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Theses and Dissertations

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Full-Text Articles in Ecology and Evolutionary Biology

Evolution Of Endurance Running Genes Across Primates, Natalia T. Grube Apr 2019

Evolution Of Endurance Running Genes Across Primates, Natalia T. Grube

Theses and Dissertations

The endurance running hypothesis has emerged as a key idea to explain several unique anatomical, physiological, and genetic features of modern humans—among these features is the evolution of ACTN3 (Bramble & Lieberman 2004, Nature), a gene linked to human athletic performance. An additional gene linked to human endurance performance is ACE. Because endurance running is a uniquely human trait, I predicted that ACE and ACTN3 genes would be evolving adaptively in the human lineage when examined in a wider primatological framework. To test this I compiled ACE and ACTN3 genes from 14 primate species and phylogenetically tested if these genes …


Phylogenetic History Of The Amy Gene Cluster In Catarrhines, Christian M. Gagnon Feb 2019

Phylogenetic History Of The Amy Gene Cluster In Catarrhines, Christian M. Gagnon

Theses and Dissertations

This study phylogenetically analyzed 30 AMY-related genes from 11 primates. The results show the gradual expansion of the AMY gene family which could have allowed primates to adapt to various ecological landscapes and maximize energy intake from starch-rich foods in periods of food scarcity.


Climatic Variables Are Strong Predictors Of Allonursing And Communal Nesting In Primates, Alexandra Louppova Feb 2019

Climatic Variables Are Strong Predictors Of Allonursing And Communal Nesting In Primates, Alexandra Louppova

Theses and Dissertations

Allomaternal care (AMC) is widespread throughout the primate order, previous studies have focused on benefits and costs to individuals. However, our understanding of environmental impacts on AMC behaviors in primates is still limited. Our study examines how ecology and environmental factors can predict certain AMC behaviors more than others.


Dolphins In Space: Quantifying The Relative Positions Of Bottlenose Dolphins (Tursiops Truncatus), Megan S. Mcgrath Feb 2019

Dolphins In Space: Quantifying The Relative Positions Of Bottlenose Dolphins (Tursiops Truncatus), Megan S. Mcgrath

Theses and Dissertations

Bottlenose dolphins (Tursiops truncatus) are socially sophisticated mammals with high fission-fusion dynamics and complex communication. The relative positioning of individual dolphins as they swim within their social group may aid in the expression of social roles. This study sought to quantify relative positioning in a small social group of female bottlenose dolphins at the National Aquarium in Baltimore that included two mother-daughter pairs, maternal and paternal half-sisters, a half-aunt and niece, and one unrelated female. We devised a method for scoring relative positioning in three dimensions. We found that the two mothers and their juvenile and adult daughters …


A Dietary Analysis On Panamanian Bat Species, John C. Waller Jan 2019

A Dietary Analysis On Panamanian Bat Species, John C. Waller

Theses and Dissertations

Bats are found all over the world, and they are the most diverse group of mammals in the tropics. They are a key component in all ecosystems as predators, pollinators, or seed dispersers. As a conservation tool, dietary studies show what different bat species need to survive. Through metabarcoding, the diet can be accurately assessed. This method involves the DNA extraction of material from the feces of the individual being studied. PCR is used to amplify the DNA and next generation sequencing is used to identify, separate, and align the DNA that was extracted. By comparing the results from different …


Upper Thermal Limits Vary Among And Within Native Bee Species In Relation To Season, Voltinism, And Nest Type, Kálmán K. Csigi Xiv Jan 2019

Upper Thermal Limits Vary Among And Within Native Bee Species In Relation To Season, Voltinism, And Nest Type, Kálmán K. Csigi Xiv

Theses and Dissertations

Native bees are only recently gaining attention for the extent to which they aid in pollination and ecosystem services. These services are threatened by predictions of warming temperatures if bees are not able to respond. Voltinism - the number of generations produced annually- can strongly influence thermal conditions experienced by both developing and adult bees based on emergence strategies for each voltinism type. Differences in experienced thermal conditions brought on by climate change could therefore affect upper thermal limits (UTL) in bees. This study observes UTLs across a foraging season within and among native bee species vi to elucidate the …


Nutrient Uptake Among Urban And Non-Urban Streams Within The Piedmont Physiographic Province Of Virginia, Joseph T. Famularo Jan 2019

Nutrient Uptake Among Urban And Non-Urban Streams Within The Piedmont Physiographic Province Of Virginia, Joseph T. Famularo

Theses and Dissertations

To assess how urbanization impacts stream nutrient uptake, a series of instantaneous (i.e. slug) nutrient additions were conducted in 3 urban and 3 non-urban streams during open and closed canopy conditions. Single additions of N, P, and combined additions of N and P were performed at each site. These data were used to test the hypothesis that high N:P concentrations in urban streams would result in P-limited conditions, and to assess differences in nutrient uptake kinetics (i.e., the relationship between uptake and concentration) between urban and non-urban streams. The results show that there were no consistent differences in N vs. …


Assessment Of Microbial Carbon Processing And Its Implications To The Carbon Budget Of Lake Superior, Lindsey Michelle Koren Jan 2019

Assessment Of Microbial Carbon Processing And Its Implications To The Carbon Budget Of Lake Superior, Lindsey Michelle Koren

Theses and Dissertations

Over the past few decades, there has been increased research focus on carbon cycling within aquatic systems, especially with the changing global climate. Inland waters play a major role in the global carbon cycle, but the fundamental features remain poorly understood, particularly the large lakes of the world. Our experimental approach assessing the carbon budget of Lake Superior, the largest freshwater lake by area, provides spatial and temporal variability that has been previously overlooked but may be critical to our understanding on the biogeochemical processes controlling the lake. Multiple stations were chosen across the lake, both nearshore and offshore, to …


Spatial Genetic Structure And Local Adaptation Within And Among Foxtail Pine (Pinus Balfouriana Subsp. Balfouriana) Populations Located In The Klamath Mountains, California, Rebecca D. Piri Jan 2019

Spatial Genetic Structure And Local Adaptation Within And Among Foxtail Pine (Pinus Balfouriana Subsp. Balfouriana) Populations Located In The Klamath Mountains, California, Rebecca D. Piri

Theses and Dissertations

Foxtail pine (Pinus balfouriana) is a subalpine conifer endemic to California, notably separated into two disjunct subspecies. Previous studies have described the northern subspecies,Pinus balfouriana subsp. balfouriana,as having an uncommonly high level of genetic differentiation and no discernible spatial patterns in phenotypic variation. This study seeks to characterize the spatial genetic structure and patterns of selection of the northern subspecies (Pinus balfouriana subsp. balfouriana) using genome-wide data and to identify the influence of ecology and environment on the unique genetic patterns. I show that genetic differentiation among populations is much less than previously estimated …


Eternal Enemies, Or Incidental Encounters? Structure And Patterns Of Interspecific Killing In Carnivora, Tor G. Bertin Jan 2019

Eternal Enemies, Or Incidental Encounters? Structure And Patterns Of Interspecific Killing In Carnivora, Tor G. Bertin

Theses and Dissertations

Lethal interactions between carnivorans (interspecific killing) may influence their population dynamics, behavior, and other important aspects of their ecology. In this study, I expand upon previous research on the broad-scale patterns of interspecific killing in Carnivora (Palomares & Caro 1999, Donadio & Buskirk 2006) with a greatly expanded dataset (inclusion of scat and stomach data and more intensive sampling of the literature), and suggest avenues for future research. While like previous studies, I found a positive effect of relative body size between killer species and killed species on the likelihood of forming a killing interaction, I failed to find evidence …


Spatial And Temporal Distributions Of Larval Clupeid Fishes In A Tidal Freshwater Marsh Complex, Philip Reid Anderson Jan 2019

Spatial And Temporal Distributions Of Larval Clupeid Fishes In A Tidal Freshwater Marsh Complex, Philip Reid Anderson

Theses and Dissertations

Tidal freshwater wetlands provide valuable ecosystem services such as nutrient cycling, coastal flood control, and reproductive habitat for early life stages of economically and ecologically important fishes. The nutrient rich environments that tidal freshwater wetlands occur in support high levels of primary productivity of phytoplankton and vegetation that provide essential reproductive habitat for anadromous clupeid fishes (Alosa spp., Brevoortia tyrannus) in Chesapeake Bay tributaries. Seasonal retention of clupeid eggs and larvae within tidal freshwater habitats may enhance early growth, survival, and year class strength. The primary goal of the present study was to characterize the relative importance of …


Characterizing Water Quality And Hydrologic Properties Of Urban Streams In Central Virginia, Rikki Lucas Jan 2019

Characterizing Water Quality And Hydrologic Properties Of Urban Streams In Central Virginia, Rikki Lucas

Theses and Dissertations

The objective of this study was to characterize water quality and hydrologic properties of urban streams in the Richmond metropolitan area. Water quality data were analyzed for six urban sites and two non-urban sites. Geomorphological surveys and conservative tracer studies were performed at four urban sites and one non-urban site to describe intra- and inter- site variability in transient storage, channel geomorphology, and related hydrologic parameters. Urban sites showed elevated concentrations of nitrogen and more variable TSS concentrations relative to reference sites. Urban channels were deeply incised with unstable banks and low sinuosity. Little Westham Creek exhibited the greatest transient …


Mechanisms Underlying Production Stability In Temperate Deciduous Forests, Shea B. Wales Jan 2019

Mechanisms Underlying Production Stability In Temperate Deciduous Forests, Shea B. Wales

Theses and Dissertations

A persistent and reliable future terrestrial carbon (C) sink will depend on how stable forest production is under more variable climate conditions. We examined how age, forest structure, and disturbance history relate to the interannual variability of above-ground wood net primary production (NPPw). Our site in northern Michigan spans two experimental forest chronosequences and three late successional stands; the chronosequences have distinct disturbance histories, originating following either clear cut harvesting (“Cut Only”) or clear cut harvesting and fire (“Cut and Burn”), and range from 21 to 108 years old. Annual NPPw was estimated using dendrochronology and site specific allometric equations. …


Geospatial Analysis Of Invasive Plant Species And Their Threats To Ecological Functionality At The Vcu Rice Rivers Center, Erik W. Kellogg Jan 2019

Geospatial Analysis Of Invasive Plant Species And Their Threats To Ecological Functionality At The Vcu Rice Rivers Center, Erik W. Kellogg

Theses and Dissertations

Invasive plants are a significant threat to native ecosystems and to biodiversity. They are often strong competitors and have multiple techniques to outcompete native plants. Thus, controlling or removing invasive plants facilitates the restoration of native ecosystems. We used GPS technology coupled with field surveying techniques adapted from the U.S. Fish and Wildlife Service to locate and identify invasive plants present within VCU’s Rice Rivers Center. We digitally overlaid a 50-meter x 50-meter grid system over the property. In each grid cell we recorded visual estimations of invasive plant coverage sorted into modified Daubenmire cover classes and used ArcGIS for …


Influence Of Environmental Features On Spermatophore Placement In Spotted Salamanders (Ambystoma Maculatum), Megan A. Kuechle Jan 2019

Influence Of Environmental Features On Spermatophore Placement In Spotted Salamanders (Ambystoma Maculatum), Megan A. Kuechle

Theses and Dissertations

Successful reproduction in salamanders is driven by behavioral, environmental, and temporal interactions among adults. While much of our understanding of salamander mating systems is based upon either courtship behavior of both sexes or aspects of female choice, the decisions made by males regarding where to place spermatophores is much less quantified. In this study, we mapped male spermatophore placement in the spotted salamander (Ambystoma maculatum) with respect to ecological and spatial locations within a vernal pool complex in Charles City County, Virginia. The overall goal was to use the spatial and ecological placement of spermatophores to determine if …


Testing For Cryptic Diversity And Inference Of Population Structure In The Cosmopolitan Hoplonemertean Emplectonema Gracile (Nemertea), Paul L. Delaney Iv Jan 2019

Testing For Cryptic Diversity And Inference Of Population Structure In The Cosmopolitan Hoplonemertean Emplectonema Gracile (Nemertea), Paul L. Delaney Iv

Theses and Dissertations

Emplectonema gracile (Johnston 1837) is a hoplonemertean of marine intertidal hard-bottom communities and is distributed throughout the Northern Hemisphere. Although possessing a planktonic larval stage in its life history, the range of such cosmopolitan marine invertebrate species is often explained by cryptic speciation and anthropogenic transport. The purpose of this study is to test for possible cryptic species using mtDNA markers (COI and 16S rDNA) and to investigate population structure in E. gracile over a portion of its geographic range using mtDNA markers and ddRADseq nuclear SNP data. The results of both phylogenetic- and tree-based species delimitation revealed that E. …


Chamaecrista Fasciculata In Tallgrass And Sand Prairies: The Potential For Differential Responses, Robert W. Philips Jun 2018

Chamaecrista Fasciculata In Tallgrass And Sand Prairies: The Potential For Differential Responses, Robert W. Philips

Theses and Dissertations

Successful establishment of a diversity of native species has become an important goal for restoration site managers to achieve, however as seed sources for a species may occur in habitats with different abiotic and biotic characteristics. Consequently, seeds from different sources may vary in their success in a restoration. Chamaecrista fasciculata, a native prairie species, occurs in two divergent prairie types - tallgrass and sand prairies. Tallgrass prairies have a moist soil with dense vegetation; in contrast, sand prairies have a well-drained sandy soil with sparse vegetation. I propose differential selection acting on populations in these prairie types would affect …


When Does Less Equal More? Assessing The Mechanisms Driving Compensatory Mortality And The Hydra Effect, Joseph T. Neale Jun 2018

When Does Less Equal More? Assessing The Mechanisms Driving Compensatory Mortality And The Hydra Effect, Joseph T. Neale

Theses and Dissertations

Many populations across taxa are regulated by negative density-dependence, wherein increased population sizes lead to decreased birth rates and/or increased mortality. By releasing such populations from some level of these density-dependent effects, extrinsic mortality can lead to counter-intuitive results, such as no change in population size (compensation), or an increase in population size (overcompensation). These results have been documented experimentally, but there currently exists a dearth of empirical studies exploring the mechanisms behind the phenomenon. We tested the relationship between extrinsic mortality level and (over)compensation in four mosquito species – Aedes aegypti, A. albopictus, A. triseriatus, and Culex pipiens – …


Learning To See The Forest For The Corn: Establishing Sense Of Place And Community In A Field-Based Ecology Course For Pre-Service Educators, Michelle Edgcomb Friday Feb 2018

Learning To See The Forest For The Corn: Establishing Sense Of Place And Community In A Field-Based Ecology Course For Pre-Service Educators, Michelle Edgcomb Friday

Theses and Dissertations

In this dissertation grounded theory techniques were used to characterize pre-service educators’ experiences in a semester-long, field-based ecology course. Through participation in a citizen science project, participants formed a community of practice that extended their conceptions of themselves as ecology students and scientists. Extended field experiences in a variety of local ecosystems contributed to the development of a sense of place. Paired fieldwork with lecture aided their developing ecological literacy and their understanding of place-based pedagogy. All of these combined to support their growing understanding of their role in field-based ecology education. Lack of background in ecology and ecology pedagogy …


How The Egg Rolls: A Morphological Analysis Of Egg Shape In The Context Of Displacement Dynamics, Ian R. Hays Jan 2018

How The Egg Rolls: A Morphological Analysis Of Egg Shape In The Context Of Displacement Dynamics, Ian R. Hays

Theses and Dissertations

Very little is known about how morphology effects the motion, stability and the resulting viability of avian eggs. The limited research that exists focuses on the pyriform or ‘pointed’ egg shapes found in the Alcidea family. This unusual shell form is thought to suppress displacement and prevents egg loss on the cliffside nesting habitat of the Uria genera. Unfortunately, these studies never isolated or quantify the specific morphological features (elongation, asymmetry and conicality) of these pyriform eggs, which limits their applicability to other taxa and hampers a robust proof of concept. We isolated each feature as a variable, produced models …


Floral Symmetry Genes Elucidate The Development And Evolution Of Oil-Bee Pollinated Flowers Of Malpighiaceae And Krameriaceae, Farahnoz N. Khojayori Jan 2018

Floral Symmetry Genes Elucidate The Development And Evolution Of Oil-Bee Pollinated Flowers Of Malpighiaceae And Krameriaceae, Farahnoz N. Khojayori

Theses and Dissertations

Specialization on insect and animal pollinators is thought to be the driving force for the evolution of floral traits. Specifically in the New World (NW), the oil-bee pollination syndrome has led to the convergence of floral characters in two distantly related families of core eudicots, Malpighiaceae and Krameriaceae. Both families display a flag-like structure that establishes a zygomorphic flower and floral oil rewards in epithelial elaiophores. These traits work concomitantly to attract and reward female oil-bees that help fertilize these flowers and in return receive oils. The underlying genetics of floral zygomorphy were studied in several clades of core eudicots, …


Improving Estuarine Water Quality In South Florida: A Quantitative Evaluation Of The Efficacy Of A Local Nutrient Ordinance, Kerstin Motsch Jan 2018

Improving Estuarine Water Quality In South Florida: A Quantitative Evaluation Of The Efficacy Of A Local Nutrient Ordinance, Kerstin Motsch

Theses and Dissertations

Degraded coastal water quality is a concern in Florida, in part due to nutrient enrichment of aquatic ecosystems causing eutrophication and excessive algal growth. In 2010, a fertilizer ordinance was enacted in Cape Coral located in Lee County Florida with the objective of reducing nutrient loads from local fertilizing practices in order to improve water quality within the city. In order to assess its efficacy, a before after control impact (BACI) design was implemented using Fort Lauderdale in Broward County Florida as a reference location. A total of twenty estuarine canal sampling locations were identified in both Lee and Broward …


Using Maximum Entropy To Model The Distribution Of An Endangered, Endemic Crayfish Cambarus Harti (Hobbs), James Kiourtsis Jan 2018

Using Maximum Entropy To Model The Distribution Of An Endangered, Endemic Crayfish Cambarus Harti (Hobbs), James Kiourtsis

Theses and Dissertations

Cambarus harti is a state-listed endangered, endemic crayfish found only in three counties in mid-west Georgia. Several studies have attempted to characterize the biology and ecology of this crayfish, however data regarding the distribution of this rare, endemic crayfish remains limited. The International Union for Conservation of nature stated that in order to create an effective conservation plan, the known distribution must be expanded. Species distribution models are a cost-effective way to identify locations that have similar habitat characteristics to those with known populations. One species distribution model, Maximum Entropy (MaxEnt), is the preferred approach when modeling species, like C. …


Red-Headed Woodpecker Full Annual Cycle Ecology At Fort A.P. Hill, Virginia, Benjamin Nickley Jan 2018

Red-Headed Woodpecker Full Annual Cycle Ecology At Fort A.P. Hill, Virginia, Benjamin Nickley

Theses and Dissertations

The red-headed woodpecker is a primary cavity excavator found throughout the Eastern Deciduous Forest and parts of the Great Plains. Although widespread, the red-headed woodpecker is generally considered uncommon, with patchily distributed populations. Over the past 50 years, this species has experienced precipitous, range-wide declines. The red-headed woodpecker uses a variety of cover types to meet resource needs across the annual cycle, ranging from oak savannas and wetlands, to mature beech forests and urban parks. Given their apparent adaptability to such a wide range of habitats, causes of declines are perplexing. To understand and stem declines, recent studies have focused …


Evolving Reproductive Isolation In The Parasitic Wasp Genus Cotesia, Justin P. Bredlau Jan 2018

Evolving Reproductive Isolation In The Parasitic Wasp Genus Cotesia, Justin P. Bredlau

Theses and Dissertations

Parasitic wasps are highly diverse and play a major role in suppression of herbivorous pest populations, but relatively little is known of the mechanisms driving their diversity. Molecular studies indicate that cryptic species complexes resulting from adaptations to specific hosts or host-foodplants may be common. The gregarious endoparasitoid, Cotesia congregata (Braconidae), is a model system for understanding parasitic wasp biology. It is reported to attack at least 15 species of sphingid caterpillars, most of which are plant family specialists. Molecular studies have demonstrated genetic differentiation of two host-foodplant complex sources originating from Manduca sexta on tobacco (MsT) and Ceratomia catalpae …


Natural And Anthropogenic Drivers Of Tree Evolutionary Dynamics, Brandon M. Lind Jan 2018

Natural And Anthropogenic Drivers Of Tree Evolutionary Dynamics, Brandon M. Lind

Theses and Dissertations

Species of trees inhabit diverse and heterogeneous environments, and often play important ecological roles in such communities. As a result of their vast ecological breadth, trees have become adapted to various environmental pressures. In this dissertation I examine various environmental factors that drive evolutionary dynamics in threePinusspecies in California and Nevada, USA. In chapter two, I assess the role of management influence of thinning, fire, and their interaction on fine-scale gene flow within fire-suppressed populations of Pinus lambertiana, a historically dominant and ecologically important member of mixed-conifer forests of the Sierra Nevada, California. Here, I find evidence …


The Role Of Vegetation-Topographic Interactions In A Barrier Island System: Island Migration In A Changing Climate, Benjamin Nettleton Jan 2018

The Role Of Vegetation-Topographic Interactions In A Barrier Island System: Island Migration In A Changing Climate, Benjamin Nettleton

Theses and Dissertations

Islands have been characterized based on vegetation and topography as exhibiting different disturbance regimes - reinforcing or resisting. This study had two objectives: quantify barrier island upland migration and vegetation cover change over 32 years (1984-2016), and assess tolerance of two prevalent dune grass species, A. breviligulata, and S. patens to sand burial. Using Landsat imagery from the Virginia Coast Reserve, islands were categorized within the disturbance resistance/reinforcing framework based on dune elevation. Resistant areas were associated with woody cover and low marsh to upland migration while reinforcing areas had low vegetation cover and high rates of migration. System-wide, …


Forest Structural Complexity And Net Primary Production Resilience Across A Gradient Of Disturbance In A Great Lakes Ecosystem, Lisa T. Haber Jan 2018

Forest Structural Complexity And Net Primary Production Resilience Across A Gradient Of Disturbance In A Great Lakes Ecosystem, Lisa T. Haber

Theses and Dissertations

Forests are an important component of the global carbon (C) cycle and contribute to climate change mitigation through atmospheric C uptake and storage in biomass and soils. However, the forest C sink is susceptible to disturbance, which modifies physical and biological structure and limits spatial extent of forests. Unlike severe, stand-replacing disturbances that reset forest successional trajectories and may simplify ecosystem structure, moderate severity disturbances may instead introduce complexity in ways that sustain net primary production (NPP), leading to the phenomenon of “NPP resilience.” In this study, we examined the linkage between disturbance severity and ecosystem biological and physical structural …


Climate Change And Mountaintop Removal Mining: A Maxent Assessment Of The Potential Dual Threat To West Virginia Fishes, Lindsey R F Hendrick Jan 2018

Climate Change And Mountaintop Removal Mining: A Maxent Assessment Of The Potential Dual Threat To West Virginia Fishes, Lindsey R F Hendrick

Theses and Dissertations

Accounts of species’ range shifts in response to climate change, most often as latitudinal shifts towards the poles or upslope shifts to higher elevations, are rapidly accumulating. These range shifts are often attributed to species ‘tracking’ their thermal niches as temperatures in their native ranges increase. Our objective was to estimate the degree to which climate change-driven shifts in water temperature may increase the exposure of West Virginia’s native freshwater fishes to mountaintop removal surface coal mining. Mid-century shifts in habitat suitability for nine non-game West Virginia fishes were projected via Maximum Entropy species distribution modeling, using a combination of …


Migratory Patterns And Population Genetic Structure In A Declining Wetland-Dependent Songbird, Matthew G. Desaix Jan 2018

Migratory Patterns And Population Genetic Structure In A Declining Wetland-Dependent Songbird, Matthew G. Desaix

Theses and Dissertations

Understanding migratory connectivity is essential for assessing the drivers behind population dynamics and for implementing effective management in migratory species. Genetic markers provide a means to describe migratory connectivity, as well as incorporate population genetic analyses, however genetic markers can be uninformative for species with weak genetic structure. In this study, we evaluate range-wide population genetic structure and migratory connectivity in the prothonotary warbler, Protonotaria citrea, a wetland-dependent neotropical migratory songbird, using high-resolution genetic markers. We reveal regional genetic structure between sampling sites in the Mississippi River Valley and the Atlantic Seaboard with overall weak genetic differentiation among populations …