Search results for "Holocene"

showing 10 items of 330 documents

STOP 12: Late-glacial and Holocene development of Lake Rāzna as recorded by biostratigraphy

2014

loss on ignitionGeographyKvartāra ģeoloģijapollen analyses:NATURAL SCIENCES::Earth sciences::Exogenous earth sciences::Sedimentology [Research Subject Categories]Glacial periodPhysical geographyBiostratigraphyLoss on ignition:NATURAL SCIENCES::Earth sciences::Exogenous earth sciences::Quaternary geology [Research Subject Categories]HoloceneLate Quaternary Terrestrial Processes, Sediments and History: From Glacial to Postglacial Environments
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Data from: Highly asymmetric fine-scale genetic structure between sexes of African striped mice and indication for condition dependent alternative ma…

2011

Sex-biased dispersal is observed in many taxa, but few studies have compared sex-biased dispersal among and within populations. We addressed the magnitude and habitat dependency of sex-biased dispersal in social African striped mice by separating group-related from population-related genetic variance to understand the contribution of each sex to deme structure. As dispersal over unoccupied habitat is likely to be more costly than dispersal within a population, we predicted that individuals leaving the natal population have a lower body condition, being inferior to heavier territorial individuals. Fine-scale genetic structure was detected in both sexes. Female relatedness decreased continuou…

medicine and health careHoloceneBehavior/Social EvolutionMedicineInbreedingRhabdomys pumilioLife sciences
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Data from: Sympatric diversification vs. immigration: deciphering host-plant specialization in a polyphagous insect, the stolbur phytoplasma vector H…

2013

The epidemiology of vector transmitted plant diseases is highly influenced by dispersal and the host-plant range of the vector. Widening the vector's host range may increase transmission potential, whereas specialization may induce specific disease cycles. The process leading to a vector's host shift and its epidemiological outcome is therefore embedded in the frameworks of sympatric evolution vs. immigration of preadapted populations. In this study, we analyse whether a host shift of the stolbur phytoplasma vector, Hyalesthes obsoletus from field bindweed to stinging nettle in its northern distribution range evolved sympatrically or by immigration. The exploitation of stinging nettle has l…

medicine and health careHoloceneCixiidaestolbur phytoplasma (16SrXII-A group)Convolvulus arvensisHyalesthes obsoletusUrtica dioicaLife SciencesMedicineHost Parasite Interactions
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Data from: Extinction and recolonization of maritime Antarctica in the limpet Nacella concinna (Strebel, 1908) during the last glacial cycle: toward …

2013

Quaternary glaciations in Antarctica drastically modified geographical ranges and population sizes of marine benthic invertebrates and thus affected the amount and distribution of intraspecific genetic variation. Here, we present new genetic information in the Antarctic limpet Nacella concinna, a dominant Antarctic benthic species along shallow ice-free rocky ecosystems. We examined the patterns of genetic diversity and structure in this broadcast spawner along maritime Antarctica and from the peri-Antarctic island of South Georgia. Genetic analyses showed that N. concinna represents a single panmictic unit in maritime Antarctic. Low levels of genetic diversity characterized this population…

medicine and health careHoloceneNacella concinnaApproximate Bayesian ComputationsfungiLife SciencesMedicineglacial refugiaprivate haplotypegeographic locations
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Data from: The dual role of rivers in facilitating or hindering movements of the false heath fritillary butterfly

2016

Background: Species movement responses to landscape structures have been studied using a variety of methods, but movement research is still in need of simple methods that help predicting and comparing movements across structurally different landscapes. We demonstrate how habitat-specific movement models can be used to disentangle causes of differentiated movement patterns in structurally different landscapes and to predict movement patterns in altered and artificial landscapes. In our case study, we studied the role of riparian landscapes to the persistence of the endangered false heath fritillary butterfly (Melitaea diamina) in its newly discovered coastal distribution region in Finland. W…

medicine and health careHoloceneRiparian corridorsHabitat-specific modelsLife SciencesMedicine15. Life on landFalse heath fritillaryCapture-recapture dataMelitaea diaminaMark-recapture data
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Data from: Predator encounters have spatially extensive impacts on parental behaviour in a breeding bird community

2016

Predation risk has negative indirect effects on prey fitness, partly mediated through changes in behaviour. Evidence that individuals gather social information from other members of the population suggests that events in a community may impact the behaviour of distant individuals. However, spatially wide-ranging impacts on individual behaviour caused by a predator encounter elsewhere in a community have not been documented before. We investigated the effect of a predator encounter (hawk model presented at a focal nest) on the parental behaviour of pied flycatchers (Ficedula hypoleuca), both at the focal nest and at nearby nests different distances from the predator encounter. We show that n…

medicine and health careHolocenepredation riskspatial impactLife SciencesMedicineFicedula hypoleuca
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Data from: Disentangling structural genomic and behavioral barriers in a sea of connectivity

2018

Genetic divergence among populations arises through natural selection or drift and is counteracted by connectivity and gene flow. In sympatric populations, isolating mechanisms are thus needed to limit the homogenizing effects of gene flow to allow for adaptation and speciation. Chromosomal inversions act as an important mechanism maintaining isolating barriers, yet their role in sympatric populations and divergence with gene flow is not entirely understood. Here, we revisit the question whether inversions play a role in the divergence of connected populations of the marine fish Atlantic cod, by exploring a unique dataset combining whole-genome sequencing data and behavioral data obtained w…

medicine and health careHolocenesympatric ecotypesAtlantic codbehavioral traitsMedicineLife scienceschromosomal rearrangements
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Data from: Successive invasion-mediated interspecific hybridizations and population structure in the endangered cichlid Oreochromis mossambicus

2013

Hybridization between invasive and native species accounts among the major and pernicious threats to biodiversity. The Mozambique tilapia Oreochromis mossambicus, a widely used freshwater aquaculture species, is especially imperiled by this phenomenon since it is recognized by the IUCN as an endangered taxon due to genetic admixture with O. niloticus an invasive congeneric species. The Lower Limpopo and the intermittent Changane River (Mozambique) drain large wetlands of potentially great importance for conservation of O. mossambicus, but their populations have remained unstudied until today. Therefore we aimed (1) to estimate the autochthonous diversity and population structure among genet…

medicine and health careOreochromis andersoniiHolocenetilapiamtDNAAnthropoceneOreochromis niloticusMedicineGenetic resourceCichlidaeamplified fragment length polymorphism (AFLP)Life sciencesOreochromis mossambicus
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Data from: Gene flow in the European coal tit, Periparus ater (Aves: Passeriformes): low among Mediterranean populations but high in a continental co…

2018

Extant phylogeographic patterns of Palearctic terrestrial vertebrates are generally believed to have originated from glacial range fragmentation. Post-Pleistocene range expansions have led to the formation of secondary contact zones among genetically distinct taxa. For coal tits (Periparus ater), such a contact zone has been localized in Germany. In this study, we quantified gene flow between Fennoscandian and southern European coal tits using a set of 13 microsatellite loci. STRUCTURE analysis revealed four genetic clusters two of these on Mediterranean islands. German populations were genetically admixed but introgression of southern alleles was evident for Fennoscandian populations. In t…

medicine and health carePleistocene to Holoceneisland populationsParidaeMedicinesubspeciesglacial refugiaLife sciencesPeriparus ater
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Data from: Characterisation of microsatellite and SNP markers from Miseq and genotyping-by-sequencing data among parapatric Urophora cardui (Tephriti…

2018

Phylogeographic analyses of the gall fly Urophora cardui have in earlier studies based on allozymes and mtDNA identified small-scale, parapatrically diverged populations within an expanding Western Palearctic population. However, the low polymorphism of these markers prohibited an accurate delimitation of the evolutionary origin of the parapatric divergence. Urophora cardui from the Western Palearctic have been introduced into Canada as biological control agents of the host plant Cirsium arvense. Here, we characterise 12 microsatellite loci with hexa-, penta- and tetra-nucleotide repeat motifs and report a genotyping-by-sequencing SNP protocol. We test the markers for genetic variation amon…

medicine and health careUrophora carduiHoloceneLife SciencesMedicineParapatry
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