Master of Science, The Ohio State University, 2023, Entomology

Bumble bees (Bombus) are essential pollinators for wildflowers and crops worldwide, but many species are currently in decline. Habitat loss and fragmentation are leading factors in these declines. Urbanization is a source of habitat loss and fragmentation; however, robust and abundant bumble bee populations are often found in metropolitan areas. Though prior research has broadly examined bumble bee abundance and diversity in urban areas, little work has focused on individual abundances of different species, which may differ in their relationships with urban land. Furthermore, the potential impacts of urban land on gene flow and other genetic health factors in bumble bees remain largely unknown. The first goal of this research was to evaluate and compare the abundances of three target species—Bombus impatiens Cresson, 1863, B. griseocollis De Geer, 1773, and B. bimaculatus Cresson, 1863—along an agricultural-to-urban gradient in Madison, WI, USA. Bumble bees were collected from 16 sites during the summer of 2019 and 19 sites during the summer of 2020. The second goal was to evaluate genetic differentiation, heterozygosity, allelic richness and colony numbers among populations of these species along the same gradient. Percentage of impervious surface cover was used as a metric for urbanization, and this percentage was measured within both 500 m and 1500 m buffers around each study site to account for both local-scale and landscape-scale effects. Impervious surface cover showed no relationship with abundances of B. impatiens or B. griseocollis, but showed a positive relationship with abundance of B. bimaculatus. Impervious surface cover also showed no relationship with genetic differentiation, allelic richness or colony number for all three species in both years, and no relationship with heterozygosity for any species in 2019. In 2020, heterozygosity was negatively correlated with impervious surface cover for B. impatiens at the 500 m buffer but not the 1500 m buffer. (open full item for complete abstract)

Committee: Jamie Strange (Advisor); Andy Michel (Committee Member); Mary Gardiner (Committee Member) Subjects: Entomology

MS, University of Cincinnati, 2022, Arts and Sciences: Biological Sciences

Global biodiversity is facing astronomical rates of extinction as a consequence of anthropological-related disturbances such as climate change, habitat fragmentation, and the introduction of invasive species. Thus, developing effective conservation strategies is urgently needed. Ex situ conservation is a method of storing the genetic information of an endangered species outside of the often-unsuitable native habitat. These ex situ populations are typically intended for future reintroduction and population augmentation efforts, so it is critical that the genetic diversity is maximized in these populations. This study used microsatellite (SSR) and amplified fragment length polymorphism (AFLP) genetic markers to investigate the ex situ populations of seven critically endangered Hawaiian plant species: Clermontia oblongifolia subsp. brevipes, Cyanea grimesiana subsp. grimesiana, Cyanea truncata, Cyrtandra gracilis, Cyrtandra kaulantha, Gardenia brighamii, and Melicope mucronulata. Many of these species have experienced drastic population decline over the last decade and have only a few extant individuals remaining. Most of the ex situ populations of these species were found to have low levels of variation; however, a few exhibited moderate levels of variation and generally high levels of polymorphic loci. As more species experience extinction threats, these results highlight the need for ex situ storage of all threatened species. Gardenia brighamii was further examined as a case study for other critically endangered plant species. The ex situ population of G. brighamii was compared with the wild population on the island of Lana'i to measure population structure between these two populations. The high levels of variation in the ex situ population relative to the wild population further emphasize the urgency of collecting wild individuals of other species for storage before significant population damage occurs. Furthermore, no population structure was found among the thre (open full item for complete abstract)

Committee: Theresa Culley Ph.D. (Committee Member); Megan Philpott Ph.D (Committee Member); Valerie Pence Ph.D. (Committee Member) Subjects: Biology

Doctor of Philosophy (PhD), Ohio University, 2022, Biological Sciences (Arts and Sciences)

Bats are the second most numerous mammalian taxon and provide critical human ecosystem services such as pollination and pest control. Globally, they are threatened by multiple factors such as habitat degradation, contamination, and emerging diseases such as white-nose syndrome (WNS). This disease is caused by a fungus, which was introduced from Europe to North America, and has killed millions of bats, with some species showing precipitous declines in abundance. A result of such population decline is the loss of genetic diversity, and hence the loss of adaptive potential. The goal of this dissertation is to use genetic data to further understand the population ecology of two bat species that are differentially affected by white-nose syndrome, the big brown bat, Eptesicus fuscus, and the northern myotis, Myotis septentrionalis. The first species doesn't show symptoms of the disease and is potentially playing a significant role in spreading the pathogen. I estimated the population genetic structure and estimated genetic differentiation among eight states using data from the cytochrome-b gene. I found moderate population structure, suggesting that dispersal and gene flow is occurring mostly within states, but movement across long-distances are possible as suggested by a moderate fixation index. In addition, I inferred population size trends and found that the big brown bat populations are declining, an unexpected result for an abundant species. The second species that I studied was the northern myotis. This species has shown a drastic decline in winter surveys, with declines of about 95%. To investigate recent population size changes, I first assembled the genome using short and long-read data. The final assembly was largely contiguous, composed of 92 fragments, and had a high completeness, with a BUSCO Score of 96.1% of the mammalia orthologs core genes. The genome annotation was very complete as well, with 55075 genes and a BUSCO SCORE of 98.5%. It also indicate (open full item for complete abstract)

Committee: Joseph S. Johnson (Advisor); Donald B. Miles (Advisor); Andor J. Kiss (Committee Member); Shawn R. Kuchta (Committee Member); Harvey E. Ballard Jr. (Committee Member) Subjects: Conservation; Ecology; Genetics; Wildlife Conservation; Zoology

Master of Science, Miami University, 2022, Biology

In an era of rapidly changing habitat conditions, integrating conservation genetics and management to maximize the adaptive capabilities of rare species is paramount to their survival. We examine the genetic diversity and reproductive strategies of a rare wildflower endemic to the Florida panhandle, the Florida skullcap (Scutellaria floridana), to inform management and recovery decisions. We revisited almost all populations still considered extant and assessed genetic diversity and prevalence of clonal reproduction using SNP data generated by ddRAD sequencing. We found that populations possess low genetic diversity, moderate evidence of inbreeding, and moderate divergence from one another. We identified eight populations as possessing the majority of diversity within S. floridana's gene pool and four populations of poor genetic diversity in need of further investigation. We established two plots to investigate asexual reproduction and identified only 2-3 genets out of 25 to 30 ramets in each. We suspect that five populations that we were unable to locate are extirpated and recommend further investigation to determine their status. Scutellaria floridana appears to have experienced a continued decline in the number of extant populations since its listing under the Endangered Species Act and will likely require ongoing monitoring and management to ensure its survival.

Committee: Richard Moore (Advisor); David Berg (Committee Member); Vivian Negron-Ortiz (Advisor) Subjects: Biology; Botany; Conservation; Genetics; Natural Resource Management

Doctor of Philosophy, The Ohio State University, 2022, Evolution, Ecology and Organismal Biology

Successful conservation actions require a detailed understanding of how individuals interact with their environment. For many threatened and endangered species, anthropogenic changes to their landscape have created barriers separating formerly connected populations. This isolation can have profound impacts on the long-term viability of these populations and ultimately the conservation status of the species. For example, as populations become more isolated, they may enter the “extinction vortex” where small populations experience high levels of inbreeding and genetic drift depressing demographic rates, driving the population into a positive feedback loop that can lead to a decline in numbers and eventual extinction. However, if barriers to movement are not complete, even infrequent dispersal between populations can counter potential vortex effects by bolstering local population sizes and introducing new genetic material. Determining if populations are connected via dispersal or if they are isolated is a difficult question with no single best approach. For the Federally threatened Eastern Massasauga Rattlesnakes, Sistrurus catenatus, their reclusive, sedentary lifestyle make many field-based methods for generating this information difficult and unreliable without unrealistic investments of time and resources. In my thesis, I used information from DNA single nucleotide polymorphisms (SNPs) from neutral genetic markers to address the following three fundamental questions regarding how S. catenatus move through their landscape in Ohio and how this information can be used to evaluate proposed activities for their conservation: (1) Do snakes in scattered habitat patches across Northeastern Ohio belong to a single connected population, a metapopulation with infrequent dispersal, or isolated populations? I used 1000s of DNA SNPs to reconstruct a pedigree across 86 individuals and showed that no individuals have moved between habitat patches separated by more than a few (open full item for complete abstract)

Committee: H. Lisle Gibbs (Advisor); Andreas Chavez (Committee Member); Bill Peterman (Committee Member) Subjects: Conservation; Ecology; Wildlife Conservation

Master of Science, The Ohio State University, 2021, Evolution, Ecology and Organismal Biology

The modern extinction crisis, following its current trajectory, is irreparably damaging the planet's biodiversity and has severe cascading effects on the environment and ecosystem processes. This is particularly true for plant species extinction, considering the vital role of plants as foundational species within many ecosystems. Despite this, conservation efforts are often focused upon charismatic megafauna; anthropomorphized animal species of cultural or social importance. Plant species, which are central to life on this planet, receive disproportionately less legal protection, conservation focus, and funding. It is therefore critical that formal extinction assessments be applied, and threats identified and mitigated, to avert mass plant extinction. This thesis presents two methods of plant conservation assessment along with administrative assessment and policy recommendations. Chapter 1 presents a machine-learning approach to assess extinction risk for plant species in Utah. Utilizing random forest classification, a supervised ensemble learning technique, two classifiers were built using geographic, climatic, anthropogenic, and administrative data. The second classifier, which incorporated both anthropogenic and ecological variables achieved 93.65% accuracy in comparison to the first classifier, which considered only anthropogenic variables and achieved a 62.79% accuracy. The second classifier was employed to assess the vulnerability status of 4,338 species based upon government classification. Seventy-eight species were identified to be at least 90% likely to be classified as a species of concern. Further, geographic patterns of vulnerability revealed the Colorado Plateau ecoregion to be particularly vulnerable. Across all predictor variables, endemism was identified as the most critical, with climatic variables measuring trends in temperature and precipitation subsequently important. A stakeholder analysis was then conducted to untangle the administrative (open full item for complete abstract)

Committee: Andrea Wolfe (Advisor); Bryan Carstens (Committee Member); Chris Rea (Committee Member) Subjects: Biology; Botany

Master of Science, The Ohio State University, 2019, Evolution, Ecology and Organismal Biology

Protected areas play a crucial role in the conservation of biodiversity, but it is unclear if these areas have an influence on genetic diversity. Since genetic diversity is a crucial component of a species ability to adapt and persist in an environment over long periods of time, its assessment is valuable when designating areas for conservation. As a first step towards addressing this issue, we compare genetic diversity inside and outside of protected areas in North America using repurposed data. We tested the null hypothesis that there is no difference between genetic diversity inside compared to outside of protected areas in 44 vertebrate species. A substantial portion of vertebrate species exhibit significant differences in the amount of intraspecific genetic diversity in a comparison between protected and unprotected areas. While our simulation testing suggests that this result is not an artifact of sampling, it is unclear what factors influence the relative amount of genetic diversity inside and outside of protected areas across species.

Committee: Bryan Carstens (Advisor); Lisle Gibbs (Committee Member); Andreas Chavez (Committee Member); Steve Hovick (Committee Member) Subjects: Conservation

Master of Science, The Ohio State University, 2018, Evolution, Ecology and Organismal Biology

In marine environments, phylogeographic approaches have the power to counteract the difficulties of studying small, highly mobile organisms that live in a fluid environment. These analyses are particularly useful for studying exploited species, as understanding connectivity and processes governing gene flow between populations is essential to sustainable management of fisheries. Among the most vulnerable of exploited species are marine invertebrates collected for the ornamental aquarium trade, as commercial culture techniques are largely not addressed and vital data on larval biology is inadequate or remain unknown. The Caribbean blue-legged hermit crab (Clibanarius tricolor) is heavily collected for its role as an aquarium cleaner; however, despite its economic and ecological importance, little is known about their population structure or genetic diversity. Here, we investigate the phylogeography and genetic diversity of C. tricolor by comparing structure across four well-defined phytogeographic breaks throughout their range in the Caribbean and west Atlantic: the Florida Straits, Mona Passage, Central America, and central Bahamas breaks. We also explore additional factors (e.g. reproductive strategies, life-history traits, habitat preference, demographic history, biogeographic processes) that may influence whether structure is present in marine organisms within this region. Prior to analyzing structure throughout C. tricolor's entire range, a preliminary study was done to determine whether high throughput sequencing approaches (i.e. double digest Restriction-site Associated DNA sequencing) were necessary for detecting phylogeographic patterns in C. tricolor. Findings indicated that Sanger sequencing of traditional loci used in decapod studies (mtDNA: cytochrome c oxidase subunit 1, 16S-rDNA; nuDNA: Histone 3) were sufficient for this study. To infer C. tricolor structure and connectivity, analyses investigating genetic diversity (# segregating sites, # haploty (open full item for complete abstract)

Committee: Marymegan Daly (Advisor); Bryan Carstens (Committee Member); John Freudenstein (Committee Member) Subjects: Biology; Conservation; Genetics

PhD, University of Cincinnati, 2018, Arts and Sciences: Biological Sciences

The preservation of biodiversity is a pressing concern for many global taxa due to threats like climate change, habitat loss, and anthropogenic pressures. While in situ preservation of species in their habitats is ideal, it is not enough as threats often outpace our ability to conserve, and ex situ conservation methods must be used as a supplement to preserve species and their genetic diversity outside of their natural habitat. For exceptional species, those species ineligible for conventional seed banking due to production of little to no seeds or recalcitrant seeds, ex situ conservation must take the form of tissue culture and cryopreservation, the storage of seeds and tissues in liquid nitrogen (LN). The present study investigates the genetic consequences of these methods on exceptional species, from the initial conservation collection, to their tenure in ex situ collections, to their ultimate use in restorations and reintroductions. For Hedeoma todsenii, a federally endangered exceptional species, collections had been focused around populations located in the San Andres mountain range. A three-year study of populations in this range and the geographically distant Sacramento mountain range indicated low genetic diversity and high inbreeding in the species. However, the Sacramento population had a higher diversity and was genetically distinct from the San Andres populations, indicating that future collection efforts should include a greater focus on the Sacramento locality. Next, the genetic effects of long-term tissue culture and cryopreservation were assessed for 18 different plant species stored in LN for up to 23 years. No association was found between the survival of species after LN storage and RNA integrity, indicating that RNA may not be one of the key indicators of survival after storage. However, evidence of genetic change in DNA after cryopreservation and tissue culture was detected in three species, although this did not appear to have an effect on the (open full item for complete abstract)

Committee: Theresa Culley Ph.D. (Committee Chair); Dennis Grogan Ph.D. (Committee Member); Valerie Pence Ph.D. (Committee Member); Sarena Selbo M.S (Committee Member); Eric Tepe (Committee Member) Subjects: Biology

Doctor of Philosophy (PhD), Ohio University, 2016, Biological Sciences (Arts and Sciences)

The Diamondback Terrapin (Malaclmeys terrapin) is a turtle found in brackish water habitats along the Gulf and Atlantic coastlines of the North American continent. Historically, terrapins have had a complex relationship with humans, including over- harvesting, habitat loss and degradation, and translocations. Furthermore, ecological and molecular studies of terrapins yield conflicting results with respect to terrapin population biology. Resolving these conflicts is integral to understanding how past human activities have influenced the contemporary distribution and abundance of terrapin genetic diversity. In Chapter 1, I surveyed the terrapin literature and identified incongruences between ecological and molecular studies. I finish Chapter 1 with recommendations for future molecular and ecological terrapin studies. In Chapter 2, I demarcated metapopulation structure and quantified gene flow between populations in Chesapeake Bay. I detected four populations with weak structure, high admixture, high genetic diversity, and genetic signatures of anthropogenic translocation. In Chapter 3, I quantified the effective population sizes of the Chesapeake Bay populations, with both ecological and molecular approaches. Using mark-recapture, Bayesian model testing, and approximate Bayesian computation, I recovered incongruent results among methods. I then used mark-recapture data to rule out spurious molecular estimates, finding that coalescent models more accurately estimate effective population size in Chesapeake Bay. In Chapter 4, I used a range-wide dataset to locate major terrapin populations, quantified historical and contemporary gene flow, and tested for bottlenecks. I used Bayesian model testing and discriminant analysis of principal components (DAPC) as well as historical terrapin literature to show the terrapin's phylogeographic structure was best explained by anthropogenic translocation events in the early 1900's. In Chapter 5, I revisited a classic terrapin phylogeo (open full item for complete abstract)

Committee: Shawn Kuchta (Advisor); Willem Roosenburg (Advisor); Morgan Vis (Committee Chair); Harvey Ballard (Committee Member); Matthew White (Committee Member) Subjects: Biology; Genetics

PhD, University of Cincinnati, 2016, Arts and Sciences: Biological Sciences

Tropical and temperate plant species in forests around the world are threatened by human-induced land-use changes which produce various outcomes such as increased spread of invasive species, habitat fragmentation, and alterations of community structure among others. These factors can lower population sizes and genetic diversity levels of native plant species, making the risk of extinction imminent. Methodologies to mitigate such effects can involve introducing endangered plant species back to their native habitats either via in situ management of exploited species, or ex situ conservation. To study such species conservation, highly-replicated predictive computer modeling can be an inexpensive tool to suggest those scenarios that can better maintain viable population sizes and genetic diversity levels over the long term, since field studies are less feasible given the limited time and resources available. I used a species-specific, spatially-explicit, individual-based computer program (NEWGARDEN) capable of modeling and monitoring plant population growth and genetic diversity patterns in simulated stands over time to comparatively model various restoration methodologies for different threatened tree species. Specifically, I examined: 1) effective reintroduction geometries of the American chestnut; 2) sustainable spatial deforestation patterns for long-lived canopy tree species in tropical lowland rain forests (TLRFs); and 3) seed collection strategies capable of maximizing the harvest of genetic variation from rare TLRF tree species for use in developing ex situ rescue populations. These species conservation methodologies were tested under differing offspring and pollen dispersal distances, as this life-history trait can affect the spatial distribution of allelic diversity in populations. Results indicate that for reintroductions of the American chestnut, planting and stewarding a limited number of individuals at least 100m in from the preserve border (for (open full item for complete abstract)

Committee: Steven Rogstad Ph.D. (Committee Chair); Theresa Culley Ph.D. (Committee Member); Stephen Matter Ph.D. (Committee Member); Eric Maurer Ph.D. (Committee Member); Stephan Pelikan Ph.D. (Committee Member) Subjects: Botany

Doctor of Philosophy, The Ohio State University, 2016, Evolution, Ecology and Organismal Biology

The Neotropics is the most species-rich region in the world. The current diversity and distribution of lineages present in this region is in part the result of complex ecological and evolutionary trends determined by environmental variables that have operated at diverse spatial and temporal scales. In addition, demographic processes have also influenced the structure of present-day phylogeographic patterns. Several studies have used Neotropical pitvipers as model organisms to explore historical diversification patterns and ecological processes that produce diversity in this region. However, few of those studies have explored patterns of diversification for groups of pitvipers likely influenced by one of the most salient features of the South American continent: The Andes. Here, I use a combination of molecular, morphological, and geographical data to explore diversification patterns and the evolutionary mechanisms implicated in the divergence of two distinct members of the genus Bothrops. First, I examine cryptic diversity present in the widespread and medically important snakes of the B. asper species complex (Chapter 2). Using a genomic and morphological dataset collected across the distribution of the group, I identified extensive phylogeographic structure, suggesting the influence of geographic barriers and/or differences in ecological niches in the recent diversification in the group. A deep divergence between a Central and South American clade is evident, but more recently diverged groups in South America show complicated patterns suggestive of recent divergence and/or gene flow among lineages. Next, I use this information to perform model-based analyses to investigate the demographic processes involved in the recent origin of two Ecuadorian montane lineages of these pitvipers (Chapter 3). This approach allowed me to resolve some of the discrepancies of evolutionary relationships found in Chapter 2. I found evidence for the isolation of one of the montane line (open full item for complete abstract)

Committee: H. Lisle Gibbs (Advisor); Paul A. Fuerst (Committee Member); Thomas Hetherington (Committee Member); John Freudenstein (Committee Member) Subjects: Ecology; Evolution and Development; Zoology

Doctor of Philosophy, Miami University, 2015, Biology

Species conservation is an enormously complex task, which includes identification of phenomena that affect the loss, maintenance, and restoration of biodiversity and advocate for sustaining evolutionary processes that promote all levels of biological organization. Endangered species conservation requires a comprehensive approach to evaluate the conservation status of a given species, develop optimal recovery plans, and establish quantitative recovery criteria, in order to remove the necessity of protection. In my dissertation, I demonstrate such a comprehensive approach for evaluating the conservation status of two imperiled freshwater mussel species: Cumberlandia monodonta and Popenaias popeii, and providing guidance for development of species recovery plans. I characterized novel microsatellite markers for the species in order to assess population genetic diversity and structure (Chapter 1 and 3). I assessed fine-scale population structure of C. monodonta and used ecological and genetic simulations to investigate the effects of future climate change on distributional shifts in suitable habitats and population genetic connectivity (Chapter 2). I also investigated evolutionary history and genetic structure of P. popeii and used long-term mark-and-recapture monitoring to determine population dynamics (Chapter 4 and 5). I used demographic and population genetic information acquired from the previous chapters to develop recovery strategies for these species (Chapter 6). Using a large number of polymorphic microsatellite markers for both species, I revealed that climate change during the mid-to-late-Pleistocene likely shaped current distribution and genetic structure in both species. Current genetic structure of C. monodonta is likely a consequence of connectivity of suitable habitat; however, future climate change will likely reduce connectivity across populations. Climate change during the mid-to-late Pleistocene caused regional and local population structures of P. p (open full item for complete abstract)

Committee: David Berg (Advisor); Bruce Cochrane (Committee Member); Thomas Crist (Committee Member); Brian Keane (Committee Member); Richard Moore (Committee Member) Subjects: Biology; Conservation; Ecology; Freshwater Ecology; Genetics

Doctor of Philosophy (PhD), Wright State University, 2015, Environmental Sciences PhD

Humans have caused drastic changes in ecosystems and communities through their modification of the natural landscape. Rare species, often highly specialized, are more impacted by these changes. Pieris virginiensis is a rare butterfly native to eastern North America that is a species of concern due to negative influences from habitat loss and plant invasion. This thesis discusses several threats to P. virginiensis, including habitat loss, climate change, competition, and the cascading effects of a novel European invasive plant, Alliaria petiolata, that attracts oviposition but does not allow for larval survival. First, I examined a local extinction event and attributed it primarily to several seasons of poor weather and extreme climatic events, but with contributions by an increasing deer population and the introduction of A. petiolata. Second, I found that A. petiolata attracts approximately two-thirds of total eggs, but no larvae survive on the novel host. I tested several chemical causes of larval death and identified two potential contributors: sinigrin, which delays growth, and alliarinoside, which reduces survival. I also examined competition between P. virginiensis, its host plants, and novel competitors in the habitats. First, I looked at shared habitat use between P. virginiensis and another, exotic Pierid butterfly P. rapae. Although habitats are occasionally shared, P. rapae is most likely not a large influence on the success or failure of P. virginiensis. Second, I examined the influence of A. petiolata when it competes with two native host plants of P. virginiensis, and found differential effects of each life stage of A. petiolata on the native host plants. Finally, I used a combination of species distribution modeling and genetic sequencing to determine the current and future states of P. virginiensis given the changing climate and other stressors on P. virginiensis populations. Although secure currently, future stressors will most likely cause (open full item for complete abstract)

Committee: Don Cipollini Ph.D. (Advisor); John Stireman Ph.D. (Committee Member); Jeffrey Peters Ph.D. (Committee Member); Thaddeus Tarpey Ph.D. (Committee Member); Francie Chew Ph.D. (Committee Member) Subjects: Biology; Botany; Climate Change; Conservation; Ecology; Environmental Science; Environmental Studies

Master of Science, University of Akron, 2014, Biology

As humans continue to influence ecosystems, the preservation of endangered species becomes increasingly important. This leads to the use of captive breeding programs as a tool while fragile habitats are restored or recover. However, the majority of captive breeding studies deal with parameters that account for optimization only while in captivity. Breeding plans look to increase fitness and or fecundity while minimizing deleterious effects associated with inbreeding and small population sizes while in captivity. Few studies focus on the interaction between inbreeding and fitness in captivity with success when released into the wild. Fewer studies still have examined the utilization of genetic variation that is partitioned within and between captive populations in meeting the objectives of breeding plans. Largely missing from current breeding plans is recognition of potential tradeoffs between fitness in the captive environment and adaptability to release environments. We simulated how population structure in and out of captivity influences long-term species success. We specifically tested if a traditional breeding design (maximum avoidance of inbreeding) preformed as well as a model that maintained traditional segregation of alleles in captivity. We found that maintaining inbred wild population structure protected genetic variation better than maximum outcrossing while in captivity. This study calls into question current practices in captive breeding when future release of captive bred populations is anticipated.

Committee: Francisco Moore Dr. (Advisor); Matthew Shawkey Dr. (Committee Member); Randall Mitchell Dr. (Committee Member); Zhong-Hui Duan Dr. (Committee Member) Subjects: Biology; Evolution and Development; Wildlife Conservation; Wildlife Management

Doctor of Philosophy, The Ohio State University, 2002, Evolution, Ecology, and Organismal Biology

This dissertation focuses on evolutionary studies of species of Platanthera, a temperate group of orchids with centers of diversity in North America and Asia. Population genetic structure and inbreeding depression are examined in Platanthera leucophaea, a threatened species occupying prairie fragments in the Midwestern US. Populations harbor little allozyme variability but higher levels of RAPD diversity. Both data sets revealed substantial population differentiation, which suggests little interpopulational gene flow and high potential for intrapopulation inbreeding. Subsequent studies determined that inbreeding depression could be strong, indicating the need to increase recruitment in smaller populations. The latter studies focus on systematics of section Limnorchis, with special emphasis on the origin of the polyploid species Platanthera huronensis. Molecular sequence data suggest the presence of two primary lineages in Limnorchis corresponding to green or white flower color. This analysis also demonstrates that P. huronensis is most similar to P. dilatata and P. aquilonis, the progenitors suggested by morphological characteristics. Platanthera huronensis displays little additivity of parental genotypes, but there is evidence of bidirectional evolution of nuclear rDNA; most individuals are most similar to P. dilatata. Molecular ISSR and RAPD data also support an allopolyploid origin of P. huronensis from P. aquilonis and P. dilatata, but these patterns are not additive of parental genotypes either. Extant polyploid lineages may have undergone further evolutionary diversification since formation of polyploid lineages. Chloroplast RFLP patterns suggested multiple origins of P. huronensis and reciprocal maternal parentage. Strong geographic differences revealed by molecular markers and quantitative morphological traits may indicate that eastern and western P. huronensis are unique entities worthy of taxonomic recognition. Although polyploids often show increased dive (open full item for complete abstract)

Committee: Wolfe Andrea Crawford Daniel (Advisor) Subjects: Biology, Botany

Master of Science (MS), Ohio University, 2003, Environmental Studies (Arts and Sciences)

The purpose of this thesis was to investigate pollen-mediated gene flow and genetic variation within populations of Manfreda virginica that occur in prairie openings in Adams County, Ohio. M. virginica was chosen because of its historic co-dominance in the xeric prairies and its role as a dominant plant in globally rare limestone seep habitats. A pollen surrogate was used to estimate pollen dispersal and inferred pollen movement is frequent within populations, but not among populations. A single species of Halictid bee appears to be the primary and perhaps sole pollinator. Genetic analysis was performed using Inter-Simple Sequence Repeat (ISSR) markers. No significant relationship was found between geographic distance and genetic distance and substantial genetic variation is found between all populations regardless of size or geographic position. Heterozygosity and polymorphism was low within all populations. Analysis indicates substantial fixation of alleles within populations, perhaps driven by drift due to genetic isolation.

Committee: Harvey Ballard (Advisor) Subjects: Biology, Botany

Master of Science, Miami University, 2012, Zoology

In recent years, the range of Peromyscus maniculatus gracilis in Michigan's Lower Peninsula (LP) contracted simultaneously with the northward expansion of the closely related Peromyscus leucopus. Recent trapping shows that the range of P. m. gracilis has shrunk to two remaining areas: one in Cheboygan and Otsego Counties and another to the east in Alpena Co. (AP). I used a Geographic Information System habitat analysis to predict where P. m. gracilis would be found across the region, trapped at selected locations, and analyzed 11 microsatellite loci for all individuals. Genetic diversity and bottleneck analyses indicate that LP populations once had good gene flow and were continuous across the area; however, trapping data and assignment tests show that the AP population is in the process of becoming geographically and genetically isolated from all other populations. The AP population is currently genetically viable, but is showing signs of becoming genetically distinct from the western populations.

Committee: Susan M. G. Hoffman (Advisor); Brian Keane (Committee Member); M. H. H. Stevens (Committee Member) Subjects: Biology; Genetics

Doctor of Philosophy, Miami University, 2009, Zoology

This dissertation consists of three chapters, each of which addresses a topic in one of three related categories of research as required by the Ph.D. program in ecology as directed through the Department of Zoology at Miami University.Chapter 1, Phylogeographic analysis reveals multiple cryptic species of amphipods (Crustacea: Amphipoda) in Chihuahuan Desert springs, investigates how biodiversity conservation and the identification of conservation units among invertebrates are complicated by low levels of morphological difference, particularly among aquatic taxa. Accordingly, biodiversity is often underestimated in communities of aquatic invertebrates, as revealed by high genetic divergence between cryptic species. I analyzed PCR-amplified portions of the mitochondrial cytochrome c oxidase I (COI) gene and 16S rRNA gene for amphipods in the Gammarus pecos species complex endemic to springs in the Chihuahuan Desert of southeast New Mexico and west Texas. My analyses uncover the presence of seven separate species in this complex, of which only three nominal taxa are formally described. The distribution of these species is highly correlated with geography, with many present only in one spring or one spatially-restricted cluster of springs, indicating that each species likely merits protection under the U.S. Endangered Species Act. I present evidence suggesting that habitat fragmentation, long-distance colonization, and isolation-by-distance have occurred at different temporal and spatial scales within this system to produce the lineages that I report. Chapter 2, Detecting conservation units using morphological versus molecular criteria: evaluating the Gammarus pecos species complex as a test case, compares the results of morphological versus molecular biodiversity assessments within the G. pecos species complex. I compared results from an earlier morphology-based study to my results from screening 166 COI gene sequences according to Moritz' Evolutionarily Significant (open full item for complete abstract)

Committee: David Berg PhD (Advisor); John Bailer PhD (Committee Member); Brian Keane PhD (Committee Member); Nancy Solomon PhD (Committee Member); Bruce Steinly PhD (Committee Member) Subjects: Bioinformatics; Biology; Biostatistics; Ecology; Environmental Science; Freshwater Ecology; Genetics; Hydrology; Molecular Biology; Zoology