On the processes of sympatric speciation in the group of «yellow» wagtails in the Middle Volga region

2021 ◽  
pp. 105-111
Author(s):  
Elena Artemieva
Keyword(s):  
Genetic Divergence ◽  
Sympatric Speciation ◽  
Genetic Distances ◽  
Middle Volga Region ◽  
Intraspecific Hybridization ◽  
Yellow Wagtail ◽  
Leading Role ◽  
European Part Of Russia ◽  
Genetic Mechanisms ◽  
Spatio Temporal

This article discusses the mechanisms of sympatric speciation in the group of species of «yellow» wagtails based on hybridization. Interspecific and intraspecific hybridization can be attributed to the genetic mechanisms of divergence of populations of «yellow» wagtails. The existence of hybridization between the subspecies of the white-eared yellow wagtail M. flava beema and the yellow-fronted wagtail M. lutea leads to the emergence and further accumulation in the population of individuals with a light-colored head to varying degrees, the so-called «gray-headed» individuals. Intraspecific hybridization of subspecies forms of the yellow wagtail M. flava — nominative M. f. flava and white-eared M. f. beema leads to constantly occurring genotypic splits, which support intraspecific polymorphism of populations and provide the basis for further genetic divergence of these subspecies and species. The form of "gray-headed" hybrids is characterized by maximum genetic distances (1306.67–1375.67), which may correspond to the species rank. The modern polytypic complex of M. flava (in the narrow sense, a series of species and subspecies of only M. flava) probably formed in historical time on the basis of fan hybridization between the original forms of M. f. flava and M. lutea. Thus, the factors of genetic differentiation and divergence, along with ecological and geographical isolation, play a leading role in the formation of the spatio-temporal and genetic structure of the genus Motacilla. Currently, there is an active process of genetic divergence and separation of subspecies and species forms of «yellow» wagtails under conditions of wide sympatry within a single polytypic complex based on intraspecific and interspecific hybridization in the European part of Russia.

scholarly journals GENETIC BASE FOR SYMPATRY OF YELLOW WAGTAIL MOTACILLA FLAVA LINNAEUS, 1758 AND YELLOW-HEADED WAGTAIL MOTACILLA CITREOLA PALLAS , 1776 (MOTACILLIDAE, PASSERIFORMES) IN THE MIDDLE VOLGA REGION

2015 ◽  
Vol 4 (2) ◽  
pp. 12-15
Author(s):  
Elena Alexandrovna Artemyeva ◽  
Andrei Vladimirovich Mishchenko ◽  
Denis Konstantinovich Makarov
Keyword(s):  
Mitochondrial Gene ◽  
Breeding Population ◽  
Genetic Distances ◽  
Volga Region ◽  
Middle Volga Region ◽  
Yellow Wagtail ◽  
The Status ◽  
European Part Of Russia ◽  
Males And Females ◽  
Middle Volga

We investigated the genetic basis between sympatric breeding population yellow wagtail Motacilla flava and yellow-headed wagtail Motacilla citreola in the Middle Volga region. We lead the phylogeographic analysis of the nucleotide sequences in the mitochondrial gene of oxidase I cytochromes in yellow wagtail Motacilla flava and yellow headed wagtail M. citreola populations of Middle Volga. As part of the traditionally recognized species M. flava and M. citreola revealed the existence of separate lines, common in the European part of Russia and neighboring countries and associated with the presence of Middle Volga populations of subspecies of M. f. flava, M. f. thunbergi and M. c. citreola, M. c. werae respectively. The forms of M. c. citreola and M. c. werae due to significant genetic distances deserve assigning them the status of the species. These results suggest that, despite the broad sympatry in nesting places, there is a selective mating between males and females of each species studied, which prevents from the free crossing and supports the insulating mechanisms in populations

DISTRIBUTION OF TEMPERATURE INDICES OF EXTREME IN THE TERRITORY OF THE EUROPEAN PART OF RUSSIA IN THE PERIOD 1980-2019

2021 ◽  
Vol 31 (4) ◽  
pp. 437-442
Author(s):  
V.V. Guryanov ◽  
A.K. Sungatullin
Keyword(s):  
Temporal Variability ◽  
Statistical Processing ◽  
European Part ◽  
The North ◽  
Hourly Data ◽  
European Part Of Russia ◽  
Spatial Grid ◽  
Temperature Indices ◽  
Spatio Temporal ◽  
Maximum Temperatures

The spatio-temporal variability of the average values of temperature indices of climate extremity in the territory of the European part of Russia (ER) in 1980-2019 is presented. To calculate the extremeness indices, we used hourly data on the maximum and minimum temperatures obtained using the ERA5 reanalysis on a 1°´1° spatial grid. Statistical processing of the index values revealed an increase in the temperature indices TNX, TNN, TXN, TXX, associated with the minimum and maximum temperatures, with the exception of the north and southeast of the region. An increase in the number of sunny days and a decrease in the number of frosty days were also revealed.

scholarly journals Null expectation of spatial correlograms under a stochastic process of genetic divergence with small sample sizes

2000 ◽  
Vol 23 (4) ◽  
pp. 739-743 ◽  
Author(s):  
Mariana Pires de Campos Telles ◽  
José Alexandre Felizola Diniz-Filho
Keyword(s):  
Stochastic Process ◽  
Genetic Divergence ◽  
Isolation By Distance ◽  
Genetic Distances ◽  
Small Sample ◽  
Group Method ◽  
Gene Frequencies ◽  
Exponential Relationship ◽  
Local Populations ◽  
Pair Group

An Ornstein-Uhlenbeck process was used to simulate the exponential relationship between genetic divergence and geographic distances, as predicted by stochastic processes of population differentiation, such as isolation-by-distance, stepping-stone or coalescence models. These simulations were based only on the spatial coordinates of the local populations that defined a spatial unweighted pair-group method using arithmetic averages (UPGMA) link among them. The simulated gene frequency surfaces were then analyzed using spatial autocorrelation procedures and Nei's genetic distances, constructed with different numbers of variables (gene frequencies). Stochastic divergence in space produced strong spatial patterns at univariate and mutivariate levels. Using a relatively small number of local populations, the correlogram profiles varied considerably, with Manhattan distances greater than those defined by other simulation studies. This method allows one to establish a range of correlogram profiles under the same stochastic process of spatial divergence, thereby avoiding the use of unnecessary explanations of genetic divergence based on other microevolutionary processes.

Conservation Genetics of Corroboree Frogs, Pseudophryne-Corroboree Moore (Anura, Myobatrachidae) - Population Subdivision and Genetic-Divergence

1991 ◽  
Vol 39 (3) ◽  
pp. 285 ◽  
Author(s):  
WS Osborne ◽  
JA Norman
Keyword(s):  
Genetic Divergence ◽  
Conservation Management ◽  
Geographic Distance ◽  
Genetic Distances ◽  
Population Subdivision ◽  
Southern Form ◽  
Eastern Australia ◽  
Geographic Populations ◽  
Taxonomic Implications ◽  
Growth Abnormalities

Reproductive compatibility and population genetic structure were examined in the corroboree frog, Pseudophryne corroboree, a species restricted to montane and subalpine environments in south-eastern Australia. The species comprises three geographic populations, represented by two morphological forms. Hybridisation experiments showed that the allopatric populations are interfertile, although crosses between the Snowy Mountains population (southern form) and each of the two northern populations (northern form) resulted in a significantly higher number of tadpoles with growth abnormalities. An electrophoretic examination of metamorphlings indicated that there was considerable genetic divergence between the two forms, with several loci approaching fixation of alternate alleles. The Snowy Mountains population also had substantially reduced levels of genetic variation compared to the two northern populations. Although genetic distances generally correlate with geographic distance, the genetic differences between the northern and southern populations form a pronounced step, not explicable by geographic distance alone. These findings have taxonomic implications which should be taken into account when considering the conservation management of this uncommon species.

scholarly journals HLA Polymorphisms and Food Allergy Predisposition

2020 ◽  
Vol 09 (02) ◽  
pp. 077-086
Author(s):  
Maria Kostara ◽  
Vasiliki Chondrou ◽  
Argyro Sgourou ◽  
Konstantinos Douros ◽  
Sophia Tsabouri
Keyword(s):  
Food Allergy ◽  
Human Leucocyte Antigen ◽  
Genetic Factors ◽  
Immune Disorders ◽  
Biological Mechanisms ◽  
Immune Disorder ◽  
Complex Disorder ◽  
Leading Role ◽  
Gene Functions ◽  
Genetic Mechanisms

AbstractFood allergy (FA) is a growing health problem that affects ∼8% of the children worldwide. Although the prevalence of FA is increasing, the underlying genetic mechanisms responsible for the onset of this immune disorder are not yet clarified. Genetic factors seem to play a leading role in the development of FA, though interaction with environmental factors cannot be excluded. The broader network of genetic loci mediating the risk of this complex disorder remains to be identified. The human leucocyte antigen (HLA) has been associated with various immune disorders, including FA. This review aims to unravel the potential associations between HLA gene functions and the manifestation and outcome of FA disorders. Exploring new aspects of FA development with the perspective to improve our understanding of the multifaceted etiology and the complex biological mechanisms involved in FA is essential.

Genetic divergence for quality, yield and yield components in Yardlong bean[Vigna unguiculata (L.) Walp. ssp.sesquipedalis Verdc.]

2016 ◽  
Author(s):  
E. Rambabu ◽  
K. Ravinder Reddy ◽  
V. Kamala ◽  
P. Saidaiah ◽  
S. R. Pandravada
Keyword(s):  
Genetic Divergence ◽  
Crop Improvement ◽  
Ascorbic Acid Content ◽  
Genetic Distances ◽  
Yield Attributes ◽  
Relative Contribution ◽  
Improvement Programme ◽  
Yardlong Bean ◽  
Clustering Pattern ◽  
Pod Length

Genetic divergence among 41 commercial Yardlong bean genotypes was investigated to select the parents for hybridization using Mahalanobis D2 statistics. The genotypes fall into seven clusters. Cluster VI had the maximum (12) and cluster VII had the minimum (1) number of genotypes. The intra cluster D2 value ranged from 0.00 (Cluster II, III, VI, VII) to 121.69 (Cluster V). The cluster V had the maximum D2 value (121.692) followed by Cluster IV (77.305) and Cluster I (46.391). The inter cluster D2 values of the seven clusters revealed that highest inter cluster generalized distance (607.945) was between cluster V and cluster VII, while the lowest (15.917) was between cluster II and cluster III. Regarding relative contribution of different traits towards divergence, pod length (48.66%) contributed maximum followed by pod ascorbic acid content (20.00%), pod girth (12.20%) and 100 seed weight (12.20%) among Yardlong bean genotypes. Based on genetic distances and clustering pattern, the most divergent genotypes identified are IC-582859, NSJ-362, IC-582850, IC-582872, IC-582851 and IC-582829 from III, V, and VI clusters could be used as best parents on crop improvement programme to produce desirable segregants for yield and yield attributes in Yardlong bean.

scholarly journals Genetic divergence among accessions of cassava (Manihot esculenta Crantz) sampled in the Tapajós region, State of Pará, using agronomic characters and microsatellite markers

2016 ◽  
Vol 37 (5) ◽  
pp. 2989 ◽  
Author(s):  
Rodrigo De Souza Silva ◽  
Elisa Ferreira Moura ◽  
João Tomé de Farias Neto ◽  
Nelcimar Reis Sousa ◽  
Mônika Fecury Moura ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Genetic Divergence ◽  
Molecular Data ◽  
Genetic Distances ◽  
Agronomic Characters ◽  
Multivariate Statistical ◽  
Manihot Esculenta Crantz ◽  
Components Analysis ◽  
Genetic Dissimilarity ◽  
Morphological And Molecular Data

The aim of this work was to estimate the genetic divergence among accessions of cassava sampled in the Tapajós region in the State of Pará, Brazil, and conserved at the Regional Germplasm Bank of Eastern Amazon, using agronomic descriptors and molecular markers. Twenty-two accessions of cassava were evaluated in the field for two successive years, based on six agronomic descriptors in twelve-months-old plants without a specific experimental design. Accessions were also evaluated with eleven microsatellite loci in an automatic DNA analyser. Descriptive and multivariate statistical analyses were applied. Based on principal components analysis, the character weight of the aerial portion of the plant contributed most to the phenotypical variation. The six traits were used in the analysis of genetic dissimilarity between accessions, and the correlation between matrices generated by morphological and molecular data was estimated. The matrices of genetic dissimilarity were used in the construction of dendrograms using the UPGMA method. We observed a high variation of agronomical descriptors and molecular markers evaluated, which were capable to separate the accessions into distinct groups. A weak positive correlation was detected among the two matrices of genetic distances, which indicates the possibility to explore the genetic diversity using crossings and accessions Amarelinha 36 and Olho roxo 13 are divergent and potentially promising for the generation of heterotic hybrids.

Data Cube Compression Techniques

2011 ◽  
pp. 367-373 ◽  
Author(s):  
Alfredo Cuzzocrea
Keyword(s):  
Input Parameter ◽  
Original Data ◽  
Data Cube ◽  
Research Activity ◽  
Loss Of Information ◽  
Useful Knowledge ◽  
Data Cubes ◽  
Leading Role ◽  
Spatio Temporal ◽  
Modeling Representation

OnLine Analytical Processing (OLAP) research issues (Gray, Chaudhuri, Bosworth, Layman, Reichart & Venkatrao, 1997) such as data cube modeling, representation, indexing and management have traditionally attracted a lot of attention from the Data Warehousing research community. In this respect, as a fundamental issue, the problem of efficiently compressing the data cube plays a leading role, and it has involved a vibrant research activity in the academic as well as industrial world during the last fifteen years. Basically, this problem consists in dealing with massive-in-size data cubes that make access and query evaluation costs prohibitive. The widely accepted solution consists in generating a compressed representation of the target data cube, with the goal of reducing its size (given an input space bound) while admitting loss of information and approximation that are considered irrelevant for OLAP analysis goals (e.g., see (Cuzzocrea, 2005a)). Compressed representations are also referred-in-literature under the term “synopsis data structures”, i.e. succinct representations of original data cubes introducing a limited loss of information. Benefits deriving from the data cube compression approach can be summarized in a relevant reduction of computational overheads needed to both represent the data cube and evaluate resource-intensive OLAP queries, which constitute a wide query class allowing us to extract useful knowledge from huge amounts of multidimensional data repositories in the vest of summarized information (e.g., aggregate information based on popular SQL aggregate operators such as SUM, COUNT, AVG etc), otherwise infeasible by means of traditional OLTP approaches. Among such queries, we recall: (i) range-queries, which extract a sub-cube bounded by a given range; (ii) top-k queries, which extract the k data cells (such that k is an input parameter) having the highest aggregate values; (iii) iceberg queries, which extract the data cells having aggregate values above a given threshold. This evidence has given raise to the proliferation of a number of Approximate Query Answering (AQA) techniques, which, based on data cube compression, aim at providing approximate answers to resource-intensive OLAP queries instead of computing exact answers, as decimal precision is usually negligible in OLAP query and report activities (e.g., see (Cuzzocrea, 2005a)). Starting from these considerations, in this article we first provide a comprehensive, rigorous survey of main data cube compression techniques, i.e. histograms, wavelets, and sampling. Then, we complete our analytical contribution with a detailed theoretical review focused on spatio-temporal complexities of these techniques.

Evolutionary Branching in a Classical Model for Sympatric Speciation

2011 ◽  
Author(s):  
Michael Doebeli
Keyword(s):  
Reproductive Isolation ◽  
Adaptive Dynamics ◽  
Classical Model ◽  
Sympatric Speciation ◽  
Disruptive Selection ◽  
General Outcome ◽  
Wide Range ◽  
Genetic Mechanisms ◽  
Basic Concepts ◽  
Smith Model

This chapter begins by considering the Maynard Smith model. Much of this work concentrated on the genetic mechanisms for assortative mating and reproductive isolation, based on the assumption that the underlying niche ecology would generate disruptive selection. However, understanding the conditions under which disruptive selection arises in the first place is equally important, and indeed necessary for assessing whether diversification is a general outcome in the Maynard Smith model. The chapter then shows that disruptive selection and polymorphism are scenarios that occur generically, that is, for a wide range of parameters, in a classical and widely used speciation model. It also provides an introduction to some of the basic concepts of adaptive dynamics theory.

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