Search results for "MTD"
showing 10 items of 86 documents
Morphology and genetics reveal an intriguing pattern of differentiation at a very small geographic scale in a bird species, the forest thrush Turdus …
2014
12 pages; International audience; Mobile organisms are expected to show population differentiation only over fairly large geographical distances. However, there is growing evidence of discrepancy between dispersal potential and realized gene flow. Here we report an intriguing pattern of differentiation at a very small spatial scale in the forest thrush (Turdus lherminieri), a bird species endemic to the Lesser Antilles. Analysis of 331 individuals from 17 sampling sites distributed over three islands revealed a clear morphological and genetic differentiation between these islands isolated by 40-50 km. More surprisingly, we found that the phenotypic divergence between the two geographic zone…
A study on Pomatoschistus tortonesei Miller 1968 (Perciformes, Gobiidae) reveals the Siculo-Tunisian Strait (STS) as a breakpoint to gene flow in the…
2009
The current genetic structure of P. tortonesei, exclusively inhabiting lagoons, may reflect a Plio-Pleistocene colonisation of an ancestor line which has undergone phases of population decline and expansion, following alternate cooling phases. Regarding the calculation of divergence time, it has been estimated that P. tortonesei seems to be the most recent species within the Pomatoschistus genus. It appears also that the discrepancy of P. tortonesei into two distinct phyletic lineages occurred 0.1 Mya. Recurring shifts in sea level and sea surface temperatures of Mediterranean Sea caused the desiccation of shallower lagoons and the consequent bottleneck phenomena of the brackish populations…
Autosomal microsatellite and mtDNA genetic analysis in Sicily (Italy).
2003
DNA samples from 465 blood donors living in 7 towns of Sicily, the largest island of Italy, have been collected according to well defined criteria, and their genetic heterogeneity tested on the basis of 9 autosomal microsatellite and mitochondrial DNA polymorphisms for a total of 85 microsatellite allele and 10 mtDNA haplogroup frequencies. A preliminary account of the results shows that: a) the samples are genetically heterogeneous; b) the first principal coordinates of the samples are correlated more with their longitude than with their latitude, and this result is even more remarkable when one outlier sample (Butera) is not considered; c) distances among samples calculated from allele an…
Isolation By Distance (IBD) signals in the deep-water rose shrimp Parapenaeus longirostris (Lucas, 1846) (Decapoda, Panaeidae) in the Mediterranean S…
2013
Abstract The identification of boundaries of genetic demes is one of the major goals for fishery management, and few Mediterranean commercial species have not been studied from a genetic point of view yet. The deep-water rose shrimp Parapenaeus longirostris (Lucas, 1846) is one of the most important components of commercial landings in Mediterranean, its fishery aspects have received much attention, regrettably without any concern for the genetic architecture of its populations. The population structure in the central and eastern Mediterranean Sea (captures from six Italian and two Greek landings) has been analysed on the basis of surveys carried out with mitochondrial and AFLP markers. Dat…
Molecular evidence for the presence of cryptic evolutionary lineages in the freshwater copepod genus Hemidiaptomus G.O. Sars, 1903 (Calanoida, Diapto…
2010
The pattern of morphological and mtDNA cytochrome b diversity of three calanoid copepod species belonging to the diaptomid genus Hemidiaptomus has been investigated with the aim of checking the reliability of the morphological characters currently used for species identification, and the possible presence of cryptic taxa. A sharply different molecular structuring has been observed in the studied species: while Hemidiaptomus amblyodon exhibits a remarkable constancy throughout the European range of its distribution area (maximum inter-populations cytochrome b divergence of 3%), observed distances between presumed conspecific lineages of Hemidiaptomus gurneyi (maximum divergence of 21.5%) and…
Genetic variability and population structuring in the European Lanner Falcon Falco biarmicus feldeggii
2019
We analysed variation in 10 polymorphic microsatellites and a variable portion of control region of mtDNA in 24 specimens from 3 populations of European Lanner Falcon Falco biarmicus feldeggii living in Sicily, continental Italy and the Balkan area to assess species' genetic diversity and population structure in the poorly investigated range of this threatened subspecies. We considered also a dataset of previously published mtDNA sequences of the other Lanner Falcon subspecies and of Hierofalco subgenus members (F. cherrug, F. rusticolus and F. jugger) to outline the genetic variation in the region on a wide-ranging basis. Regard with mtDNA we identified 6 haplotypes from our 24 European La…
One Species, Hundreds of Subspecies? New Insight into the Intraspecific Classification of the Old World Swallowtail (Papilio machaon Linnaeus , 1758)…
2022
The Old World swallowtail Papilio machaon Linnaeus, 1758 is one of the most well-known and most characteristic members of the family Papilionidae. Over the past two centuries, the butterfly has been the subject of many studies. P. machaon is characterised by a tendency to change the wing colour pattern. In turn, due to the great interest of collectors and amateur entomologists, these studies have been converted into the description of over 100 colour forms, aberrations and subspecies. In this study, mitochondrial DNA (mtDNA), 16S rDNA and cytochrome b sequences were used to examine the correlation between the intraspecific classification and genetic structure of P. machaon. The study used 8…
Facies Architecture and Evolution of a Cretaceous, Tectonically-Controlled, Carbonate Slope from Western Sicily (Italy)
2018
The stratigraphic architecture of a Cretaceous carbonate slope from north western Sicily (Italy) has been reconstructed on the basis of detailed field sections. The wire cut walls of a number of quarries that extract the Cretaceous limestones as ornamental stones allowed the mapping of the stratal architecture and lithologies at various scales. The vertical and lateral facies relationships in this about 1000 m thick depositional system account for a complex sedimentary dynamics along a carbonate platform escarpment that was strongly influenced by syn-sedimentary transtensional tectonics associated to magmatism. Although the original relationships with the carbonate platform were obscured by…
Two end-members of carbonate slope evolution during the Late Cretaceous in the peri-Tethyan domain (Western Sicily and Southern Albania)
2019
Climatic and tectonic processes are major mechanisms influencing tropical carbonate platform development, sediment production and sediment export. Mass transport deposits (including slides, slumps and debrites) and calciturbidites are some of the sediment export products resulting from the interplay of aforementioned redeposition mechanisms. They reflect distinct variations in both production and export of sediments from the carbonate factories. The gravitary export deposits provide information on their sediment source and result in sedimentary sequences with specific porosity / permeability properties prone to host hydrocarbon resources. Climate-controlled sea-level variations are well-con…
Slope Failures and MTDs along a Cretaceous Escarpment in Western Sicily (Italy)
2018
In the last decades, many contributions have examined the Mass Transport Deposits (MTDs) in both modern and ancient examples for the comprehension of the sedimentary dynamics along the carbonate escarpments. Such sedimentary bodies have a great economic significance, since they are widely considered prone to the development of petroleum systems. In particular, MTDs from Cretaceous escarpments are well known from many regions of the world, since they are typically rich in rudists aragonite fragments determining high percentages of porosity. In these respect the deep knowledge on the facies architecture of these depositional systems is of broad interest as can offer examples for the predictio…