Approximate Bayesian Computation Reveals the Crucial Role of Oceanic Islands for the Assembly of Continental Biodiversity

The perceived low levels of genetic diversity, poor interspecific competitive and defensive ability, and loss of dispersal capacities of insular lineages have driven the view that oceanic islands are evolutionary dead ends. Focusing on the Atlantic bryophyte flora distributed across the archipelagos of the Azores, Madeira, the Canary Islands, Western Europe, and northwestern Africa, we used an integrative approach with species distribution modeling and population genetic analyses based on approximate Bayesian computation to determine whether this view applies to organisms with inherent high dispersal capacities. Genetic diversity was found to be higher in island than in continental populations, contributing to mounting evidence that, contrary to theoretical expectations, island populations are not necessarily genetically depauperate. Patterns of genetic variation among island and continental populations consistently fitted those simulated under a scenario of de novo foundation of continental populations from insular ancestors better than those expected if islands would represent a sink or a refugium of continental biodiversity. We, suggest that the northeastern Atlantic archipelagos have played a key role as a stepping stone for transoceanic migrants. Our results challenge the traditional notion that oceanic islands are the end of the colonization road and illustrate the significant role of oceanic islands as reservoirs of novel biodiversity for the assembly of continental flora

Orações adverbiais reduzidas de gerúndio: o ensino do português e a perspectiva da gramática discursivofuncional

Esta pesquisa tem como objetivo central discutir o modo como são tratadas as orações adverbiais reduzidas de gerúndio pelas gramáticas prescritivas e pelos livros didáticos, orientados pelos Parâmetros Curriculares Nacionais (PCNs), com a finalidade de verificar em que grau essa abordagem se aproxima ou se distancia da descrição deste tipo de adverbial no uso cotidiano. Para tanto, foram utilizados os fundamentos metodológicos da Gramática Discursivo-Funcional (HENGEVELD e MACKENZIE, 2008), verificando-se como tais embasamentos podem contribuir para que se faça uma abordagem mais ampla das orações adverbiais reduzidas de gerúndio, levando os alunos à reflexão sobre o uso e o funcionamento da língua. Para a análise dos dados, foram utilizadas ocorrências de uso real extraídas da mídia virtual que compõe a esfera jornalística. Os dados revelam que, dependendo da situação comunicativa em que estão inseridas, elas podem autorizar mais de uma interpretação, possíveis de serem recuperadas pela intuição do interlocutor por meio do próprio contexto; também revelam que as orações adverbiais reduzidas de gerúndio possuem sujeito correferencial ao da oração principal, são orações factuais e, geralmente, apresentam-se como estadode-coisas

Controlling Population Evolution in the Laboratory to Evaluate Methods of Historical Inference

Natural populations of known detailed past demographic history are extremely valuable to evaluate methods of historical inference, yet are extremely rare. As an alternative approach, we have generated multiple replicate microsatellite data sets from laboratory-cultured populations of a gonochoric free-living nematode, Caenorhabditis remanei, that were constrained to pre-defined demographic histories featuring different levels of migration among populations or bottleneck events of different magnitudes. These data sets were then used to evaluate the performances of two recently developed population genetics methods, BayesAss+, that estimates recent migration rates among populations, and Bottleneck, that detects the occurrence of recent bottlenecks. Migration rates inferred by BayesAss+ were generally over-estimates, although these were often included within the confidence interval. Analyses of data sets simulated in-silico, using a model mimicking the laboratory experiments, produced less biased estimates of the migration rates, and showed increased efficiency of the program when the number of loci and sampled genotypes per population was higher. In the replicates for which the pre-bottleneck laboratory-cultured populations did not significantly depart from a mutation/drift equilibrium, an important assumption of the program Bottleneck, only a portion of the bottleneck events were detected. This result was confirmed by in-silico simulations mirroring the laboratory bottleneck experiments. More generally, our study demonstrates the feasibility, and highlights some of the limits, of the approach that consists in generating molecular genetic data sets by controlling the evolution of laboratory-reared nematode populations, for the purpose of validating methods inferring population history

Phylogeography of Gonioctena pallida

info:eu-repo/semantics/nonPublishe

Phylogeography of leaf beetles at different geographic scales

info:eu-repo/semantics/nonPublishe

Comparative phylogeography of two montane leaf beetles in Europe

info:eu-repo/semantics/nonPublishe

Phylogénie du genre Gonioctena (Coleoptera; Chrysomelidae) basée sur des caractères moléculaires (allozymes et séquences d'ADN mitochondrial). Evolution des associations spécifiques avec les plantes hôtes et de la défense des larves

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe