Spelling suggestions: "subject:"1species delimitation"" "subject:"1species elimitation""
61 |
Systématique du genre Essigella (Hemiptera : Sternorrhyncha) au moyen de données moléculairesThéry, Thomas 01 1900 (has links)
No description available.
|
62 |
Avaliação sistemática de camarões de água doce do gênero Atya Leach, 1816 (Crustacea: Decapoda: Atyidae) por meio de dados moleculares / Systematic evaluation of freshwater prawns of the genus Atya Leach, 1816 (Crustacea: Decapoda: Atyidae) by means of molecular dataCaio Martins Cruz Alves de Oliveira 30 May 2017 (has links)
Os camarões do gênero Atya Leach, 1816 são os maiores camarões da família Atyidae, sendo que as 13 espécies reconhecidas estão distribuídas em rios e riachos das regiões tropicais e subtropicais da América (vertentes atlântica e pacífica) e oeste da África. O primeiro relato de uma Atya ocorreu no séc. XVII e, desde então, novas espécies foram descritas e descrições prévias revisadas, produzindo um histórico de instabilidade e reclassificações. Embora ao longo do séc. XX revisões taxonômicas tenham estabilizado a sistemática do gênero, a variabilidade morfológica e distribuição geográfica trans-ístmica da espécie A. innocous gerou questionamentos. Além disso, mais recentemente trabalhos de filogenia molecular da família Atyidae que incluíram representantes de Atya suscitaram questões em relação à sistemática do gênero (possível não monofilia) e de algumas espécies como A. gabonensis, A. margaritacea e A. scabra. Visto que o uso de marcadores moleculares nunca foi empregado para a delimitação das espécies de Atya e que seu uso de forma complementar à morfologia poderia aperfeiçoar a sistemática do gênero, o objetivo do presente estudo foi avaliar por meio de dados moleculares as hipóteses taxonômicas das espécies A. gabonensis, A. innocous, A. margaritacea e A. scabra. Sequências dos genes mitocondriais 16S e Citocromo Oxidase I e gene nuclear Histona 3 foram geradas por meio de protocolos de extração e sequenciamento de DNA a partir do tecido de espécimes obtidos em empréstimos/doações. Potenciais espécies evidenciadas pelas análises de similaridade nucleotídicas (distâncias genéticas), compartilhamento de caracteres em um contexto evolutivo (reconstruções filogenéticas), Automatic Barcode Gap Discovery, Poisson Tree Processes e Generalized Mixed Yule Coalescence foram confrontadas com as hipóteses taxonômicas específicas atuais. A avaliação sistemática com dados moleculares aqui realizada, adicionalmente às informações morfológicas existentes na literatura sustentaram A. gabonensis como uma espécie de distribuição anfi-atlântica, mas não corroborou a hipótese de A. innocous como uma espécie trans-ístmica. Assim, o uso do nome A. innocous para as populações do Mar do Caribe e A. tenella para aquelas restritas ao Pacífico é sugerido. A espécie A. margaritacea, distribuída ao longo da costa pacífica da América foi considerada uma espécie válida e distinta de A. scabra, amplamente distribuída na vertente atlântica da América do Sul, África e Mar do Caribe. Contudo, é discutida a possibilidade de uma espécie críptica restrita no Golfo do México existir. Adicionalmente, o conhecimento existente e pertinente para futuros estudos de sistemática e taxonomia sobre os camarões do gênero Atya foram sumarizados e são apresentados. / The genus Atya Leach, 1816 shrimps are the largest of the Atyidae family, and the 13 acknowledge species are geographically distributed in rivers and stream in the tropical and subtropical regions of America (Atlantic and Pacific drainages) and West Africa. The first registry of an Atya was in the XVII century and since then new species were described and previous description revised in an eventful taxonomic historic. Although throughout the XX century taxonomic revisions stabilized the genus systematics, the morphological variability and the trans-isthmic geographic distribution of A. innocous caused questioning. Moreover, molecular phylogenetic studies that included Atya representatives raised doubt on the genus systematics (possibly non-monophyletism) and some species A. gabonensis A. margaritacea and A. scabra hypothesis. As molecular markers have never been used concerning Atya species delimitation complementary to the morphology and it could improve the genus systematics, the goal of this study was to evaluate with molecular markers the taxonomic hypothesis of the species A. gabonensis, A. innocous, A. margaritacea e A. scabra. Sequences of the mitochondrial genes 16S and Cytochrome Oxidase I and nuclear gene Histone 3 were generated by means of DNA extraction and sequence protocols from specimens obtained in loans/donations. Putative species evidenced by the analysis of nucleotide similarity (genetic distances), character sharing (phylogenetic reconstitutions), Automatic Barcode Gap Discovery, Poisson Tree Processes and Generalized Mixed Yule Coalescence were compared to the prevailing taxonomic hypothesis. The systematic evaluation with the molecular data of this study, in addition with the morphological information in the literature sustain A. gabonensis as an amphi-atlantic distributed species, but do not corroborated A. innocous hypothesis as an trans-isthmian species. In this sense, the use of A. innocous stricto sensu for the Caribbeans Sea populations and A. tenella to that restricted to the pacific drainage of America is suggested. Atya margaritacea, distributed along the pacific drainage of America, is considered a valid species distinct from A. scabra, widespread distributed in the Atlantic drainage of America and Africa, besides Caribbean Sea. However, the possibility of a cryptic species in the Gulf of Mexico population is discussed. Aditionally, the relevant knowledge to future systematic and taxonomy studies about the shrimps of the genus Atya were summarized and are shown.
|
63 |
Relações filogenéticas e filogeográficas das espécies do complexo Cattleya coccinea (Orchidaceae) / Phylogenetic and phylogeographic relationships of the species of the complex \'Cattleya coccinea\' (Orchidaceae)Jucelene Fernandes Rodrigues 26 August 2015 (has links)
Delimitar espécies e reconstruir a história evolutiva em complexos de espécies pode demandar grandes esforços uma vez que grupos taxonomicamente problemáticos são muitas vezes consequência de eventos de especiação recente ou de rápida especiação. O complexo \'Cattleya coccinea\', da família Orchidaceae, é composto por orquídeas com alto valor ornamental, epifíticas e rupícolas de porte pequeno. Apesar de estarem descritas com caracteres morfológicos diagnósticos claros que permitem sua identificação, a delimitação das espécies atualmente reconhecidas é problemática. Portanto, os objetivos dessa pesquisa foram revisar a delimitação de espécies do complexo e a relação entre as espécies, além de avaliar a diversidade e estrutura genética, aliadas às análises filogeográficas para testar a ocorrência de eventos demográficos históricos. Para responder tais questões foram utilizadas regiões de sequência de cpDNA e nrDNA, 11 locos microssatélites, além de inferência bayesiana e modelo coalescente somadas às estatísticas tradicionais como metodologia. Os resultados suportam o monofiletismo para o clado para as regiões de cpDNA concatenadas. Indicam também quatro grandes eventos de reticulação das espécies do clado C. coccinea com outras espécies do gênero Cattleya. Adicionalmente, suportam o reconhecimento de sete diferentes espécies para o clado C. coccinea, composto por duas principais linhagens evolutivas mais ao norte da região Sudeste: C. brevipedunculata predominante da Serra do Espinhaço e C. wittigiana do norte da Serra do Mar. E cinco espécies distribuídas ao longo da Serra do Mar e Serra da Mantiqueira (C. coccinea, C. mantiqueirae, e mais três espécies correspondentes às populações de DMES; SJPSP e CSRS/JOSC/PMPR. As análises de diversidade mostraram de moderados a altos níveis de diversidade genética e apontam que as espécies C. coccinea e C. brevipedunculata apresentam os maiores níveis de diversidade comparadas a outras espécies do clado. A estruturação genética entre populações dentro de espécies mostrou variação entre níveis baixos a altos. A análise de atribuição de indivíduos a partir de inferência bayesiana mostrou a formação de oito grupos geneticamente distintos. A análise de taxa de dispersão de fluxo gênico pólen x semente mostrou que a dispersão via pólen é aproximadamente oito vezes mais eficiente que a dispersão via sementes somente para C. coccinea. Além disso, a rede de haplótipos indicou que as espécies raramente compartilham haplótipos e que C. coccinea e C. brevipedunculata apresentam maior diversidade com eventos de expansão. A análise de estimativa de tempo de divergência demonstrou que C. brevipedunculata e C. wittigiana provavelmente se originaram entre o Plioceno e o Pleistoceno. As outras espécies do clado se diversificaram no Pleistoceno. Eventos de expansão populacional foram observados para todas as espécies em eras glaciais do Pleistoceno. Por se tratarem de espécies ameaçadas, esse estudo recomenda a conservação \"in situ\" como também a conservação \"ex situ\" de todas as espécies do clado, com atenção especial às duas espécies do Espírito Santo: C. wittigiana e a espécie da localidade DMES, além da espécie da localidade SJPSP em São Paulo. / Species delimitation and reconstruction of the evolutionary history of species complexes may require great efforts since taxonomically problematic groups are often a result of recent speciation events or rapid speciation. The \'Cattleya coccinea\' complex, of the orchid family, consists of epiphytic and small rupicolous orchids with high ornamental value. Despite being described with clear diagnostic morphological characters that allow their identification, delimitation of the currently recognized species is problematic. Therefore, the objectives of this study were to review the species delimitation of the complex and the relationship between species, and to evaluate the genetic diversity and structure, combined with phylogeographic analyzes to test the occurrence of historical demographic events. To answer such questions, cpDNA and nrDNA sequence regions, 11 microsatellite loci, and Bayesian inference and coalescent model were used, combined with traditional statistics and methodology. The results support the monophyly for the clade for concatenated cpDNA regions. They also indicate four major reticulation events of C. coccinea species clade with other species of the genus Cattleya. Additionally, results support the recognition of seven different species for C. coccinea clade, composed of two main evolutionary lineages further north in the Southeast: C. brevipedunculata predominant in the Serra do Espinhaço and C. wittigiana from northern Serra do Mar. And five species distributed along the Serra do Mar and Serra da Mantiqueira (C. coccinea, C. mantiqueirae, and three other species of the populations DMES; SJPSP and CSRS/JOSC/PMPR. The diversity analyzes showed moderate to high levels of genetic diversity and point out that the species C. coccinea and C. brevipedunculata have the highest levels of diversity compared to other species of the clade. The genetic structure of populations within species showed variation from low to high. Assigning individuals analysis from Bayesian inference showed the formation of eight genetically distinct groups. The dispersal rate analysis of pollen x seed gene flow showed that dispersal through pollen is approximately eight times more efficient than the dispersal through seeds only for C. coccinea. Furthermore, the haplotype network indicated that the species rarely share haplotypes and that C.coccinea and C. brevipedunculata present greater diversity with expansion events. The divergence time estimation analysis showed that C. brevipedunculata and C. wittigiana probably originated between the Pliocene and the Pleistocene. The other clade species have diversified in the Pleistocene. Population expansion events were observed for all species in the Pleistocene ice ages. Because they are endangered species, this study recommends the \"in situ\" conservation as well as \"ex situ\" conservation for all species of clade, with special attention for two species of Espírito Santo: C. wittigiana and the species of DMES locality, in addition to the species of SJPSP location in São Paulo.
|
64 |
Exploring the taxonomy of a facultative selfing, polymorphic land snail: the genus Rumina, Gastropoda Pulmonata / Etude de la taxonomie d'un escargot terrestre polymorphique et capable de se reproduire par l'autofécondation: le genre Rumina, Gastropoda PulmonataPrévot, Vanya 14 September 2011 (has links)
Le genre Rumina Risso, 1926 (Subulinidae) est constitué de gastéropodes terrestres, hermaphrodites et capables de réaliser de l’autofécondation ainsi que de la fécondation croisée. Plusieurs espèces ont été décrites sur base de subtiles différences morphologiques telles que la forme et la taille de la coquille et la coloration du corps. Trois espèces sont actuellement toujours reconnue dans la littérature: Rumina decollata (Linnaeus, 1758), R. saharica Pallary, 1901 et R. paivae (Lowe 1861). Cependant, uniquement le statut spécifique de R. decollata et R. saharica a été confirmé par la morphologie de la coquille et l'anatomie génitale. L’objectif de la thèse est de clarifier la taxonomie du genre Rumina par une approche de taxonomie intégrative en associant des caractères moléculaires, morphologiques et anatomiques ainsi que les méthodes issues de la génétique des populations. Quatre gènes mitochondriaux et deux gènes nucléaires ont été séquencés pour reconstruire la phylogénie de Rumina. Les résultats confirment le statut d’espèce de R. saharica, excluent R. paivae en tant qu’espèce et proposent une nouvelle classification pour R. decollata en 6 espèces phylogénétiques. R. saharica est aussi confirmé en tant qu’espèce morphologique suite à une étude morphomètrique, cependant les nouvelles espèces de R. decollata n’ont pas pu être différenciées ni par les variables morphologiques testées, ni par des particularités dans l’anatomie génitale. Néanmoins, deux des espèces de R. decollata correspondent à deux morphotypes (clair et foncé) auparavant décrits et étudiés dans la région de Montpellier. L’étude de ces deux espèces phylogénétiques avec des microsatellites et allozymes permettent de confirmer le statut spécifique des deux morphotypes et révèlent que R. decollata pratique l’autofécondation croisée à un taux supérieur à celui rapporté dans la littérature, défiant ainsi la règle selon laquelle les hermaphrodites pratiqueraient exclusivement l’autofécondation ou exclusivement la fécondation croisée. L’espèce correspondante au morphotype foncé a été introduite en plusieurs endroits du monde et semble être l’espèce possédant la plus grande capacité invasive parmi les Rumina. Ainsi, nos résultats suggèrent que le genre Rumina, auparavant décrit comme étant composé de trois espèces, est en fait un complexe de sept espèces, qui doivent être davantage étudiées de façon à confirmer leur statut d’espèce par d’autres concepts d’espèce. / Rumina spp. Risso, 1826 (family Subulinidae) is a hermaphroditic terrestrial snail, performing both selfing and outcrossing. Several nominal species have been described based on subtle differences in the shape and size of the shell, and body coloration. Currently, three taxa are still recognized, viz. R. decollata (Linnaeus, 1758), R. saharica Pallary, 1901 and R. paivae (Lowe, 1860). Yet, species-specific differentiation has only been confirmed for R. decollata and R. saharica, based on shell and genital morphology. This work aims at resolving the taxonomy of the genus Rumina through an integrative taxonomic approach by combining molecular, morphological and anatomical characters, as well as population genetic methods. Four mitochondrial and two nuclear genes were used to infer Rumina’s phylogeny. Results suggest that R. saharica is a phylogentic species, R. paivae is not a phylogenetic species and R. decollata is composed by 6 phylogenetic species. The specific status of R. saharica was confirmed by a morphometric analysis, however the remaining phylogenetic species of R. decollata could not be differentiated neither by the shell characters analyzed nor by the genital anatomy. Nevertheless, two phylogenetic species of Rumina representing the dark and light colored strains previously described in the Montpellier region. The study of both these strains with microsatellites and allozymes confirmed their specific status and revealed that outcrossing might be more prevalent than was previously suggested in the literature, therefore defying the alleged rule that hermaphroditic species should be either strict self-fertilizers or strict outcrosser. The dark strain was introduced in several places through the world and seems to be the one with highest invasive character within the genus Rumina. Therefore, our results suggest that the genus Rumina, previously described as having three species, is in fact a complex of seven species that need to be further explored in order to confirm their species status under other species concepts. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
|
65 |
Etude écologique et génétique du complexe d'espèces cryptiques Ophioderma longicauda (Ophiuroidea : Echinodermata) : comparaison entre lignées incubantes et lignées produisant des larves planctoniques. / Ecological and genetic study of the cryptic species complex Ophioderma longicauda (Ophiuroidea : Echinodermata) : comparison between brooding and broadcasting lineages.Weber, Alexandra 16 January 2015 (has links)
Ophioderma longicauda (Bruzelius, 1805) est un complexe d’espèces cryptiques incluant six lignées mitochondriales (L1-L6), dont certaines (L2-L3-L4) incubent leur descendance, alors que d'autres se reproduisent probablement via des larves lécithotrophes. Afin de définir les limites d’espèces dans le complexe O. longicauda, le statut reproductif des lignées L1 et L3 a été étudié. L’analyse morphologique et génétique a montré qu’il s’agissait d’espèces biologiques différentes, avec notamment différentes périodes de reproduction. De plus, l’analyse par DAPC de 31 marqueurs génétiques a montré que le complexe O. longicauda était constitué de six groupes génétiques distincts. Deuxièmement, l’influence des traits d’histoire de vie sur la connectivité et la diversité génétique a été étudiée. Pour ce faire, 10 marqueurs ont été séquencés pour six populations sympatriques des lignées L1 et L3 en Grèce. La structure génétique était très marquée pour l’espèce incubante L3, tandis que l’espèce dispersante L1 n’a pas montré de structure génétique à cette échelle. L’analyse de la diversité génétique pour ces 10 marqueurs a montré que celle des dispersantes était trois à quatre fois plus élevée que celle des incubantes. De plus, l’analyse de la diversité génétique dans les transcriptomes des L1 et L3 a montré qu’elle était 1.5 à 2 fois plus élevée chez les dispersantes que chez les incubantes. Finalement, deux canaux ioniques impliqués dans la mobilité des spermatozoïdes ont montré une évolution sous sélection positive. Ces résultats suggèrent que la compétition des spermatozoïdes pourrait être un mécanisme d’isolement pré-zygotique chez Ophioderma longicauda. / Ophioderma longicauda (Bruzelius, 1805) is a cryptic species complex including six mitochondrial lineages (L1-L6), of which three (L2-L3-L4) brood their juveniles, whereas the other lineages most likely reproduce using lecithotrophic larvae. In order to define the species limits in the O. longicauda complex, the reproductive status of lineages L1 and L3 was studied. The morphological and genetic study showed that they were different biological species, with notably different reproductive periods. In addition, the analysis of 31 genetic markers using DAPC showed that the O. longicauda complex included six distinct genetic groups. Secondly, the influence of life-history traits on connectivity and genetic diversity was studied. To do so, 10 markers were sequenced for six sympatric populations of lineages L1 and L3 from Greece. The genetic structure was high for the brooding species, whereas the broadcasting species did not display any genetic structure at that scale. The analysis of genetic diversity for these 10 markers showed that diversity was three to four times higher in broadcasters than in brooders. In addition, the analysis of genetic diversity in the L1 and L3 transcriptomes showed that diversity was 1.5 to 2 times higher in broadcasters than in brooders. Finally, two ion channels involved in sperm motility showed an evolution under positive selection. These results suggest that sperm competition might be a mechanism of pre-zygotic isolation in Ophioderma longicauda.
|
66 |
Caractérisation et délimitation des sous-espèces de Gesneria viridiflora (Gesneriaceae) dans les AntillesLambert, François 01 1900 (has links)
Une taxonomie révisée et une connaissance des limites d’espèces demeurent toujours importantes dans les points chauds en biodiversité comme les Antilles où de nombreuses espèces endémiques sont retrouvées. Des limites d’espèces divergentes impliquent un différent nombre d’espèces retrouvées dans un écosystème, ce qui peut exercer une influence sur les décisions prises face aux enjeux de conservation. Les genres Gesneria et Rhytidophyllum qui forment les principaux représentants de la famille des Gesneriaceae dans les Antilles comprennent plusieurs taxons aux limites d’espèces ambigües et quelques espèces qui ont des sous-espèces reconnues. C’est le cas de Gesneria viridiflora (Decne.) Kuntze qui comprend quatre sous-espèces géographiquement isolées et qui présentent des caractères végétatifs et reproducteurs similaires et variables. Une délimitation d’espèces approfondie de ce complexe d’espèce est effectuée ici à partir d’une approche de taxonomie intégrative considérant des données morphologiques, génétiques et bioclimatiques. Les données morphologiques quantitatives et qualitatives obtenues à partir de spécimens d’herbier sont utilisées pour délimiter des groupes morphologiques à l’aide d’une analyse en coordonnées principales. Ces groupes sont ensuite testés à l’aide de séquences d’ADN de quatre régions nucléaires en utilisant une méthode bayesienne basée sur la théorie de la coalescence. Finalement, les occurrences et les valeurs de variables de température et de précipitation qui y prévalent sont utilisées dans une analyse en composantes principales bioclimatique pour comparer les groupes délimités morphologiquement et génétiquement. Les résultats de l’analyse morphologique multivariée supportent la distinction entre les groupes formés par les sous-espèces actuellement reconnues de G. viridiflora. Les résultats, incluant des données génétiques, suggèrent une distinction jusqu’ici insoupçonnée des populations du Massif de la Hotte au sud-ouest d’Haïti qui sont génétiquement plus rapprochées des populations de Cuba que de celles d’Hispaniola. Bioclimatiquement, les groupes délimités par les analyses morphologiques et génétiques sont distincts. L’approche de taxonomie intégrative a permis de distinguer cinq espèces distinctes plutôt que les quatre sous-espèces acceptées jusqu’à aujourd’hui. Ces espèces sont : G. acrochordonanthe, G. quisqueyana, G. sintenisii, G. sylvicola et G. viridiflora. Une carte de distribution géographique, un tableau de la nouvelle taxonomie applicable et une clé d’identification des espèces sont présentés. La nouvelle taxonomie déterminée dans cette étude démontre un endémisme insoupçonné dans plusieurs régions du point chaud en biodiversité des Antilles et souligne l’importance d’investiguer les limites d’espèces dans les groupes diversifiés comprenant des taxons aux limites d’espèces incomprises. / An accurate taxonomy and knowledge of species limits is of great importance in endemic species-rich biodiversity hotspots like the Caribbean. Indeed, conflicting species limits can alter biodiversity estimates and influence the decisions taken on conservation issues. The genera Gesneria and Rhytidophyllum constitute the main representatives of the Caribbean Gesneriaceae and comprise a few species with unclear boundaries as well as species having several recognized subspecies. Gesneria viridiflora (Decne.) Kuntze is a good example of the latter and consists of four geographically isolated subspecies that possess similar but variable vegetative and reproductive characters. We conducted a thorough investigation of species delimitation in this species complex using an integrative taxonomic approach that includes morphology, genetics and bioclimatic data. Qualitative and quantitative morphological data obtained from herbarium specimens were used to circumscribe morphologically distinct groups using a principal coordinates analysis. These groups were then tested at the genetic level using a Bayesian Phylogenetics and Phylogeography (BPP) species delimitation approach based on four nuclear regions. Bioclimatic multivariate analyses of temperature and precipitation variables obtained from occurrence data were used to compare the groups delimited by morphological and genetic data. The results suggest the presence of five distinct species in this complex. Four of these broadly correspond to the actually defined subspecies: G. quisqueyana, G. sintenisii, G. sylvicola and G. viridiflora. An additional highly endemic species was recognized, G. acrochordonanthe, that consists of the populations found at the Massif de la Hotte in Southwestern Haiti. A distribution map, a table of the new taxonomy and an identification key to the species are provided. The new taxonomy proposed in this study shows an unsuspected species endemism in some regions of the Caribbean biodiversity hotspot and underlines the importance of investigating species boundaries in diversified groups containing taxa with poorly understood boundaries.
|
67 |
Taxonomy of selected groups of the genus \kur{Caloplaca} / Taxonomy of selected groups of the genus \kur{Caloplaca}ŠOUN, Jaroslav January 2011 (has links)
The thesis deals with phylogeny, taxonomy and nomenclature of selected groups of the lichen genus Caloplaca. Particularly, the C. cerina group was closely investigated using molecular methods (ITS sequences), morphology and chemistry, based on material from Europe, and to some extent also from North America and western Asia. This approach resulted in the description of three new species (C. sterilis, C. subalpina, C. thracopontica), and detected an unexpected richness of lineages. Nomenclature, taxonomy, morphology and ecology of C. aurantia and C. flavescens from the C. aurantia group were studied in detail, including selection of the neotype of the former species. Their distribution was reviewed for the territory of the Czech Republic. Poorly known taxon C. aurantiomurorum from Algeria was lectotypified and synonymized with C. aurantia. Apart from the two groups, C. phlogina and C. scythica, differing partly in thallus colour and distinctly in distribution, were examined using both molecular (ITS sequences) and phenotypic data and found to be conspecific.
|
Page generated in 0.1695 seconds