<p>This thesis explored species-level phylogenetic relationships of the African cycad genus Encephalartos, which is one of the eleven genera of cycads. The genus is confined to Africa and comprises approximately 65 species, 38 of which are found naturally in South Africa. The phylogenetic studies on Encephalartos to date still result in many unresolved polytomies so it is not possible to fully understand the relationships between different taxa. In this study, AFLPs were used together with DNA sequencing to reconstruct the phylogenetic relationships of the genus. This study was the first to be presented with aims of resolving the relationships of Encephalartos using AFLPs together with DNA sequences.</p>

No description available.

No description available.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2006. / Härtill 5 uppsatser.

Thesis (M.S.)--University of New Mexico, 2005. / "July, 2005." Includes bibliographical references (leaves 32-35). FINDMODEL can be accessed with a web-browser.

Thesis (Ph.D.) - University of Queensland, 2005. / Includes bibliography.

Thesis (M.S.)--University of New Mexico, 2005. / "July, 2005." Includes bibliographical references (leaves 50-51). Distplot can be accessed with a web-browser.

Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (p. 119-126).

Made available in DSpace on 2014-06-11T19:35:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-21Bitstream added on 2014-06-13T21:08:02Z : No. of bitstreams: 1 grazziotin_fg_dr_rcla.pdf: 876560 bytes, checksum: 3e4c47b55167b94d86962842d103f78a (MD5) / A relação filogenética entre os caenofídeos (serpentes avançadas) tem sido matéria de debate durante décadas. As principais questões para a sistemática eram representadas pela condição monofilética da família Colubridae, e a composição de sua subfamílias. Mais recentemente, novos métodos para inferir filogenias baseadas em critérios objetivos, bem como a utilização da biologia molecular, lançaram alguma luz sobre estas questões tradicionais. Aqui, são apresentados os resultados de duas análises filogenéticas moleculares das serpentes cenofídeas, focando principalmente nas serpentes neotropicais (subfamílias Xenodontinae e Dipsadinae). Otimização direta com base na máxima parcimônia, e homologia estática (alinhamento múltiplo), utilizando máxima parcimônia e máxima verossimilhança foram aplicados em uma matriz expandida de dados molecular. Os principais resultados de ambas as análises são: posicionamento de Acrochordus, Xenodermatideos e Pareatideos como grupos irmãos sucessivos de todos os caenofídeos restantes; viperídeos e homalopsideos são clados irmãos sucessivos de todos as demias serpentes, foram recuperados os seguintes clados monofiléticos dentro do crown-group Caenophidia: psammofídeos Afro-Asiaticos (incluindo Mimophis de Madagascar), Elapidae, Pseudoxyrhophiinae, Colubrinae, Natricinae, Dipsadinae e Xenodontinae. Homoroselaps está associada com os atractaspidídeos. Dois grupos taxonômicos superiores dentro de Caenophidia e uma nova subfamília dentro Dipsadidae foram nomeados. As análises filogenéticas sugerem mudanças taxonômicas dentro dos xenodontíneos; cinco novas tribos, oito novos gêneros foram criados e dois gêneros foram ressuscitados. Os gêneros Xenoxybelis e Pseudablabes foram sinonimizados com Philodryas; Liophis e Umbrivaga com Erythrolamprus e Lystrophis e Waglerophis com Xenodon / The phylogenetic relationship among the caenophidian (advanced) snakes has been a matter of debate for decades. The principal issues for the systematic were represented by the monophyletic condition of the large family Colubridae, and the composition of its subfamilies. More recently, new methods for infering phylogenies based on objective criteria, and the use of molecular biology, shed some light on these traditional issues. Here, two molecular phylogenetic analyses of caenophidian snakes focusing principally in the Neotropical snakes (subfamilies Xenodontinae and Dipsadinae) are presented. Direct optimization based on maximum parsimony, and static homology (multiple alignment) using maximum parsimony and maximum likelihood were applied on a expanded molecular data matrix. The major results of both analyses are: placement of Acrochordus, Xenodermatids, and Pareatids as successive outgroups to all remaining caenophidians; viperids and homalopsids are sucessive sister clades to all remaining snakes; the following monophyletic clades within crown group caenophidians: Afro- Asian psammophiids (including Mimophis from Madagascar), Elapidae, Pseudoxyrhophiinae, Colubrinae, Natricinae, Dipsadinae, and Xenodontinae. Homoroselaps is associated with atractaspidids. Two higher taxonomic clades within Caenophidia one new subfamily within Dipsadidae were nomed. The phylogenetic analyses suggest taxonomic changes within xenodontines, five new tribes, eight new genera were created and two genera were resurrected. The genera Xenoxybelis and Pseudablabes were synonymize with Philodryas; Liophis and Umbrivaga with Erythrolamprus; and Lystrophis and Waglerophis with Xenodon

The phylogeny of Juncaceae and Cyperaceae is still not fully understood. The morphology of this group is intricate and without clear homology, and molecular relationships are mostly studied on smaller parts of this large group of Monocots. Proper study is therefore needed. To obtain the most objective view on the phylogeny of these two families, we gathered data on 1174 taxa of rbcL, trnL-trnF, and ITS and analysed them by maximum parsimony, maximum likelihood, and Bayesian inference. Markers of cpDNA appeared much more useful than nDNA (ITS) due to the high rate of mutations in ITS which led to homoplasy and unsure alignment. By considering taxonomical impact of our study, the monophyly of the families and main inner topology of Juncaceae and several tribes of Cyperaceae (Abildgaardieae, Bisboeckelereae, Cariceae, Cypereae, Cryptangieae, Eleocharideae, Rhynchosporeae, Sclerieae, and Trilepideae) were confirmed; some changes in taxonomy were suggested (uniting of Chrysitricheae and Hypolytreae; division of Fuireneae; uniting of Cariceae, Dulicheae, Scirpeae, and Khaosokia caricoides into one tribe, or division of Scirpeae; and separation of Cladieae); changes in the classification of certain taxa were also suggested (the transfer of Distichia, Marsippospermim, Oxychloë, Patosia, and Rostkovia into Juncus, or division of Juncus into more genera; the transfer of Nemum spadiceum into Bulbostylis; Schoenoplectus corymbosus, S. gemmifer, S. hondoensis, and S. multisetus into the genus Schoenoplectiella; and Oreobolopsis into Trichophorum); and the identification of some taxa which possess special combinations of molecular and morphological features and should be studied further was made (Juncus capitatus, J. dregeanus, Bulbostylis juncoides, Crosslandia setifolia, Schoenoplectus litoralis, S. americanus, Cyperus iria, and Amphiscirpus nevadensis).