Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 34 for “"phylogenetic signal"”.
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Improving gene trees without more data
… of data often make estimating highly accurate phylogenetic trees a difficult task. Moreover, gene alignments used to estimate trees on individual loci often have low phylogenetic signal (e.g., short alignment length), resulting in poorly estimated gene trees. Species tree estimation on the …
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Assessing the information content of fossilizable data, with a focus on the Asian origin and diversification of Glires (Mammalia)
… of fossil Glires (rodents + rabbits) effects phylogenetic reconstruction and the implications for downstream analysis and interpretation. The first two chapters take a detailed look at the phylogenetic signal contained within fossil Glires, while the third and fourth chapters put …
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A phylogenetic analysis of the Accipitridae (class Aves).
… likelihood methods were used to explore the phylogenetic relationships among the Accipitridae. Major findings of the molecular study includes support for the polyphyly of the Kite genera and the sister group relationship of the Osprey (Pandion) with Acciptrid taxa. Evidence based on branch …
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Non-structural Deterrents and Opportunistic Dispersal in an Invasive Fish: The Role of Among-Individual Variation on Common Carp Movement
… applications. This is the first study to find a phylogenetic signal in fish responses to a non-structural deterrent. In chapter 4, individuals captured at the fishway were measured for morphology,subjected to laboratory behavioural trials and then released to be acoustically tracked. Significant …
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Nonrandom seed dispersal by lemur frugivores: mechanism, patterns and impacts
… To do this, I used modeling, trait-based and phylogenetic approaches combined with field observations and experiments, focusing on seed dispersal by three frugivorous lemur species in the biodiverse rainforest of Ranomafana National Park, Madagascar. An analysis of traits suggested that 84% of …
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Evolutionary Genomics of Dominant Bacterial and Archaeal Lineages in the Ocean
… are mediated by microorganisms. The extent of phylogenetic and metabolic diversity of key culture and uncultured marine microbial clades started to be revealed due to progress in sequencing technologies, however we still lack a comprehensive understanding of the evolutionary processes that led …
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What’s in a Tooth? Signals of Ecogeography and Phylogeny in the Dentition of Macaques (Cercopithecidae: Macaca)
… and a type of multivariate regression, both in a phylogenetic framework. Phylogenetic signal was tested for by means of Blomberg’s K. Macaque teeth differ in their variability. All teeth covary with each other, although correlations are strongest within tooth classes. Size was a strong …
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On The Cranial Osteology of <em>Eremiascincus</em> and Its Use For Identification.
… the skull during ontogeny, it only displayed a phylogenetic signal for small, closely related groups. Also, geometric morphometrics was just as capable distinguishing <em>Eremiascincus</em> from <em>Ctenotus</em> as qualitative characters.</p>
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The Phylogenetic Reconstruction of the Grass Family (Poaceae) Using matK Gene Sequences
… of the chloroplast trnK gene, was evaluated for phylogenetic utility above the family level and within the grass family (Poaceae). There are three major objectives in the research. The first one is to study the utility of the matK gene in plant evolution. The second objective is to characterize …
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Identifying Myotis Species Using Geometric Morphometrics and its Implications for the Fossil Record and Conservation
… high degree of accuracy. Evidence was found of a phylogenetic signal in the morphology of the Neotropical and Nearctic <em>Myotis </em>sub-clades. There is also evidence of convergence in the morphology of the dentary among <em>Myotis </em>species that feed primarily by gleaning. When analyzed …
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CLIMATE DRIVEN RANGE SHIFTS OF NORTH AMERICAN SMALL MAMMALS: SPECIES’ TRAITS AND PHYLOGENETIC INFLUENCES
… However, a refined perspective based on phylogenetic relatedness provided some evidence of a relationship between evolutionary history and the biological factors that underlie species responses to climate change. I hypothesized that species responses to climate change reflect underlying …
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Hard-wired for success? Unravelling genomic signatures in pollinators
… among bumblebees shows strong evidence of phylogenetic structure, with the subgenus Pyrobombus over-represented among stable/range-expanding species. Based on this striking pattern, a hypothesis was drawn up suggesting that Pyrobombus species have acquired advantageous traits that enhance …
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A cause for consilience: Utilizing multiple genomic data types to resolve problematic nodes within Arthropoda and Ecdysozoa
… long periods of divergent evolution. Phylogenetic signal to resolve the relationships of these lineages is diluted, increasing the likelihood of recovery of phylogenetic artifacts. In an attempt to resolve the relationships within Ecdysozoa, consilience of three independent …
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Supertree-like methods for genome-scale species tree estimation
… tree. This heterogeneity across the genome is phylogenetic signal that can be leveraged to estimate species evolution with greater accuracy. Hence, species tree estimation is expected to be greatly aided by current large-scale sequencing efforts, including the 5000 Insect Genomes Project, the …
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What are southern Cape renosterveld geophytes storing in their underground organs?
… nutrients stored. Furthermore, the potential for phylogenetic signal, ecological similarity of species because they are phylogenetically related, could be explored.
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Phylogenetic Analyses of Andean and Amazonian Tree Communities in Ecuador
… that have been little studied in a community phylogenetic context. The implementation of elevational transects and trait based analyses having proven useful in gaining a better understanding of how environmental factors are affecting the tree community structure in these habitats. The goal of …
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Phylogenetics of North American Psoraleeae (Leguminosae): Rates and Dates in a Recent, Rapid Radiation
<p>The scientific discipline of phylogenetics involves understanding the diversity of life in the context of history. Technological advances in molecular biology and computational power have created an exponential increase in the number and kind of phylogenetic studies, allowing exploration of all …
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Systematic studies on Thysanotus R.Br. (Asparagales: Laxmanniaceae).
… and this placement required testing under a phylogenetic framework. The generic relationships within Laxmanniaceae/Lomandraceae are considered uncertain; therefore, a phylogenetic analysis using molecular and morphological data is necessary to properly understand the generic relationships of …
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Dead bugs do tell tales: implications of a new fossil assassin bug (Heteroptera: Reduviidae) for the evolutionary history and systematics of an extant lineage
… use of this newly described taxon to inform the phylogenetic history of the family, and (3) a survey of previously-described extinct taxa compiled into the first taxonomic catalog of fossil Reduvioidea. The first chapter presents a new Eocene (Ypresian) fossil assassin bug, Aphelicophontes …
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Expression and Function of the Chloroplast-encoded Gene matK
… length mutations in matK has provided a strong phylogenetic signal for resolving plant phylogenies at various taxonomic levels. However, these same features have raised questions as to whether matK produces a functional protein product. matK is the only proposed chloroplast-encoded group II …
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