65 research outputs found
Phylogeography of an endangered disjunct herb: long-distance dispersal, refugia and colonization routes
Quaternary glacial cycles appear to have had a consistent role in shaping the genetic diversity and
structure of plant species. Despite the unusual combination of the characteristics of the western Mediterranean–
Macaronesian area, there are no studies that have specifically examined the effects of palaeoclimatic and palaeogeographic
factors on the genetic composition and structure of annual herbs. Astragalus edulis is a disjunct endemic
found in the easternmost Canary Islands and the semi-arid areas of north-eastern Africa and south-eastern Iberian
Peninsula. This endangered species shows no evident adaptations to long-distance dispersal. Amplified fragment
length polymorphism (AFLP) data and plastid DNA sequences were analysed from a total of 360 individuals distributed
throughout the range of this species. The modelled potential distribution of A. edulis under current conditions
was projected over the climatic conditions of the Last Interglacial (130 ka BP) and Last Glacial Maximum (21
ka BP) to analyse changes in habitat suitability and to look for associations between the modelling and genetic
results. Amplified fragment length polymorphism analysis showed clear phylogeographic structure with four distinct
genetic clusters. Approximate Bayesian computation (ABC) models based on plastid DNA sequences indicated a
Middle Pleistocene long-distance dispersal event as the origin of the populations of the Canary Islands. The models
also suggested south-western Morocco as the ancestral area for the species, as well as subsequent colonization of
north-eastern Morocco and the Iberian Peninsula. The data compiled indicated the possibility of the presence of refuge
areas at favourable locations around the High Atlas and Anti-Atlas mountain ranges. Moreover, palaeodistribution
models strongly support the events inferred by ABC modelling and show the potential distribution of the species
in the past, suggesting a putative colonization route.This work has been financed by the Spanish Ministerio
de Ciencia e InnovaciĂłn through the projects CGL2012-
32574 and REN2003-09427, as well as by the Andalusian
ConsejerĂa de InnovaciĂłn, Ciencia y TecnologĂa through
the project RNM1067. The funders had no role in study
design, data collection and analysis, decision to publish
or preparation of the manuscript
Cryptic invasion drives phenotypic changes in central European threespine stickleback
Cryptic invasions are commonly associated with genetic changes of the native species or genetic lineage that the invaders replace. Phenotypic shifts resulting from cryptic invasions are less commonly reported given the relative paucity of historical specimens that document such phenotypic changes. Here, I study such a case in two populations of threespine stickleback from central Europe, comparing contemporary patterns of gene flow with phenotypic changes between historical and contemporary population samples. I find gene flow from an invasive lineage to be associated with significant phenotypic changes, where the degree of phenotypic change corresponds with the level of gene flow that a population receives. These findings underline the utility of combining genetic approaches with phenotypic data to estimate the impact of gene flow in systems where anthropogenic alterations have removed former geographic barriers promoting cryptic invasions
Super-Genotype: Global Monoclonality Defies the Odds of Nature
The ability to respond to natural selection under novel conditions is critical for the establishment and persistence of introduced alien species and their ability to become invasive. Here we correlated neutral and quantitative genetic diversity of the weed Pennisetum setaceum Forsk. Chiov. (Poaceae) with differing global (North American and African) patterns of invasiveness and compared this diversity to native range populations. Numerous molecular markers indicate complete monoclonality within and among all of these areas (FST = 0.0) and is supported by extreme low quantitative trait variance (QST = 0.00065–0.00952). The results support the general-purpose-genotype hypothesis that can tolerate all environmental variation. However, a single global genotype and widespread invasiveness under numerous environmental conditions suggests a super-genotype. The super-genotype described here likely evolved high levels of plasticity in response to fluctuating environmental conditions during the Early to Mid Holocene. During the Late Holocene, when environmental conditions were predominantly constant but extremely inclement, strong selection resulted in only a few surviving genotypes
Gardens of happiness: Sir William Temple, temperance and China
This is the author accepted manuscript. The final version is available from Taylor & Francis via the DOI in this recordSir William Temple, an English statesman and humanist, wrote “Upon the
Gardens of Epicurus” in 1685, taking a neo-epicurean approach to happiness
and temperance. In accord with Pierre Gassendi’s epicureanism, “happiness” is
characterised as freedom from disturbance and pain in mind and body, whereas
“temperance” means following nature (Providence and one’s physiopsychological constitution). For Temple, cultivating fruit trees in his garden was
analogous to the threefold cultivation of temperance as a virtue in the humoral
body (as food), the mind (as freedom from the passions), and the bodyeconomic (as circulating goods) in order to attain happiness. A regimen that was
supposed to cure the malaise of Restoration amidst a crisis of unbridled
passions, this threefold cultivation of temperance underlines Temple’s reception
of China and Confucianism wherein happiness and temperance are highlighted.
Thus Temple’s “gardens of happiness” represent not only a reinterpretation of
classical ideas, but also his dialogue with China.European CommissionLeverhulme Trus
Expanding the Kachemak: Surplus Production and the Development of Multi-Season Storage in Alaska's Kodiak Archipelago
Cod Fishing in Russian America: The Archaeology of a 19th-Century Alutiiq Work Camp on Alaska's Kodiak Island
Herbarium specimens as a source of DNA for AFLP fingerprinting of Phragmites (Poaceae): possibilities and limitations
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