scholarly journals Cytoplasmic incompatibility between Old and New World populations of a tramp ant

2020 ◽  
Author(s):  
Çiğdem Ün ◽  
Eva Schultner ◽  
Alejandro Manzano-Marín ◽  
Laura V. Flórez ◽  
Bernhard Seifert ◽  
...  
Keyword(s):  
Reproductive Isolation ◽  
New World ◽  
Evolutionary Dynamics ◽  
Cytoplasmic Incompatibility ◽  
Isolated Populations ◽  
First Case ◽  
Rapid Spread ◽  
Tramp Ant ◽  
Globally Distributed ◽  
Geographically Isolated

AbstractAs we enter the Anthropocene, the evolutionary dynamics of species will change drastically, and as yet unpredictably, due to human activity. Already today, increases in global human traffic have resulted in the rapid spread of species to new areas, leading to the formation of geographically isolated populations. These go on to evolve in allopatry, which can lead to reproductive isolation, and potentially, the formation of new species. Surprisingly, little is known about such eco-evolutionary processes in ants, even though numerous invasive ant species are globally distributed in geographically isolated populations. Here, we describe the first case of cytoplasmic incompatibility (CI) between populations of a cosmotropic distributed tramp ant with Asian roots, Cardiocondyla obscurior, which has acquired a novel Wolbachia strain in the New World. Our study uncovers the first symbiont-induced mechanism of reproductive isolation in ants, providing a novel perspective on the biology of globally distributed ants.

scholarly journals Cytoplasmic incompatibility between Old and New World populations of a tramp ant

Evolution ◽  
2021 ◽  
Author(s):  
Çiğdem Ün ◽  
Eva Schultner ◽  
Alejandro Manzano‐Marín ◽  
Laura V. Flórez ◽  
Bernhard Seifert ◽  
...  
Keyword(s):  
New World ◽  
Cytoplasmic Incompatibility ◽  
Tramp Ant

scholarly journals FURTHER STUDIES ON GENE POLYMORPHISM IN THE MAINBODY AND GEOGRAPHICALLY ISOLATED POPULATIONS OF DROSOPHILA PSEUDOOBSCURA

Genetics ◽  
1977 ◽  
Vol 85 (4) ◽  
pp. 713-719
Author(s):  
Satya Prakash
Keyword(s):  
Gene Polymorphism ◽  
Reproductive Isolation ◽  
Drosophila Pseudoobscura ◽  
Isolated Population ◽  
Isolated Populations ◽  
Apparent Lack ◽  
Unique Allele ◽  
Geographically Isolated

ABSTRACT We have examined polymorphism at 22 additional loci in the populations from the mainbody of Drosophila pseudoobscura and an isolated population from Bogotá, Colombia, which also shows partial reproductive isolation from mainbody populations. These studies extend our previous observations of reduced gene polymorphism and apparent lack of unique allele in the Bogotá population.

An ultrastructural study of sertoli cells in two geographically isolated populations of Aphanius dispar

1992 ◽  
Vol 50 (1) ◽  
pp. 548-549
Author(s):  
Taber A. Ba-Omar ◽  
Philip F. Prentis
Keyword(s):  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
Freshwater Teleost ◽  
Isolated Populations ◽  
En Bloc ◽  
The North ◽  
Group A ◽  
Ultrathin Sections ◽  
Group B ◽  
Geographically Isolated

We have recently carried out a study of spermiogenic differentiation in two geographically isolated populations of Aphanius dispar (freshwater teleost), with a view to ascertaining variation at the ultrastructural level. The sampling areas were the Jebel Al Akhdar in the north (Group A) and the Dhofar region (Group B) in the south. Specimens from each group were collected, the testes removed, fixed in Karnovsky solution, post fixed in OsO, en bloc stained with uranyl acetate and then routinely processed to Agar 100 resin, semi and ultrathin sections were prepared for study.

A test for rate‐coupling of trophic and cranial evolutionary dynamics in New World bats

Evolution ◽  
2021 ◽  
Author(s):  
Jeff J. Shi ◽  
Erin P. Westeen ◽  
Daniel L. Rabosky
Keyword(s):  
New World ◽  
Evolutionary Dynamics

The speciation continuum and species relations between populations: in search of agreement between the theory and practice of systematics

2021 ◽  
pp. 173-179
Author(s):  
Oleksandr Zinenko
Keyword(s):  
Reproductive Isolation ◽  
Species Concept ◽  
Climatic Conditions ◽  
Point Of View ◽  
Theory And Practice ◽  
Hybrid Origin ◽  
Isolated Populations ◽  
As Species ◽  
Mitochondrial Cytochrome B ◽  
Traditional Taxonomy

From an evolutionary point of view, the achievement of species status by a group of populations is an ongoing process (except for rare cases of instantaneous speciation), during which isolated populations acquire traits and adaptations that minimize gene flow between them. However, depending on the group, the ways and timing of the gaining of reproductive isolation may be different. In such a complex group for systematics as small vipers (genus Vipera, subgenus Pelias), there are a number of problematic situations for species delimitation: the ability to form hybrids and hybrid populations between species, adaptive hybridization and hybrid speciation, and possible traces of reversed speciation, which indicate that complete and irreversible reproductive isolation may not be achieved at all. The effectiveness of reproductive isolation largely depends on external factors, mostly related to the range spatial structure, ecology of species in areas of sympatry, as well as climatic conditions and their changes, landscape dynamics, etc. The only species concept that allows to describe new species in the absence of reproductive isolation, recognizes the possibility of hybrid and reverse speciation — de Queiroz unified species concept — is practically unsuitable due to the need to consider as species a large number of isolated populations. Therefore, the solution is a conservative approach in practical taxonomy, which takes into account as a species criterion the ecological divergence of species, the possibility of their sympatric existence, which is usually achieved at 5% divergence of the mitochondrial cytochrome b gene. Stabilized hybrid populations occupying distinct ecological niche different from those of parental species also deserve recognition as species of hybrid origin. Not only species deserves to be protected, but also a distinguishable and diverged group of populations — Evolutionary Significant Unit (ESU) or subspecies in traditional taxonomy.

scholarly journals Comparative Analysis of Chlamydia psittaci Genomes Reveals the Recent Emergence of a Pathogenic Lineage with a Broad Host Range

mBio ◽  
2013 ◽  
Vol 4 (2) ◽  
Author(s):  
Timothy D. Read ◽  
Sandeep J. Joseph ◽  
Xavier Didelot ◽  
Brooke Liang ◽  
Lisa Patel ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
New World ◽  
Evolutionary Dynamics ◽  
Chlamydia Psittaci ◽  
South American ◽  
Content Type ◽  
Sexually Transmitted ◽  
Genome Wide ◽  
Life Threatening ◽  
History Of

ABSTRACT Chlamydia psittaci is an obligate intracellular bacterium. Interest in Chlamydia stems from its high degree of virulence as an intestinal and pulmonary pathogen across a broad range of animals, including humans. C. psittaci human pulmonary infections, referred to as psittacosis, can be life-threatening, which is why the organism was developed as a bioweapon in the 20th century and is listed as a CDC biothreat agent. One remarkable recent result from comparative genomics is the finding of frequent homologous recombination across the genome of the sexually transmitted and trachoma pathogen Chlamydia trachomatis. We sought to determine if similar evolutionary dynamics occurred in C. psittaci. We analyzed 20 C. psittaci genomes from diverse strains representing the nine known serotypes of the organism as well as infections in a range of birds and mammals, including humans. Genome annotation revealed a core genome in all strains of 911 genes. Our analyses showed that C. psittaci has a history of frequently switching hosts and undergoing recombination more often than C. trachomatis. Evolutionary history reconstructions showed genome-wide homologous recombination and evidence of whole-plasmid exchange. Tracking the origins of recombinant segments revealed that some strains have imported DNA from as-yet-unsampled or -unsequenced C. psittaci lineages or other Chlamydiaceae species. Three ancestral populations of C. psittaci were predicted, explaining the current population structure. Molecular clock analysis found that certain strains are part of a clonal epidemic expansion likely introduced into North America by South American bird traders, suggesting that psittacosis is a recently emerged disease originating in New World parrots. IMPORTANCE Chlamydia psittaci is classified as a CDC biothreat agent based on its association with life-threatening lung disease, termed psittacosis, in humans. Because of the recent remarkable findings of frequent recombination across the genome of the human sexually transmitted and ocular trachoma pathogen Chlamydia trachomatis, we sought to determine if similar evolutionary dynamics occur in C. psittaci. Twenty C. psittaci genomes were analyzed from diverse strains that may play a pathogenic role in human disease. Evolution of the strains revealed genome-wide recombination occurring at a higher rate than for C. trachomatis. Certain strains were discovered to be part of a recent epidemic clonal expansion originating in South America. These strains may have been introduced into the United States from South American bird traders, suggesting that psittacosis is a recently emerged disease originating in New World parrots. Our analyses indicate that C. psittaci strains have a history of frequently switching hosts and undergoing recombination.

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