39 research outputs found
Integration of new and revised chronological data to constrain the terrace evolution of the Danube River (Gerecse Hills, Pannonian Basin)
Terrace ages deduced from diverse geochronological records yielded inconsistent data in the Danube valley in
Hungary. The problem of discrepancies in the different chronological datasets has to be resolved before the Quaternary
tectonic and climatic processes leading to valley incision and terrace formation may be properly evaluated.
To establish a more robust chronology of the Danube valley in Hungary, new cosmogenic nuclide- (10Be depth
profiles, 26Al/10Be burial durations and burial depth profile) and luminescence-based (pIRIR290) terrace ages
were acquired and compared to revised paleontological and published U/Th and magnetostratigraphic data. All
the applied geo-chronometers led to concordant terrace ages, with the exception of the U/Th method applied on
travertine deposits covering terraces. U/Th ages predating the last interglacial manifest a bias towards younger
ages, and so they were ignored in relation to the quantification of terrace ages. As a result, terrace ages from
the Late Pliocene to Late Pleistocene were settled. With regard to data from the Middle Pleistocene onwards, the
combination of diverse methodologies led to a tighter bracketing of terrace ages than would be possible using
a single dating method. The modelling of cosmogenic 26Al and 10Be concentrations enabled to derive surface
denudation rates and their combination with paleontological data also allowed us to decide between diverse
landscape evolution scenarios
Diverse responses of common vole (Microtus arvalis) populations to Late Glacial and Early Holocene climate changes – Evidence from ancient DNA
The harsh climatic conditions during the Last Glacial Maximum (LGM) period have been considered the cause of local extinctions and major faunal reorganizations that took place at the end of the Pleistocene. Recent studies have shown, however, that in addition many of these ecological events were associated with abrupt climate changes during the so-called Late Glacial and the Pleistocene/Holocene transition. Here we used ancient DNA to investigate the impact of those changes on European populations of temperate vole species (Microtus arvalis). The genetic diversity of modern populations and the fossil record suggests that the species may have survived cold episodes, like LGM, not only in the traditional Mediterranean glacial refugia but also at higher latitudes in cryptic northern refugia located in Central France, the northern Alps as well as the Carpathians. However, the details of the post-glacial recolonization and the impact of the Late Glacial and Early Holocene climate changes on the evolutionary history of the common vole remains unclear. To address this issue, we analysed mtDNA cytochrome b sequences from more than one hundred common vole specimens from 36 paleontological and archaeological sites scattered across Europe. Our data suggest that populations from the European mid- and high latitudes suffered a local population extinction and contraction as a result of Late Glacial and Early Holocene climate and environmental changes. The recolonization of earlier abandoned areas took place in the Mid- to Late Holocene. In contrast, at low latitudes, in Northern Spain there was a continuity of common vole populations. This indicates different responses of common vole populations to climate and environmental changes across Europe and corroborates the hypothesis that abrupt changes, like those associated with Younger Dryas and the Pleistocene/Holocene transition, had a significant impact on populations at the mid- and high latitudes of Europe
Post-glacial colonisation of Europe by the wood mouse, Apodemus sylvaticus : evidence of a northern refugium and dispersal with humans
The wood mouse Apodemus sylvaticus is an opportunistic rodent that is found throughout most of
the European mainland. It is present on many islands around the margins of the continent and in
northern Africa. The species has been the subject of previous phylogeographic studies but these
have focussed on the more southerly part of its range. A substantial number of new samples,
many of them from the periphery of the species’ range, contribute to an exceptional dataset
comprising 981 mitochondrial cytochrome b sequences. These new data provide sufficient
resolution to transform our understanding of the species’ survival through the last glaciation and
its subsequent re-colonisation of the continent. The deepest genetic split we found is in
agreement with previous studies and runs from the Alps to central Ukraine, but we further
distinguish two separate lineages in wood mice to the north and west of this line. It is likely that
this part of Europe was colonised from two refugia, putatively located in the Iberian peninsula and
the Dordogne or Carpathian region. The wood mouse therefore joins the growing number of
species with extant populations that appear to have survived the Last Glacial Maximum in
northern refugia, rather than solely in traditionally recognised refugial locations in the southern
European peninsulas. Furthermore, the existence of a northern refugium for the species was
predicted in a study of mitochondrial variation in a specific parasite of the wood mouse,
demonstrating the potential value of data from parasites to phylogeographic studies. Lastly, the
presence of related haplotypes in widely disparate locations, often on islands or separated by
substantial bodies of water, demonstrates the propensity of the wood mouse for accidental
human-mediated transport
Contrasting and congruent patterns of genetic structuring in two Microtus vole species using museum specimens
The common vole (Microtus arvalis) and the field vole (Microtus agrestis) are morphologically similar species but are ecological distinctive and differ in the details of their evolutionary history as revealed by mitochondrial DNA (mtDNA). The aim of this study is to describe patterns of genetic variability using microsatellite markers in populations of the common and field vole in Poland using museum specimens, to assess the degree of congruence with mtDNA variation and thereby determine the factors that influence current patterns of gene flow. We genotyped 190 individuals of the common vole at 11 loci and 190 individuals of the field vole at 13 loci. Overall differentiation based on F ST was higher for the common vole than in the field vole. We detected a significant isolation by distance pattern for both species. Bayesian analysis in STRUCTURE identified Eastern and Western geographic groups in Poland based on microsatellites for both species. The location of river barriers is likely to be the main factor in these partitions. The eastern-western subdivision with microsatellites does not coincide with the distribution of mtDNA lineages for either species. Unlike previous studies in the common and field vole elsewhere in Europe, we found no evidence of reproductive isolation between the mtDNA lineages of these species at their contact zones in Poland. This study highlights the different roles of evolutionary history and landscape in shaping contemporary genetic structure in voles in Poland
Taxonomic study of the dormice (Gliridae, Mammalia) fauna from the late Early Pleistocene Somssich Hill 2 locality (Villány Hills, South Hungary) and its palaeoecological implications
Th e Somssich Hill 2 is one of the richest Early Pleistocene vertebrate localities of Hungary.
Four dormice species were distinguished from this site: Glis sackdillingensis, G. minor, Muscardinus
dacicus, and Dryomimus eliomyoides. Th e age of the fauna is considered approximately 900
ka, and so, this is the last known occurrence of D. eliomyoides. So far, this species was known only
from Late Pliocene to middle Early Pleistocene sediments. Based on morphometrical analysis of
Glis material from 7 Pliocene and Pleistocene localities, the smaller form (G. minor) occurred until
the Holsteinian (MIS 11). According to the morphotype analysis of the fossil and recent Muscardinus
M1
presented in this study, morphologically M. dacicus is very similar to a morphotype of M.
avellanarius. Although dormice are relatively rare fossils, these animals could have important role
in the reconstruction of the past environments. On the basis of dormice fauna, three periods were
recognized here, which have been characterized by shrubby or forested vegetation during the period
represented by the sediments of Somssich Hill 2 locality. With 13 fi gures and 4 tables
Data for: Microtus (Microtus) nivaloides from the Somssich Hill 2 site (southern Hungary): an Early Pleistocene forerunner of modern ’true’ Microtus voles revealed by morphometric analyses
Supplementary Table 1. The resulting p-values of the normality tests in the case of four recent vole species and fossil material from the Somssich Hill 2, Villány 6, Villány 8, and Kövesvárad sites.
Supplementary Table 2. Linear morphometric measurements (in mm) for each studied specimen.
Supplementary Table 3. Uncentered and unscaled raw coordinates (prior to the Procrustes superimposition) for each studied specimen
Lower Jurassic stable isotope stratigraphy (carbon, oxygen and nitrogen) in the Mediterranean Tethys (Umbria-Marche and subbetic basins)
Dottorato di ricerca in scienze geologiche. 10. ciclo. Relatore Guido Parisi Coordinatore G. Paolo PialliConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal
Integration of new and revised chronological data to constrain the terrace evolution of the Danube River (Gerecse Hills, Pannonian Basin)
International audienc