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Insights Into The Etheostoma Spectabile Species Complex: Incongruence Between Mitochondrial And Nuclear Gene Sequence Data, Christen M. Bossu
Insights Into The Etheostoma Spectabile Species Complex: Incongruence Between Mitochondrial And Nuclear Gene Sequence Data, Christen M. Bossu
Masters Theses
Hybridization is recognized as an evolutionary process that can provide a significant source of genetic variation and whose genetic consequences have been investigated across a wide taxonomic range of plants and animals. Darters (Percidae: Etheostomatinae) are a clade with documented interspecific hybridization and many species with a recent evolutionary origin, yet most molecular phylogenetic analyses of darters to date have relied primarily on mitochondrial DNA (mtDNA) sequences. Inferring relationships within and between closely related species using a single locus gene tree is potentially confounded by introgression as well as retention of ancestral polymorphisms. This can lead to incongruence between the …
The Effects Of Pathogen Infection On Nitrogen Remobilization In Arabidopsis Thaliana, Michelle Ann Boercker
The Effects Of Pathogen Infection On Nitrogen Remobilization In Arabidopsis Thaliana, Michelle Ann Boercker
Masters Theses
The natural enemies of plants are ubiquitous and can reduce plant fitness. Plants have evolved two defense strategies to ameliorate the fitness cost associated with natural enemy attack. The first strategy, resistance, reduces the frequency and/or severity of natural enemy damage. The second strategy, tolerance, attenuates the fitness cost of natural enemy damage. Very little is known about the traits through which tolerance is manifested, particularly with respect to plant-pathogen systems (pathosystems). Diseased and naturally senescing leaves are often similar in their visible symptoms and molecular activities, suggesting that they may involve similar processes. One process that may be shared …
A Test Of The Enemy Release Hypothesis Using A Congeneric Pair Of Lespedeza Species, Mary Gail Caflisch
A Test Of The Enemy Release Hypothesis Using A Congeneric Pair Of Lespedeza Species, Mary Gail Caflisch
Masters Theses
The enemy release hypothesis (ERH) postulates that invasive species are released from the effects of the herbivores, predators, pathogens, and other enemies that control population sizes in the native ranges of the invasive species. In a one-year common garden experiment, I compared the native species Lespedeza capitata to the invasive species Lespedeza cuneata. I examined relative fitness and performance over the first growing season and manipulated arthropod abundance using insecticide applications. While L. capitata had higher germination and survivorship than did L. cuneata, it also sustained more natural enemy damage. Arthropod reduction increased height and apparent survivorship for L. capitata. …
A Shelf-To-Basin Examination Of Food Supply For Arctic Benthic Macrofauna And The Potential Biases Of Sampling Methodology, Rebecca Pirtle-Levy
A Shelf-To-Basin Examination Of Food Supply For Arctic Benthic Macrofauna And The Potential Biases Of Sampling Methodology, Rebecca Pirtle-Levy
Masters Theses
Macrofaunal samples (benthic fauna) and sediment samples were collected in association with the sampling programs of the Bering Strait Environmental Observatory (BSEO; Cooper et al. 2006, see http://arctic.bio.utk.edu/) during the summer of 2003 and 2004 and the Western Arctic Shelf-Basin Interactions (SBI; Grebmeier and Harvey 2005, see http://sbi.utk.edu for further information) during the spring (May-June) and summer (July-August) of 2004. Benthic measurements of sediment chlorophyll a, grain size, total organic carbon, C/N ratios, and macroinfaunal community composition were measured on the shelf, slope and basin of the region. The current study focuses on sediment chlorophyll a inventories of surface …