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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Filogenia molecular de Lamiales, com ênfase em espécies nativas de Gratiolaceae / Phylogeny of Lamiales, with emphasis on Gratiolaceae species to Brazil

Cristiane Del Nero Rodrigues 16 October 2009 (has links)
O histórico da classificação das Scrophulariaceae inclui muitos tratamentos que diferem na delimitação da família. Algumas propostas incluíram grupos que atualmente correspondem a famílias, como Globulariaceae, Lentibulariaceae, Orobanchaceae, Plantaginaceae e Selaginaceae. A tribo Gratioleae, tradicionalmente incluída em Scrophulariaceae, nos últimos anos vem sendo considerada um grupo de Plantaginaceae. Contudo, em trabalho recente a tribo Gratioleae foi promovida para o nível de família (G ratiolaceae). Como até o momento o posicionamento dos gêneros em Gratiolaceae tem-se baseado somente em caracteres morfológicos, pretendeu-se neste trabalho estabelecer os relacionamentos de afinidade dentro da família com base em critérios da filogenia molecular. Outro objetivo foi avaliar a monofilia de seus gêneros constituintes. O estudo compreendeu a obtenção de sequências de DNA mitocondrial (NAD) e do cloroplasto (rps16 e trnL-trnL-F). Inferências filogenéticas foram realizadas com base nas sequências de DNA por meio dos critérios de máxima parcimônia e probabilidades posteriores (análise bayesiana). A congruência das topologias obtidas com análises filogenéticas de parcimônia baseadas em sequências de regiões de DNA individuais foi avaliada por meio do teste ILD. Os resultados apóiam propostas de estudos filogenéticos anteriores de exclusão de Gratiolaceae de quatro gêneros: Capraria, Limosella, Lindenbergia e Stemodiopsis. Com isso, Gratiolaceae assume a condição monofilética, sendo constituída pelos gêneros Achetaria, Bacopa, Conobea, Dopatrium, Gratiola, Hydrotriche, M ecardonia, Otacanthus, Philcoxia, Scoparia, Stemodia e Tetraulacium. Dentre eles, além de Tetraulacium (gênero monoespecífico), outros gêneros monofiléticos e bem sustentados são Gratiola,Mecardonia e Scoparia. Os resultados sugerem a combinação de Achetaria e Otacanthus num único gênero. Essa proposta foi também sugerida com base em caracteres morfológicos e palinológicos. No clado de Scoparia, observa-se uma correlação entre o posicionamento das espécies e sua distribuição geográfica. A espécie com posição basal no clado (S. dulcis) apresenta distribuição mais ampla, seguida de S. montevidensis com distribuição mais restrita, abrangendo os estados do sul e chegando ao Mato Grosso e parte da Amazônia. S. pinnatifida e S. ericacea, em posição mais derivada no clado, apresentam distribuição restrita ao sul do Brasil. Bacopa é um gênero parafilético, havendo necessidade de inclusão de Conobea scoparioides para se conseguir a monofilia. Conobea multifida é filogeneticamente relacionada a Scoparia e a um grupo de espécies de Stemodia. As análises não permitiram o estabelecimento confiável de relacionamentos entre Tetraulacium o os demais gêneros. Gratiola é um gênero monofilético e fortemente relacionado a Achetaria, Otacanthus e a um grupo de espécies de Stemodia. Stemodia mostrou-se polifilético nas análises, com as seguintes relações de afinidades filogenéticas: S. vandellioides -M ecardonia; S. stellata -Philcoxia; (S. durantifolia, S. glabra, S. maritima, S. microphylla, S. veronicoides) (Achetaria, Otacanthus); (S. foliosa, S. trifoliata e S. verticillata) (Scoparia, Conobea multifida). S. maritima é a espécie tipo do gênero e somente S. durantifolia e S. glabra emergiram no mesmo clado que S. maritima. S. microphylla e S. veronicoides formam um clado fortemente sustentado e apoiado também por sinapomorfias morfológicas. / The history of Scrophulariaceae has been characterized by different treatments regarding the circumscription of the family. Some proposals have included in the family groups currently recognized as belonging to families such as Globulariaceae, Lentibulariaceae, Orobanchaceae, Plantaginaceae e Selaginaceae. Tribe Gratioleae, traditionally included in Scrophulariaceae, inrecent yearshas been assumed as a member of Plantaginaceae. However, a recent study raised this tribe to family status (Gratiolaceae). Affinity relationships among Gratiolaceae genera have so far been established on bases of morphological characters. The aim of the present work was to establish affinity relationships inside the family on bases of molecular phylogeny criteria and to test the monophyly of the constituent G ratilaceae genera. Sequences of mitochondrial NAD and plastid rbcL and trnL-trnL-F were obtained. Phylogenetic inferences were obtained based on DNA sequences and maximum parsimony and bayesian analysis. The congruence of topologies based on individual DNA regions were evaluated by means of the ILD test. The results obtained give support to previous studies which proposed exclusion from Gratiolaceae of four genera: Capraria, Limosella, Lindenbergia e Stemodiopsis. In this way, family Gratiolaceae is monophyletic and comprises the genera Achetaria, Bacopa, Conobea, Dopatrium, Gratiola, Hydrotriche, M ecardonia, Otacanthus, Philcoxia, Scoparia, Stemodia e Tetraulacium. Among these, in addition to Tetraulacium (a monospecific genus), other monophyleti and strongly supported genera are Gratiola, Mecardonia e Scoparia. The results suggest merging Achetaria and Otacanthus into a single genus. The same treatment has been suggested based on morphologic and palynologic characters. In the Scoparia clade a correlation is apparent between the position of species and its geographic distribution. The species with basal position (S. dulcis) has wide distribution, followed by S. montevidensis, with narrower distribution, covering the southern states and reaching M ato Grosso and part of Amazon. S. pinnatifida and S. ericaceae, in more derived condition, have distributions restricted to the south of Brazil. Bacopa is a paraphyletic genus, inclusion of Conobea scoparioides being required to reach monophyly. Conobea multifida is phylogenetically related to Scoparia and a group of Stemodia. The analysis failed to allow a reliable establishment of relationships between Tetraulacium and other genera. Gratiola is monophyletic and strongly linked to Achetaria, Otacanthus and a group of Stemodia. The latter genus is polyphyletic, the following phylogenic links having been observed: Stemodia vandellioides -M ecardonia; S. stellata -Philcoxia; (S. durantifolia, S. glabra, S. maritima, S. microphylla, S. veronicoides) (Achetaria, Otacanthus); (S. foliosa, S. trifoliata e S. verticillata) (Scoparia, Conobea multifida). S. maritima is the type species in the genus and only S. durantifolia and S. glabra emerged in the same clade with S. maritima. S. microphylla and S. veronicoides comprise a strongly supported clade, which is further supported by.
22

Sistemática de Anthurium sect. Urospadix (Araceae) / Systematics of Anthurium sect. Urospadix (Araceae)

Livia Godinho Temponi 08 February 2007 (has links)
Este estudo consta da análise filogenética de Anthurium seção Urospadix e grupos correlatos. O gênero tem sido considerado complexo taxonomicamente e tem sido considerado com pouca resolução interna. Nós realizamos análises de parcimônia com os dados morfológicos e moleculares e com os conjuntos de dados combinados. Caracteres anatômicos têm sido empregados em clássicos tratamentos para Araceae e a anatomia foliar pode prover vários caracteres para esclarecer as relações filogenéticas dentro de Anthurium. Com o intuito de averiguar os caracteres já descritos em um número maior de espécies de Anthurium, além de buscar novos caracteres, nós realizamos estudos anatômicos da folha de 77 espécies de Anthurium, sendo 35 da seção Urospadix. Especificamente, os dados foram obtidos de dissociações epidérmicas e secções transversais da porção mediana da nervura principal, limbo e pecíolo. Nós observamos 17 caracteres, nove dos quais são potencialmente informativos para a filogenia de Anthurium. Estudos palinológicos de 34 espécies de Anthurium também foram realizados e revelaram pólen 3-4-porado em todas as espécies. Grãos de pólen de todas as espécies examinadas são altamente similares quanto à forma e dimensões. Entretanto, o tipo de abertura e a ornamentação da exina exibem variações e podem ser úteis em estudos sistemáticos do grupo. Os três caracteres apresentados aqui aparecem como sinapomorfias para o gênero ou grupos dentro de Anthurium. Os resultados de 64 caracteres morfológicos (anatomia, morfologia externa e palinologia) e 177 caracteres moleculares (regiões trnC-ycf6, trnG e trnH-psbA do cloroplasto), ofereceram um arcabouço filogenético para avaliar os caracteres utilizados na sistemática destes grupos, bem como discutir questões da sistemática do grupo e os padrões evolutivos e biogeográficos envolvidos. Baseado nos conceitos tradicionais, a seção Urospadix contém 74 espécies e apresenta uma distribuição disjunta, com dois centros de diversidade: a América Central e Oeste da América do Sul e o leste do Brasil. Entretanto, baseado na nova circunscrição que aceitamos aqui, Anthurium seção Urospadix Engl., contém um menor número de espécies e, como tratado aqui, o grupo é restrito à Costa Atlântica Brasileira. / We present a phylogenetic analysis of Anthurium sect. Urospadix and related groups (Araceae). The genus has traditionally been considered taxonomically difficult and there has been little resolution of relationship within it. We performed parsimony analyses on morphological and molecular, and combined data sets. Anatomical characters have been used in classic taxonomic treatments of Araceae and it appears that leaf anatomy may provide several characters for addressing phylogenetic relationships within Anthurium. To verify these characters in a larger number of species and to examine new ones, we investigated the leaf anatomy of 77 Anthurium species, including 35 of section Urospadix. Specifically, we investigated the anatomy of the epidermis and traverse sections of the mid rib, leaf lamina, and petiole. We identified 17 characters, nine of which are potentially informative with respect to the Anthurium phylogeny. The palynological studies of 34 Anthurium species indicate that pollen is 3-4 porate in all species. Pollen grains from all examined species are highly similar in form and dimensions. However, the aperture type and the exine sculpturing are variable and may be useful for systematic studies of the group. The three characters presented here appear to provide synapomorphies for the genera or groups within Anthurium. The results of analyses on morphological (external morphology, palynology, and leaf anatomy; 64 characters), molecular (trnCycf6, trnG, and trnH-psbA regions of the chloroplast; 177 varied characters), and combined data sets, provide a phylogenetic framework for evaluating the characters used in systematic studies of the group, as well as for discussing evolutionary and biogeographic patterns. Based on the traditional concept sect. Urospadix contains 74 species and it had a disjunct distribution, with centers of diversity in Central America–western South America and in eastern Brazil. However, based on the new circumscription that we consider here, Anthurium sect. Urospadix Engl. contains a smaller number of species and, as treated here, the group is restricted to Atlantic Coast of Brazil.
23

Phylogeny and Taxonomy of Commelinaceae (Commelinales) / ツユクサ科(ツユクサ目)の系統と分類

Lee, Chung-Kun 23 March 2021 (has links)
京都大学 / 新制・課程博士 / 博士(理学) / 甲第23047号 / 理博第4724号 / 新制||理||1677(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 田村 実, 教授 鹿内 利治, 教授 工藤 洋 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
24

Caractérisation génétique du genre Iris évoluant dans la méditerranée orientale / Genetic characterization of Iris genus evovlving in the East Mediterranean region

Abdel Samad, Nour 21 September 2016 (has links)
Le genre Iris appartenant à la famille des Iridacées comprend plus de 220 espèces distribuées à travers l’hémisphère Nord. La section Oncocyclus (Siems.) Baker de ce genre est confinée au Sud-ouest de l’Asie et comprend plus de 65 espèces au statut taxonomique souvent discuté.La présente étude porte sur le complexe d’espèces d’Iris évoluant dans les pays de la Méditerranée orientale : Liban, Syrie, Jordanie, Palestine/Israël, Arménie, Turquie et Iran.Le taux d’endémisme au sein de ce genre est relativement élevé et la cueillette excessive ainsi que la destruction de leurs habitats menace un grand nombre de ces espèces.En vue de préciser le statut taxonomique des espèces et d’élucider les relations phylogénétiques qui les relient plusieurs méthodes sont employées : l’analyse de la taille du génome, l’étude du caryotype, l’organisation du génome basée sur la localisation des gènes ribosomiques et l’étude de la structuration de la diversité génétique et la phylogénie basée sur des marqueurs moléculaires nucléaires et chloroplastiques.Les études de laboratoires sont complétées par des travaux de terrain afin de suivre l’évolution de la dynamique des taxons endémiques du Liban en vue de leur préservation.Au cours de notre étude, les régions ITS, TrnL-F et matk de tous les iris du Liban et 20 Oncocylus de la région Est-Méditerranéenne ont été séquencées pour construire les arbres phylogénétiques. Les deux techniques FISH et Feulgen ont été appliquées sur plusieurs espèces Oncocyclus du Liban. Des études cytogénétiques approfondies ont été menées sur toutes les espèces d’Iris collectées. / The Iris genus belonging to the Iridaceae family includes over 220 species distributed throughout the Northern Hemisphere. The Oncocyclus section (Siems.) Baker is confined to the Southwest Asia and includes more than 65 species with a discussed taxonomic status.This study focuses on the Iris species complex evolving in the countries of the Eastern Mediterranean Region: Lebanon, Syria, Jordan, Palestine / Israel, Armenia, Turkey and Iran.The rate of endemism within this genus is relatively high. The overharvesting and the destruction of their habitats threaten many of its species.To clarify the taxonomic status of the species and to elucidate the phylogenetic relationships that connect them, several methods are used: the analysis of the genome size, the study of the karyotype, genome organization based on the ribosomal genes location and the study of genetic diversity and phylogeny based on nuclear and chloroplast molecular markers.Laboratory studies are complemented by field work to monitor the dynamics of Lebanon's endemic taxa for their preservation.In our study, the ITS regions, trnL-F and matK of all Lebanese irises and 20 Oncocylus irises of the East Mediterranean region were sequenced to construct phylogenetic trees. Both techniques FISH and Feulgen were applied to several Lebanese Oncocyclus species. Extensive cytogenetic studies have been conducted on all species of collected Iris taxa.
25

Molecular phylogeny of the genus Goniopora and taxonomic revision of the family Poritidae (Cnidaria: Scleractinia) / ハナガササンゴ属の分子系統解析およびハマサンゴ科の分類の再検討

Kitano, Yuko 24 March 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18102号 / 理博第3980号 / 新制||理||1574(附属図書館) / 30960 / 京都大学大学院理学研究科生物科学専攻 / (主査)講師 宮崎 勝己, 教授 朝倉 彰, 教授 疋田 努 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
26

Diversity and Phylogeny of the Order Arthrotardigrada (Tardigrada: Heterotardigrada) / フシクマムシ目(緩歩動物門異クマムシ綱)の多様性と系統

Fujimoto, Shinta 23 March 2016 (has links)
Fujimoto, S. (2015) Quisarctus yasumurai gen. et sp. nov. (Arthrotardigrada: Halechiniscidae) from a submarine cave, off Iejima, Ryukyu Islands, Japan. Zootaxa. 3948 (1): 145-150. Fujimoto, S. (2014) A new Stygarctus (Arthrotardigrada: Stygarctidae) from Japan, with entangled seminal receptacle ducts. Zootaxa. Magnolia Press. 3784 (2): 187-195. / 京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19533号 / 理博第4193号 / 新制||理||1602(附属図書館) / 32569 / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 疋田 努, 教授 沼田 英治, 教授 曽田 貞滋 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
27

Diversity and evolution of the bryophyte-feeding insects in two early-diverging clades of Lepidoptera and Diptera / 鱗翅目と双翅目の2つの初期クレードに属するコケ食昆虫の多様性と進化

Imada, Yume 23 March 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(人間・環境学) / 甲第20458号 / 人博第808号 / 新制||人||194(附属図書館) / 28||人博||808(吉田南総合図書館) / 京都大学大学院人間・環境学研究科相関環境学専攻 / (主査)教授 加藤 眞, 教授 市岡 孝朗, 准教授 西川 完途 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DGAM
28

Structure and function of microbial communities in acid sulfate soil and the terrestrial deep biosphere

Wu, Xiaofen January 2016 (has links)
This thesis describes the use of different DNA sequencing technologies to investigate the structure and function of microbial communities in two extreme environments, boreal acid sulfate soil and the terrestrial deep biosphere. The first of the two investigated environments was soils containing un-oxidized metal sulfides that are termed ‘potential acid sulfate soil’ (PASS) materials. If these materials are exposed to atmospheric oxygen by either natural phenomena (e.g., land uplift) or human activities (e.g., drainage) then the metal sulfides become oxidized and the PASS becomes acidic and is defined as an ‘acid sulfate soil’ (ASS). The resulting acid and metal release from metal sulfide oxidation can lead to severe environmental damage. Although acidophilic microorganisms capable of catalyzing acid and metal release have been identified from many sulfide mineral containing environments, the microbial community of boreal PASSs/ASSs remains unclear. This study investigated the physicochemical and microbial characteristics of PASSs and ASSs from the Risöfladan experimental field in Vasa, Finland. Sanger sequencing of 16S rRNA gene sequences of microorganisms present in the PASSs and ASSs were mostly assigned to acidophilic species and environmental clones previously identified from acid- and metal-contaminated environments. Enrichment cultures inoculated from the ASS demonstrated that the acidophilic microorganisms were responsible for catalyzing acid and metal release from PASSs/ASSs. Lastly, the study investigated how to mitigate metal sulfide oxidation and the concomitant formation of sulfuric acid by treating ASSs in situ with CaCO3 or Ca(OH)2 suspensions. The DNA sequencing still identified acidophilic microorganisms after the chemical treatments. However, the increased pH during and after treatment suggested that the activity of the acidophiles might be inhibited. This study was the first to identify the microbial community present in boreal PASSs/ASSs and suggested that treatment with basic compounds may inhibit microbial catalysis of metal sulfide dissolution. The second studied environment was the deep, dark terrestrial subsurface that is suggested to be both extremely stable and highly oligotrophic. Despite the scarcity of carbon and energy sources, the deep biosphere is estimated to constitute up to 20% of the total biomass on earth and thus, represents the largest microbial ecosystem. However, due to the difficulties of accessing this environment and our inability to cultivate the indigenous microbial populations, details of the diversity and metabolism of these communities remain largely unexplored. This study was carried out at Äspö Hard Rock Laboratory, Sweden and utilized second-generation sequencing to identify the taxonomic composition and genetic potential of planktonic and biofilm populations. Community DNA sequencing of planktonic cells from three water types at varied age and depth (‘modern marine’, ‘undefined mixed’, and ‘old saline’) showed the existence of ultra-small cells capable of passing through a 0.22 μm filter that were phylogenetically distinct communities from the >0.22 μm fraction. The reduced cell size and/or genome size suggested a potential adaptation to the oligotrophic environment in the terrestrial deep biosphere. The identified planktonic communities were dominated by Proteobacteria, Candidate divisions, unclassified archaea, and unclassified bacteria. Functional analysis of the assembled genomes showed that the planktonic population from the shallow modern marine water demonstrated a predominantly anaerobic and heterotrophic lifestyle. In contrast, the deeper, old saline water was more closely aligned with the hypothesis of a hydrogen-driven deep biosphere. Metagenomic analysis of subsurface biofilms from ‘modern marine’ and ‘old saline’ water types suggested only a subset of populations were involved in initial biofilm formation. The identified biofilm populations from both water types were distinct from the planktonic community and were suggested to be dominated by hydrogen fed, chemolithoautotrophic and diazotrophic populations.
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Diversité globale des poissons coralliens : histoire évolutive et influence de l'environnement passé / Global diversity of coral reef fishes : evolutionnary history and influence of Paleo-environment

Gaboriau, Théo 09 March 2018 (has links)
L’étude de la diversité des espèces de poissons habitant les récifs coralliens fascine les chercheurs du monde entier depuis plus de 200ans. Comment ces organismes qui n’occupent que 1% de la surface des océans du globe ont-ils pu former un des groupes les plus riches des vertébrés existants ? La complexité de cette question ne réside pas seulement dans l’exceptionnelle diversité de formes, de couleurs et de comportements de ces espèces mais aussi dans l’inégale répartition de cette richesse. Des explorations du lagon de Mayotte, des côtes Cubaines ou de la grande barrière de corail donneront des perspectives très différentes de la diversité des poissons coralliens. Ces différences très importantes sont le résultat de processus ayant modelé, pendant des millions d’années, la répartition des espèces coralliennes, leur morphologie et leur comportement. Pendant ces millions d’années d’évolution, les poissons coralliens, ainsi que les espèces de coraux qui les abritent, ont été confrontés à des changements drastiques des conditions climatiques et à la dérive des continents. C’est l’influence de ces facteurs sur la répartition et la diversité des poissons coralliens, que j’ai étudié pendant ma thèse. Comprendre comment les espèces et les écosystèmes ont réagi aux changements environnementaux passés peut nous apporter des clés essentielles pour anticiper les changements à venir des écosystèmes que nous connaissons, sous l’influence des changements globaux. Les récifs coralliens étant sous une menace de plus en plus présente, je me suis particulièrement intéressé à l’influence de la disponibilité de l’habitat corallien sur les processus d’extinction, de dispersion et de spéciation (formation de nouvelles espèces par divergence génétique) des poissons coralliens.Afin de répondre à ces objectifs, plusieurs méthodes ont été employées. Dans un premier temps, une approche descriptive basée sur la répartition de la co-occurrence entre espèces sœurs et une comparaison entre une reconstruction globale de la dynamique des habitats coralliens allant du Crétacé (≈ -140 millions d’années) et les taux de diversification de plusieurs grands groupes de poissons récifaux, ont permis de montrer que les taux de diversification de plusieurs familles de poissons récifaux étaient dépendant de la fragmentation des habitats coralliens, et d’observer la concordance entre des évènements climatiques et tectoniques majeurs et l’évolution de la biodiversité des poissons coralliens.Après avoir identifié un lien entre fragmentation de l’habitat corallien et la diversification des poissons, une grande question demeure : Comment cette dynamique de l’habitat influence-t-elle dans l’espace et le temps la diversité des poissons récifaux ? Pour répondre à cette question, une approche unique permettant de modéliser la dispersion, la spéciation et l’extinction des espèces dans un espace formé de grilles d’habitat dynamique a été développée et appliquée à plusieurs clades d’organismes marins côtiers (coraux, palétuviers et poissons). Cette approche a permis de démontrer comment la dérive des continents a contraint la dynamique de l’habitat corallien et a façonné les gradients de diversité de plusieurs groupes d’organismes marins côtiers. Enfin, l’extension de cette approche aux récifs tempérés, a permis de montrer l’interaction entre l’influence de la dérive des continents et des processus écologiques sur la colonisation et le maintien d’espèces de poissons récifaux dans les milieux tempérés, expliquant en partie la formation du gradient latitudinal de diversité des poissons récifaux.Ces travaux ouvrent la voie vers l’utilisation d’une nouvelle génération de modèles spatialisés de diversification et la prise en compte de la dynamique des habitats passés dans l’étude des processus de diversification. / The exceptional diversity of fishes that inhabit coral reefs fascinates researched from all over the world since over 200years. How can those organisms, that only occupy 1% of the surface of the oceans, form one of the richest group of extant vertebrates? The complexity of this question does not only lie in the extraordinary diversity of morphologies, colors and behaviors, but also roots in the heterogeneous repartition of that richness. Explorations of Mayotte’s lagoon, Cuban coasts or the great barrier reef will show different perspectives of coral-reef fish’ diversity. Those pervasive differences are the result of processes that shaped, during millions of years the repartition of coral-reef species, their morphology and their behavior. During those millions of years of evolution, coral-reef fishes along with species that shelter them, faced massive climatic and tectonic changes. During my PhD, I studied the influence of those factors on the repartition and the diversity of coral-reef fishes. Understanding how species and ecosystems responded to important environmental changes can provide essential insights to anticipate future changes of ecosystem composition and functioning under global changes’ pressure. As coral-reefs are under more and more threatening pressures, I particularly focused on the influence of coral habitat availability on extinction, dispersion and speciation processes of coral-reef fishes.To achieve this goal, several methods have been employed. First, a descriptive approach based on sister-species co-occurrence patterns and the comparison between a global reconstruction of coral-reef habitat dynamics from the Cretaceous (≈ -140 million years) to present and the evolution of several speciose groups of coral-reef fishes permitted to identify a link between diversification rates of several groups of coral-reef fishes and coral habitat fragmentation and to observe the concordance between major earth-history events and biodiversity dynamics of coral-reef fishes.After the identification of a link between habitat fragmentation and coral-reef fishes’ diversification, an important question remains: What are the mechanisms underlying the influence of habitat dynamics on temporal and spatial variations of reef-fish biodiversity? To answer this question a unique approach allowing modeling of species dispersal, extinction and speciation in a gridded space varying in function of habitat dynamics, has been developed and applied to several groups of coastal marine organisms (corals, mangroves, fishes). This approach provided mechanistic insights about how plate movements drove coral reef habitat dynamics and shaped biodiversity gradients of several groups of coastal marine organisms. Finally, the extension of this approach to temperate reefs (rocky reefs), provided mechanistic insights about the interplay between the influence of tectonic events and ecological processes in the formation of present-day latitudinal gradient of biodiversity of reef-fishes.This thesis paves the way towards the use of a new generation of spatialized mechanistic models of macroevolution and the consideration of the influence of past-habitat dynamics in the study of diversification processes.
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Filogenia e revisão de Pseudotrimezia (Iridaceae) / Phylogeny and taxonomic revision of Pseudotrimezia (Iridaceae)

Lovo, Juliana 14 August 2009 (has links)
Diversos estudos filogenéticos moleculares em Iridaceae confirmam o monofiletismo de Trimezieae. Entretanto, a tribo é pobremente caracterizada e carece de sinapomorfias morfológicas que a sustentem. Por outro lado, o gênero Pseudotrimezia, apesar de morfologicamente bem caracterizado, nunca teve seu monofiletismo investigado. Estudos envolvendo a tribo Trimezieae demonstram que caracteres anatômicos podem contribuir para a taxonomia do grupo além de auxiliar na sua reconstrução filogenética. No presente estudo foram realizados estudos filogenéticos envolvendo caracteres morfológicos e moleculares, separadamente e em análise de evidência total. Foram levantados 50 caracteres morfológicos, incluindo anatomia foliar, em Pseudotrimezia e nos gêneros relacionados, Neomarica e Trimezia. Os caracteres moleculares foram obtidos de três regiões plastidias (trnG, trnH-psbA e trnK) e uma nuclear (ITS). A análise de parcimônia com os dados morfológicos resultou em uma filogenia com Pseudotrimezia monofilético, sem sustentação, enquanto Neomarica e Trimezia emergem como polifiléticos. Assim, os caracteres morfológicos mostraram-se insuficientes para a compreensão da história evolutiva do grupo. A análise de evidência total apresenta Pseudotrimezia monofilético em um clado bem caracterizado morfologicamente sustentado por 10 sinapomorfias homoplásticas. Não obstante, Trimezia e Neomarica emergem agrupados em quatro clados distintos, a maioria sem sustentação, revelando que os gêneros reconhecidos na tribo Trimezieae não correspondem a grupos monofiléticos. As análises filogenéticas fornecem um arcabouço para discutir a sistemática de Pseudotrimezia, gênero endêmico dos campos rupestres da porção mineira da Cadeia do Espinhaço. Apesar de sua distribuição restrita e morfologia floral relativamente uniforme, 24 nomes surgiram desde sua criação em 1945, e muitas das espécies são endêmicas de localidades restritas. É apresentada a revisão de 16 espécies reconhecidas, respectivos mapas de distribuição, ilustrações e chave de identificação / Several molecular phylogenetic studies focusing on Iridaceae contribute to confirm Trimezieae as a monophyletic group. Despite that, the tribe is poorly characterized and lacks morphological synapomorphies as support. On the other hand, Pseudotrimezia is morphologically well characterized, but its monophyly has never been investigated. Anatomical studies carried out with tribe Trimezieae indicates that this kind of data can be a good source for taxonomic and phylogenetic analyses. This study performed phylogenetic analysis using morphological and molecular data, separately and combined in a total evidence approach. Molecular data were obtained from three plastid regions (trnG, trnH-psbA and trnK), and one nuclear (ITS). Fifty morphological characters, including leaf anatomy, were selected within Pseudotrimezia and the related genera Neomarica and Trimezia. Parsimony morphological analysis results in a monophyletic Pseudotrimezia with no support, and, Neomarica and Trimezia aspolyphyletic; therefore, morphological characters were insufficient to help understand the evolutionary history of this group.The total evidence analysis shows Pseudotrimezia monophyletic in a morphologically well-characterized clade, suppported by 10 homoplastic synapomorfies. Nevertheless, Trimezia and Neomarica arise mixed together in four distinct clades, most of them with no support, suggesting that tradicionally recognized genera in the tribe do not correspond to monophyletic groups. Neverthless, phylogenetic analyses provide an important framework for systematic studies of Pseudotrimezia (Iridaceae), an endemic genus from \"campos rupestres\" in Espinhaço Range, Minas Gerais State, Brazil. Despite its restricted distribution and quite uniform morphology, 24 names have been created since the genus was first described in 1945, and many species are endemic of particular localities. The revision of 16 recognized species, their distribution maps, illustrations, and identification key are presented.

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