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The Evolution Of Coral Snake Mimicry, Renan Janke Bosque
The Evolution Of Coral Snake Mimicry, Renan Janke Bosque
Electronic Theses and Dissertations
Scientists have regarded mimicry as one of the most amazing examples of the power of natural selection. Early observations by naturalists of the mimetic association between venomous New World coral snakes of the genus Micrurus and harmless mimics has stimulated an intense debate about the causes and consequences of mimicry that persists today. Despite its medical, evolutionary and historical importance our understanding of evolution within the genus Micrurus is negligible. My dissertation explores the evolution of mimicry within South American coral snakes and their mimics using a multi-scale framework involving macroevolutionary (Chapter I), geographic/morphological concordance (Chapters II and III), behavioral …
Historical Refuges And Recolonization Routes In The Southern Appalachian Mountains, Inferred Through Phylogeographic Analysis Of The Spotted Wintergreen (Chimaphila Maculata), John Daniel Banusiewicz
Historical Refuges And Recolonization Routes In The Southern Appalachian Mountains, Inferred Through Phylogeographic Analysis Of The Spotted Wintergreen (Chimaphila Maculata), John Daniel Banusiewicz
Electronic Theses and Dissertations
Phylogeography has recently benefited from incorporation of coalescent modeling to test competing scenarios of population history of a species. Ecological niche modeling has also been useful in inferring areas of likely suitable habitat during past climate conditions. Several studies have examined the population history of biota in the Southern Appalachian Mountains and how they responded to climate change associated with the end of the Last Glacial Maximum (~18,000 years ago), though few studies have focused on understory plants. This study redressed that knowledge gap thorough examination of the phylogeographic history of the understory plant Chimaphila maculata, which is native to …
The Biotic Effects Of Tertiary Geoclimatic Change In The Southern Hemisphere, Stuart Val Nielsen
The Biotic Effects Of Tertiary Geoclimatic Change In The Southern Hemisphere, Stuart Val Nielsen
Electronic Theses and Dissertations
I explore how pre-Quaternary geoclimatic phenomena and geographical heterogeneity influenced sub-continental speciation processes and contemporary biogeographic patterns across the Southern Hemisphere, with particular focus on two regions that have experienced elevated levels of ongoing aridification – sub-Saharan (particularly Southern) Africa and Australia. I used standard methods from the molecular phylogeneticists’ toolbox (e.g. tree building using maximum likelihood and Bayesian approaches, haplotype networks, uncorrected p-distances) combined with environmental niche modeling, morphometric principal components and fossil calibrated molecular dating analyses in order to ascertain the role that Miocene geo-climatic events played in promoting lineage accumulation and diversification through time. I found a …
Biogeography And Systematics Of The Nerodia Clarkii/Nerodia Fasciata Clade In Florida, Gregory Territo
Biogeography And Systematics Of The Nerodia Clarkii/Nerodia Fasciata Clade In Florida, Gregory Territo
Electronic Theses and Dissertations
Biogeography provides a window into the evolutionary history of populations, and helps explain the diversity and distribution of life through time. Viewed from a systematic perspective, biogeographic studies generate convincing arguments to explain the relationships among organisms and categorize them into useful taxonomies. When taxonomies do not reflect evolutionary histories, inaccurate representations of biodiversity confound future studies and conservation efforts. Two thamnophiine snakes, Nerodia clarkii and Nerodia fasciata, harbor unique morphological and ecological adaptations that obscured natural groupings, leading to controversial taxonomic delimitations. Additionally, population declines documented in N. clarkii compressicauda and N. clarkii taeniata led managers to list N. …
Phylogeography Of The Malagasy Ant Species Otontomachus Coquereli, Jason Jackson
Phylogeography Of The Malagasy Ant Species Otontomachus Coquereli, Jason Jackson
Electronic Theses and Dissertations
Madagascar is an extremely diverse and geographically complex area boasting levels of endemism that blatantly raise questions about their origins. There is evidence that these endemics arose via insitu diversification during Madagascar's ~88 million year isolation, even though it was essentially in the middle of Gondwana with ample opportunity to acquire inhabitants. Madagascar's high levels of diversity and endemism make it an ideal location to study speciation, especially considering the evidence that such high levels speciation occurred in Madagascar itself. Several hypotheses have been formulated to relate the complex geography to genetic divergence, and thereby speciation. I explore three hypotheses …
Conservation And Population Biology: Genetics, Demography And Habitat Requirements Of The Atlantic Coast Beach Mice, Haakon Myklevoll Kalkvik
Conservation And Population Biology: Genetics, Demography And Habitat Requirements Of The Atlantic Coast Beach Mice, Haakon Myklevoll Kalkvik
Electronic Theses and Dissertations
The conservation biology field seeks to preserve biodiversity and the processes shaping that variation. Conservation biology is intimately tied to evolutionary research, in order to identify evolutionary distinct lineages that may be in danger of disappearing. Interestingly, patterns and processes of lineage divergence and persistence change with respect to spatial and temporal scale. I seek to evaluate biodiversity, the factors that have shaped this heterogeneity, and how this variability persists. To accomplish this I used a phylogeographic approach as well as niche and population modeling on the Peromyscus maniculatus species group found widely distributed in North America. My emphasis was …
Comparative Analysis Of Microsatellite And Mitochondrial Genetic Variation In Ixodes Scapularis, Cynthia Tak Wan Chan
Comparative Analysis Of Microsatellite And Mitochondrial Genetic Variation In Ixodes Scapularis, Cynthia Tak Wan Chan
Electronic Theses and Dissertations
Ixodes scapularis, the black legged tick, is a species endemic to North America with a range including most of the eastern-half of the United States and portions of Canada and Mexico. The tick is an important vector of diseases transmitted to humans and animals. Since its first description in 1821, the taxonomy of the species has been controversial. Biological differences have been identified in the northern and southern populations, yet no consensus exists on population structure and the causes of this disparity. Earlier molecular studies utilizing nuclear and mitochondrial genetic markers have revealed the occurrence of two distinct lineages: …
Biogeography And Diversification In The Neotropics: Testing Macroevolutionary Hypotheses Using Molecular Phylogenetic Data, Juan Manuel Daza Rojas
Biogeography And Diversification In The Neotropics: Testing Macroevolutionary Hypotheses Using Molecular Phylogenetic Data, Juan Manuel Daza Rojas
Electronic Theses and Dissertations
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 …
Genetic And Phenotypic Evolution In The Ornate Chorus Frog (Pseudacris Ornata): Testing The Relative Roles Of Natural Selection,, Jacob Degner
Electronic Theses and Dissertations
Understanding how migration, genetic drift, and natural selection interact to maintain the genetic and phenotypic variation we observe in natural populations is a central goal of population genetics. Amphibians provide excellent model organisms for investigating the interplay between these evolutionary forces because amphibians are generally characterized by limited dispersal abilities, high philopatry, and are obligately associated with the areas around suitable habitats (e.g. breeding ponds). Thus, on relatively small geographic scales, the relative effects of all of these evolutionary forces can be studied together. Here, we study the interaction of migration, genetic drift, natural selection, and historical process in the …