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The Potential For Dickeya Dianthicola To Be Vectored By Two Common Insect Pests Of Potatoes, Jonas K. Insinga Dec 2019

The Potential For Dickeya Dianthicola To Be Vectored By Two Common Insect Pests Of Potatoes, Jonas K. Insinga

Electronic Theses and Dissertations

Dickeya dianthicola (Samson) causing blackleg and soft rot was first detected in potatoes grown in Maine in 2014. Previous work has suggested that insects, particularly aphids, may be able to vector bacteria in this genus between plants, but no conclusive work has been done to confirm this theory. In order to determine whether insect-mediated transmission is likely to occur in potato fields, two model potato pests common in Maine were used: the Colorado potato beetle (Leptinotarsa decimlineata Say) and the green peach aphids (Myzus persicae Sulzer). Olfactometry and recruitment experiments evaluated if either insect discriminates between infected and …


Age And Seasonal Change In The Chronobiology Of A Spider With An Exceptionally Long-Period Circadian Clock, Shae Crain Dec 2019

Age And Seasonal Change In The Chronobiology Of A Spider With An Exceptionally Long-Period Circadian Clock, Shae Crain

Electronic Theses and Dissertations

This study examines locomotor activity in samples of Frontinella pyramitela collected over its active season (April-October) to investigate whether seasonality and/or age may help explain the exceptional variability typically found in spider clock systems. Despite its noteworthy variability (%CV= 7.7), we have found that Frontinella has a mean free-running period of 28.4±2.18 hours that does not significantly vary over time. There is no correlation between day length and free-running period, indicating that varying length of FRP is not a function of photoperiod length. In LD 12:12 h, the window of activity is significantly smaller in April, gradually widening as the …


Role Of Topoisomerase Ii Alpha In Dna Topology And T Cell Responses During Chronic Viral Infections, Stella Chinyere Ogbu Dec 2019

Role Of Topoisomerase Ii Alpha In Dna Topology And T Cell Responses During Chronic Viral Infections, Stella Chinyere Ogbu

Electronic Theses and Dissertations

The clearance of viruses is largely dependent upon the activation of T cells to generate a robust immune response. However, host responses are suppressed during chronic viral infections. In this thesis, we explored the role of Top2α in DNA topology in individuals with chronic HBV, HCV, and HIV infections. We found that Top2α protein expression and activity were low in T cells derived from chronically virus-infected individuals compared to healthy subjects. Using CD4+ T cells treated with Top2α inhibitor or poisoner as a model, we demonstrated that Top2α inhibition disrupts the DNA topology, suppresses DNA repair kinase (ATM), and …


Understanding Object Motion Encoding In The Mammalian Retina., Victor Julian Depiero Dec 2019

Understanding Object Motion Encoding In The Mammalian Retina., Victor Julian Depiero

Electronic Theses and Dissertations

Phototransduction, transmission of visual information down the optic nerve incurs delays on the order of 50 – 100ms. This implies that the neuronal representation of a moving object should lag behind the object’s actual position. However, studies have demonstrated that the visual system compensates for neuronal delays using a predictive mechanism called phase advancing, which shifts the population response toward the leading edge of a moving object’s retinal image. To understand how this compensation is achieved in the retina, I investigated cellular and synaptic mechanisms that drive phase advancing. I used three approaches, each testing phase advancing at a …


Osmoregulation And Salinity Preference In Juvenile Sandbar Sharks (Carcharhinus Plumbeus) In Winyah Bay, Sc, Usa, Jessica Wingar Aug 2019

Osmoregulation And Salinity Preference In Juvenile Sandbar Sharks (Carcharhinus Plumbeus) In Winyah Bay, Sc, Usa, Jessica Wingar

Electronic Theses and Dissertations

Juvenile sandbar sharks (Carcharhinus plumbeus) have been caught in salinities ranging from 7 – 40. In Winyah Bay, a partially mixed estuary in Northeast SC, juvenile sandbar sharks tidally alternate between higher tides in middle bay and lower tides in lower bay. To assess salinity preference and duration in eight acoustically-tagged juvenile sandbar sharks in different salinities, acoustic receivers with salinity loggers were placed throughout Winyah Bay. Juvenile sandbar sharks were caught in salinities from 17.2 to 36.1 and acoustic detections were recorded from 11.5 to 24.7 by salinity loggers in middle bay. Smaller juvenile sandbar sharks used lower salinities, …


Does Thermotolerance In Daphnia Depend On The Mitochondrial Function?, Rajib Hasan Aug 2019

Does Thermotolerance In Daphnia Depend On The Mitochondrial Function?, Rajib Hasan

Electronic Theses and Dissertations

Thermotolerance limit in aquatic organism is set by the ability to sustain aerobic scope to sudden temperature shifts. This study tested the genetic and plastic differences in thermotolerance of Daphnia that can be explained by the differences in the ability to retain mitochondrial integrity at high temperatures. Five genotypes with different biogeographic origins were acclimated to 18C and 25C. We developed a rhodamine 123 in-vivo assay to measure mitochondrial membrane potential and observed higher fluorescent in heat damaged tissues as the disruption of the mitochondrial membrane potential. Significant effects on temperature tolerance were observed with CCCP …


The Effects Of Urbanization On Avian Seed Dispersal Success Of Toxicodendron Radicans (Anacardiaceae), Amber M. Stanley Aug 2019

The Effects Of Urbanization On Avian Seed Dispersal Success Of Toxicodendron Radicans (Anacardiaceae), Amber M. Stanley

Electronic Theses and Dissertations

Urbanization is increasing at a dramatic rate as the human population increases. While it is well-known that urbanization tends to decrease species diversity (i.e., biotic homogenization), it is not known how urbanization affects the frequency and efficiency of species interactions. Seed dispersal is a plant-animal interaction that depends on disperser feeding rate, disperser diversity, probability of seed dispersal and germination. How these factors are affected by urbanization however is unknown. In this study, we evaluate how urbanization alters these factors. Urban sites had 2x higher feeding rate and 3x higher number of disperser species. The probability of seed dispersal however …


Transforming Moss P. Patens With Lignin Peroxidase Through Heterologous Protein Expression., Jesse Lee Rozsa Aug 2019

Transforming Moss P. Patens With Lignin Peroxidase Through Heterologous Protein Expression., Jesse Lee Rozsa

Electronic Theses and Dissertations

Lignin peroxidase is an enzyme secreted by white-rot fungi Phanerochaete chrysosporium. Our laboratory is attempting to produce several lignin degrading enzymes in our protein expression system that utilizes the moss, Physcomitrella patens. During our experiments we discovered that this particular species of fungus produces altered splicing variants that are not represented in the previously reported reference sequence. Despite several attempts to produce a positive transformant containing a desired transgene encoding; lignin peroxidase, production of the proper construct eluded our efforts, possibly due to toxic effects associated with lignin peroxidase expression. Our laboratory has created a stepping stone for other laboratories …


Landscape Pattern And Wild Bee Communities In Maine, Brianne Du Clos May 2019

Landscape Pattern And Wild Bee Communities In Maine, Brianne Du Clos

Electronic Theses and Dissertations

Commercial production of lowbush blueberry (Vaccinium angustifolium Aiton) in Maine relies primarily on managed honeybee hives; however, naturally occurring wild bees are more efficient pollinators of the crop. Wild bees have short foraging distances and must nest near crop fields to provide pollination services. After crop bloom, the surrounding landscape must provide sufficient forage to maintain wild bee populations for the remainder of the growing season. Lowbush blueberries in Maine are produced in a mixed-use landscape with two distinct landscape contexts. Here, we document bee communities and habitat resources (nesting and floral) in power line rights-of-way and eight land …


Microplastics In The Digestive System Of The Atlantic Sharpnose Shark (Rhizoprionodon Terraenovae) In Winyah Bay, Sc, Elise Virginia Pullen May 2019

Microplastics In The Digestive System Of The Atlantic Sharpnose Shark (Rhizoprionodon Terraenovae) In Winyah Bay, Sc, Elise Virginia Pullen

Electronic Theses and Dissertations

The digestive tracts and livers of adult male Atlantic sharpnose sharks (N=16), Rhizoprionodon terraenovae, from Winyah Bay, South Carolina were examined for ingested microplastics. R. terraenovae is a small, locally abundant, coastal mesopredatory elasmobranch belonging to the family Carcharhinidae. Microfibers comprised the largest categories of plastics (94% of the total), and were found in 100% of sharks examined. The number of micro- and other plastics ranged from 34 to 75 per individual and totaled 927. The majority of plastics (40%) were blue in coloration, and 55% were <1 mm in length. Microplastics were observed on both the interior and exterior of the organs examined, and three microfibers were embedded within the stomach lining, an observation not previously reported in marine vertebrates and one which represents a potential pathway for the translocation of ingested microplastics.


Pine, Aphids, And Parasitoid Wasps: Patterns Of Cospeciation And Host Switches In A Tri-Trophic System, Amber Bass May 2019

Pine, Aphids, And Parasitoid Wasps: Patterns Of Cospeciation And Host Switches In A Tri-Trophic System, Amber Bass

Electronic Theses and Dissertations

Ecological interactions may drive speciation events, and the processes that drive these speciation events can leave behind patterns in the phylogenies of interacting taxa. These patterns have been studied extensively in herbivores and host plants, as well as parasites and their hosts, but rarely in tri-trophic systems. Here, we examine three closely related groups of interacting taxa, including parasitoid wasps (Pauesia), aphid herbivores (Cinara), and pine trees (Pinus) to determine if the patterns between each interacting taxa indicate that cospeciation or host switches are more dominant. We create phylogenies of Cinara and Pauesia in the southeastern United States using ddRADseq …


Do Per-Capita Impact Or Abundance Dominate The Impact Of An Invader? Interactions Among Neighboring Species In Context-Dependent Competition, Haoyu Li May 2019

Do Per-Capita Impact Or Abundance Dominate The Impact Of An Invader? Interactions Among Neighboring Species In Context-Dependent Competition, Haoyu Li

Electronic Theses and Dissertations

Evaluating relative species competitive strength is a central question in community ecology, with strong implications for invasion ecology. Models assessing invader success consider three components: distribution, abundance and per-capita impact. However, relative strength and interactions among these factors remain unclear when applying to specific invasion scenarios. We hypothesized that performance of native and non-native species will vary as a function of direct and indirect effects at different abundances and scales. We conducted a replacement experiment between two dominant grasses in subtropical grasslands (the native Axonopus fissifolius and the non-native Paspalum notatum) in central Florida, USA. Thirty fenced plots (1 m …


Biogeochemical Effects Of Sea Level Rise-Induced Transitions Within Coastal Wetlands, Havalend Steinmuller May 2019

Biogeochemical Effects Of Sea Level Rise-Induced Transitions Within Coastal Wetlands, Havalend Steinmuller

Electronic Theses and Dissertations

As sea level rise (SLR) affects coastal wetlands, ecosystem responses can include vertical accretion, landward transgression, or submergence. Sea level rise-induced transitions can alter key biogeochemical transformations within wetland soils, impacting the ability of these systems to provide ecosystem services, specifically carbon (C) storage and water quality regulation. Through a series of complementary laboratory and field-based studies, biogeochemical responses to salinity, vegetation shifts, and submergence were investigated. Changes in nutrient dynamics associated with saltwater intrusion were evaluated by artificially adding saline water to different freshwater wetland soil types, indicating that potential exports of critical nutrients (forms of nitrogen, phosphorus, and …


Differentiating Black Bears (Ursus Americanus) And Brown Bears (U. Arctos) Using Linear Tooth Measurements And Identification Of Ursids From Oregon Caves National Monument, Emily Bogner May 2019

Differentiating Black Bears (Ursus Americanus) And Brown Bears (U. Arctos) Using Linear Tooth Measurements And Identification Of Ursids From Oregon Caves National Monument, Emily Bogner

Electronic Theses and Dissertations

North American black bears and brown bears can be difficult to distinguish in the fossil record due to similar dental and skeletal morphologies. Challenges identifying ursid material from Oregon Caves National Monument (ORCA) called for an accurate tool to distinguish the species. This study utilized a large database of lower tooth lengths and ratios in an attempt to differentiate black and brown bears in North America. Further, this project examined how these linear measurements differ geographically. Analysis of variance (ANOVA) found significant differences between black and brown bears from across North America for every variable studied. Stepwise discriminant analyses (DA) …


Preparation Of A Flavonol Specific Glucosyltransferase Found In Grapefruit And Site-Directed Mutants For Protein Crystallization, Aaron Birchfield May 2019

Preparation Of A Flavonol Specific Glucosyltransferase Found In Grapefruit And Site-Directed Mutants For Protein Crystallization, Aaron Birchfield

Electronic Theses and Dissertations

This research was designed to determine the conditions necessary to remove c-myc and 6x-His tags from a flavonol specific glucosyltransferase found in grapefruit (CP3GT) using thrombin in preparation for crystallization. X-ray crystallography of CP3GT crystals may elucidate structural features that account for flavonol specificity in some glucosyltransferase enzymes. A thrombin cleavage site was inserted into WT CP3GT and one mutant. Recombinant CP3GT was expressed in yeast and purified. Optimal conditions for thrombin digestion were explored. Digestion with 100U of thrombin for 2 hours at 4o C was optimal for removing tags from CP3GT. Storage at 4o C for …


Defects In Fetal Mouth Movement And Pharyngeal Patterning Underlie Cleft Palate Caused By Retinoid Deficiency., Regina Friedl May 2019

Defects In Fetal Mouth Movement And Pharyngeal Patterning Underlie Cleft Palate Caused By Retinoid Deficiency., Regina Friedl

Electronic Theses and Dissertations

Cleft palate is a common birth defect. Etiologic mechanisms of palate cleft include defects in palate morphogenesis, mandibular growth, or spontaneous fetal mouth movement. Cleft palate linked to deficient fetal mouth movement has been demonstrated directly only in a single experimental model of loss of neurotransmission. Here, using retinoid deficient mouse embryos, we demonstrate directly for the first time that deficient fetal mouth movement and cleft palate occurs as a result of mis-patterned development of pharyngeal peripheral nerves and cartilages. Retinoid deficient embryos were generated by inactivation of retinol dehydrogenase 10 (Rdh10), which is critical for production of …


Exploring Multi-Scale Variation Of Fish Community Diversity In A Dynamic Coastal Estuary, Brittany Troast Jan 2019

Exploring Multi-Scale Variation Of Fish Community Diversity In A Dynamic Coastal Estuary, Brittany Troast

Electronic Theses and Dissertations

Examining diversity over multiple spatial and temporal scales affords the opportunity to develop a mechanistic understanding of the factors influencing community diversity dynamics, and how these may shift in a changing world. This thesis first examines multi-decadal fish community diversity metrics across a coastal biogeographic transition zone to quantify changes in species assemblages, assess relationships between fish community diversity and the abiotic environment, and capture potential shifts in the location of a putative biogeographic break. Results of this chapter indicate not only a change in fish community composition, but also a shift in the location of the biogeographic transition zone. …


Assessing The Effects Of Habitat And Manatee Exclusion Devices On Red Drum (Sciaenops Ocellatus) Movement Patterns In Estuarine Impoundments, Steven Baker Jan 2019

Assessing The Effects Of Habitat And Manatee Exclusion Devices On Red Drum (Sciaenops Ocellatus) Movement Patterns In Estuarine Impoundments, Steven Baker

Electronic Theses and Dissertations

The Integrate-Transfer-Launch (ITL) complex impoundments located within the Kennedy Space Center security zone are known spawning sites for red drum (Sciaenops ocellatus). However, recent construction of manatee exclusion bollards around culverts leading into these impoundments may impede movement to and from this critical habitat. The goals of this study were to: 1) utilize passive acoustic telemetry to document patterns of red drum movement and habitat use within and around the ITL impoundments to assess how manatee exclusion bollards and environmental conditions may impact movement of red drum; and 2) explore red drum movement in response to environmental disturbance, specifically a …


Increasing Accumulation Of Glyceollins In Soybeans Via Optimization Of The Fungal Incubation Process, Stephanie Wootton Jan 2019

Increasing Accumulation Of Glyceollins In Soybeans Via Optimization Of The Fungal Incubation Process, Stephanie Wootton

Electronic Theses and Dissertations

Continual use of antibiotics in the feed of food animals was viewed a solution to the problem of disease outbreaks in livestock produced in confinement operations. This practice also improved animal performance, likely due to the reduction in sub-clinical infections. Unfortunately, this practice led to a new problem, the development of antibiotic resistant microbes. This increase in antibiotic resistance reduced the direct benefits of antibiotics in animal production. Moreover, as antibiotic resistance spread from animal to human pathogens, this practice created a major public health concern. This led the FDA to enact the Veterinary Feed Directive in 2017 that greatly …


Understanding Sediment Biogeochemistry And The Role Of Juvenile Oysters On Recently Restored Eastern Oyster Reefs, Bryan Locher Jan 2019

Understanding Sediment Biogeochemistry And The Role Of Juvenile Oysters On Recently Restored Eastern Oyster Reefs, Bryan Locher

Electronic Theses and Dissertations

In recent decades, goals for the restoration of eastern oyster (Crassostrea virginica) populations along the eastern coast of the United States have shifted from increasing harvestable oyster fisheries to enhancing the range of ecosystem services provided by oyster reefs. By filtering large volumes of water and releasing nutrient-rich feces and pseudofeces, oysters can locally enhance sediment biogeochemical cycling compared to that of unstructured benthic environments. An ongoing restoration program in Mosquito Lagoon, FL was leveraged to assess the immediate impacts ( < 1 year) of restoration on sediment biogeochemical properties of oyster reefs. The first study measured both short-term and long-term pools of carbon, nitrogen and phosphorus on dead, natural and restored reefs periodically over one year. The second study investigated one of the contributions to sediment nutrient pools by comparing feeding and feces/pseudofeces nutrient content of juvenile and older oysters. Results show that inorganic nitrogen and phosphorus pools can change within weeks after restoration and total nutrient pools by 6 months post-restoration. Restored reefs experienced a 136 % increase in ammonium, 78 % increase in total nitrogen, 46 % increase in total phosphorus, and 75 % increase in organic matter concentrations after 12 months of restoration. These nutrient increases were all positively correlated with oyster density, shell length and reef height measured on each reef. When standardized to grams of dry tissue weight, juvenile oysters showed significantly higher rates of chlorophyll-a removal, release of ammonium, and biodeposits with higher concentrations of dissolved organic carbon, nitrite + nitrate, and ammonium. The short-term changes to biogeochemical cycling on eastern oyster reefs within the first year of restoration are important to managers seeking to monitor ecosystem service recovery and overall coastal ecosystem health.


Business In The Estuary, Party In The Sea: Migration Patterns Of Striped Mullet (Mugil Cephalus) Within The Indian River Lagoon Complex, Olivia Myers Jan 2019

Business In The Estuary, Party In The Sea: Migration Patterns Of Striped Mullet (Mugil Cephalus) Within The Indian River Lagoon Complex, Olivia Myers

Electronic Theses and Dissertations

Commercial and recreational environmental enterprises in the Indian River Lagoon (IRL), Florida supply nearly 10,000 jobs and produce $1.6 billion dollars a year in revenue. These waters contain iconic species of sportfish, including red drum, snook, and sea trout, as well as their lower trophic level prey such as snapper and mullet. Striped mullet (Mugil cephalus) are both commercially valuable as well as an indicator species for overall ecosystem health. From September to December, mullet in the IRL undergo an annual migration from their inshore foraging habitats to oceanic spawning sites. However, their actual migratory pathways remain unknown. To address …


Seascape Genetics And Rehabilitation Efficiency In The Florida Manatee, Madison Hall Jan 2019

Seascape Genetics And Rehabilitation Efficiency In The Florida Manatee, Madison Hall

Electronic Theses and Dissertations

The Florida manatee (Trichechus manatus latirostris) was recently downlisted federally from "endangered" to "threatened" despite acknowledgments of remaining threats to long term population persistence. Challenges to future manatee conservation include, but are not limited to, increases in frequency of harmful algal blooms, intensifying anthropogenic disturbance, and loss of warm-water habitat. The goals of this dissertation were 1) to assess threats to the manatee via a comprehensive, long-term (1973-2016), retrospective analysis of the manatee rescue and rehabilitation partnership (MRRP) and 2) to use seascape genetics analysis to examine whether abiotic, biotic, or anthropogenic seascape variables could significantly describe genetic distance patterns …


The Ecology Of Central Florida's Thief Ants (Hymenoptera: Formicidae: Solenopsis), Leo Ohyama Jan 2019

The Ecology Of Central Florida's Thief Ants (Hymenoptera: Formicidae: Solenopsis), Leo Ohyama

Electronic Theses and Dissertations

Thief ants of the genus Solenopsis are a diverse group of ants that are found in ant communities throughout the world. They have long been purported to practice lestobiosis, an interaction between small and larger-bodied ants, where small ants cryptically tunnel into larger-bodied ant nests within the subterranean environment and steal brood or eggs for consumption. Thief ants are extremely small, measuring 1-2 mm in length and many of the species within this group practice a subterranean life history, where they live the entirety of their lives exclusively belowground. Due to these key characteristics, the ecology and natural history of …


Hydrodynamic Limitations And The Effects Of Living Shoreline Stabilization On Mangrove Recruitment Along Florida Coastlines, Christian Pilato Jan 2019

Hydrodynamic Limitations And The Effects Of Living Shoreline Stabilization On Mangrove Recruitment Along Florida Coastlines, Christian Pilato

Electronic Theses and Dissertations

The recruitment success of mangroves is influenced by a variety of factors, including propagule availability, desiccation, herbivory, and hydraulic habitat limitations. Hydrodynamic forces (waves and currents) act as obstacles to mangrove recruitment, restricting the successful colonization of mangrove species. We evaluated the biological and physical limitations to mangrove recruitment through monthly shoreline surveys and lateral pull-tests. Surveys followed mangroves from propagule release through recruitment along the shorelines of De Soto National Memorial (Bradenton, FL), capturing differences in propagule availability and recruitment along natural areas and across differing forms of shoreline stabilization ("living shorelines" and revetments). Propagule densities were highest along …


Characterization Of Vps41 And Its Role In The Regulated Secretory Pathway, Christian Henry Burns Jan 2019

Characterization Of Vps41 And Its Role In The Regulated Secretory Pathway, Christian Henry Burns

Electronic Theses and Dissertations

Insulin secretory granules (SGs) mediate the regulated secretion of insulin, which is essential for glucose homeostasis. The basic machinery responsible for this regulated exocytosis consists of specific membrane proteins present both at the plasma membrane and on insulin SGs. The protein composition of insulin SGs thus dictates their release properties, yet the mechanisms controlling insulin SG formation, which determines this molecular composition, remain poorly understood. VPS41, a component of the endolysosomal tethering HOPS complex, was recently identified as a cytosolic factor involved in the formation of neuroendocrine/neuronal granules. We now find that a stable pool of VPS41 exists outside of …


Qualitative And Quantitative Fitness Consequences Of Advanced Maternal Age, Claudia Jean Hallagan Jan 2019

Qualitative And Quantitative Fitness Consequences Of Advanced Maternal Age, Claudia Jean Hallagan

Electronic Theses and Dissertations

Parental age can affect offspring fitness across taxa and through various mechanisms. However, the effect(s) of advanced maternal age on offspring, particularly in insects, has not been comprehensively reviewed making it difficult to draw conclusions about the effects of advanced maternal age on offspring in insects. In my first chapter, I reviewed maternal age literature and found overall negative effects of advanced maternal age on offspring fitness. However, results vary depending on which fitness measures were used, the life stages at which offspring were measured, and the experimental design of the study. In my second chapter, I conducted an experiment …


Diversification In The Neotropics – Evolution And Population Genetics Of The Armored Catfish Hypancistrus Sp. From The Xingu River, Marcella Goncalves Santos Jan 2019

Diversification In The Neotropics – Evolution And Population Genetics Of The Armored Catfish Hypancistrus Sp. From The Xingu River, Marcella Goncalves Santos

Electronic Theses and Dissertations

The Xingu River, one of the largest tributaries of the Amazon River, is currently in peril due to the recent construction of hydroelectric dams, but little is known about the numerous fish species it supports. This dissertation focuses on three pleco catfish species belonging to the genus Hypancistrus from the Xingu River with partially overlapping distributions: H. zebra, H. sp. (L174), and H. sp. (L66/333). Chapter 1 is a bibliographic review of Amazonian freshwater fish diversity, with the goal of discussing the hypotheses of speciation mechanisms that can be tested in this system, including the relative importance of ecological adaptation …


The Evolution Of Coral Snake Mimicry, Renan Janke Bosque Jan 2019

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 …


Effects Of Impoundments On The Community Assemblage And Gene Flow Of Stream Crayfishes, Zanethia Choice Barnett Jan 2019

Effects Of Impoundments On The Community Assemblage And Gene Flow Of Stream Crayfishes, Zanethia Choice Barnett

Electronic Theses and Dissertations

Dams and their impoundments block movement of stream organism and change stream physiochemical properties, which subsequently changes biological assemblages and creates barriers to gene flow. While changes in species assemblages and gene flow have been assessed for numerous impoundments and stream organisms, no study has assessed the effects of large impoundments on crayfish assemblages and population genetic diversity and connectivity. I examined the physiochemical, biological, and genetic effects of impoundments on crayfishes. Between May 2015 and August 2017, I sampled multiple sites up- and downstream of three impounded streams, and along the lengths of two unimpounded streams, in the Bear …


Examining The Role Of Reproductive Interference In The Decline Of Native Green Treefrogs Following Cuban Treefrog Invasions, Joseph Kennedy Jan 2019

Examining The Role Of Reproductive Interference In The Decline Of Native Green Treefrogs Following Cuban Treefrog Invasions, Joseph Kennedy

Electronic Theses and Dissertations

Reproductive interference occurs when the mating behaviors of one species negatively impact the fitness of another species. It is of increasing interest in invasive species biology because the introduction of alien species often leads to novel sexual interactions with native taxa, which can contribute to their decline. I examined whether reproductive interference plays a role in the decline of native green treefrogs (Hyla cinerea) following invasions of Cuban treefrogs (Osteopilus septentrionalis) in the southeastern United States. The impetus for this study revolves around similarities in spectro-temporal features of Cuban treefrog courtship calls and green treefrog aggressive calls. The significance of …