Search results for "endemism"
showing 10 items of 206 documents
Human fascioliasis in Argentina: retrospective overview, critical analysis and baseline for future research
2010
Abstract In Argentina, human fascioliasis has never been adequately analysed, although having a physiography, climate, animal prevalences and lymnaeids similar to those of countries where the disease is endemic such as Bolivia, Peru and Chile. We performed a literature search identifying 58 reports accounting for 619 cases, involving 13 provinces, their majority (97.7%) from high altitudes, in central mountainous areas and Andean valleys, concentrated in Cordoba (430 cases), Catamarca (73), San Luis (29) and Mendoza (28), the remaining provinces being rarely affected. This distribution does not fit that of animal fascioliasis. Certain aspects (higher prevalence in females in a local survey,…
A new species ofLimonium(Plumbaginaceae) from Soqotra (Yemen)
2009
Abstract Limonium guigliae, from the island of Soqotra (Yemen) is described. This new species, close to L. paulayanum differs from it by its size, flower morphology and ecology.
Hybridization between mouse lemurs in an ecological transition zone in southern Madagascar
2009
Hybrid zones in ecotones can be useful model systems for the study of evolutionary processes that shape the distribution and discreteness of species. Such studies could be important for an improved understanding of the complex biogeography of Madagascar, which is renowned for its outstanding degree of small-scale endemism. Certain forest remnants in central Madagascar indicate that transitional corridors across the island could have connected microendemics in different forest types in the past. Evolutionary processes in such corridors are difficult to study because most of these corridors have disappeared due to deforestation in central Madagascar. We studied a hybrid zone in one of the few…
The evolution of substrate differentiation inMinuartiaseriesLaricifoliae(Caryophyllaceae) in the European Alps: In situ origin or repeated colonizati…
2013
Premise of the study Substrate specialization is often considered an important factor in evolutionary diversification. A classic example of divergence related to different substrate types is the dichotomy between calcicole and calcifuge plants on calcareous and siliceous substrates as found in the European Alps. When closely related species with contrasting substrate preferences are found in the same area, it is generally hypothesized that they diverged where they now occur. However, it is possible that Alpine edaphic diversity instead allows the coexistence of related species whose edaphic differentiation took place deeper in the phylogeny, in some other part of the range of their clades. …
The origin of the serpentine endemic Minuartia laricifolia subsp. ophiolitica by vicariance and competitive exclusion.
2013
Serpentine soils harbour a unique flora that is rich in endemics. We examined the evolution of serpentine endemism in Minuartia laricifolia, which has two ecologically distinct subspecies with disjunct distributions: subsp. laricifolia on siliceous rocks in the western Alps and eastern Pyrenees and subsp. ophiolitica on serpentine in the northern Apennines. We analysed AFLPs and chloroplast sequences from 30 populations to examine their relationships and how their current distributions and ecologies were influenced by Quaternary climatic changes. Minuartia laricifolia was divided into four groups with a BAPS cluster analysis of the AFLP data, one group consisted only of subsp. ophiolitica, …
Genetic diversity ofNarcissus tortifolius, an endangered endemic species from Southeastern Spain
2015
AbstractIn this work, we analyzed inter-simple sequence repeat markers from 10 populations (298 individuals) spanning the whole distribution range of the endemic Narcissus tortifolius. We assessed genetic variation levels and distribution by estimates of genetic diversity, analysis of molecular variance (AMOVA), principal coordinates and Bayesian methods. N. tortifolius showed moderate genetic diversity at intrapopulation level and low genetic differentiation of populations. In general, Almerian populations showed slightly higher levels of genetic diversity than Murcian populations. Our results indicate that habitat fragmentation has not caused genetic depauperation in N. tortifolius but di…
Genetic diversity and local population structure in Ambrosina bassii (Araceae, Ambrosineae), a Mediterranean relict species
2009
The effects of habitat fragmentation on the genetic structure of Ambrosina bassii are analyzed. The species, whose reproductive biology is mostly unknown, is the only representative of its genus and tribe and it is endemic to the central Mediterranean area. The selected study area was the island of Sicily, in which wild populations show a wide morphological variability and ecological amplitude. Patterns of within- and among-population genetic diversity in eleven Sicilian populations, occurring in six disjunct areas, were examined by means of allozyme electrophoresis. High levels of genetic diversity were found as shown by the mean expected heterozygosity (He ¼ 0.263), the percentage of poly…
Assessing the genetic diversity ofCentaurea parlatorisgroup (sect.Dissectae, Compositae) in Sicily using isozymes
2011
Abstract The Centaurea parlatoris group belongs to sect. Dissectae and is one of the most taxonomically critical groups in Sicily. The taxa included in it inhabit dry slopes, pastures and rocky places. Some of them are narrow endemics to Sicily, and others to Italy. The great morphological variability at the intrapopulation level has not permitted the creation of an adequate taxonomic scheme. The recent proposal of two new species from Sicily confirms the insufficient knowledge of the taxonomic diversity. This study involves eight Sicilian populations of the C. parlatoris group. Seven loci from nine enzyme systems [isocitrate dehydrogenase (IDH), malate dehydrogenase (MDH), 6-phosphoglucona…
Genetic variations in the endangered Sicilian endemic Brassica rupestris: proposals for a conservation strategy
2012
Brassica rupestris Raf. is a chasmophyte species that includes two subspecies, both endemic to Central-Western Sicily (Italy). Inter-Simple Sequence Repeat (ISSR) markers were used to detect genetic diversity within and among eight populations representative of the species' distribution range. High levels of genetic diversity were revealed both at the population (PPB = 53.88%, HS = 0.212, Sh = 0.309) and at the species level (PPB = 96.55%, HT = 0.307, Sh = 0.464). The correlation between genetic and geographical distances was negative (Mantel test, r = -0.06, P < 0.95). The two subspecies of B. rupestris, subsp. rupestris and subsp. hispida, showed remarkable genetic similarity and molec…
Molecular and morphological evidence for hybridization between endemic Canary Island Convolvulus
2007
Morphological data and molecular data from the chloroplast trnH-psbA region and nuclear ribosomal ITS region are used to test the hypothesis that the problematic Canary Island endemic Convolvulus floridus var. virgatus is a hybrid between the endemic species C. floridus and C. scoparius. Analysis of mean leaf length and width of 58 individuals indicates that accessions referable to C. floridus var. virgatus are intermediate between the parental taxa in leaf dimensions. Direct sequencing of the ITS region of C. scoparius and C. floridus revealed two species-specific ribotypes distinguished by 10 base differences. Examination of ITS chromatograms for putative hybrids revealed polymorphisms at…