scholarly journals A young age of subspecific divergence in the desert locustSchistocerca gregaria, inferred by ABC Random Forest

2019 ◽  
Author(s):  
Marie-Pierre Chapuis ◽  
Louis Raynal ◽  
Christophe Plantamp ◽  
Christine N. Meynard ◽  
Laurence Blondin ◽  
...  
Keyword(s):  
Random Forest ◽  
Schistocerca Gregaria ◽  
Computational Cost ◽  
Molecular Data ◽  
Population Divergence ◽  
Statistical Selection ◽  
Independent Information ◽  
History Of ◽  
Key Issues ◽  
Approximate Bayesian

AbstractDating population divergence within species from molecular data and relating such dating to climatic and biogeographic changes is not trivial. Yet it can help formulating evolutionary hypotheses regarding local adaptation and future responses to changing environments. Key issues include statistical selection of a demographic and historical scenario among a set of possible scenarios, and estimation of the parameter(s) of interest under the chosen scenario. Such inferences greatly benefit from new statistical approaches including approximate Bayesian computation - Random Forest (ABC-RF), the latter providing reliable inference at a low computational cost, with the possibility to take into account prior knowledge on both biogeographical history and genetic markers. Here, we used ABC-RF, including independent information on evolutionary rate and pattern at microsatellite markers, to decipher the evolutionary history of the African arid-adapted pest locust,Schistocerca gregaria. We found that the evolutionary processes that have shaped the present geographical distribution of the species in two disjoint northern and southern regions of Africa were recent, dating back 2.6 Ky (90% CI: 0.9 – 6.6 Ky). ABC-RF inferences also supported a southern colonization of Africa from a low number of founders of northern origin. The inferred divergence history is better explained by the peculiar biology ofS. gregaria, which involves a density-dependent swarming phase with some exceptional spectacular migrations, rather than a continuous colonization resulting from the continental expansion of open vegetation habitats during more ancient Quaternary glacial climatic episodes.

scholarly journals Reconstructing the demographic history of Atlantic Salmon (Salmo salar) across its distribution range using Approximate Bayesian Computations

2017 ◽  
Author(s):  
Quentin Rougemont ◽  
Louis Bernatchez
Keyword(s):  
North America ◽  
Atlantic Salmon ◽  
Northern Hemisphere ◽  
Demographic History ◽  
Secondary Contact ◽  
Population Divergence ◽  
Isolated Populations ◽  
Quaternary Period ◽  
History Of ◽  
Approximate Bayesian

AbstractUnderstanding the dual roles of demographic and selective processes in the buildup of population divergence is one of the most challenging tasks in evolutionary biology. In the Northern hemisphere in particular, species genetic makeup has been largely influenced by severe climatic oscillations of the Quaternary Period. Here, we investigated the demographic history of Atlantic Salmon across the entire species range using 2035 anadromous individuals from 77 sampling sites from North America and Eurasia genotyped at 4,656 SNPs. By combining results from admixture graphs, geogenetic maps and an approximate Bayesian computation framework, we validate previous hypotheses pertaining to secondary contact between European and Northern American populations, but also demonstrate that European populations from different glacial refugia have been exchanging alleles in contemporary times. We further identify the major sources of admixture from the southern range of North America to more northern populations along with a strong signal of secondary gene flow between genetic regional groups. We hypothesize that these patterns reflects the spatial redistribution of ancestral variation across the entire American range. Results also point to a role for linked selection in the form of background selection and or positive hitchhiking. Altogether, differential introgression and linked selective effects likely played an underappreciated role in shaping the genomic landscape of species in the Northern hemisphere Therefore we conclude that such heterogeneity among loci should be systematically integrated into demographic inferences of the divergence process, even between incompletely reproductively isolated populations.

Other Biological Approaches to OCD

2012 ◽  
Author(s):  
Nicole C. R. McLaughlin ◽  
Benjamin D. Greenberg
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Response To Treatment ◽  
History Of ◽  
Key Issues ◽  
Term Management ◽  
Deep Brain

Interest in psychiatric neurosurgery has waxed and waned since the 1930s. This chapter reviews the history of these methods, with a focus on OCD. This review of lesion procedures and deep brain stimulation includes neuropsychological and neuroimaging research in the context of putative neurocircuitry underlying symptoms and response to treatment. The chapter highlights how an abundance of caution is needed, as well as key issues in long-term management of patients so treated.

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.

scholarly journals Molecular and Biological Characterisation of Turnip mosaic virus Isolates Infecting Poppy (Papaver somniferum and P. rhoeas) in Slovakia

Viruses ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 430 ◽  
Author(s):  
Miroslav Glasa ◽  
Katarína Šoltys ◽  
Lukáš Predajňa ◽  
Nina Sihelská ◽  
Slavomíra Nováková ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Phylogenetic Analyses ◽  
Molecular Data ◽  
Turnip Mosaic Virus ◽  
Biological Assays ◽  
Genetic Complexity ◽  
The World ◽  
History Of ◽  
Virus Isolates

In recent years, the accumulated molecular data of Turnip mosaic virus (TuMV) isolates from various hosts originating from different parts of the world considerably helped to understand the genetic complexity and evolutionary history of the virus. In this work, four complete TuMV genomes (HC9, PK1, MS04, MS15) were characterised from naturally infected cultivated and wild-growing Papaver spp., hosts from which only very scarce data were available previously. Phylogenetic analyses showed the affiliation of Slovak Papaver isolates to the world-B and basal-B groups. The PK1 isolate showed a novel intra-lineage recombination pattern, further confirming the important role of recombination in the shaping of TuMV genetic diversity. Biological assays indicated that the intensity of symptoms in experimentally inoculated oilseed poppy are correlated to TuMV accumulation level in leaves. This is the first report of TuMV in poppy plants in Slovakia.

New and modern history of the Arab world

2019 ◽  
Author(s):  
Rouben Karapetyan
Keyword(s):  
International Relations ◽  
Historical Development ◽  
Arab World ◽  
Arab Countries ◽  
Modern History ◽  
The Past ◽  
Wide Range ◽  
History Of ◽  
Key Issues ◽  
Oriental Studies

The textbook covers the main events and developments in the recent history of the Arab world. The key issues of the past and present of the major Arab countries are examined. The general patterns, main stages and peculiarities of the historical development of these countries are presented. The work is designed for students of the faculties of “Oriental Studies”, “History” and “International Relations”, as well as wide range of readers interested in the history of the Arab world.

“The unity based on memories of former intimacy is an attempt to warm up at a went out fire…” The letters from V.M. Chernov to O.S. Minor and M.I. Klyaver

2021 ◽  
Vol 2021 (04-1) ◽  
pp. 4-39
Author(s):  
Olga Konovalova ◽  
Vera Fedorova ◽  
Anna Dvoretskaya
Keyword(s):  
Civil War ◽  
Social History ◽  
Russian Revolution ◽  
International Institute ◽  
Warm Up ◽  
History Of ◽  
Key Issues ◽  
Shed Light ◽  
Foreign Delegation

In the publication, O.V. Konovalova, V.I. Fedorova, A.P. Dvoretskaya presented letters 1931-1932 of the leader and theoretician of the party of socialists-revolutionaries V.M. Chernov to a prominent figure of the party O.S. Minor and a representative of Harbin socialists-revolutionaries organization M. I. Klyaver regarding the split of the Foreign delegation of the socialists-revolutionaries. They are preserved in the collection of VM. Chernov of the International Archives and Collections at the International Institute of Social History in Amsterdam. The presented letters help to clarify VM. Chernov’s position on the key issues of the history of the SR party during the Russian revolution, Civil War, and emigration of the 1920s, and also shed light on the deep reasons for the split of the ZD AKP.

Peculiar Whiteness

2021 ◽  
Author(s):  
Justin Mellette
Keyword(s):  
Southern Literature ◽  
White Trash ◽  
Poor Whites ◽  
Thomas Dixon ◽  
Close Proximity ◽  
Disparate Treatment ◽  
History Of ◽  
Poor White ◽  
Key Issues ◽  
Fear And Anxiety

Peculiar Whiteness argues for deeper consideration of the complexities surrounding the disparate treatment of poor whites throughout southern literature and attests to how broad such experiences have been. While the history of prejudice against this group is not the same as the legacy of violence perpetrated against people of color in America, individuals regarded as ‘white trash’ have suffered a dehumanizing process in the writings of various white authors. Poor white characters are frequently maligned as grotesque and anxiety-inducing, especially when they are aligned in close proximity to blacks or with other troubling conditions such as physical difference. Thus, as a symbol, much has been asked of poor whites, and various iterations of the label (e.g., ‘white trash,’ tenant farmers, or even people with a little less money than average) have been subject to a broad spectrum of judgment, pity, compassion, fear, and anxiety. Peculiar Whiteness engages key issues in contemporary critical race studies, whiteness studies, and southern studies, both literary and historical. Through discussions of authors including Charles Chesnutt, Thomas Dixon, Erskine Caldwell, William Faulkner, and Flannery O’Connor, the book analyzes how we see how whites in a position of power work to maintain their status, often by finding ways to re-categorize and marginalize people who might not otherwise have seemed to fall under the auspices or boundaries of ‘white trash.’

scholarly journals The taxonomic history of Indo-Papuan groundsnakes, genus Stegonotus Duméril et al., 1854 (Colubridae), with some taxonomic revisions and the designation of a neotype for S. parvus (Meyer, 1874)

Zootaxa ◽  
2018 ◽  
Vol 4512 (1) ◽  
pp. 1
Author(s):  
CHRISTINE M. KAISER ◽  
HINRICH KAISER ◽  
MARK O’SHEA
Keyword(s):  
New Guinea ◽  
Molecular Data ◽  
The Philippines ◽  
Morphological Data ◽  
Valid Species ◽  
Museum Specimens ◽  
Type Specimens ◽  
History Of ◽  
Original Species ◽  
Species Specific

Since its conceptualization in 1854, 29 species of the colubrid genus Stegonotus have been recognized or described, of which 15 (admiraltiensis, batjanensis, borneensis, cucullatus, derooijae, diehli, florensis, guentheri, iridis, heterurus, melanolabiatus, modestus, muelleri, parvus, poechi) are still considered valid today. Original species descriptions for the members of this genus were published in Dutch, English, French, German, and Italian and, perhaps as a consequence of these polyglot origins, there has been a considerable amount of confusion over which species names should be applied to which populations of Stegonotus throughout its range across Borneo, the Philippines, Wallacea, New Guinea, Australia, and associated archipelagos. In addition, the terminology used to notate characteristics in the descriptions of these forms was not uniform and may have added to the taxonomic confusion. In this paper, we trace in detail the history of the type specimens, the species, and the synonyms currently associated with the genus Stegonotus and provide a basic, species-specific listing of their characteristics, derived from our examination of over 1500 museum specimens. Based on our data, we are able to limit the distribution of S. modestus to the islands of Ambon, Buru, and Seram in the central Moluccas of Indonesian Wallacea. We correct the type locality of S. cucullatus to the Manokwari area on the Bird’s Head Peninsula of West Papua, Indonesian New Guinea and designate a neotype for S. parvus, a species likely to be a regional endemic in the Schouten Archipelago of Cenderawasih Bay (formerly Geelvink Bay), Indonesian New Guinea. We unequivocally identify and explain the problematic localities of the type specimens of S. muelleri and Lycodon muelleri, which currently reside in the same specimen jar. We remove L. aruensis and L. lividum from the synonymy of S. modestus and recognize them as S. aruensis n. comb. and S. lividus n. comb., respectively. We remove S. keyensis and Zamenophis australis from the synonymy of S. cucullatus and recognize them as S. keyensis n. comb. and S. australis n. comb., respectively. We further remove S. reticulatus from the synonymy of S. cucullatus, S. dorsalis from the synonymy of S. diehli, and S. sutteri from the synonymy of S. florensis. We designate lectotypes for S. guentheri, S. heterurus, S. lividus, and S. reticulatus. Lastly, we introduce S. poechi, a valid species not mentioned in the scientific literature since its description in 1924. This brings the diversity in the genus Stegonotus to 22 species. We also caution that in a complex group of organisms like Stegonotus any rush to taxonomic judgment on the basis of molecular and incomplete morphological data sets may perpetuate errors and introduce incongruities. Only through the careful work of connecting type material with museum specimens and molecular data can the taxonomy and nomenclature of complex taxa be stabilized. 

Molecular phylogeny of diploid Hordeum species and incongruence between chloroplast and nuclear datasets

Genome ◽  
2011 ◽  
Vol 54 (12) ◽  
pp. 986-992 ◽  
Author(s):  
Huan Wang ◽  
Dongfa Sun ◽  
Genlou Sun
Keyword(s):  
Evolutionary History ◽  
Nuclear Gene ◽  
Intergenic Spacer ◽  
Molecular Data ◽  
Genome Species ◽  
Different Types ◽  
History Of ◽  
Morphological And Molecular Data ◽  
Hordeum Species ◽  
Eurasian Species

The phylogeny of diploid Hordeum species has been studied using both chloroplast and nuclear gene sequences. However, the studies of different nuclear datasets of Hordeum species often arrived at similar conclusions, whereas the studies of different chloroplast DNA data generally resulted in inconsistent conclusions. Although the monophyly of the genus is well supported by both morphological and molecular data, the intrageneric phylogeny is still a matter of controversy. To better understand the evolutionary history of Hordeum species, two chloroplast gene loci (trnD-trnT intergenic spacer and rps16 gene) and one nuclear marker (thioreoxin-like gene (HTL)) were used to explore the phylogeny of Hordeum species. Two obviously different types of trnD-trnT sequences were observed, with an approximately 210 base pair difference between these two types: one for American species, another for Eurasian species. The trnD-trnT data generally separated the diploid Hordeum species into Eurasian and American clades, with the exception of Hordeum marinum subsp. gussoneanum. The rps16 data also grouped most American species together and suggested that Hordeum flexuosum has a different plastid type from the remaining American species. The nuclear gene HTL data clearly divided Hordeum species into two clades: the Xu + H genome clade and the Xa + I genome clade. Within clades, H genome species were well separated from the Xu species, and the I genome species were well separated from the Xa genome species. The incongruence between chloroplast and nuclear datasets was found and discussed.

scholarly journals Systematic placement of an enigmatic Southeast Asian taxon Eupetes macrocerus and implications for the biogeography of a main songbird radiation, the Passerida

2007 ◽  
Vol 3 (3) ◽  
pp. 323-326 ◽  
Author(s):  
Knud A Jønsson ◽  
Jon Fjeldså ◽  
Per G.P Ericson ◽  
Martin Irestedt
Keyword(s):  
South African ◽  
Plate Tectonics ◽  
Molecular Data ◽  
Sister Taxon ◽  
Long Distance ◽  
Biogeographic History ◽  
Basal Group ◽  
History Of ◽  
Biogeographic Regions ◽  
Wallace’S Line

Biogeographic connections between Australia and other continents are still poorly understood although the plate tectonics of the Indo-Pacific region is now well described. Eupetes macrocerus is an enigmatic taxon distributed in a small area on the Malay Peninsula and on Sumatra and Borneo. It has generally been associated with Ptilorrhoa in New Guinea on the other side of Wallace's Line, but a relationship with the West African Picathartes has also been suggested. Using three nuclear markers, we demonstrate that Eupetes is the sister taxon of the South African genus Chaetops , and their sister taxon in turn being Picathartes , with a divergence in the Eocene. Thus, this clade is distributed in remote corners of Africa and Asia, which makes the biogeographic history of these birds very intriguing. The most parsimonious explanation would be that they represent a relictual basal group in the Passerida clade established after a long-distance dispersal from the Australo-Papuan region to Africa. Many earlier taxonomic arrangements may have been based on assumptions about relationships with similar-looking forms in the same, or adjacent, biogeographic regions, and revisions with molecular data may uncover such cases of neglect of ancient relictual patterns reflecting past connections between the continents.

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