Search results for "Gene Flow"
showing 10 items of 177 documents
Species cohesion despite extreme inbreeding in a social spider.
2011
Colonial social spiders experience extreme inbreeding and highly restricted gene flow between colonies; processes that question the genetic cohesion of geographically separated populations and which could imply multiple origins from predecessors with limited gene flow. We analysed species cohesion and the potential for long-distance dispersal in the social spider Stegodyphus dumicola by studying colony structure in eastern South Africa and the cohesion between this population and Namibian populations previously published. Data from both areas were (re)analysed for historic demographic parameters. Eastern South African S. dumicola were closely related to an east Namibian lineage, showing coh…
Effect of cropping systems on species dynamics and gene flow at the landscape level. A modelling approach
2008
International audience
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…
Contextualising the Last Survivors: Population Structure of Marine Turtles in the Dominican Republic.
2013
Nesting by three species of marine turtles persists in the Dominican Republic, despite historic threats and long-term population decline. We conducted a genetic survey of marine turtles in the Dominican Republic in order to link them with other rookeries around the Caribbean. We sequenced a 740bp fragment of the control region of the mitochondrial DNA of 92 samples from three marine turtle species [hawksbill (n = 48), green (n = 2) and leatherback (n = 42)], and incorporated published data from other nesting populations and foraging grounds. The leatherback turtle (Dermochelys coriacea) in the Dominican Republic appeared to be isolated from Awala-Yalimapo, Cayenne, Trinidad and St. Croix bu…
Reproductive isolation among allopatric Drosophila montana populations
2014
An outstanding goal in speciation research is to trace the mode and tempo of the evolution of barriers to gene flow. Such research benefits from studying incipient speciation, in which speciation between populations has not yet occurred, but where multiple potential mechanisms of reproductive isolation (RI: i.e., premating, postmating-prezygotic (PMPZ), and postzygotic barriers) may act. We used such a system to investigate these barriers among allopatric populations of Drosophila montana. In all heteropopulation crosses we found premating (sexual) isolation, which was either symmetric or asymmetric depending on the population pair compared. Postmating isolation was particularly strong in c…
Human Y-chromosome variation in the Western Mediterranean area: Implications for the peopling of the region
2001
Y-chromosome variation was analyzed in a sample of 1127 males from the Western Mediterranean area by surveying 16 biallelic and 4 multiallelic sites. Some populations from Northeastern Europe and the Middle East were also studied for comparison. All Y-chromosome haplotypes were included in a parsimonious genealogic tree consisting of 17 haplogroups, several of which displayed distinct geographic specificities. One of the haplogroups, HG9.2, has some features that are compatible with a spread into Europe from the Near East during the Neolithic period. However, the current distribution of this haplogroup would suggest that the Neolithic gene pool had a major impact in the eastern and central …
Conservation, Spillover and Gene Flow within a Network of Northern European Marine Protected Areas
2013
Published version of an article in the journal: PLoS ONE. Also available from the publisher at: http://dx.doi.org/10.1371/journal.pone.0073388 Open access To ensure that marine protected areas (MPAs) benefit conservation and fisheries, the effectiveness of MPA designs has to be evaluated in field studies. Using an interdisciplinary approach, we empirically assessed the design of a network of northern MPAs where fishing for European lobster (Homarus gammarus) is prohibited. First, we demonstrate a high level of residency and survival (50%) for almost a year (363 days) within MPAs, despite small MPA sizes (0.5-1 km2). Second, we demonstrate limited export (4.7%) of lobsters tagged within MPAs…
Phylogeographic patterns of decapod crustaceans at the Atlantic-Mediterranean transition.
2012
9 páginas, 4 figuras, 3 tablas.
The Pillars of Hercules as a bathymetric barrier to gene flow promoting isolation in a global deep-sea shark (Centroscymnus coelolepis).
2015
Catarino, Diana ... et. al.-- 19 pages, 5 figures, 4 tables, data accessibility http://dx.doi.org/10.5061/dryad.ss368, supporting information http://dx.doi.org/10.1111/mec.13453
Allozyme Similarity in Two Morphologically Distinguishable Populations ofParacentrotus Lividus(Echinodermata) From Distinct Areas of the Mediterranea…
1998
Allozymes ofParacentrotus lividusfrom Palermo Gulf in the northern Sicilian coast (Italy) and from a small body-size population in the western Greek coast (Ionian Sea) were investigated by PAGE. Five of the twenty examined loci were polymorphic(AAT*, ADH*, ME*, PGI*andPGM*)over each population with a polymorphism value of 0–25. Average heterozygosity was equal to 0081 in the Sicilian sample and 0084 in the Greek. Deviations from Hardy-Weinberg equilibrium were significant inME*andPGI*loci (as calculated byy).Nei's (1978) genetic distance (D=0–0025) index described a close identity between the two samples. FSTvalue of polymorphic loci ranged from 0001 to 0029, its mean value (0–008) resultin…