Ecology and Evolutionary Biology Commons^™

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, …

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 Status Of Snapping Turtles (Chelydra Serpentina) In Virginia: Population Viability, Demography, Regulatory Analysis, And Conservation, Benjamin C. Colteaux

Theses and Dissertations

Snapping turtles (Chelydra serpentina) are being harvested in unprecedented numbers in the United States (US) to meet the needs of international markets. Over three million live snapping turtles from farm and wild caught stock were exported from the US to Asia in 2012-14 alone. In the Commonwealth of Virginia, records indicate that 29,860 snapping turtles were commercially harvested between 2000 and 2015. Size limits are often used to regulate harvest pressure in snapping turtles and other game species. I analyzed the historic harvest of eleven US states to test the efficacy of minimum-size limit regulations at reducing commercial …

Evolution Of Antagonistic Relationships In Proteins: A Case Study Of Radialis- And Diviricata-Like Genes, Ao Gao

Theses and Dissertations

The antagonistic relationship of proteins describes the opponent interactions that result in one protein suppressing the function of another. Developmental genetic studies of Antirrhinum majus demonstrated that two transcription factors from the MYB gene family, RAD and DIV, interact through antagonism to regulate floral dorsoventral asymmetry. Interestingly, similar antagonistic interactions were found among proteins of FSM1 (RAD-like), MYBI (DIV-like), and DRIF in Solanum lycopersicum, which is involved in fruit development. Here, we report on the homology of these antagonistic MYB proteins based on reconstruction of the phylogeny of I-box-like and R-R-type clades, where RAD- and DIV-like belong, …

Assessment Of Benthic Habitat Quality In Lower Green Bay, Lake Michigan With Special Regard To Potential Hexagenia Recolonization, Christopher Michael Groff

Theses and Dissertations

With environmental remediation in the Great Lakes, Hexagenia have recovered or are recovering in systems from which they were once extirpated. An active Hexagenia recovery does not appear to be taking place in lower Green Bay. This study first examines the highly fluidized nature of lower Green Bay sediment as a possible cause for their lack of recovery due to nymphs’ potential inability to construct and maintain burrows essential to the completion of their life cycles. Hexagenia bilineata nymphs collected from the Upper Mississippi River were distributed into oxygenated aquaria containing substrates from lower Green Bay or the Upper Mississippi …

Natural Selection By Insect Pollinators And Seed Predators On Floral Head Traits Of Helianthus Grosseserratus (Sawtooth Sunflower), Jason Stephen Servi

Theses and Dissertations

Flowering plants must invest energy and resources to produce floral displays that are attractive to pollinators, but these same displays may also attract detrimental insects. How floral traits are shaped by the preferences of both pollinators and herbivores/seed predators is not fully understood. Using Helianthus grosseserratus (sawtooth sunflower) as my study species, I investigated these conflicting selective pressures on floral head traits through a 2-year study in a large, unbroken tract of mesic prairie in Wisconsin. In the first season, I followed individual heads over time and recorded insect visitation patterns and phenological changes to floral head traits. I also …

Blood Parasite Infection And Plumage Elaboration Of Migratory And Resident Populations Of The Common Yellowthroat, Rebecca Leigh Schneider

Theses and Dissertations

In birds, blood parasite diversity varies with latitude, seasonal changes, and habitat type. As a consequence, migratory populations of birds have greater exposure to parasites during their annual cycle than resident populations. Parasite infections may negatively affect the health of individuals which could, in turn, affect the development of elaborate plumage ornaments. We compared migratory (Wisconsin) and resident (Florida) populations of common yellowthroats (Geothlypis trichas) to test whether migratory birds in Wisconsin have more prevalent, intense and diverse infections of blood parasites and subsequently less elaborate ornamentation than their resident counterparts in Florida. As predicted, we found higher prevalence, intensity …

Are We Missing The Forest For The Trees? Quantifying The Maintenance Of Diversity In Temperate Deciduous Forests, Kathryn Barry

Theses and Dissertations

One of the most pressing questions of community ecology is: Why do we have so many species? Over 100 hypotheses have been proposed to answer this question for woody plants over the past 70 years, yet there remains no consensus among community ecologists. In this dissertation, I explore the evidence supporting several different hypotheses (Chapter 1). I provide evidence that negative density dependence, where individuals perform poorly near members of their own species, may only be relevant for canopy tree species (Chapter 2). Understory species do not demonstrate negative density dependence while canopy trees demonstrate negative density dependence that increases …

Consequences Of Loss Of An Abundant Pollinator: An Experimental Study, Allysa Hallett

Theses and Dissertations

Pollinator populations are declining worldwide, and this may lower the quantity and quality of pollination services. Since pollinators often compete for floral resources, loss of an abundant pollinator species may release others from competition and potentially alter floral visitation rates. We explored how the removal of a frequent pollinator, bumble bees, influenced pollination success of whorled milkweed (Asclepias verticillata). In three small and three large populations we quantified pollinator visitation rates and pollination success for control plots and for plots where bumble bees were experimentally excluded. We found that exclusion of bumble bees did not reduce A. verticillata pollination success. …

Why Are Students Doing Research? Examining The Motivation Of Students Involved In Undergraduate Research Programs, Andrew Layne Mcdevitt

Theses and Dissertations

Use of self-determination theory (SDT) within the science classroom focuses primarily on ways to integrate intrinsic motivation into students' identity. Experiential learning plays a large role in promoting learning by shaping students' interests, identity, and intrinsic aspirations. This phenomenological research study sought to understand how experiential learning experiences helped influence career aspirations of graduate students within ecological disciplines. By determining how their experiences met three basic psychological needs outlined by SDT (competence, autonomy, and relatedness), we were able to examine which regulators drove motivation.

In the qualitative pilot study, participants developed a genuine enjoyment and appreciation for their discipline as …

Independent Origination Of Floral Zygomorphy, A Predicted Adaptive Response To Pollinators: Developmental And Genetic Mechanisms, Ghadeer Bukhari, Wenheng Zhang

Theses and Dissertations

Observations of floral development indicate that floral organ initiation in pentapetalous flowers more commonly results in a medially positioned abaxial petal (MAB) than in a medially positioned adaxial petal (MAD), where the medial plane is defined by the stem and the bract during early floral development. It was proposed that the dominant MAB petal initiation might impose a developmental constraint that leads to the evolution of limited patterns of floral zygomorphy in Asteridae, a family in which the floral zygomorphy develops along the medial plane and results in a central ventral (CV) petal in mature flowers. Here, I investigate whether …

Seasonal Variation Of Fish And Macroinvertebrate Biomass Spectra In Southern West Virginia Streams, Andrew J. Kirk

Theses and Dissertations

The biomass size spectrum - the power-law scaling relationship between average individual size and total biomass - has often been studied in lake and marine ecosystems, but rarely in lotic systems. The objective of this study was to test for characteristic biomass spectra in small temperate streams. Seasonal fish and macroinvertebrate data, including population abundance and biomass estimates, were collected in three wadeable, southern West Virginia streams from October 2013 to May 2015. Fish abundances were estimated with 3-pass electrofishing (depletion) surveys and individuals were weighed in the field. Macroinvertebrates were collected with a Hess sampler and returned to the …

The Curiosity Of Con, Petrified Breath, And An Accident Known As Blue., Steven Randall

Theses and Dissertations

My thesis installation emerged from an interest in visualizing breath. The resulting work came to exist at the intersection between art, biology, and performance.

The unicorn tapestries were used as a generative point of departure to explore the preservation and transformation of images through time, by time, and with time. Reproductions of the six tapestries were each etched into paper and then submerged into solutions of Phenol Red dye, Ferric Ferrocyanide (also known as Prussian Blue), and various forms of sodium chloride. Exhaled breath was used to encrust these images of the tapestries into physical objects which gradually crystallized and …

Contribution Of Lianas To Plant Area Index And Canopy Structure In A Panamanian Forest, Maria Elizabeth Rodriguez-Ronderos

Theses and Dissertations

Lianas are an important component of tropical forests, where they reduce tree growth, fecundity and survival. Competition for light among plants may be intense; however the amount of light that lianas intercept is poorly understood. We used a large-scale liana removal experiment to quantify light interception by lianas in a Panamanian secondary forest. We measured the change in plant area index (PAI) and forest structure six weeks after cutting lianas in eight 80x80 m plots and in eight control plots, and then annually for four years. We used ground-based LiDAR to measure the 3-dimensional canopy structure before cutting lianas and …

A Tale Of Two Morphs: Genetic And Genotypic Structure Between Macrocystis Pyrifera And Macrocystis Integrifolia, Heidi Hargarten

Theses and Dissertations

Organisms living along environmental gradients often utilize phenotypic plasticity to maximize their survival across a range of conditions. Wherever gradients occur, there is potential for divergence through isolation-by-adaptation (IBA) to build-up between genotypes experiencing different selective pressures. Plasticity in traits pertaining to mating systems in particular are likely to constitute an interesting and revealing model for the study of the underlying mechanisms behind parapatric speciation. Giant kelp, Macrocystis spp., shows striking plasticity in holdfast morphology and reproductive strategy when colonizing intertidal (M. integrifolia morph) versus subtidal (M. pyrifera morph) areas along temperate rocky coastlines of the eastern Pacific Ocean. In …

Factors Constraining The Reproductive Output Of Baptisia Alba Macrophylla, Ashley Morgan Hembrough

Theses and Dissertations

Baptisia alba macrophylla, a native, herbaceous perennial legume, produces inflorescences with a large number of flowers, yet matures relatively few fruits. We hypothesized that the number of seeds matured by B. alba macrophylla is maximized based on resource availability at each stage of development, but this optimal number is further compromised by extrinsic factors including pollen limitation and pre-dispersal seed predation by the weevils Apion rostrum and Tychius sordidus. To test this hypothesis, we conducted a field experiment at two sites: (i) the John English Prairie, located in Hudson, IL, and also (ii) the Sugar Grove Nature Center and Funks …

Switching Tactics: Phenotypic Plasticity In The Alternative Mate-Finding Tactics Of Burying Beetles, Theresa Mulrey

Theses and Dissertations

Male Nicrophorus burying beetles utilize two alternative mate-finding tactics, representing an ideal model system to test the influence of environmental cues on the expression of alternative tactics. The "searching" tactic involves flying in search of a carcass on which to mate. This tactic can result in high levels of paternity, but is risky in that carcasses are rare and competition for carcasses is fierce. The "signaling" tactic, which involves emitting pheromone in the absence of a carcass to attract females, is energetically less costly, but a signalling male must mate with multiple females to achieve the same reproductive returns as …

Hatching Asynchrony In European Starlings ( Sturnus Vulgaris ), Jason Hanser

Theses and Dissertations

Across a wide range of avian taxa, eggs within clutches hatch asynchronously, placing later hatched nestlings at a disadvantage. Here, we explore the proximate and ultimate causes of hatching asynchrony within European starlings, Sturnus vulgaris. Specifically, we investigate the effect of ambient temperature on egg viability and incubation behavior prior to clutch completion. Additionally, we examine the potential for storage time and maternally-deposited yolk testosterone to influence rates of embryonic development and hatching patterns within European starlings.

Environmental Impacts On Life History In Container Breeding Mosquitoes, Kathleen May Westby

Theses and Dissertations

In this dissertation I explore different ways that the environment impacts life history in mosquitoes in ways that may alter vectorial capacity. In chapter I, I tested if short-term sugar deprivation experienced after exposure to La Crosse virus altered infection rates in Aedes albopictus and if sugar treatment and virus infection status altered blood feeding behavior and fecundity. I found no evidence that sugar deprivation impacted infection rates or fecundity. Sugar deprivation did increase blood feeding. There was no effect of infection status on blood feeding or fecundity. In chapter II, I tested for effects of seasonal cues (temperature and …

Speed And Resolution In The Age Of Technological Reproducibility, Shawn Taylor

Theses and Dissertations

The rate of acceleration of the biologic and synthetic world has for a while now, been in the process of exponentially speeding up, maxing out servers and landfills, merging with each other, destroying each other. The last prehistoric relics on Earth are absorbing the same oxygen, carbon dioxide and electronic waves in our biosphere as us. A degraded .jpeg enlarged to full screen on a Samsung 4K UHD HU8550 Series Smart TV - 85” Class (84.5” diag.). Within this composite ecology, the ancient limestone of the grand canyon competes with the iMax movie of itself, the production of Mac pros, …

Consequences Of Vine Infestation: Linking Abiotic Influences And Biotic Interactions To Successional And Structural Changes In Coastal Communities, Spencer N. Bissett

Theses and Dissertations

Located at the interfaces of terrestrial and marine environments, coastal habitats are inherently vulnerable to the effects of global change. Barrier island systems in particular serve not only as protective buffers against storm events, but also as sentinel ecosystems for observation of the impacts of sea level rise, and of increasing storm frequency and intensity. In the mid-Atlantic region, shrub thickets of Morella species compose the dominant forest community. The often monospecific nature of these plant community assemblages is advantageous to ecological studies and cross-scale applications; the relatively low diversity facilitates transitions between scales. My objective was to investigate the …

The Effects Of Invasive Macrophytes Phragmites Australis And Typha Angustifolia On Nitrate Removal In High Nitrate Wetland Sediments, Lauren Mackenzie Beal

Theses and Dissertations

Constructed wetlands are quickly becoming inundated with invasive species like Phragmites australis and Typha angustifolia which are capable of changing whole ecosystem function and community composition. We wanted to assess how plants affect dissolved oxygen (DO) and dissolved organic carbon concentrations (DOC), and in turn if they increase nitrate (NO3-N) removal rates relative to barren sediments. Using a NO3-N/Br tracer test, we tested NO3-N removal rates, DO, and DOC concentrations. After the tracer test, we measured above- and below-ground plant biomass and sediment characteristics. NO3-N removal did not differ across the treatments. Phragmites australis microcosms had significantly higher sediment bulk …

Lake Michigan Hydrodynamics: Mysis And Larval Fish Interactions, Yutta Wang

Theses and Dissertations

I studied the interactions between Lake Michigan hydrodynamics (the spring thermal bar) and Mysis, deepwater sculpin, and burbot larvae. The thermal bar is a zone of sinking 4º С water that separates warmer inshore water from colder offshore water. Mysis was a major bycatch of sampling for larval fishes. The density of Mysis did not differ statistically between inshore (about 6º С) and offshore of the thermal bar, but the percentage of Mysis that were newborns was significantly higher inshore (P = 0.007). These "early start" coastal Mysis may have an advantage in growth and survival, but with the risk …

Seasonality Of Conceptions Under Varying Conditions In A Rhesus Macaque Breeding Colony, Ryan Disney Patrick Dunk

Theses and Dissertations

Rhesus macaques (Macaca mulatta) are well documented as seasonal breeders. Despite this, little is known about what factors influence seasonal reproduction in rhesus. It has been proposed that rhesus are "relaxed income breeders" (Brockman and van Schaik, 2005), which means they respond to changes in photoperiod but endogenous cues can allow deviations from photoperiod-timed seasonality. This study presents the results of a natural experiment on the influence of different housing conditions (featuring different levels of environmental exposure) on the seasonal pattern of reproduction in rhesus. Once the number of attempts was controlled for, rhesus did not exhibit a seasonal distribution …

The Effects Of Channelization And Water Impoundment On The Macroinvertebrates In The Weber River, Summit County, Utah, Parley V. Winger

Theses and Dissertations

Macroinvertebrate populations in the Weber River, Summit County, Utah, were analyzed to determine what effects channelization resulting from Interstate-80 construction and water impoundment had on the standing crop, species diversity and species composition. Bottom samples were collected monthly from riffle areas in channeled and unchanneled sections and above Echo and Wanship Reservoirs. Macroinvertebrate populations in the channeled areas were similar in standing crop, species diversity and species composition to those in unchanged areas within six months following channelization. Species diversities were higher (d=4.1, 3.7) above the reservoirs than below (d=2.0). The reservoirs restricted the distribution of several species of macroinvertebrates. …