MA, Kent State University, 2023, College of Arts and Sciences / Department of Anthropology

Understanding the microevolutionary processes that drive variation in material culture is a critical component of comprehending cultural evolution. This study investigated the impact of material resolution on error rates in reductive manufacturing by employing an experimental approach. Participants (N=30) were tasked with replicating three-dimensional models using either Lego or Duplo bricks, representing high and low-resolution materials, respectively. We hypothesized that the resolution of building material would significantly affect the error rates, with different resolutions introducing varying amounts of variation. To evaluate errors, we employed XY and XYZ error calculation systems to assess surface area and volume discrepancies, respectively. Contrary to our hypothesis, statistical analysis revealed no significant difference in error rates between the two groups. While our study enhances the understanding of factors influencing cultural microevolution, it also opens new avenues for exploring other variables, such as learning mechanisms and environmental conditions, that contribute to variation in material culture. This research represents an important step forward in elucidating the intricacies of cultural evolution and its underlying mechanisms.

Doctor of Philosophy, The Ohio State University, 2005, Entomology

The phylogenetics, systematics, taxonomy, and biology of Gelechioidea (Insecta: Lepidoptera) are investigated. This superfamily is probably the second largest in all of Lepidoptera, and it remains one of the least well known. Taxonomy of Gelechioidea has been unstable historically. In Chapters Two and Three, I review the taxonomy of Gelechioidea and characters that have been important. Chapter Four provides the first phylogenetic analysis of Gelechioidea to include molecular data. I combine novel DNA sequence data from Cytochrome oxidase I and II with morphological matrices for exemplar species. The results challenge current concepts of Gelechioidea, suggesting that traditional morphological characters may not be homologous structures and are in need of further investigation. I conduct in Chapter Five an in-depth study of morphological evolution, host-plant selection, and geographical distribution of a medium-sized genus Depressaria Haworth (Depressariinae), larvae of which generally feed on plants in the families Asteraceae and Apiaceae. Host-plant use is commonly studied in this group because of physiological and behavioral responses exhibited by Depressaria pastinacella to furanocoumarins produced by their host plants, yet no species level phylogeny is available. This study is the only modern phylogeny of the genus, and includes all North American species but one, and about half the Old World species. In Chapter Six I describe nine new species of Scythris Hubner (Scythridinae) from the Galapagos Islands, Ecuador, and provide a key and illustration of genitalia and abdominal modifications. Finally, Chapter Seven represents an application of moth taxonomy to address questions of sampling protocols used for studies of biodiversity and conservation. I use Gelechioidea in eastern North America as indicators of diversity, with attention to the effectiveness of different sampling protocols with respect to active versus passive sampling, and plot-based versus plotless sa (open full item for complete abstract)

Master of Science, Miami University, 2023, Computer Science and Software Engineering

Meta-model co-evolution is when a modeling language, defined by its meta-model, and any con- forming instance models evolve together. As domains change and requirements evolve, changes to meta-models become critical to ensure their alignment with reality. This thesis presents META- IM, a process capable of identifying changes made to meta-models from one version to the next and applying necessary updates to conforming instance models. META-IM is able to detect any type of change made to a meta-model, including additions, modifications, and deletions of each type of model element. By detecting and tracking these changes, META-IM is able to effectively ensure that all changes are propagated through to the conforming instance models, which allows for the seamless co-evolution of the meta-model and its instances. This enables domain-specific modeling languages to adapt to evolving needs and maintain the relevance and usefulness over time. META- IM was systematically evaluated and was able to correctly transform and adapt 100% of the test models.

Master of Arts (M.A.), University of Dayton, 2021, Theological Studies

The Vatican's condemnation of Fr. John Augustine Zahm's most famous work, Evolution and Dogma, in the autumn of 1898 has traditionally been the subject of great interest among religious scholars and historians. This thesis describes several coalescing factors that negatively affected the book's fate: the neo-Thomists' critical reaction to Zahm's use of Saints Augustine and Aquinas in defense of evolutionism; the author's Americanist connections; the release of the French translation of Walter Elliott's The Life of Father Hecker; and the Church's resistance to the advancements of liberalism in European society, especially after the French Revolution. However, this thesis also takes a step further and argues that Fr. Zahm's writing and teaching career did not cease after the condemnation of his book. His passion for imparting an intelligent faith to his Catholic readers and audiences did not cease; his expansion efforts at the University of Notre Dame as Provincial of the Congregation of Holy Cross and his later publications, such as the trilogy of South American travelogues and the apologetic work Woman in Science, are testaments to his enduring “teaching heart” -- his passion for pursuing knowledge and communicating new understandings to others. This thesis emphasizes the importance of acknowledging Fr. Zahm's life holistically, in broad strokes. His contribution to American Catholic history need not be limited to the intrigue surrounding Evolution and Dogma.

Doctor of Philosophy, Case Western Reserve University, 2022, Macromolecular Science and Engineering

The oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) are critical electrocatalytic reactions for clean and renewable energy technologies, such as fuel cells, metal-air batteries, and water-splitting. Current commercial applications of these reactions utilize noble-metal-based catalysts (e.g., Pt, Pd, RuO2, IrO2). The high cost of these precious metal-based catalysts and their limited reserve have precluded these renewable energy technologies from large-scale applications. Therefore, research efforts have focused on the development of alternative catalysts that are readily available and cost-effective, with superior electrocatalytic performance compared to noble-metal-based catalysts. In 2009, nitrogen-doped carbon nanotubes (N-CNTs) were discovered to demonstrate electrocatalytic ORR activity attributed to the doping-induced charge transfer from carbon atoms adjacent to the nitrogen atoms to change the chemisorption mode of O2. More recent studies have further demonstrated that certain heteroatom-doped carbon nanomaterials can even act as multi-functional metal-free electrocatalysts for ORR/OER/HER, leading to the potential development of low-cost, highly efficient, and multi-functional electrocatalysts for advanced clean and renewable energy technologies. The work presented herein develops new carbon-based metal-free electrocatalysts (C-MFECs) by utilizing different design strategies. Chapter two demonstrates carbonization of a newly-synthesized pair of enantiotopic chiral metal-organic frameworks (MOFs) to produce Co-coordinated N-doped carbon materials with a hierarchical rod-like morphology and remarkable bi-functional electrocatalytic activity and stability for both OER and ORR – comparable to both commercial RuO2 for OER and Pt/C electrocatalysts for ORR. The observed excellent electrocatalytic activities were attributed to their unique hierarchical rod-like structure with homogeneously distributed cob (open full item for complete abstract)

Master of Science (MS), Bowling Green State University, 2021, Biological Sciences

Pharmaceutical companies have slowed the discovery and development of antibiotics due to low-profit margins. Therefore, antibiotic discovery is at an all-time low, and pathogens have evolved resistance to all currently available drugs. As a result, multi-drug resistant (MDR) bacterial infections are becoming more difficult to treat, especially in individuals at a high risk for infection such as cystic fibrosis (CF) patients. CF is a genetically inherited disease that inhibits or decreases chloride ion transport across epithelial cell membranes, resulting increased mucus viscosity, impairing normal clearance in the lungs. This environment is ideal for bacterial colonization and leads to a chronic lung infection. A major pathogen that colonizes the CF lung over time is Pseudomonas aeruginosa. A promising alternative treatment against MDR P. aeruginosa is bacteriophage therapy which has several advantages compared to antibiotics. First, phage therapy exhibits minimal side effects because phage are highly host-specific and do not inhibit other bacteria that are part of the human microbiome. Second, phage replicate itself exponentially when killing its host; and third, phage can be applied directly to the site of infection. However, like antibiotics, bacteria can evolve resistance to phage. To circumvent the problem of phage and drug resistance, trade-off effects may promote opportunities against both entities that may be exploited to treat MDR infections. I hypothesize that the effectiveness of antibiotics can be restored after selective pressure from bacteriophage. To test this hypothesis, MDR P. aeruginosa strains were exposed to phage in trade-off experiments, and results showed that the evolved phage resistant P. aeruginosa strain became antibiotic susceptible. In one trade-off experiment, a temperate phage recombined in the P. aeruginosa pathogen at a location downstream of a multidrug resistance efflux pump that may directly affect antibiotic susceptibility. In an (open full item for complete abstract)

Doctor of Philosophy, Case Western Reserve University, 2021, Epidemiology and Biostatistics

Tuberculosis (TB) is a major public health problem, causing more deaths globally than any other pathogen prior to COVID19. It is also the leading cause of death among people infected with human immunodeficiency virus (HIV). Susceptibility to TB can be influenced by human genetic variation. However, factors underlying variation in TB severity are less well studied. Clinical severity is an important phenotype that encompasses prognosis, patient experience, and risk of mortality. Thus, it is important to study severity, as it can help us better understand patients' quality of life, disease experience, and to predict survival among TB patients receiving treatment. There is also evidence that MTB genetic variation as delineated by phylogenetic lineage can affect TB disease severity, when considered simultaneously with human genetic variations and the interaction between the two. Many genetic studies of TB stop short of linking these genetic effects to biological function. The proposed study will address these fundamental gaps by 1) studying the genomic underpinnings of active TB severity using a meaningful, replicable, and validated clinical phenotype; 2) demonstrating evidence of co-evolution between humans and MTB on a population level how it affects severity; and 3) bridging the gap between genetic variants and immunological function by studying gene expression in the macrophage response. The overall goal is to examine how genomic variation in humans and MTB impact the immunological response to active TB disease and how this correlates with clinical severity.

Master of Science, The Ohio State University, 2020, Public Health

Breast cancer is the most common form of cancer among women. Triple negative breast cancers are a particularly aggressive subtype of breast cancer, accounting for an outsized proportion of disease related deaths. Metastatic TNBC is not curable and has limited options for palliative treatments, relying on a series of carefully managed monotherapies to slow disease progression. Advances in monitoring techniques may aid in the management of therapies in the metastatic context, as well as provide additional, actionable information on emergent biomarkers and targetable sites. In this work, we detail the application of PyClone, a hierarchical-Bayes framework for modeling clonal cell populations in cancer, to deep targeted panel sequencing of circulating tumor DNA, derived from serum collected in the phase-II biomarker study of cabozantinib in mTNBC. We demonstrate that important lesions can be tracked simultaneously through as many as eight time points in treatment, and that these lesions can be modeled into representative clonal populations, despite data sparsity. Our findings indicate that individuals can display markedly different clonal dynamics over similar windows of time, with identical diagnoses and treatments. Modeling variant populations gives us limited but valuable insight into phylogenetic origins of tumor clone populations. We also observe discordance between prognostic tumor fraction estimates of ctDNA and RECIST response categories, as well as demonstrate the ability to use whole exome sequencing of ctDNA to make computational predictions on the emergence of novel neoantigens throughout the course of treatment. Our successful application of these technologies suggests that ctDNA-based genomic profiling is an under-utilized tool for the study of cancer evolution, response to therapy, and disease progression monitoring. We suspect that ctDNA-based genomic profiling may provide valuable information through minimally invasive means in translational cancer rese (open full item for complete abstract)

Doctor of Philosophy, The Ohio State University, 2020, Evolution, Ecology and Organismal Biology

This dissertation explores the radiation of Primates during the Paleogene. The first radiation of Primates began with the plesiadapiforms near the Cretaceous-Paleogene boundary and the second radiation marked the introduction and diversification of euprimates at the beginning of the Eocene. Questions surrounding these radiations include their general patterns of evolution, rates of dental evolution, and potential influences of abiotic and biotic drivers. I explore these questions in euprimates by presenting a study of the Tetonius- Pseudotetonius primate lineage. Rates of evolution and the roles of neutral and adaptive processes across this lineage remain unclear. Linking Tetonius and Pseudotetonius are a series of stratigraphic and morphologic intermediates revealing possible functional and developmental reorganization within the dentition. Notable changes involved a reduction of the P3 and the P4 became a robust tall-cusped tooth. I test whether neutral evolution can explain the phenotypic differences in the lineage, and whether P4 lost developmental association with P3 and became integrated with the molars. I calculate the rate of evolutionary differentiation, based on the ratio between inter- and intra-species variation in length and width of the premolars and molars, between lineage segments and the entire lineage. I test for correlations between teeth within lineage segments. Correlations between P3 and the molars diminished, whereas correlations between P4 and the molars increased. I found evidence of varying degrees of stabilizing selection in the lengths and widths of most tooth metrics and neutral evolution in P4 width. This suggests a trend towards P4 becoming integrated into the molar field and that rates of evolution and selective pressures vary through time. The following chapters focus on the radiation of the family Paromomyidae during the late Paleocene and early Eocene. Their focus is on two paromomyid genera, Ignacius and Phenacolemur, which (open full item for complete abstract)

Master of Science in Biomedical Sciences (MSBS), University of Toledo, 2019, Biomedical Sciences (Bioinformatics and Proteomics/Genomics)

Every human has about 100 novel mutations that are absent in the genomes of his/her parents. This intense influx of mutations degrades information that is stored in the DNA sequences and, at the same time, provides an opportunity for creation of new genetic messages. Currently, over one hundred million mutations have been characterized in the public databases. The dynamics of mutation have been investigated for decades in both experiments and sophisticated mathematical models, yet our understanding of genome evolution is still ambiguous. In this project, we computationally processed eighty million human mutations to get clear answers to basic questions about DNA evolution. Specifically, how is the non-randomness in nucleotide composition in vast genomic regions maintained? What biological forces preserve sequence non-randomness from being degraded by novel mutations? Our goal was to uncover peculiarities in dynamics of G+C nucleotide content and evaluate the equilibrium of GC-percentage in the human genome. We found that novel mutations that convert G:C pairs into A:T pairs are 1.39 times more frequent than opposite mutations that change A:T → G:C. This effect is more striking if we take into account the fact that the total number of G:C pairs (42%) is significantly less than the number of A:T pairs (58%). Hence, calculating per nucleotide pair, the mutations of G:C → A:T is 1.93 times more frequent than A:T → G:C mutations. Such bias should create fewer and fewer G:C pairs in the genomes from generation to generation, until it reaches equilibrium at 34% of GC-composition. However, the GC-percentage of the human genome is stable at 42%. There are two possible biological processes that may be responsible for preserving GC-composition from degradation: i) natural selection or ii) biased gene conversion. However, estimated parameters for both processes are unable to explain the maintenance of CG-percentage. We re-evaluated the biased gene conversion paramete (open full item for complete abstract)

Doctor of Philosophy, The Ohio State University, 2018, Industrial and Systems Engineering

A novel class of gamma-prime strengthened cobalt-based superalloys may enable a significant temperature and efficiency capability improvement relative to nickel-base superalloys for future generation turbine engine hardware. However, little information exists regarding deformation processing of these novel Co-Al-W alloys into useable product forms with the necessary microstructure refinement at an industrially relevant scale with industrially relevant processes. To address this need, an ingot metallurgy thermomechanical processing sequence was demonstrated for a novel class of cobalt-base gamma-prime containing superalloys. From an as-cast ingot, the material was characterized and a homogenization heat treatment was developed and executed to reduce residual segregation from casting. Representative ingot conversion steps using extrusion were evaluated and performed followed by a recrystallization heat treatment to produce the desired fine-grain, wrought microstructure. Deformation processing of wrought material was completed at supersolvus hot-working temperatures using both cylindrical upset specimens to establish flow-stress behavior and custom-designed double-cone upset specimens to experimentally quantify the effect of strain, strain-rate, and temperature in microstructure evolution during hot-working, including the dynamic recrystallization and grain growth. All upset testing was completed at two supersolvus temperatures (1149 °C or 1204 °C) and one of three strain-rates (0.01/s, 0.1/s, or 1.0/s) depending on the type of testing completed. Required thermophysical and thermomechanical data was determined for material property inputs to a finite element model which was used to correlate observed microstructures to location-specific thermomechanical processing history. As part of this development, a significant effort was undertaken at each stage of processing to sufficiently characterize the microstructure through optical microscopy, electron microscopy, (open full item for complete abstract)

Master of Arts (MA), Bowling Green State University, 2018, American Culture Studies

The archetypal dragon, a composite of different living animals, has been popular for centuries, and we still tell stories about it today. One other monster seems to match the dragon in popularity, though it is not among the ranks of the traditional or legendary. Since their discovery in the late 18th century, dinosaurs have been wildly popular in both science and mass culture. The scientific status of dinosaurs as animals has not prevented people from viewing them as monsters, and in some cases, treating these prehistoric reptiles like dragons. This thesis investigates the relationship between the dragon and the dinosaur and the interplay between dragon iconography and dinosaur imagery in five dinosaur monster films from the mid-20th century: The Beast from 20,000 Fathoms (1953), Gojira (1954), Godzilla Raids Again (1955), Gorgo (1961), and Ghidorah, the Three-Headed Monster (1964). In addressing the arguments other critics have made against equating the dragon with the dinosaur, I will show that the two monstrous categories are treated as similar entities in specific instances, such as in monster-slaying narratives. The five films analyzed in this thesis are monster-slaying narratives that use the dinosaur in place of the dragon, thus “draconifying” the dinosaur. The dinosaur, as symbol of prehistory and evolution, renders the monster-slaying narrative concerned with evolutionary theory and humanity's place in nature, with each film interacting with culturally specific ideologies related to Darwin's theory of evolution. I show how there are two different types of dino-monster narrative that use the dinosaur either as an evil dragon that must be destroyed or as a dragon that can save humanity from internal or external threats. This thesis concludes with an examination of the ideology that surrounds the dragon-slaying myth, ideas about human-animal relations, and an analysis of recent monster movies that continue the discourse involving evolutionary theory.

Master of Science (M.S.), University of Dayton, 2018, Biology

Some phenotypes have more ability to evolve than others, captured by the term “evolvability.” While some traits can evolve rapidly, such as the shape, color and size of a butterfly wing, the Drosophila testis specific beta-2 (ß2) tubulin protein, a fundamental component of the spermtail axonemes, has not evolved in over 60 million years. This protein is a main element of the microtubules within the axoneme which supports the motility of the sperm cell. There is a 9+2 configuration of microtubules, nine doublets of microtubules arranged along the outer edge of the structure with two central microtubules. Each microtubule consists of tubulin dimers of ß2 tubulin and the major alpha tubulin isoform 84B which is present in most cells of the body. Previous studies have shown that substitutions of the of beta-1 tubulin, a 95% identical paralog of beta-2 expressed in somatic cells, and chimeric tubulins composed of beta-1 and beta-2 tubulin sequence are unable to support a motile axoneme, indicating the axoneme is highly sensitive to beta tubulin structure. From these findings, evolutionary conservation and highly sensitive structure/ function relationship, two hypotheses tested here were developed for the long conservation of ß2 tubulin. The first, stabilizing selection: nature is constantly selecting a particular sequence even though other sequences may work due to differences in the quality of sperm produced. Or, it may be that there is no alternative sequences that function, and a co-evolutionary event with another protein found within the axoneme is required to release beta-2 tubulin to evolve. These hypotheses were tested using the substitution of a beta-2 ortholog, the gene in a different species which evolved from a common ancestor, was examined to determine its ability to produce a functional sperm in the Drosophila melanogaster model. If able to produce a functional sperm, stabilizing selection is supported; if unable, a co-evolutionary event has occurred. Throug (open full item for complete abstract)

Master of Science, University of Akron, 2018, Polymer Science

Electrochemical water splitting has drawn a lot of attention for renewable energy generation.1 Oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are two half-cell reactions for water splitting. In order to drive these two reactions under reasonable overpotential, noble metals electrocatalysts such as platinum (for HER) and ruthenium oxide/iridium oxide (for OER) were used. However, the high price of the noble metals hampered the used electrochemical water splitting in large scale.2 It is therefore urgent to develop efficient electrocatalysts with low cost and earth-abundant materials. Recently, transition metal phosphides (TMPs) have been reported as a promising family of highly active and low-cost electrocatalysts for water splitting.3 In this research, a facile fabrication method was developed to obtain TMPs loaded OER or HER electrode. The electrode scaffold is commercial carbon cloth, on which nickel phosphide (Ni-P) and nickel-iron phosphide (Ni-Fe-P) were coated by electroless deposition. The Ni-Fe-P catalysts exhibited better OER performance than that of Ni-P catalysts. The highly efficient catalyst reached a low OER overpotential of 229 mV under an anodic current density of 10 mA cm-2 in alkaline solutions. The HER performances obtained from Ni-P and Ni-Fe-P based catalysts exhibited similar performance, with the best HER catalysts having a overpotential of 248 mV under a cathodic current density of 100 mA cm-2 in 1 M KOH solutions.

Doctor of Philosophy, Case Western Reserve University, 2017, Astronomy

In this dissertation, I present a series of studies on the low surface brightness outskirts of galaxies, which contain a record of tidal interactions and secular evolution processes. Each study utilized new deep imaging from the Burrell Schmidt Telescope in either broadband filters or narrow-band filters targeting Halpha emission. Regarding tidal interactions, I present a study of the M96 Group (or Leo I Group), as well as deep imaging of the interacting pair M51. I find that the M96 Group's intragroup light (IGL) consists of only three faint linear streams. I find no stellar counterpart to the group's H I ring, unusual if it were collisional in origin, and few signs of interaction among its four most massive members, implying a very calm tidal history. In M51, I discover several extremely diffuse plumes of starlight, yet find no stellar counterpart to its H I tail. Additionally, I measure red (B - V ~ 0.8) colors in all of its most extended tidal features, implying dominantly old populations and thus a lack of interaction-induced extended star formation. Regarding secular evolution, I conduct a detailed photometric study of three nearby galaxies' outer disks. Each outer disk lacks both ongoing star formation and the spiral structure necessary to migrate stars from the inner disk, hence it is unclear how these red outer disks formed. Finally, I conduct a study of the H II regions and diffuse ionized gas (DIG) throughout the M101 Group, to determine whether star formation in low density environments occupies a distinct physical regime from its high density counterpart. I find that the distribution of Halpha/FUV flux ratios (a tracer of the initial mass function, IMF) is constant among all H II region populations throughout the group. Also, the Halpha/FUV ratio in the DIG appears tied only to the local intensity of star formation, leaving little room for changing star formation physics. In total, this dissertation shows that tidal interactions in low-density (open full item for complete abstract)

Master of Science, University of Akron, 2016, Biology

Long term evolution experiments have long proven that there are both genetic and environmental factors that are important in changing the way evolution progresses. Factors such as deep phylogenetic history, recent shallow histories, adaptation to novel environments and random chance events can all directly affect the fate of a population. However, understanding the interplay between such factors remains relatively unexplored. In this study we set out to examine the roles of natural selection, history and chance and their influence on determining evolutionary rate. We find that despite all populations showing an increased gain in fitness, the trajectory of an evolving population is constrained by an interaction of effects. The results of this study aligns with Sewall Wright's idea that adaptive evolution is contingent on the interactions of other evolutionary forces. Studies like this can therefore allow us to further investigate these sophisticated interactions that change the way evolution progresses.

Doctor of Philosophy, The Ohio State University, 2015, Evolution, Ecology and Organismal Biology

The flowering plant genus Asarum (Aristolochiaceae) comprises approximately 110 species in north temperate forests worldwide. This dissertation represents the most comprehensive assessment of the diversification and genomic evolution in the group. Chapter one is a multi-locus phylogeny upon which an evaluation of the evolution of outcrossing and a new intra-generic classification scheme are founded. Chapter two uses these same loci to investigate rates of diversification and their association with morphological features to investigate the potential impact of key morphological or life-history innovations in the genus. Chapter three is a description of a new species discovered during the course of this work, along with multivariate investigations that distinguish it from similar species. Lastly, chapter four is a description of the first plastomes sequenced from this family of plants and hypotheses as to how they have come to be found in their present states.

PhD, University of Cincinnati, 2015, Arts and Sciences: Biological Sciences

The natural world reflects profound biodiversity in every corner of the globe. These phenotypes range from wing spot variation for camouflage in butterflies, to protective armored plates in marine stickleback fish, to extravagant mating displays in peacocks. For many phenotypes, the “selective”?benefit is self-evident. However, some forms of phenotypic evolution?are less obvious, such as regressed or “lost” characters, since it can be difficult to determine the association between a? discarded trait and a selective advantage. Cave-dwelling animals such as the blind Mexican cavefish, Astyanax mexicanus, serve as excellent models to investigate regressive evolution. The surface form is extant, allowing for direct comparisons between river- and cave-dwelling conspecifics. Cavefish likely evolved from an “ancestral” surface-dwelling form, which invaded the caves of Northeastern Mexico. As a consequence of roughly 3 million years in darkness, these remarkable cavefish lost their coloration. Moreover, the recurrent loss of pigmentation in geographically isolated populations renders this system ideal for investigating the broader changes mediating regressive evolution in nature. To investigate these fundamental questions, we utilize an integrative approach to characterize genetic mechanisms contributing to coloration loss in nature. For this, we aimed to describe multiple genetic components – simple traits, complex characters and global changes in gene expression – that may contribute to regressive pigmentation. Although some simple traits (albinism and brown) have been characterized, the roles of cis-regulatory mutations affecting these single locus traits have not been described. We investigated populations of cavefish that harbor “brown” yet depict an intact coding sequence. We discovered many sequence alterations present in the 5' putative promoter region of the causative locus Mc1r, some of which co-localized to highly conserved non-coding elements that may play a c (open full item for complete abstract)

Doctor of Philosophy, University of Akron, 2015, Integrated Bioscience

Complexity of organisms is ultimately dependent upon the number of cells present within an organism. Single-celled organisms are arguably the least complex of all living things with complexity increasing as cells are gained. The first major step in this process was achieving coloniality. The choanoflagellate species, Salpingoeca rosetta, used primarily in this study has a colonial life stage. Following that, organisms transitioned to true multicellularity with cell specialization being one of the requirements for that distinction. This transition, from colonial to multicellular animal life, is the topic of investigation in this dissertation. Multicellular animals evolved ~700 million years ago in the late Proterozoic, 1.4 billion years after the evolution of the eukaryotic cell. Investigations into the transition typically cite at least one of three major causes of the end to stasis in the animal lineage: Nursall's "Oxygen Control Hypothesis", the evolution of macrophagous predation, and changes in the chemical environment. Without direct fossilized evidence recorded and because the metazoan ancestor cannot be studied directly, a close relative, Salpingoeca rosetta was used in neontological tests of the roles of dissolved oxygen, predation, and the presence of serotonin, an ancient signaling molecule, in multicellular development. This is the first study to include long term experimental evolution of choanoflagellates to investigate the impacts of environment on the transition to multicellularity in animals. The combined evidence from the following studies indicates that the transition may have been brought about by a combination of the factors with a strong dependence on the common ancestor of unicellular and multicellular animals being pre-adapted for multicellular life. Genes for cell adhesion and intercellular communication are two of those pre-adaptations possessed by a close relative of the common ancestor, the choanoflagellates. Both were (open full item for complete abstract)

Master of Science, University of Akron, 2014, Biology

Trait plasticity is critical for success of organisms in a variable environment. Heat shock proteins are a well-known set of proteins providing plastic response that can improve an organism's survival in stressful conditions. There is limited experimental data on how genes imparting plastic response in an organism affect the ability of a population to adapt to the extremes of that environment. Using genetic knockout lines of Escherichia coli, we investigate how genes coding for heat shock proteins affect adaptation to a high temperature environment. Specifically, we look at how heat shock protein knockouts affect adaptive rate of life history traits at two different temperatures. We find that expressing heat shock proteins has a cost on an organism in thermally neutral environments. We further find that the absence of a heat shock protein affects adaptive rate differently depending on the temperature.