| 1. |
- Buerki, Sven, et al.
(författare)
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An evaluation of new parsimony-based versus parametric inference methods in biogeography : a case study using the globally distributed plant family Sapindaceae
- 2011
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Ingår i: Journal of Biogeography. - : Wiley. - 0305-0270 .- 1365-2699. ; 38:3, s. 531-550
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Tidskriftsartikel (refereegranskat)abstract
- Aim Recently developed parametric methods in historical biogeography allow researchers to integrate temporal and palaeogeographical information into the reconstruction of biogeographical scenarios, thus overcoming a known bias of parsimony-based approaches. Here, we compare a parametric method, dispersal-extinction-cladogenesis (DEC), against a parsimony-based method, dispersal-vicariance analysis (DIVA), which does not incorporate branch lengths but accounts for phylogenetic uncertainty through a Bayesian empirical approach (Bayes-DIVA). We analyse the benefits and limitations of each method using the cosmopolitan plant family Sapindaceae as a case study. Location World-wide. Methods Phylogenetic relationships were estimated by Bayesian inference on a large dataset representing generic diversity within Sapindaceae. Lineage divergence times were estimated by penalized likelihood over a sample of trees from the posterior distribution of the phylogeny to account for dating uncertainty in biogeographical reconstructions. We compared biogeographical scenarios between Bayes-DIVA and two different DEC models: one with no geological constraints and another that employed a stratified palaeogeographical model in which dispersal rates were scaled according to area connectivity across four time slices, reflecting the changing continental configuration over the last 110 million years. Results Despite differences in the underlying biogeographical model, Bayes-DIVA and DEC inferred similar biogeographical scenarios. The main differences were: (1) in the timing of dispersal events - which in Bayes-DIVA sometimes conflicts with palaeogeographical information, and (2) in the lower frequency of terminal dispersal events inferred by DEC. Uncertainty in divergence time estimations influenced both the inference of ancestral ranges and the decisiveness with which an area can be assigned to a node. Main conclusions By considering lineage divergence times, the DEC method gives more accurate reconstructions that are in agreement with palaeogeographical evidence. In contrast, Bayes-DIVA showed the highest decisiveness in unequivocally reconstructing ancestral ranges, probably reflecting its ability to integrate phylogenetic uncertainty. Care should be taken in defining the palaeogeographical model in DEC because of the possibility of overestimating the frequency of extinction events, or of inferring ancestral ranges that are outside the extant species ranges, owing to dispersal constraints enforced by the model. The wide-spanning spatial and temporal model proposed here could prove useful for testing large-scale biogeographical patterns in plants.
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| 2. |
- Buerki, Sven, et al.
(författare)
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Phylogeny and circumscription of Sapindaceae revisited : molecular sequence data, morphology and biogeography support recognition of a new family, Xanthoceraceae
- 2010
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Ingår i: Plant Ecology and Evolution. - : Agentschap Plantentuin Meise. - 2032-3913 .- 2032-3921. ; 143:2, s. 148-159
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Tidskriftsartikel (refereegranskat)abstract
- Background and aims Recent studies have adopted a broad definition of Sapindaceae that includes taxa traditionally placed in Aceraceae and Hippocastanaceae, achieving monophyly but yielding a family difficult to characterize and for which no obvious morphological synapomorphy exists. This expanded circumscription was necessitated by the finding that the monotypic, temperate Asian genus Xanthoceras, historically placed in Sapindaceae tribe Harpullieae, is basal within the group. Here we seek to clarify the relationships of Xanthoceras based on phylogenetic analyses using a dataset encompassing nearly 3/4 of sapindaceous genera, comparing the results with information from morphology and biogeography, in particular with respect to the other taxa placed in Harpullieae. We then re-examine the appropriateness of maintaining the current broad, morphologically heterogeneous definition of Sapindaceae and explore the advantages of an alternative family circumscription. Methods Using 243 samples representing 104 of the 142 currently recognized genera of Sapindaceae s. lat. (including all in Harpullieae), sequence data were analyzed for nuclear (ITS) and plastid (matK, rpoB, trnD-trnT, trnK-matK, trnL-trnF and trnS-trnG) markers, adopting the methodology of a recent family-wide study, performing single-gene and total evidence analyses based on maximum likelihood (ML) and maximum parsimony (MP) criteria, and applying heuristic searches developed for large datasets, viz, a new strategy implemented in RAxML (for ML) and the parsimony ratchet (for MP). Bootstrap analyses were performed for each method to test for congruence between markers. Key results Our findings support earlier suggestions that Harpullieae are polyphyletic: Xanthoceras is confirmed as sister to all other sampled taxa of Sapindaceae s. lat.; the remaining members belong to three other clades within Sapindaceae s. lat., two of which correspond respectively to the groups traditionally treated as Aceraceae and Hippocastanaceae, together forming a clade sister to the largely tropical Sapindaceae s. str., which is monophyletic and morphologically coherent provided Xanthoceras is excluded. Conclusion To overcome the difficulties of a broadly circumscribed Sapindaceae, we resurrect the historically recognized temperate families Aceraceae and Hippocastanaceae, and describe a new family, Xanthoceraceae, thus adopting a monophyletic and easily characterized circumscription of Sapindaceae nearly identical to that used for over a century.
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| 3. |
- De Paz Urueña, Rafael, et al.
(författare)
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Momate. Moderniser la formation sur les Energies Renouvelables (ER) au Maghreb : Transfer de l'expérience
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Le projet vise à développer une formation de type DUT (Diplôme Universitaire de Technologie) en ingénierie des Energies Renouvelables et à soutenir l'émergence de technopoles spécialisées dans les Energies Renouvelables. L'objectif est de développer des compétences permettant d'acquérir des connaissances de base sur la production d'électricité à partir d'énergies renouvelables (éolienne, solaire, photovoltaïque, etc.). El proyecto pretende desarrollar un programa de formación como el DUT (Diplôme Universitaire de Technologie) en ingeniería de Energías Renovables y apoyar la aparición de tecnopolos especializados en Energías Renovables. Para ello se pretende desarrollar competencias que permitan adquirir conocimientos básicos sobre la producción de energía eléctrica a partir de energías renovables (eólica, solar, fotovoltaica, etc.)
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| 4. |
- Kebe, Khadim, et al.
(författare)
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Global phylogeography of the insect pest Callosobruchus maculatus (Coleoptera: Bruchinae) relates to the history of its main host, Vigna unguiculata
- 2017
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Ingår i: Journal of Biogeography. - : Wiley. - 0305-0270 .- 1365-2699. ; 44:11, s. 2515-2526
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Tidskriftsartikel (refereegranskat)abstract
- Aim: The seed beetle Callosobruchus maculatus is an important tropical and subtropical pest of legumes distributed world-wide. Archaeological evidence suggests an African origin with later world-wide invasion facilitated by the last centuries' legume trading and exchange. To date, no studies could identify the routes or timing of dispersal of the species. Here, we investigate the global phylogeography of this pest to shed light on the main inter-continental dispersal routes that led to it becoming a cosmopolitan pest. Location: World-wide.Methods: We sampled seed beetles over a large fraction of the species' range and sequenced one nuclear and three mitochondrial loci. Using this data, we estimated spatio-temporal phylogeographical reconstructions, and the demographic history of the species. We also used our dataset to evaluate the effect of panmixia on Bayesian demographic estimations.Results: Callosobruchus maculatus exhibited regional and continental genetic structure, with the highest genetic diversity found in Africa. Our discrete Bayesian phylogeographical approach indicated that the species first dispersed to Asia and then colonized the pantropical belt. The three methods used for inferring the demographic history of C. maculatus indicated a recent demographic expansion in the world-wide dataset, as well as in the subset restricted to African samples. Such a signal was, however, not observed in the subset composed of Asian specimens. This demographic expansion occurred in the Holocene and is likely explained by the spread of cowpea and other host legumes across and out of Africa.Main conclusions: The inferred dispersal routes support the idea that the evolutionary history of C. maculatus relates to the trade of its main host plant, Vigna unguiculata. Human-mediated processes appear to have shaped the global genetic structure of this pest. As a methodological implication, we demonstrate that coalescent-based demographic reconstructions can be erroneous if the dataset violates the assumption of panmixia.
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| 5. |
- Kenyon, Sarah G., et al.
(författare)
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Uncovering Cryptic Parasitoid Diversity in Horismenus (Chalcidoidea, Eulophidae)
- 2015
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:9
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Tidskriftsartikel (refereegranskat)abstract
- Horismenus parasitoids are an abundant and understudied group of eulophid wasps found mainly in the New World. Recent surveys based on morphological analyses in Costa Rica have quadrupled the number of named taxa, with more than 400 species described so far. This recent revision suggests that there is still a vast number of unknown species to be identified. As Horismenus wasps have been widely described as parasitoids of insect pests associated with crop plants, it is of high importance to properly establish the extant diversity of the genus, in order to provide biological control practitioners with an exhaustive catalog of putative control agents. In this study, we first collected Horismenus wasps from wild Phaseolus bean seeds in Central Mexico and Arizona to assess the genetic relatedness of three morphologically distinct species with overlapping host and geographical ranges. Sequence data from two nuclear and two mitochondrial gene regions uncovered three cryptic species within each of the three focal species (i.e., H. missouriensis, H. depressus and H. butcheri). The monophyly of each cryptic group is statistically supported (except in two of them represented by one single tip in which monophyly cannot be tested). The phylogenetic reconstruction is discussed with respect to differences between gene regions as well as likely reasons for the differences in variability between species.
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