species delimitation analyses to solve taxonomic issues. In this study, we use a maximum likelihood framework to combine morphological and molecular traits to study the case of Xylodon australis (Hymenochaetales, Basidiomycota) using the locate.yeti function from the phytools R package. Xylodon australis has been considered a single species distributed across Australia, New Zealand and Patagonia. Multi-locus phylogenetic analyses were conducted to unmask the actual diversity under X. australis as well as the kinship relations respect their relatives. To assess the taxonomic position of each clade, locate.yeti function was used to locate in a molecular phylogeny the X. australis type material for which no molecular data was available using morphological continuous traits. Two different species were distinguished under the X. australis name, one from Australia–New Zealand and other from Patagonia. In addition, a close relationship with Xylodon lenis, a species from the South East of Asia, was confirmed for the Patagonian clade. We discuss the implications of our results for the biogeographical history of this genus and we evaluate the potential of this method to be used with historical collections for which molecular data is not available.

Insight into the enhanced photocatalytic properties of AgBr/Ag4P2O7 composites synthesized via in situ ion exchange reaction

2021 ◽  
Vol 9 (1) ◽  
pp. 104889
Author(s):  
Wyllamanney da S. Pereira ◽  
Fabrício B. Destro ◽  
Cipriano B. Gozzo ◽  
Edson R. Leite ◽  
Júlio C. Sczancoski
Keyword(s):  
Ion Exchange ◽  
Exchange Reaction ◽  
Photocatalytic Properties ◽  
Ion Exchange Reaction ◽  
Insight Into

scholarly journals In situ synthesis of methane using Ag–GDC composite electrodes in a tubular solid oxide electrolytic cell: new insight into the role of oxide ion removal

2021 ◽  
Vol 5 (7) ◽  
pp. 2055-2064
Author(s):  
Saheli Biswas ◽  
Aniruddha P. Kulkarni ◽  
Daniel Fini ◽  
Sarbjit Giddey ◽  
Sankar Bhattacharya
Keyword(s):  
Electrolytic Cell ◽  
Composite Electrodes ◽  
Ion Removal ◽  
Single Temperature ◽  
Methanation Catalyst ◽  
Oxide Ion ◽  
Insight Into ◽  
Electrochemical Phenomenon

In situ synthesis of methane in a single-temperature zone SOEC in the absence of any methanation catalyst is a completely electrochemical phenomenon governed by the thermodynamic equilibrium of various reactions.

Sign in / Sign up

Export Citation Format

Share Document