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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.
11

Phylogenetics of the genus Scotophilus (Chiroptera: Vespertilionidae): perspectives from paternally and maternally inherited genomes with emphasis on African species

Trujillo, Robert Greg 30 October 2006 (has links)
Bats of the genus Scotophilus are distributed throughout sub-Saharan Africa, parts of southern and Southeast Asia, a majority of the Indomalayan Islands, Reunion Island, and Madagascar. The genus is composed of 14 recognized species with seven distributed throughout sub-Saharan Africa including: (S. dinganii (A. Smith, 1833), S. leucogaster (Cretzschmar, 1830), S. nigritellus de Winton, 1899, S. nigrita (Schreber, 1774), S. nucella Robbins, 1983, S. nux Thomas, 1904, and S. viridis (Peters, 1852). The remaining species include four from southern and southeast Asia (S. celebensis Sody, 1928; S. collinus Sody 1936; S. heathi (Horsfield, 1831); S. kuhlii Leach, 1821), two on Madagascar (S. sp. nov. Goodman et al., in press; and S. robustus Milne-Edwards, 1881), and one endemic to Reunion Island (S. borbonicus (E. Geoffroy, 1803). The systematics and taxonomy of this genus have been controversial and continue to be confusing. The genus is plagued with problems in species definition and the systematic relationships among members of the genus are poorly understood. The major goal of this study was to use a molecular phylogenetic approach to clarify some of the controversy and confusion surrounding the members of this genus. Nucleotide differences from mtDNA and the Y chromosome were used to examine phylogenetic patterns within Scotophilus. Based on these data two new species of Scotophilus were identified. Phylogenetically, African Scotophilus were found to comprise a monophyletic group with S. nux as the most basal African taxon. Overall, the Asian S. kuhlii was the most basal taxon. A distant relationship was identified between S. kuhlii and S. heathi, the other Asian species examined. The multiple origins of Malagasy Scotophilus are apparent as the two Malagasy taxa in the study do not share a sister-group relationship. The large bodied S. nigrita is closely related to S. dinganii and the S. dinganii-like species all share a close relationship. S. nigrita has a S. dinganii-like mtDNA haplotype and a very distinct zfy haplotype, suggesting a possible hybridization event with a S. dinganii-like ancestor.
12

Phylogenetics of the genus Scotophilus (Chiroptera: Vespertilionidae): perspectives from paternally and maternally inherited genomes with emphasis on African species

Trujillo, Robert Greg 30 October 2006 (has links)
Bats of the genus Scotophilus are distributed throughout sub-Saharan Africa, parts of southern and Southeast Asia, a majority of the Indomalayan Islands, Reunion Island, and Madagascar. The genus is composed of 14 recognized species with seven distributed throughout sub-Saharan Africa including: (S. dinganii (A. Smith, 1833), S. leucogaster (Cretzschmar, 1830), S. nigritellus de Winton, 1899, S. nigrita (Schreber, 1774), S. nucella Robbins, 1983, S. nux Thomas, 1904, and S. viridis (Peters, 1852). The remaining species include four from southern and southeast Asia (S. celebensis Sody, 1928; S. collinus Sody 1936; S. heathi (Horsfield, 1831); S. kuhlii Leach, 1821), two on Madagascar (S. sp. nov. Goodman et al., in press; and S. robustus Milne-Edwards, 1881), and one endemic to Reunion Island (S. borbonicus (E. Geoffroy, 1803). The systematics and taxonomy of this genus have been controversial and continue to be confusing. The genus is plagued with problems in species definition and the systematic relationships among members of the genus are poorly understood. The major goal of this study was to use a molecular phylogenetic approach to clarify some of the controversy and confusion surrounding the members of this genus. Nucleotide differences from mtDNA and the Y chromosome were used to examine phylogenetic patterns within Scotophilus. Based on these data two new species of Scotophilus were identified. Phylogenetically, African Scotophilus were found to comprise a monophyletic group with S. nux as the most basal African taxon. Overall, the Asian S. kuhlii was the most basal taxon. A distant relationship was identified between S. kuhlii and S. heathi, the other Asian species examined. The multiple origins of Malagasy Scotophilus are apparent as the two Malagasy taxa in the study do not share a sister-group relationship. The large bodied S. nigrita is closely related to S. dinganii and the S. dinganii-like species all share a close relationship. S. nigrita has a S. dinganii-like mtDNA haplotype and a very distinct zfy haplotype, suggesting a possible hybridization event with a S. dinganii-like ancestor.
13

Biogeography and evolution of Melanesian and South Pacific ants

MATOS MARAVÍ, Pável Fortunato January 2016 (has links)
This thesis investigates the systematics, biogeography, and diversification dynamics of a large and ecologically important insect group in SE Asia and the Indo-Pacific region: the ants. This study utilizes a multidisciplinary framework to elucidate the evolutionary history of selected ant clades with the overall aim to shed light on similar ecological and evolutionary processes intervening in ant diversity.
14

Filogenia molecular das abelhas Augochlorini (Hymenoptera, Apidae) / Molecular phylogeny of Augochlorini bees (Hymenoptera, Apidae)

Rodrigo Barbosa Gonçalves 23 May 2011 (has links)
Augochlorini (Halictinae) e um elemento comum na região Neotropical, e a historia natural das suas espécies e marcada pela plasticidade quando comparada a outras abelhas. A tribo e grupo-irmão de Halictini, e seus fosseis datam pelos menos do âmbar Dominicano (cerca de 20 milhões de anos). As relações entre os gêneros de Augochlorini foram reconstruídas de maneira insatisfatoria, sendo as hipóteses existentes em parte incongruentes, pouco robustas e baseadas apenas em dados morfológicos. Neste sentido, o presente estudo apresenta uma abordagem filogenética empregando dados moleculares. Para 76 terminais, foram obtidas sequências de DNA de quatro genes, 28S, Fator de Alongamento 1-alfa, Rodopsina Verde e wingless, somando 3043 pares de bases alinhadas. Análises de máxima parcimônia, máxima verossimilhança e inferência bayesiana foram conduzidas para os dados moleculares em conjunto, incluindo ou não regiões de alinhamento ambíguo (alças e íntrons). Os resultados, em consenso, apontam para a parafilia das duas subtribos de Augochlorini sensu Engel, com três grupos de gêneros, gr. Corynura, gr. Rhinocorynura e gr. Chlerogella formando uma politomia na base. Os demais gêneros formam um agrupamento que e dividido em três grandes clados, cujas relações não foram bem resolvidas. O primeiro e composto pelo grupo Megaloptidia e os gêneros Augochloropsis, Augochlorodes e Pseudaugochlora, o segundo pelo grupo Neocorynura mais Chlerogas, Paroxystoglossa e Temnosoma, e o terceiro pelo grupo Augochlora e Caenaugochlora, Megalopta e Thectochlora. As primeiras linhagens de Augochlorini se diversificaram entre 7060 milhões de anos atrás, sendo que desde 50 milhões de anos vem ocorrendo uma gradativa diversificação do grupo. A re-análise da morfologia externa do grupo não foi útil para entender melhor a evolução do grupo que em trabalhos anteriores, inclusive diminuindo o poder explicativo da hipótese gerada pela evidencia total. As hipóteses moleculares apresentaram novas evidencias que guiam futuros estudos para o grupo, para que se possa entender a evolução dentro de cada um dos seus clados. / Augochlorini (Halictinae) is a common element in the Neotropical region, and his natural history is known by their relatively plasticity when compared to other bees. Augochlorini is sister-group of Halictini, and its oldest fossils date from the Dominican amber (about 20 million years before present). The phylogenetic relationships among their genera were only superficially reconstructed, the competing hypothesis are not entirely congruent nor robust and were based only on morphological data. With this background, this study aims to present a molecular phylogeny to Augochlorini. It was obtained, for 76 terminals, DNA sequences of four genes, 28S, Elongation Factor 1-alpha, Green Rodopsin and Wingless, giving a 3043 base pair alignment. Maximum parsimony, maximum likelihood and Bayesian inference analyses were carried out for the molecular data, including or excluding regions of ambiguous alignment (loops and introns). The results, based on consensus trees, suggest the paraphyly of both Augochlorini subtribes (sensu Engel), with three groups of genera, gr. Corynura, gr. Rhinocorynura e gr. Chlerogella forming a basal polytomy with a clade containing the remaining genera. This clade has three subgroups, whose phylogenetic relationships were not well stabilized. The first group consists of gr. Megaloptidia and Augochloropsis, Augochlorodes, and Pseudaugochlora, the second group of gr. Neocorynura plus Chlerogas, Paroxystoglossa, and Temnosoma, and the third group consists of gr. Augochlora and Caenaugochlora, Megalopta, and Thectochlora. The first Augochlorini lineages diversified by 70 to 60 million years ago, and since 50 mya there has been a gradual diversification of the group. The reanalysis of augochlorines external morphology was not helpful for understanding the evolution of the group, and also reduced the explanatory power of the total evidence hypothesis. The molecular hypothesis brought new evidences to guide future studies for the group, and positively favored the conception about the evolution of Augochlorini main clades.
15

Análise da identidade taxonômica de Dendropsophus nanus e Dendropsophus walfordi ( Anura, Hylidae) com base em dados moleculares / Taxonomic identity analysis of Dendropsophus nanus e Dendropsophus walfordi (Anura, Hylidae) based on molecular data

Seger, Karin Regina, 1983- 27 August 2018 (has links)
Orientador: Luciana Bolsoni Lourenço / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-27T00:43:09Z (GMT). No. of bitstreams: 1 Seger_KarinRegina_M.pdf: 1961069 bytes, checksum: ac950c9cf223e51f3374d9378d583572 (MD5) Previous issue date: 2014 / Resumo: O gênero Dendropsophus apresenta uma grande diversidade de espécies, compreendendo atualmente mais de 90 espécies de anuros hilídeos, e se caracteriza por apresentar como principal sinapomorfia o número cromossômico 2n=30. Muitas problemáticas taxonômicas ainda cercam esse grupo, como a referente a Dendropsophus nanus e Dendropsophus walfordi. Tais espécies já foram consideradas sinônimas com base em dados morfológicos, proposta que foi refutada após análise de canto. Recentes inferências filogenéticas têm apontado o possível parafiletismo dessas duas espécies de anuros, mas nenhuma delas teve a amostragem devidamente desenhada para avaliar cuidadosamente a questão taxonômica decorrente dessa observação. Mesmo o estudo filogenético que incluiu o maior número de representantes dessas espécies contou com apenas cerca de 700 pb de um único marcador genético (gene ribossomal mitocondrial 12S). Além disso, não incluiu nenhum exemplar da localidade-tipo de ambas as espécies e, embora a amostra dessa espécie tenha sido a maior utilizada até o momento em análises filogenéticas, ainda não foi suficiente para cobrir toda a grande área de ocorrência desses anuros. Com o intuito de solucionar tais problemas e contribuir para a análise da delimitação dessas espécies, foi investigado o possível parafiletismo entre as espécies D. nanus e D. walfordi, por meio da comparação de sequências dos genes mitocondriais 12S, 16S e CO1, e com a amostragem de indivíduos de 24 localidades abrangendo a maior parte da distribuição incluindo as localidades-tipo de cada uma das duas espécies. Foi observada alta estruturação genética do grupo de interesse pela análise de variância molecular (AMOVA) e cinco principais clados (A-E) foram identificados em todos os cladogramas inferidos. O parafiletismo de D. nanus com relação a D. walfordi foi observado em todas as análises filogenéticas. As distâncias genéticas entre os clados A-E foram altas e permitem sugerir que o grupo em questão represente na realidade um complexo com mais de duas espécies diferentes / Abstract: The Dendropsophus genus presents a great diversity of species, currently including more than 90 species of hylid frogs, and its main synapomorphy is the chromosome number 2n = 30. Many taxonomic problems still surround this group, as those referred to Dendropsophus nanus and Dendropsophus walfordi. Such species have been considered synonymous based on morphological data, but that proposal was rejected after call analysis. Recent phylogenetic inferences have pointed out the possible paraphyly of these species of frogs, but they were not designed to carefully evaluate the taxonomic question arising from this observation. Even the phylogenetic study that included a large number of representatives of these species did not sampled their type locality and was based on only ~ 700 bp of a single genetic marker (mitochondrial 12S ribosomal gene). In order to solve these problems and contribute to the analysis of these species delimitation, we investigated the possible paraphyly between D. nanus and D. walfordi by comparing the sequences of the mitochondrial genes 12S, 16S and CO1, and sampling specimens from 24 localities, including the type-locality of each of these species. High genetic structuration was observed inside this group by the analysis of molecular variance (AMOVA) and five major clades (A-E) were recognized in all inferred cladograms. The paraphyly of D. nanus with respect to D. walfordi was observed in all phylogenetic analyses. The genetic distances among the Clades A-E were high and allowed to suggest that in fact a complex with more than two different species exist in the analyzed group / Mestrado / Biodiversidade Animal / Mestra em Biologia Animal
16

Filogenia, biogeografia e revisão taxonômica de Nycticalanthus Ducke e Spiranthera A.St.-Hil. (Rutaceae, Galipeeae) / Phylogeny, biogeography and taxonomic revision of Nycticalanthus Ducke and Spiranthera A.St.-Hil. (Rutaceae, Galipeeae)

Lilian de Andrade Brito 05 December 2017 (has links)
Os gêneros Nycticalanthus (monotípico) e Spiranthera (quatro espécies), pertencentes à família Rutaceae, tribo Galipeeae, são semelhantes morfologicamente e possuem distribuição restrita à América do Sul. São predominantemente arvoretas ciófilas de florestas úmidas, exceto Spiranthera odoratissima, que possui hábito arbustivo savânico e é a espécie de distribuição mais ampla, com a maior variabilidade morfológica. Este estudo teve como objetivo investigar as relações de parentesco entre Nycticalanthus e Spiranthera e suas espécies, utilizando dados moleculares (região ETS do DNA nuclear e espaçador trnL-F do DNA plastidial), visando entender os processos subjacentes à sua diversificação e biogeografia, além de realizar uma revisão taxonômica do grupo. Baseado na filogenia obtida e nas características morfológicas compartilhadas entre as espécies de ambos os gêneros, muitas delas sinapomórficas, é proposta a sinonimização do gênero monotípico Nycticalanthus sob Spiranthera. A revisão taxonômica apresentada baseia-se em uma extensa análise morfológica do grupo, incluindo expedições a campo e estudo de espécimes de herbários, elaboração de chave de identificação, descrição e ilustrações das seis espécies reconhecidas, incluindo uma espécie nova de Iquitos, Peru, além de dados de distribuição geográfica, habitats e variabilidade morfológica de cada táxon / The genera Nycticalanthus Ducke (monotypic) and Spiranthera A.St.-Hil. (four species), belonging to Rutaceae, tribe Galipeeae, are morphologically similar and restricted to South America. They are mostly sciophyllous treelets from rainforests, except for Spiranthera odoratissima, the most widespread species, which is a shrub inhabiting savannic formations and showing the highest morphological variation. This study investigated the phylogenetic relationships between the two genera, and among their species as well, using molecular data (ETS from the nuclear DNA, and trnL-F spacer from the plastidial DNA), aiming at understanding the processes involved in their diversification and biogeographic history. I also studied the taxonomic circunscription of both genera (all species included) carrying out a taxonomic revision of them. Based on the phylogeny and morphological characteristics shared by the species of both genera (most of them synapomorphies), I have proposed the synonymization of the monotypic genus Nycticalanthus under Spiranthera. The taxonomic revision is based on extensive morphological analysis of the group, including collecting and observation during field trips, and study of herbarium specimens. I also present identification keys, descriptions and illustrations for all the six species, including a new one from Iquitos, Peru, as well as updated geographic distribution range, habitats, and discussion about the morphological variation of each taxon
17

Biogeography And Diversification In The Neotropics: Testing Macroevolutionary Hypotheses Using Molecular Phylogenetic Data

Daza Rojas, Juan Manuel 01 January 2010 (has links)
Lineage diversification in the Neotropics is an interesting topic in evolutionary biology and one of the least understood. The complexity of the region precludes generalizations regarding the historical and evolutionary processes responsible for the observed high diversity. Here, I use molecular data to infer evolutionary relationships and test hypotheses of current taxonomy, species boundaries, speciation and biogeographic history in several lineages of Neotropical snakes. I comprehensively sampled a widely distributed Neotropical colubrid snake and Middle American pitvipers and combined my data with published sequences. Within the colubrid genus Leptodeira, mitochondrial and nuclear markers revealed a phylogeograhic structure that disagrees with the taxonomy based only on morphology. Instead, the phylogenetic structure corresponds to specific biogeographic regions within the Neotropics. Molecular evidence combined with explicit divergence time estimates reject the hypothesis that highland pitvipers in Middle America originated during the climatic changes during the Pleistocene. My data, instead, shows that pitviper diversification occurred mainly during the Miocene, a period of active orogenic activity. Using multiple lineages of Neotropical snakes in a single phylogenetic tree, I describe how the closure of the Isthmus of Panama generated several episodes of diversification as opposed to the Motagua-Polochic fault in Guatemala where a single vicariant event may have led to diversification of snakes with different ecological requirements. This finding has implications for future biogeographic studies in the region as explicit temporal information can be readily incorporated in molecular clock analyses. Bridging the gap between the traditional goals of historical biogeography (i.e., area relationships) with robust statistical methods, my research can be applied to multiple levels of the biological hierarchy (i.e., above species level), other regional systems and other sub-disciplines in biology such as medical research, evolutionary ecology, taxonomy and conservation.
18

Floral Morphogenesis and Molecular Systematics of the Family Violaceae

Feng, Min 17 October 2005 (has links)
No description available.
19

A Systematic Investigation of Batrachospermum section Helminthoidea (Batrachospermales, Rhodophyta) Using Molecular and Morphological Analyses

Salomaki, Eric D. 11 September 2012 (has links)
No description available.
20

Sistemática molecular e biogeografia histórica do gênero Aratinga (Psittacidae, Aves) / Molecular systematics and historical biogeography of genus Aratinga (Psittacidae, Aves)

Freddi, André Murilo Magro 16 April 2012 (has links)
A família Psittacidae possui 332 espécies de papagaios, periquitos e afins, e os táxons Neotropicais formam um grupo monofilético (tribo Arini), dentro desta tribo está o gênero Aratinga. A sistemática deste gênero é mal resolvida, com poucos estudos morfológicos e algumas filogenias moleculares que apontam que não seja monofilético. Porém, é preciso destacar que esses estudos não amostraram uma quantidade representativa de espécies do gênero, o que deixa essas relações incertas. Para melhor compreender a história evolutiva do gênero Aratinga, realizamos uma análise filogenética com 21 das 22 espécies do gênero, o táxon monotípico Nandayus nenday que é proximamente relacionado a algumas espécies de Aratinga e representantes de outros gêneros da tribo Arini. Foram sequenciados cinco genes mitocondriais (12S, 16S, citocromo b, NADH2, COIII) e um nuclear (RAG-1). As filogenias obtidas por máxima verossimilhança e análise Bayesiana foram congruentes e indicam a ausência de monofilia do gênero Aratinga. A maioria das espécies do gênero foi posicionada em três clados com alto suporte, mas que não se apresentam agrupados em um clado monofilético. Estes três clados são congruentes com grupos previamente propostos com base em caracteres morfológicos. Nandayus nenday está dentro de um destes clados, que é grupo irmão de um clado que contém outros quatro gêneros da tribo Arini. A única espécie que não foi incluída em nenhum destes clados é Aratinga acuticaudata, que aparentemente é mais proximamente relacionada aos gêneros Diopsittaca e Guarouba. A maioria dos eventos de divergência das espécies do gênero Aratinga nesses diferentes clados parece ter ocorrido nos últimos 5 milhões de anos (Ma.). Enquanto as estimativas de datas de divergências entre os principais clados sugerem que elas ocorreram durante o Mioceno inicial. O padrão biogeográfico da diversificação dos clados de Aratinga foi complexo, possivelmente relacionado com o soerguimento dos Andes, com múltiplas colonizações da América Central antes e depois do fechamento do Istmo do Panamá e com ciclos glaciais do Pleistoceno. Esses resultados refutam a monofilia do gênero e uma revisão taxonômica do táxon parece ser necessária. / Family Psittacidae includes 332 species of parrots and all Neotropical taxa form a monophyletic group (tribe Arini), among those, is the parakeet genus Aratinga. This genus has an unresolved systematics, with few morphological studies and some molecular phylogenies suggest that it is not monophyletic. However, these phylogenies did not include a representative sample of species of the genus. To better understand the evolutionary history of genus Aratinga, we conducted a phylogenetic analysis that included 21 of 22 species of the genus, the monospecific taxon Nadayus nenday that is closely related to some Aratinga species, plus various taxa from tribe Arini. We sequenced five mitochondrial (12S, 16S, cytochrome b, NADH2, COIII) and one nuclear (RAG-1) genes. The phylogenies were reconstructed based on maximum likelihood analysis and Bayesian inference. Relaxed molecular clock estimates were conducted under a Bayesian analysis for inferring the divergence times of the phylogeny and to study the biogeographic history of these species. The phylogenies recovered by both methods were highly congruent and support the absence of monophyly for genus Aratinga. The majority of the species from the genus Aratinga was placed in three highly supported clades that did not group in a monophyletic clade. These three clades match previously suggested groups based on morphological characters. Nandayus nenday was included in one of these clades, that is closely related to a clade that contains four other Arini genera. The only species that was not included in any of these clades was Aratinga acuticaudata, that seems to be more closely related to the genera Diopsittaca and Guarouba with high support values. Most of the speciation within the Aratinga clades may have occurred during the last 5 Mya., but the divergence times between these clades seems to have occurred during the early Miocene. The biogeograhic pattern of the diversification of the Aratinga clades was complex, possibly related to the history of the Andes, multiple colonization of Central America before and after the closure of the Panama Isthmus and also Pleistocene glacial cycles. These results further refute the monophyly of genus Aratinga and a taxonomical revision may be necessary for the taxon.

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