Life Sciences Commons^™

Testing For Character Displacement Between Two Abundant Stream Fishes, Amber Nations

Honors Theses

Character displacement is a pattern that can be used to explain differences between similar species in sympatric and allopatric situations. Gause’s Principle explains that a niche can only be occupied by one species at a time, so character displacement may be a way for similar species in the same habitat to shift resource use and compensate in order for the species to coexist. The Southeastern United States offers a unique opportunity to study this pattern because the diversity of freshwater fauna is quite high. However, the question of “How did this region become so diverse?” remains unanswered. One way for …

Hybrid Viability: An Analysis Of Drosophila Hybrid Competition And Mating Success Amongst Its Parental Species, Konrad Drzymalski

Honors Theses

The topic of hybrid offspring viability and mating preference between the two parental species of Drosophila athabasca (West Northern) and Drosophila mahican (Eastern A) is a still largely unexplored avenue of study. While the two aforementioned parental Drosophila species exist in distinct geographical regions across North America, they occupy a sympatric zone in the North East. Due to the absence of hybrid offspring in nature and the high levels of sexual isolation between these two parental species, it is necessary to establish if, and how hybrid offspring suffer in nature. By utilizing no choice mating systems involving audio playback of …

Analysis Of Differential Gene Expression Patterns During Spiral Intestine Development In Leucoraja Erinacea, Kelsey Cox

Honors Theses

The vertebrate gut is a specialized structure responsible for the intake and digestion of food, absorption of nutrients, and expulsion of waste products. The organs of the digestive tract have been conserved over time, but modifications to the size and shape of individual structures exist within the different vertebrate lineages. The skate’s spiral intestine has evolved to maximize nutrient absorption within a compact structure to create space in the body cavity for the organs needed for buoyancy. Studying the unique intestinal morphology of Leucoraja erinacea, or the little skate, provides an opportunity to understand the role of differential gene expression …

Ecology Of Estuarine Birds: Differences In Desensitization Of Year-Round And Transient Species, Sarah Thomas

Honors Theses

Huntington Beach State Park in Murrells Inlet, SC, USA is considered a “hotspot” for birds, according to the eBird database (eBird, 2020). The park is also visited by approximately 300,000 people, annually (Hobdy, 2019). The causeway at the park is an area of high human and wildlife activity. Here, the differences in desensitization, or lack thereof, of year-round and transient bird species to the stimuli of vehicles and humans were determined. Multiple surveys of the birds at Huntington Beach State Park were conducted from 22nd September, 2019 to 13th June, 2020. Desensitization was quantified by use of a range finder …

Predator-Prey Interactions Between Escherichia Coli Strains And Caenorhabditis Elegans At Various Temperatures And Resource Levels, Elizabeth Haynes Whitaker

Honors Theses

Predation is an important component of both evolutionary and ecological interactions across nature. The predator-prey relationship can be altered by differential species’ responses to changes in abiotic factors. The purpose of this study was to examine the effect of temperature, resource levels, and their potential interactions using two strains of Escherichia coli prey and a Caenorhabditis elegans predator. It is concluded that an interaction exists between temperature and resource level on this predator-prey relationship however further testing must be done to confirm results due to contamination in the results.

Troglofauna Of Van Buren And White County: A Survey Of Four Caves In The Mideastern Cumberland Plateau, Gavin Page

Honors Theses

The Cumberland Plateau in Tennessee has the highest cave-obligate biodiversity in North America. Cave-obligate species are entirely restricted to subterranean habitat and demonstrate unique troglomorphy. These species are categorized as troglobionts. However, because of their isolated occurrences, theses species are vulnerable to a variety of disturbances. This issue is furthered in the fact that only approximately 7% of the caves in this region have been surveyed. Of these caves that have been surveyed, only a small portion were professional entomological surveys, while almost no cave has ever been extensively repeat sampled. This study involved newly sampling one cave and repeat …

The Effects Of Urbanization On Insect Morphology: A Meta-Analysis, Evann L. Bailey

Honors Theses

Urbanization has been shown to create a rapid change in the environment as you move from rural areas to urban areas. It can create a multitude of effects on the environment. Some examples include, land disturbance, pollution, increasing temperatures and a disturbance in vegetation and biodiversity. Insects are useful organisms that provide maintenance and upkeep for ecosystem functioning. The rapid development of urbanization and how it is changing the environment may impact insect morphology. Measuring morphological change in organisms have been used successfully as indicators of environmental and ecological disturbance. Changes that take place in an insect’s morphology may indicate …

Incorporating Demographic Structure And Variable Interaction Types Into Community Assembly Models, Akhil Reddy Alasandagutti, Nayan Chawla

Honors Theses

Theoretical studies of ecological food webs have allowed ecologists to remove the constraints of specific location and timescales from their study of ecological communities; food webs are generally complex and thus empirical study is difficult. Further, this theoretical approach allows ecologists to compare ecological processes and outcomes across any possible food web structures. However, these simulated communities are only as useful as the model from which they were constructed. Modifying existing considerations in these models, and generating new ones, are the jobs of theoretical ecologists that seek to achieve the shared goal of a majority of simulations: representation of real …

An Experiment To Test For Rapid Evolution In An Introduced Ectomycorrhizal Symbiosis, Valerie Rewa

Honors Theses

The rapid evolution of introduced ectomycorrhizal-plant partnerships is an under- explored topic that may have immense impacts on ecosystems around the world. This experiment sought to identify and quantify this evolution and its impacts on both fungal colonization as well as plant growth. I used a laboratory experiment to analyze these factors in native and exotic genotypes of Suillus cothurnatus and Pinus species. Much of the data was not able to be collected, but that which was did not support the presence of rapid evolution in the mutualistic partnership. Pine species was seen to have a significant effect on plant …

A Baseline Documentation Report For The Delta Wind Birds Sky Lake Nature Reserve, James Dubberly

Honors Theses

The purpose of this baseline documentation is to conduct a report on our subject property and discuss the findings. A conservation easement is established by upholding a certain standard of a property’s current condition which makes a baseline documentation necessary for an easement to be enacted. Baseline documentation reports are used as a resource to monitor and enforce the legal agreements of the conservation easement. The subject property is currently owned by the Delta Wind Birds organization. In our scenario, this documentation report will serve to aid in the conversion of our subject property into a conservation easement in which …

Density Dependent Growth Of Pseudomonas Fluorescens In The Presence And Absence Of C. Elegans Predation In Liquid Media, Jack Landmann

Honors Theses

The purpose of this study was to understand the predator-prey relationship between C. elegans worms and P. fluorescens bacteria in liquid media. We were aiming to create a predation model of the relationship between these two species.

This study was performed through three experiments. Using 96-well plates, we were able to measure the change in optical density (OD) of these wells and calculate the growth rate. This growth rate was then graphed and analyzed. The first experiment contained P. fluorescens and KB liquid media, this study demonstrated that the bacterial population has a carrying capacity. We were also able to …

Warming Stimulates Sporulation Rates And Alters Community Structure Of Litter-Associated Fungi In Streamside Channel Experiment, Kaitlin D. Beasley-Polko

Honors Theses

Fungi, such as aquatic hyphomycetes, are important decomposers of plant litter in temperate forested headwater streams providing energy and nutrients for the higher trophic levels in these ecosystems. According to current climate change predictions, stream water temperatures are expected to rise significantly in the near future. This project addressed the effects of temperature on sporulation rates and community structure of aquatic hyphomycetes on substrates of different carbon quality (maple and rhododendron leaf litter and wood veneers). The experiment was conducted in streamside channels fed with stream water (ambient, +2°C and +4°C) and set up to mimic small streams. We found …

Morphological Variance In Mouthparts And Foraging Behavior In Bumblebees, Ye Jin Lee

Honors Theses

Bumblebees (Hymenoptera: Apidae: Bombus) show an incredible degree of size variation within and between species. Individuals from the same hive may vary up to 10-fold in mass. This variation allows individuals to specialize in foraging on different flowers suited to their morphology. However, as different species have different foraging behaviors, their variation in mouthparts and scaling of mouthparts to body size may have been under different kinds of stabilizing selection as they adapted to collect nectar from flowering plants over evolutionary time. Here, we examined the scaling relationships between body size and mouthpart structures, and the variation in mouthpart shape …

Impact Of The North American Monsoon On Molt Migrant Passerines, Liuqingqing Yang

Honors Theses

Breeding, molt, and migration place considerable yearly demands on migrating passerines in North America. Due to conflicts in energy allocation, many species have evolved migration strategies that prevent temporal overlap in these processes. However, there is recent evidence that some passerines which breed in western North America migrate to intermediate stopover sites to carry out molt, conflating molt and migration. Factors influencing the evolution of such a strategy are believed to include both aridity on breeding grounds and dependable flushes of late-summer productivity in the southwestern United States and northwestern Mexico. This productivity occurs due to the brisk rainfall of …

Contrasting Patterns Of Nutrient Limitation In The Littoral And Pelagic Zones Of Mesotrophic Maine Lakes, Grace C. Neumiller

Honors Theses

Intense nutrient loading of nitrogen (N) and phosphorus (P) causes sudden regime shifts in freshwater ecosystems from clearwater to turbid conditions with frequent cyanobacterial blooms. Characterization of nutrient limitation patterns of primary productivity in these ecosystems is necessary for effective management of algal blooms. However, much of this research has focused on pelagic habitats. The influence of lake habitat (i.e. benthic littoral versus pelagic zones) on nutrient limitation of primary production in mesotrophic lakes is largely unknown, particularly in contrast to research on pelagic nutrient limitation in eutrophic systems. Using paired nutrient diffusing substrata and mesocosm experiments, we measured chlorophyll- …

A Foray Into The Interval Timing Capabilities Of Tufted Capuchin Monkeys (Cebus [Sapajus] Apella), Gryff Griffin

Honors Theses

Time is a critical part of life and timing on the range from milliseconds to minutes has proven to be critical for several behaviors such as foraging and movement. While the exact neurological structures of interval timing are currently undefined, several studies have been completed comparing the interval timing capabilities of humans and nonhuman primates. However, these studies have unanimously utilized members of Macaca, which limits the abilities for researchers to make apt comparisons between humans and all nonhuman primates. This study sought to investigate whether tufted capuchins (Cebus [Sapajus] apella) have the capability to measure time …

Genetic Diversity & Connectivity Of Chasmanthium Latifolium (Poaceae) In Pennsylvania & The Effect On Conservation Status Of A Rare Species, Jonathan D. Hayes

Honors Theses

Chasmanthium latifolium (Michx.) Yates (Poaceae) is a loosely colonial, rhizomatous, perennial grass species that lives in riparian habitats, making it fittingly referred to as river oats. Native to the southern Midwest and the eastern half of the United States, C. latifolium reaches the northeastern edge of its range in Pennsylvania. Within Pennsylvania, eleven extant C. latifolium populations are found along four waterways: the Monongahela River, the Susquehanna River, and two tributaries to the Susquehanna River. This limited state distribution exhibits an east-west disjunct distribution, where western populations are largely separated from eastern populations with one centrally located population. Between the …