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LSU Doctoral Dissertations

Theses/Dissertations

2008

Speciation

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Phylogeogaphy Of Nothoprocta Tinamous And The The Phylogeny Of The Tinamidae, Thomas Valqui Jan 2008

Phylogeogaphy Of Nothoprocta Tinamous And The The Phylogeny Of The Tinamidae, Thomas Valqui

LSU Doctoral Dissertations

Understanding how diversity is attained and maintained is one of the central questions in biology. In the Neotropics most attention has centered on the Amazonian lowlands, despite the recognized importance of the role of the Andes in South American diversity. In this dissertation, I address the question by using Nothoprocta tinamous as a model case for examining diversification in the Andes. As a group, they are a manageable size, they exhibit near-restriction to the Andes, they show multi-species parapatric distributions, and they have presumed limited dispersal ability. These are all useful attributes for a system to study speciation and diversification. …


Species Boundaries, Biogeography, And Intra-Archipelago Genetic Variation Within The Emoia Samoensis Species Group In The Vanuatu Archipelago And Oceania, Alison Madeline Hamilton Jan 2008

Species Boundaries, Biogeography, And Intra-Archipelago Genetic Variation Within The Emoia Samoensis Species Group In The Vanuatu Archipelago And Oceania, Alison Madeline Hamilton

LSU Doctoral Dissertations

Speciation, geographic variation, and genetic differentiation are fundamental processes that generate diversity, and understanding these processes are major goals of evolutionary biology. Evolutionary phenomena may be more observable on islands as compared to continental landmasses as a result of small population sizes, unoccupied niches, and the relative simplicity of island systems and their populations: physical isolation, shorter (and often well documented) geologic time scale, reduced faunal diversity, and lack of outside faunal influence. Yet, despite their incredible diversity, Pacific island faunas have received little research attention relative to other tropical regions. Using molecular data from several species of scincid lizards …


Evolutionary History And Hybridization In Passerina Buntings, Matthew D. Carling Jan 2008

Evolutionary History And Hybridization In Passerina Buntings, Matthew D. Carling

LSU Doctoral Dissertations

Understanding the genetic basis of speciation is of fundamental importance to evolutionary biology and hybrid zones offer unique natural laboratories in which to investigate the ecological and evolutionary processes important in creating and maintaining biological diversity. By comparing introgression patterns of different loci, researchers can begin to identify genetic regions that contribute to reproductive isolation between hybridizing taxa. In taxa, like birds, with heterogametic females, Haldane’s rule predicts that mtDNA and z-linked loci will introgress less than autosomal loci. I tested this prediction using the hybrid zone between Passerina cyanea (Indigo Bunting) and Passerina amoena (Lazuli Bunting), two species that …