scholarly journals Evolution and taxonomy of nematode-associated entomopathogenic bacteria of the genera Xenorhabdus and Photorhabdus: an overview

Symbiosis ◽  
2020 ◽  
Vol 80 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Ewa Sajnaga ◽  
Waldemar Kazimierczak
Keyword(s):  
Evolutionary History ◽  
Entomopathogenic Nematode ◽  
Bacterial Species ◽  
Entomopathogenic Bacteria ◽  
Insecticidal Toxins ◽  
The Family ◽  
The World ◽  
History Of ◽  
Phylogenetic Origin ◽  
Animal Hosts

AbstractEntomopathogenic bacteria from the genera Photorhabdus and Xenorhabdus are closely related Gram-negative bacilli from the family Enterobacteriaceae (γ-Proteobacteria). They establish obligate mutualistic associations with soil nematodes from the genera Steinernema and Heterorhabditis to facilitate insect pathogenesis. The research of these two bacterial genera is focused mainly on their unique interactions with two different animal hosts, i.e. nematodes and insects. So far, studies of the mutualistic bacteria of nematodes collected from around the world have contributed to an increase in the number of the described Xenorhabdus and Photorhabdus species. Recently, the classification system of entomopatogenic nematode microsymbionts has undergone profound revision and now 26 species of the genus Xenorhabdus and 19 species of the genus Photorhabdus have been identified. Despite their similar life style and close phylogenetic origin, Photorhabdus and Xenorhabdus bacterial species differ significantly in e.g. the nematode host range, symbiotic strategies for parasite success, and arrays of released antibiotics and insecticidal toxins. As the knowledge of the diversity of entomopathogenic nematode microsymbionts helps to enable the use thereof, assessment of the phylogenetic relationships of these astounding bacterial genera is now a major challenge for researchers. The present article summarizes the main information on the taxonomy and evolutionary history of Xenorhabdus and Photorhabdus, entomopathogenic nematode symbionts.

scholarly journals Unraveling the evolutionary history of the cave-dwelling Dysderidae in the Dinarides

2018 ◽  
Vol 1 ◽  
Author(s):  
Martina Pavlek ◽  
Miquel Arnedo ◽  
Fulvio Gasparo ◽  
Silvia Adrian
Keyword(s):  
Family Relationships ◽  
Evolutionary History ◽  
Species Level ◽  
Taxonomic Structure ◽  
The North ◽  
The Family ◽  
The World ◽  
North Part ◽  
History Of ◽  
Dinaric Mountains

Because of their size, abundance and active predatory lifestyle, spiders of the family Dysderidae are among the most conspicuous creatures in the Dinaric caves. Historically, the interest for this group dates back to 1847, to the description of the first cave spider in the world, Stalita taenaria, and peaks in the middle of 20th century with the works of Joseph Kratochvíl and Christa L. Deeleman-Reinhold among others. However, after all these years, an explicit phylogenetic hypothesis about the family relationships is still missing and the taxonomy of some genera is a matter of debate. Dinaric cave representatives belong to two subfamilies: Rhodinae, with 13 species from five genera (Rhode, Stalita, Parastalita, Mesostalita and Stalitella) and Harpacteinae, with eight species from two genera (Folkia and Stalagtia). All species are considered troglobiotic and are Dinaric endemics, with Harpacteine restricted to the south part of the Dinaric Mountains and Rhodinae (with few exceptions) to the north part. Here, we present the results of a mutli-locus phylogenetic analysis of the family combining mitochondrial and nuclear genes of the focal group along with representatives of the other dysderid genera. Our data reveal a more complex taxonomic structure than currently recognized, with several instances of paraphyly, and uncover some overlooked diversity at the species level.

Systematic evidence from gene duplication and regulation

1990 ◽  
Vol 3 (1) ◽  
pp. 145
Author(s):  
DJ Colgan
Keyword(s):  
Gene Duplication ◽  
Evolutionary History ◽  
Tandem Duplication ◽  
Fragment Length Polymorphism ◽  
Duplicate Genes ◽  
Polymorphism Analysis ◽  
Multiple Origins ◽  
The Family ◽  
History Of ◽  
Phylogenetic Hypotheses

This paper is a review of the use of information regarding the presence of duplicate genes and their regulation in systematics. The review concentrates on data derived from protein electrophoresis and restriction fragment length polymorphism analysis. The appearance of a duplication in a subset of a group of species implies that the members of the subset belong to the same clade. Suppression of the duplication may render this clade apparently paraphyletic, but may itself be informative of relations within the lineage through patterns of loss of expression in all, or some tissues, or through restrictions of the formation of functional heteropolymers in polymeric enzymes. Examples are given of studies which have used such information to establish phylogenetic hypotheses at the family level, to identify an auto- or allo-polyploid origin of polyploid species and to determine whether there have been single or multiple origins of such species. The likelihood of homoplasy in the patterns of appearance and regulation of duplicates depends on the molecular basis of the duplication. In particular, the contrast between the expected consequences of tandem duplication and the expression of pseudogenes emphasises the value of determining the mechanism of the original duplication. Many instances of sporadic gene duplication are now known, and polyploidisation is a common event in the evolutionary history of both plants and animals. So the opportunities to discover duplicationrelated characters will arise in many systematic studies. A program is presented to increase the chances that such useful information will be recognisable during the studies.

scholarly journals Renouncing the World and Taking Ordination

2021 ◽  
Vol 13 (2021/1) ◽  
Author(s):  
Krisztina Teleki
Keyword(s):  
20Th Century ◽  
Dominant Role ◽  
Family Members ◽  
Family Ties ◽  
The Family ◽  
The World ◽  
Monastic Life ◽  
History Of ◽  
Similarities And Differences ◽  
Written Sources

The 20th century brought different periods in the history of Mongolia including theocracy, socialism and democracy. This article describes what renouncing the world (especially the home and the family), taking ordination, and taking monastic vows meant at the turn of the 20th century and a century later. Extracts from interviews reveal the life of pre-novices, illustrating their family backgrounds, connections with family members after ordination, and support from and towards the family. The master-disciple relationship which was of great significance in Vajrayāna tradition, is also described. As few written sources are available to study monks’ family ties, the research was based on interviews recorded with old monks who lived in monasteries in their childhood (prior to 1937), monks who were ordained in 1990, and pre-novices of the current Tantric monastic school of Gandantegčenlin Monastery. The interviews revealed similarities and differences in monastic life in given periods due to historical reasons. Though Buddhism could not attain its previous, absolutely dominant role in Mongolia after the democratic changes, nowadays tradition and innovation exist in parallel.

Systematics and biogeography of the “Metacryphaeus group” Calmoniidae (Trilobita, Devonian), with comments on adaptive radiations and the geological history of the Malvinokaffric Realm

1993 ◽  
Vol 67 (4) ◽  
pp. 549-570 ◽  
Author(s):  
Bruce S. Lieberman
Keyword(s):  
New Species ◽  
South African ◽  
Evolutionary History ◽  
Geological History ◽  
Parsimony Analysis ◽  
Evolutionary Patterns ◽  
The Family ◽  
History Of ◽  
Adaptive Radiations ◽  
Rapid Diversification

Phylogenetic parsimony analysis was used to classify the Siegenian–Eifelian “Metacryphaeus group” of the family Calmoniidae. Thirty-eight exoskeletal characters for 16 taxa produced a shortest-length cladogram with a consistency index of 0.49. A classification based on retrieving the structure of this cladogram recognizes nine genera: Typhloniscus Salter, Plesioconvexa n. gen., Punillaspis Baldis and Longobucco, Eldredgeia n. gen., Clarkeaspis n. gen., Malvinocooperella n. gen., Wolfartaspis Cooper, Plesiomalvinella Lieberman, Edgecombe, and Eldredge (used to represent the malvinellid clade), and Metacryphaeus Reed. The malvinellid clade is most closely related to a revised monophyletic Metacryphaeus. Typhloniscus is the basal member of the “Metacryphaeus group,” and the monotypic Wolfartaspis is sister to the clade containing the malvinellids and Metacryphaeus. Six new species are diagnosed: Punillaspis n. sp. A, “Clarkeaspis” gouldi, Clarkeaspis padillaensis, Malvinocooperella pregiganteus, Metacryphaeus curvigena, and Metacryphaeus branisai. Primitively, this group has South African and Andean affinities, and its evolutionary history suggests rapid diversification. In addition, evolutionary patterns in this group, and the distribution of character reversals, call into question certain notions about the nature of adaptive radiations. The distributions of taxa may answer questions about the number of marine transgressive/regressive cycles in the Emsian–Eifelian of the Malvinokaffric Realm.

Adaptive convergent evolution of genome proofreading in SARS-CoV2: insights into the Eigen’s paradox

2021 ◽  
Author(s):  
Keerthic Aswin ◽  
Srinivasan Ramachandran ◽  
Vivek T Natarajan
Keyword(s):  
Convergent Evolution ◽  
Genome Stability ◽  
Evolutionary History ◽  
Rna Binding ◽  
Phylogenetic Analyses ◽  
Comparative Genome Analysis ◽  
The Family ◽  
History Of ◽  
Key Residues

AbstractEvolutionary history of coronaviruses holds the key to understand mutational behavior and prepare for possible future outbreaks. By performing comparative genome analysis of nidovirales that contain the family of coronaviruses, we traced the origin of proofreading, surprisingly to the eukaryotic antiviral component ZNFX1. This common recent ancestor contributes two zinc finger (ZnF) motifs that are unique to viral exonuclease, segregating them from DNA proof-readers. Phylogenetic analyses indicate that following acquisition, genomes of coronaviruses retained and further fine-tuned proofreading exonuclease, whereas related families harbor substitution of key residues in ZnF1 motif concomitant to a reduction in their genome sizes. Structural modelling followed by simulation suggests the role of ZnF in RNA binding. Key ZnF residues strongly coevolve with replicase, and the helicase involved in duplex RNA unwinding. Hence, fidelity of replication in coronaviruses is a result of convergent evolution, that enables maintenance of genome stability akin to cellular proofreading systems.

Alcohol and Humans

2019 ◽  
pp. 196-206
Author(s):  
Kimberley J. Hockings ◽  
Robin I.M. Dunbar
Keyword(s):  
Alcohol Consumption ◽  
Evolutionary History ◽  
Social Role ◽  
Medical Profession ◽  
Future Research ◽  
The Social ◽  
The World ◽  
History Of

Humans and alcohol have shared a very long history. In this final chapter, we highlight some of the key findings that emerge from the chapters in this book, in particular the evolutionary history of our adaptation to alcohol consumption and the social role that alcohol consumption plays, and has played, in human societies across the world. This raises a major contradiction in the literature, namely the fact that, despite this long history, the medical profession typically views alcohol as destructive. We draw attention to several avenues that would repay future research and how humans’ relationship with alcohol stands to change and evolve.

scholarly journals New perspectives on the evolution of the genus Typhlatya (Crustacea, Decapoda): first record of a cavernicolous atyid in the Iberian Peninsula, Typhlatya miravetensis n. sp.

1995 ◽  
Vol 65 (2) ◽  
pp. 79-99
Author(s):  
Sebastián Sanz ◽  
Dirk Platvoet
Keyword(s):  
Iberian Peninsula ◽  
First Record ◽  
Evolutionary Development ◽  
The Family ◽  
The World ◽  
The Status ◽  
History Of ◽  
World Distribution ◽  
A New Species

On several occasions, shrimps belonging to a new species of the genus Typhlatya were collected in a cave in the province of Castellón, Spain. This is the first record of the genus in the Iberian Peninsula. The species is described and the validity, distribution, and zoogeography of the genus, as well as the status of the genus Spelaeocaris, are discussed. Former models for the evolution of the genus Typhlatya and its genus group are reviewed, as well as the system of inner classification of the Atyidae and its biogeographical meaning. For the age and evolution of the genus we developed a new model based on vicariance principles that involves further evolution of each species after the disruption of the ancestral range. This allows new estimations for the age of the genus. Accordingly, we suppose that other proposals, such as recent dispersal through the sea, should be disregarded for this genus. The evolutionary development of this species is discussed in the context of the geological history of the area and the world distribution of the genus, the genus group, and the family.

Wedge-tailed Eagle

2005 ◽  
Author(s):  
Penny Olsen
Keyword(s):  
Natural History ◽  
Final Section ◽  
Comprehensive Overview ◽  
The Family ◽  
The World ◽  
Chick Development ◽  
History Of ◽  
Rock Paintings ◽  
Large Predators

Australia’s Wedge-tailed Eagle belongs to the family of eagles, which together span the world. Eagles are powerful predators, with exceptional powers of flight and sight. They may kill to survive, but they also sleep, play, enjoy a bath, make tender parents, and form lasting relationships. This book gives a comprehensive overview of Australia’s largest true eagle and one of the country’s few large predators and scavengers. First appearing in Aboriginal rock-paintings more than 5000 years ago, the Wedge-tailed Eagle was little more than a curiosity to the early European settlers. The book traces the subsequent changes in perception—from its branding as a vicious sheep killer to an iconic species worthy of conservation—and covers distribution, habitat, hunting, relationships, reproduction and chick development. A final section deals with threats to the existence of this magnificent bird. Winner of the 2006 Whitley Award for Best Natural History of an Iconic Species.

Human Evolution

1984 ◽  
Vol 8 ◽  
pp. 182-198
Author(s):  
Catherine Badgley
Keyword(s):  
Human Evolution ◽  
Evolutionary History ◽  
Pan Paniscus ◽  
Homo Sapiens ◽  
Great Apes ◽  
Sister Group ◽  
The Family ◽  
History Of ◽  
Living Species ◽  
Single Living

The evolutionary history of humans is well understood in outline, compared to that of many other groups of mammals. But human evolution remains enigmatic in its details, and these are compelling both scientifically and personally because they relate to the biological uniqueness of humans. Humans are placed in the primate family Hominidae, which, in traditional classifications, contains a single living species, Homo sapiens. The closest living relatives of humans are great apes: the chimpanzees Pan paniscus and Pan troglodytes, the gorilla Gorilla gorilla, and the orangutan Pongo pygmaeus. These apes have traditionally been placed in the family Pongidae as the sister group of Hominidae. Living Hominidae and Pongidae, together with Hylobatidae (gibbons) comprise the modern representatives of the primate suborder Hominoidea.

XVI.—Quantitative Evolution. III. Dp-ages of Gramineæ

1938 ◽  
Vol 57 ◽  
pp. 221-227
Author(s):  
James Small
Keyword(s):  
Time Scale ◽  
Evolutionary History ◽  
Geological Time ◽  
Exponential Curve ◽  
The Family ◽  
History Of ◽  
Geological Origin ◽  
Fossil Records

Applying Udny Yule's formulæ (1924) to the Compositæ, Small (1937) found that the average ages in doubling periods (Dp-ages) of the tribes of Compositæ, when plotted against a time-scale, gave points on an exponential curve called the BAT curve. If this curve is characteristic of average families of Angiosperms it should be possible to place the Dp-ages of tribes within other families on this curve as plotted against geological time, and thus obtain an order of geological origin which is quite independent of actual fossil records and which can be checked against any facts known concerning the evolutionary history of the family.

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