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Full-Text Articles in Life Sciences
Effects Of Riverine Barriers On Avian Evolution In The Amazon Basin, Andre Eugene Moncrieff
Effects Of Riverine Barriers On Avian Evolution In The Amazon Basin, Andre Eugene Moncrieff
LSU Doctoral Dissertations
The high biodiversity found in the Amazon Basin has long captivated the attention of naturalists and evolutionary biologists seeking to explain its origins. Early observations by Alfred Wallace highlighted the role of rivers in delimiting the geographic ranges of many species; furthermore, where rivers narrow towards their headwaters, he noted that some species cross rivers freely. A major goal of this dissertation is to investigate how these and other observations about riverine barriers might inform our understanding of how speciation unfolds in Amazonia. My approach involved generating genomic data with dense geographic sampling for manakins in the genus Lepidothrix, …
Evolution Of Green Blood In New Guinea Lizards: Phylogenomics, Biogeography, And Comparative Genomics, Zachary Rodriguez
Evolution Of Green Blood In New Guinea Lizards: Phylogenomics, Biogeography, And Comparative Genomics, Zachary Rodriguez
LSU Doctoral Dissertations
Non-model organisms with evolutionary novelties and complex distributions can provide valuable insight into the mechanisms underlying biological diversity. Green blood is one of the most unusual vertebrate physiologies and has repeatedly evolved in lizards from the megadiverse island of New Guinea. An unusually high concentration of the toxic green bile pigment biliverdin causes the green coloration of these lizards' blood, muscles, and bones. This dissertation uncovered the complex history of this novel trait (Chapter 2), identified protein-coding sequences that underlie green blood in lizards (Chapter 3), and explored evolutionary processes that drive genetic diversity in high-elevation lizards. To accurately trace …
High-Throughput Cultivation Of Bacterioplankton From The Gulf Of Mexico And Genomics Of The First Cultured Ld12 Representative, Michael Winslow Henson
High-Throughput Cultivation Of Bacterioplankton From The Gulf Of Mexico And Genomics Of The First Cultured Ld12 Representative, Michael Winslow Henson
LSU Doctoral Dissertations
Cultivation of microorganisms facilitates characterization of metabolism, interspecies dependencies, virus-host interactions, and other information necessary to resolve the functions and distribution of individual taxa. However, the metabolic and physiological capacities for the majority of microbes remains unresolved because of the lack of cultivated representatives for many groups limits our ability to test cultivation-independent observations. The Northern Gulf of Mexico offers a diversity of ecosystems under the continuous threat from natural and anthropogenic disturbances, yet little is known about its native bacterioplankton community. This dissertation sought to use high-throughput cultivation over three-years at six sites to isolate important coastal bacteria to …
Speciation And Hybridization In Jamaican-Endemic Streamertail Hummingbirds (Trochilus Polytmus And T. Scitulus), Caroline D. Judy
Speciation And Hybridization In Jamaican-Endemic Streamertail Hummingbirds (Trochilus Polytmus And T. Scitulus), Caroline D. Judy
LSU Doctoral Dissertations
Streamertails hummingbirds (Trochilus polytmus and T. scitulus) are recently diverged sister taxa that appear to have speciated in situ on the island of Jamaica. They are distinguished by male bill color, a secondary sexual trait that is coral red in T. polytmus and jet black in T. scitulus. They hybridize in a narrow zone where their ranges meet in eastern Jamaica. In Chapter 2, I performed a formal population survey of T. scitulus to determine the size of the population, which was unknown. I determined that the total population contains well over 100,000 individuals despite its limited …