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| Registros recuperados: 50 | |
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| Allen, Craig R; U.S. Geological Survey, Nebraska Cooperative Fish and Wildlife Research Unit; allencr@unl.edu; Holling, C. S.; Department of Zoology, University of Florida; holling@zoo.ufl.edu. |
| We present a conceptual framework that explores some of the forces creating innovation and novelty in complex systems. Understanding the sources of variability and novelty may help us better understand complex systems. Understanding complex phenomena such as invasions, migration, and nomadism may provide insight into the structure of ecosystems and other complex systems, and aid our attempts to cope with and mitigate these phenomena, in the case of invasions, and better understand and or predict them. Our model is broadly applicable to ecological theory, including community ecology, resilience, restoration, and policy. Characterizing the link between landscape change and the composition of species communities may help policymakers in their decision-making... |
| Tipo: Peer-Reviewed Insight |
Palavras-chave: Adaptation; Cross-scale; Extinction; Innovation; Invasion; Speciation. |
| Ano: 2010 |
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| Almaca, Carlos. |
| Coming from Oriental Asia and Siberia, the Cyprinidae reached the Iberic Peninsula probably at the end of the Oligocene. Their populations bore speciation processes which led to the formation of a fauna rich in endemic species and subspecies. Populations of two of the genera Barbus and Pseudophoxinus reached Northwestern African forming there several endemic species. Concerning the speciation forms, it is probable that the allopatric form, whether by foundation effect or by subdivision, played an important part. Pyrenees and Mediterranean Sea settled probably efficient barriers for the Iberic Cyprinidae isolation. The present geographical repartition of Cyprinidae in Iberic Peninsula suggests that altitude lines and glaciations which reached the north of... |
| Tipo: Text |
Palavras-chave: Portugal; Spain; Cyprinidae; Biogeography; Speciation. |
| Ano: 1976 |
URL: http://archimer.ifremer.fr/doc/1976/publication-1997.pdf |
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| Auvinet, Juliette; Graça, Paula; Dettai, Agnès; Amores, Angel; Postlethwait, John H.; Detrich, H. William; Ozouf-costaz, Catherine; Coriton, Olivier; Higuet, Dominique. |
| Background Chromosomal rearrangements are thought to be an important driving force underlying lineage diversification, but their link to speciation continues to be debated. Antarctic teleost fish of the family Nototheniidae (Notothenioidei) diversified in a changing environmental context, which led to ecological, morphological, and genetic differentiation among populations. In addition, extensive chromosomal repatterning accompanied species divergence in several clades. The most striking karyotypic changes involved the recent species radiation (about 10 My) of the genus Trematomus, with chromosomal pair numbers ranging between 29 and 12. These dramatic reductions in chromosome number resulted mostly from large-scale chromosome fusions. Multiple centric... |
| Tipo: Text |
Palavras-chave: BAC-FISH; Chromosomal painting; Chromosomal rearrangements; Chromosomal structural units; Chromosomal synteny; Nototheniidae; Speciation. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00615/72731/71831.pdf |
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| Boluda, C.G.; Rico, V.J.; Divakar, P.K.; Nadyeina, O.; Myllys, L.; McMullin, R.T.; Zamora, J.C.; Scheidegger, C.; Hawksworth, D.L.. |
| In many lichen-forming fungi, molecular phylogenetic analyses lead to the discovery of cryptic species within traditional morphospecies. However, in some cases, molecular sequence data also questions the separation of phenotypically characterised species. Here we apply an integrative taxonomy approach ‒ including morphological, chemical, molecular, and distributional characters ‒ to re-assess species boundaries in a traditionally speciose group of hair lichens, Bryoria sect. Implexae. We sampled multilocus sequence and microsatellite data from 142 specimens from a broad intercontinental distribution. Molecular data included DNA sequences of the standard fungal markers ITS, IGS, GAPDH, two newly tested loci (FRBi15 and FRBi16), and SSR frequencies from 18... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Chemotypes; Cryptic species; Haplotypes; Incomplete lineage sorting; Integrative taxonomy; Microsatellites; Speciation; Species concepts. |
| Ano: 2019 |
URL: http://www.repository.naturalis.nl/record/660277 |
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| Bonilla-Rivero,Ana; López-Rojas,Héctor. |
| We conducted a phylogeographic analysis of the genus Gephyrocharaxin Venezuela to evaluate geomorphologic evidence for the formation of the country's main watersheds and to establish a biogeographical hypothesis of possible diversification mechanisms of the Neotropical freshwater fish fauna. We assayed eight enzyme systems and general proteins to estimate genetic variability (H, P), intraspecific structuring in several Gephyrocharax valencia and G. venezuelae populations (FIS, FIT, and FST), and a phylogenetic approach for the three species of Gephyrocharax in Venezuela, using Corynopoma riisei as the external group. Fourteen presumptive lociindicate that populations of the three species of Gephyrocharaxanalyzed show a clear genetic inter-specific... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Isoenzymes; Speciation; Venezuela; Vicariance. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000300487 |
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| Briant, Nicolas; Chouvelon, Tiphaine; Martinez, Laura; Brach-papa, Christophe; Chiffoleau, Jean-francois; Savoye, N.; Sonke, J.; Knoery, Joel. |
| Marine mercury (Hg) concentrations have been monitored in the French coastline for the last half a century using bivalves. The analyses presented in this study concerned 192 samples of bivalves (mussels: Mytilus edulis and Mytilus galloprovincialis and oysters: Crassostrea gigas and Isognomon alatus) from 77 sampling stations along the French coast and in the French Antilles sea. The goals of this study were to assess MeHg levels in various common bivalves from French coastline, and to identify possible geographic, taxonomic or temporal variations of concentrations. We show that the evolution of methylmercury (MeHg) concentrations covary with total mercury (HgT) concentrations. Moreover, in most of the study sites, HgT concentrations have not decreased... |
| Tipo: Text |
Palavras-chave: Mercury; Methylmercury; France; Bivalves; Speciation. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00353/46465/46398.pdf |
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| Bustamante, Paco; Lahaye, V; Durnez, C; Churlaud, C; Caurant, Florence. |
| Total (T-Hg) and organic (O-Hg) mercury concentrations and tissue distribution were examined in 20 species of cephalopods (n = 278) from the north eastern Atlantic waters, i.e. from the Bay of Biscay to the Faroe Islands. Concentrations of T-Hg in whole cephalopods showed elevated variations among species, i.e. from 40 to 3560ng g(-1) dwt, but a low variability within each species (mean CV%=39%). With the exception of oceanic squids, the digestive gland globally displayed higher T-Hg concentrations than the remaining tissues. In contrast, O-Hg concentrations determined in selected species were generally higher in the remaining tissues. Despite higher T-Hg concentrations, the digestive gland weakly contributed to the total body burden of both T-Hg and O-Hg... |
| Tipo: Text |
Palavras-chave: Cuttlefish; Octopus; Squid; Body distribution; Speciation; Bioaccumulation. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1873.pdf |
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| CAMPOS,RAQUEL A.; PATRÍCIO,PAMELA R.; VARGAS,SILVIA JULIANA R.; SILVA,LUIS HENRIQUE M. DA; HESPANHOL,MARIA C.. |
| Abstract Fe(II) and Fe(III) have distinct chemical and biological functions. Consequently, it is more important to determine the fraction of both oxidation state that knowing the total iron concentration in a sample. However, green methods for iron speciation are still limited. This work uses aqueous two-phase system, a safe alternative to liquid–liquid extraction, to perform the chemical speciation of iron. This method is based on the reaction of Fe(II) with 1,10-phenanthroline extractant, forming a complex of Fe(II)-phenanthroline that concentrates in the top phase of the system. The Fe(III) specie concentrated in the bottom phase of the system. Iron speciation was affected by the electrolyte nature, macromolecule type, quantity of phenanthroline added,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aqueous two-phase system; Flame atomic absorption spectrometry; Iron; Speciation; Green chemistry. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652018000501929 |
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| Dange, Catherine. |
| Most of trace elements have a non conservative behavior in estuarine environments. It is the case of cadmium, cobalt and caesium for which the fate in estuarine and coastal zones is largely controlled by their distribution between water and suspended particles, which generally have high residence times or can be definitely deposited in these areas. Metallic contaminants and radionuclides can be present under various species : dissolved (mineral and organic complexes), colloidal and particulate forms (adsorbed, precipitated) or integrated by various mechanisms in the organisms. Such distributions are the result of processes (physical, chemical, biological) which are controlled by many factors (ionic strengh, pH, Eh, major cations concentration, nature and... |
| Tipo: Text |
Palavras-chave: Modeling; French estuaries; Caesium; Cobalt; Cadmium; Radionuclides; Trace metals; Speciation; Modélisation; Estuaires français; Cesium; Cobalt; Cadmium; Radionucléides; Métal trace; Speciation. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/these-183.pdf |
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| Depa, L.; Kanturski, M.; Taszakowski, A.; Wieczorek, K.. |
| Firm matching of genitals during copulation is of critical importance to effective insemination and thus, gene flow. During the evolution of insects, an effective position during copulation promoted higher fecundity through control over the act of mating or elimination of competitors. Usually during insect copulation, either twisting or flexing of the male abdomen occurs, and genitals remain symmetrically or asymmetrically disposed following changes in the mating position. However, it is always the dorsal side of the male genitalia that makes contact with the ventral side of female abdomen. Here we present the unusual case of a ‘belly-to-belly’ copulation, with symmetrically positioned male genitals and no twisting of the abdomen. During the mating of two... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Aphididae; Dwarfism; Mate guarding; Sexual competition; Speciation; 42.75. |
| Ano: 2014 |
URL: http://www.repository.naturalis.nl/record/480053 |
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| Gonzalez, Jean-louis; Dange, Catherine; Thouvenin, Benedicte. |
| In estuarine environment, cadmium has a nonconservative behavior. It can be present under various species: dissolved (mineral and organic complexes), colloidal and particulate forms (adsorbed, precipitated), or integrated by various mechanisms in the organisms. This distribution is the result of processes (physical, chemical and biological) which are controlled by many factors (salinity, pH, Eh, nature and concentration of suspended matter, primary production). Geochemical modeling is a very useful approach to understand the dynamics of this type of contaminant, especially in the complex systems which are the estuaries. A speciation model was used to simulate the measurements taken (dissolved and particulate Cd) during various cruises carried out in the... |
| Tipo: Text |
Palavras-chave: Cadmium; Estuary; Speciation; Modeling; Surface complexation; Cadmium; Estuaire; Spéciation; Modélisation; Complexation de surface. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/00480/59120/61749.pdf |
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| Gonzalez, Jean-louis; Thouvenin, Benedicte; Dange, Catherine; Chiffoleau, Jean-francois; Boutier, Bernard. |
| The role of particles in the fate and speciation of trace metals in macrotidal estuaries was studied using a surface complexation model (MOCO). Cadmium was selected as the target metal contaminant due to its reactivity in estuaries: cadmium behavior is mainly controlled by heterogeneous processes (sorption/desorption) related to salinity and suspended matter gradients. Various scenarios of suspended matter distribution according to salinity were simulated. The impact of surface properties (specific surface area, density of surface sites, acido-basic properties, and complexation constant) was evaluated using data collected on particles from the Gironde, Loire, and Seine estuaries. Our results show that particle surface properties, evaluated on the basis... |
| Tipo: Text |
Palavras-chave: Turbidity maximum; Speciation; Sorption; Particles; Modeling; Macrotidal estuaries; Cadmium. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2005.pdf |
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| Haverkamp, Thomas H. A.; Geslin, Claire; Lossouarn, Julien; Podosokorskaya, Olga A.; Kublanov, Ilya; Nesbo, Camilla L.. |
| Thermosipho species inhabit thermal environments such as marine hydrothermal vents, petroleum reservoirs, and terrestrial hot springs. A 16S rRNA phylogeny of available Thermosipho spp. sequences suggested habitat specialists adapted to living in hydrothermal vents only, and habitat generalists inhabiting oil reservoirs, hydrothermal vents, and hotsprings. Comparative genomics of 15 Thermosipho genomes separated them into three distinct species with different habitat distributions: The widely distributed T. africanus and the more specialized, T. melanesiensis and T. affectus. Moreover, the species can be differentiated on the basis of genome size (GS), genome content, and immune system composition. For instance, the T. africanus genomes are largest and... |
| Tipo: Text |
Palavras-chave: Extremophiles; Hydrothermal vents; Mobile DNA; Speciation; Thermotogae; Vitamine B-12. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00478/58934/61503.pdf |
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| HEYER,W. RONALD; REID,YANA R.. |
| The frog Leptodactylus fuscus is found throughout much of South America in open and disturbed habitats. Previous study of genetic differentiation in L. fuscus demonstrated that there was lack of genetic exchange among population units consistent with multiple species, rather than a single species. We examine advertisement vocalizations of L. fuscus to determine whether call variation coincides with genetic differentiation. Calls were analyzed for 32 individual frogs from 25 localities throughout the distributional range of L. fuscus. Although there is variation in calls among geographic samples, call variation is not concordant with genetic variation or geographic distance and the call variation observed is less than that typically found among other... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Advertisement calls; Leptodactylus fuscus; Speciation. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652003000100006 |
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| Kappes, H.. |
| Blood-feeding terrestrial leeches of the family Haemadipsidae are a notorious part of the invertebrate diversity in Asian and Australian rain forests. All hitherto published records of terrestrial leeches of Borneo belong to the genus Haemadipsa. Here, a second, poorly known haemadipsid genus is reported from Mount Kinabalu and Crocker Range National Park. The individuals were barcoded and compared to sequences available in GenBank. The results show that the genus Tritetrabdella has representatives in the Indochinese and the Sundaic bioregions. All six specimens from Borneo are from a single new Tritetrabdella lineage, T. kinabaluensis spec. nov. Within the Bornean lineage, two groups differing 4-5% in the COI barcoding sequence were identified. Because 1)... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Annelida; Clitellata; Ecological specialization; Genetic distance; Parasite; Phylogeny; Speciation; Tropical mountains; 42.76; 42.64. |
| Ano: 2013 |
URL: http://www.repository.naturalis.nl/record/462900 |
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| Registros recuperados: 50 | |
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