Life Sciences Commons^™

Examining Population Structure Of Cismontane And Desert Populations Of Zebra-Tailed Lizards (Callisaurus Draconoides) Using Mitochondrial And Nuclear Intron Dna., Lauren Nicole Morrison

Electronic Theses, Projects, and Dissertations

Callisaurus draconoides, also known as the Zebra-Tailed lizard, belongs to the family Phrynosomatidae family (Pianka, et al. 1972). C. draconoides is a widespread desert lizard found western North America. In California, this species can be found in the Mojave and Colorado Deserts. There are currently several populations that reside in the San Bernardino basin on the cismontane side of the Transverse and Peninsular ranges. These mountain ranges have the potential to have isolated the cismontane populations from their typical desert ranges. In addition, geological passes have the potential to serve as migration corridor between the Deserts and cismontane regions. The …

A Case Of Incipient Budding Speciation In The California Floristic Province, Infraspecific Divergence In Abronia Villosa, Eli J. Allen

Cal Poly Humboldt theses and projects

Physical barriers to gene flow are the traditional evidence for species divergence. Conversely, there has been increasing acknowledgment of speciation in the face of gene flow as an evolutionary process. Budding speciation involves peripheral populations adapting to local ecological conditions, thereby budding off from a widespread progenitor species. Budding speciation is distinguished by ecological divergence and is generally evidenced by asymmetrical range size and nested phylogenetic relationships of sister species. The narrow endemic Abronia villosa var. aurita is adapted to montane sandy washes adjacent to its widespread sister variety, the desert dwelling var. villosa. Here, I tested the hypothesis …

Phylogeographic History Of The Leaf-Eared Mouse, Phyllotis Xanthopygus Complex, Tabitha R. Mcfarland

Biology ETDs

Museum collections provide essential biodiversity sampling needed to understand the species limits, phylogeny, and biogeographic history of mammals, all key features of the foundation for comparative analyses in ecology and evolution. We add to this framework a diverse assemblage of species of leaf-eared mice (genus Phyllotis) in South America and then focus on the Phyllotis xanthopygus complex by combining available mitochondrial sequence (cytochrome b; cytb) data (351 GenBank samples) with 52 newly sequenced museum samples from the northern extent of this complex’s range (51 from Bolivia and 1 from northern Chile) to reconstruct evolutionary relationships using maximum …

Machine Kinship: The Impossible Duet, Diana Sanchez

Masters Theses

Machine Kinship: The impossible duet What does it mean to vanish from earth when you are the last of your kind? In 1987 the Kauai OO was recorded singing his final song. It was meant to be a duet, but as the last of his kind his song hangs in the air, unanswered. The other half of the duet is forever lost. Built to sing at dawn, birds must wake up earlier to hear each other before human chaos interferes. So here, it is always almost sunrise. As a parallel past-future response, the last birdsong was fed into a machine …

Impacts Of Bacterial Evolution On Host Lethality In Drosophila, Andrew Preston

College of Arts & Sciences Senior Honors Theses

Evolution is the process by which species change their genetic traits, such as the pathogenicity of bacteria, over time in response to changes in their environment. Although the genetic mechanisms underlying many evolutionary processes have been revealed, it is still not well understood how opportunistic pathogens, such as Pseudomonas aeruginosa, become virulent. The overall goal of this thesis is to test the Coincidental Evolution Hypothesis, which proposes that the virulence of opportunistic pathogens evolves coincidentally as a by-product of their interaction with their natural predators. I hypothesized that the virulence of ancestral Pseudomonas aeruginosa changes over time if it co-evolves …

Past And Present Patterns Of Neutral And Adaptive Genetic Diversity In Wild Mandrills (Mandrillus Sphinx), Anna Weber

University of New Orleans Theses and Dissertations

Although primates have fascinated researchers and the public alike for generations, one species that has remained enigmatic is the mandrill (Mandrillus sphinx), a large Cercopithecine monkey endemic to Central Africa. Mandrills are currently in decline due to bushmeat hunting, urbanization, and habitat loss. Neutral and adaptive genetic diversity are important tools for understanding evolutionary history and future viability, since diversity influences a species’ ability to adapt to a changing environment. However, thus far, minimal genetic information has been available for wild mandrills. Because of the dense vegetation in their tropical forest habitat, studying wild mandrills has proven to …

Context-Dependency And Sex-Specificity Of Dispersal Syndromes, Allyssa Kilanowski

Theses and Dissertations--Biology

For populations in landscapes with increasingly heterogeneous and fragmented habitat patches (e.g., metapopulations), dispersal is an important behavior that leads to gene flow and connectivity among isolated patches. Because dispersal is a complex process, there are many traits involved. When suites of morphological, behavioral, physiological, and life-history traits covary with dispersal (e.g., a dispersal syndrome), the correlated traits can assist dispersing individuals through the complex process. Furthermore, once dispersal is completed, the correlated traits can influence the fitness of those dispersed individuals. Dispersal syndromes will likely interact with the local environment to produce ecological and evolutionary feedbacks on the metapopulation. …

Ecology And Evolution Of Social Information Use, Clare T. M. Doherty

Dartmouth College Ph.D Dissertations

Sociality is a strategy many animals employ to cope with their environments, enabling them to survive and reproduce more successfully than would otherwise be possible. When navigating their environments and making decisions, social individuals often use information provided by conspecifics (in the form of social cues and signals), thereby increasing the scope and reliability of the information they can gather. However, social information use may be influenced by many factors, including key differences in context across the physical and social environment. My thesis asks and answers a series of questions regarding the trade-offs in social information use across different contexts, …

Constraints Of The Imagination: How Phenotypes Are Shaped Through Genetics, The Environment, And Development, Michelle Gilbert

Doctoral Dissertations

Phenotypic constraints are ubiquitous throughout nature, being found throughout all stages of life and at multiple different biological levels including cellular, genetic, environmental, behavioral, evolutionary, and developmental. These constraints have shaped, not only the natural world, but the way that we perceive what is possible, or impossible, an observation made clear by François Jacob in his 1977 paper “Evolution and Tinkering”. This is reflected in the literature, repeatedly, by the regular occurrence of densely packed visualization of phenotypic space that seemingly always have large areas that go unoccupied. Despite constrained regions of space being observable across countless taxa, identifying the …

Ecology And Phytochemistry Of The Non-Native Plant Thlaspi Arvense (Brassicaceae) In Subalpine Meadows Of Colorado, Usa, Elsa Cousins

Doctoral Dissertations

Climate change is altering ecosystems at multiple scales. Globally, warming temperatures and increasing irregularity of precipitation will have large scale impacts on species distribution and success. Locally, understanding species response to fine scale microhabitat variation can provide key insights into population adaptation. Non-native plants represent an opportunity to investigate population level response and adaptation to relatively novel combinations of biotic and abiotic environments. Subalpine meadows are at the intersection of biotic and abiotic change, as large-scale climatic shifts alter water and temperature regimes and species range shifts become increasingly common and larger in scale. This dissertation addresses these questions of …

Phylogenetic Relationships Among Fishes In The Order Zeiformes Based On Molecular Data From Three Mitochondrial Loci, Lindsay Scarpitta

Master's Theses

The Zeiformes (dories) are mid-water or deep (to 1000 m) marine acanthomorph fishes with a global, circumtropical, and circumtemperate distribution. Some species have a near-worldwide distribution, while others appear to be regional endemics, e.g., near New Zealand. Six families, 16 genera, and 33 species are currently recognized as valid. Relationships among them, however, remain unsettled, especially in light of recent proposals concerning the phylogenetic placement of zeiforms within the Paracanthopterygii rather than allied with beryciforms or percomorphs. The present study uses mtDNA characters to investigate zeiform interrelationships given their revised phylogenetic placement and attendant changes to their close outgroups, carried …

Development Of Graphical Models And Statistical Physics Motivated Approaches To Genomic Investigations, Yashwanth Lagisetty

Dissertations & Theses (Open Access)

Identifying genes involved in disease pathology has been a goal of genomic research since the early days of the field. However, as technology improves and the body of research grows, we are faced with more questions than answers. Among these is the pressing matter of our incomplete understanding of the genetic underpinnings of complex diseases. Many hypotheses offer explanations as to why direct and independent analyses of variants, as done in genome-wide association studies (GWAS), may not fully elucidate disease genetics. These range from pointing out flaws in statistical testing to invoking the complex dynamics of epigenetic processes. In the …

Survivorship Of Columbian Black-Tailed Deer In A Predator-Free Environment, Grace Hope Barthelmess

Honors Projects

Future management of Columbian black tailed deer (Odocoileus hemionus columbianus) populations requires an understanding of survivorship and potential drivers of mortality. Little is currently known about the survivorship of O. h. columbianus, specifically in a predator-free environment. Analyzing the survivorship of deer in these contexts may be crucial for wildlife conservation efforts throughout the United States, as it could provide insight into how deer populations may be impacted by lack of population control by predation. Here, I present age analysis of O. h. columbianus based on the cementum annuli of the lower first molar in 489 males …

Assessing The Utility Of The Pmm And Mmc Indices Among Extant Hominoid Genera, Julie A. Strain

Theses and Dissertations

This thesis set out to incorporate extant hominoid genera into an analysis of PMM and MMC to assess utility in phylogeny and predicting known taxonomic groups. Based on previous claims, we expect PMM/pmm and MMC/mmc to perform better than M1/m1 shape and size, our baseline for success, but they do not.

Rodent Dental Microwear Texture Analysis As A Proxy For Fine-Scale Paleoenvironment Reconstruction, Jenny H. E. Burgman

Graduate Theses and Dissertations

Dental microwear texture analysis (DMTA) of fossil fauna has become a valuable tool for dietary inference and paleoenvironment reconstruction. Most of this work has utilized larger taxa with larger home ranges. These studies may result in broader-scale habitat inferences that could mask the details of complex mosaic habitats. Rodent DMTA offers an opportunity to work at finer spatial scales because most species have smaller home ranges. Rodents are also keystone species within their ecosystems, abundant, ubiquitous, and found in many fossil deposits. These attributes make them excellent proxies for environmental reconstructions. However, the application of DMTA to rodents remains relatively …

Evolution Of Floral Microbes And The Resulting Effects On Pollinator Preference, Hailey Hatch

Undergraduate Honors Capstone Projects

Floral microbes are an overlooked aspect of the extended floral phenotype. Through altering floral nectar chemistry, they can mediate interactions between flowers, pollinators, and other floral microbes, with significant implications for plant and pollinator health. Interactions between floral microbes and pollinators are critically important to understand, as pollinators provide important ecosystem services in both natural and agriculture systems. Here, I explored how floral nectar traits affected both evolution and competition within the floral yeast Metschnikowia reukaufii, the floral bacterium Bacillus subtilis, and other microbes isolated from Brassica rapa nectar, an important plant model system and oilseed crop. To …

Evolution Of Life-History Characteristics In Gadoidei, Joshua Hittie

Master's Theses

Life-history characteristics (e.g., age and growth) have been used extensively to understand the temporal population dynamics of fish species, but less so within a phylogenetic framework. This study investigates life-history characteristics within the suborder Gadoidei (order: Gadiformes) and to test the extent of phylogenetic signal for those characteristics. To accomplish this, a phylogeny of Gadoidei was first constructed based on both mitochondrial and nuclear genes. Within this phylogenetic framework, life-history traits, including growth rate, age at maturity, and longevity, as well as ecological data, such as water depth and diet type, were mapped to the phylogeny using parsimony analysis to …

Nutrient Scarcity And Cellular Cooperation In A Clonal Hydroid, Weam S. El Rahmany

Graduate Research Theses & Dissertations

Biological complexity forms when lower-level units (e.g., genes, cells, organisms) cooperatively band together. This complexity may be exemplified by multicellularity, the cooperation between the cells of the same species, or symbiosis, cooperation between the cells of different species. This cooperation is under continual threat, as defection, the opposite of cooperation, is favored by default by lower-level units (i.e., cells). Animal cancers may be the most well-known phenomena that exemplify the concept of cellular defection. Cancer cells have been shown to feature morphological and metabolic traits, developed through differential gene expression or mutations, that favor their growth at the cost of …

Evaluating Population Genetic Structure And Potential Genomic Signals Of Natural Selection In A Migratory Songbird (Protonotaria Citrea), Tyler A. Hohenstein

Theses and Dissertations

In this study I attempted to further resolve the population genetic structure in the Prothonotary Warbler (Protonotaria citrea), and conducted an outlier SNP analysis and exploratory gene ontology analysis to investigate potential ongoing natural selection in the species. This analysis of population structure confirms previous work by DeSaix et al. (2019), where weak population structure was observed between eastern sites along the Atlantic Coastal Plain, and western sites in the Mississippi Alluvial Valley, possibly due to a genetic discontinuity across the Appalachian Mountains. I conducted two forms of outlier SNP analyses, a principal component analysis (PCA)-based approach to identify SNPs …

Population Genomics Of Redbreast Sunfish (Lepomis Auritus): Exploring Gene Flow And Local Adaptation In A Widely Distributed Freshwater Fish, Garret J. Strickland

Electronic Theses and Dissertations

Little information is available concerning the distribution of genetic diversity in non-salmonid, non-imperiled, freshwater fish. In order to fill in this knowledge gap, I conducted a population genomics survey in Redbreast Sunfish (Lepomis auritus; RBS), a widespread, generalist species distributed along the Atlantic slope rivers of eastern North America. I sampled four basins (ACF, Savannah, Roanoke, and James) at eight sites each with a factorial experimental design. Sites were distributed among coastal plain, Piedmont, or mountain ecoregions in order to capture the greatest range of environmental states experienced by RBS, with the intention of finding evidence for local adaptation to …

Drought Tolerance In Native And Invasive Populations Of The Centaurea Jacea Hybrid Complex, Zoe Portlas

Graduate College Dissertations and Theses

Introduced plants face many ecological and evolutionary challenges when establishing in a new range, such as strong abiotic stressors and potentially novel selective environments. One such abiotic stress is water availability, which is a strong selective force shaping physiological and phenological traits that enable plants to tolerate or avoid drought stress. Despite the challenges of establishing in a new range, thousands of species have become invasive in recent centuries. Two hypotheses that may explain how a species is able to withstand stress in its introduced range are preadaptation, which posits that species are adapted to similar environments in their native …

Lipidomic Analysis Of Various Developmental Stages Of Physcomitrium Patens, Deepshila Gautam

Electronic Theses and Dissertations

Lipids maintain fluidity of the cell membrane during the lifetime of all organisms. The moss Physcomitrium patens, an early land plant, enters reproductive phase under cold (15°C) conditions relative to its gametophytes (22°C). Thus, we hypothesized that their lipid content and composition would be distinct. Using ESI-MS/MS, we showed that the content and acyl composition of 11 lipid classes varied during development. Galactolipids were abundant in gametophytes but insignificant in sporophytes; among phospholipids, phosphatidylcholine was predominant in both phases. Although, sporophytes contained around five-fold less lipids than the gametophyte, their phosphatidic acid content, which accumulates during stress, was 18-fold …

Resource Allocation And Phenotypic Plasticity Of Simultaneous Hermaphroditic Turtle Barnacles (Chelonibia Testudinaria), Kevin C. Cash

All HCAS Student Capstones, Theses, and Dissertations

This research addresses the knowledge gap of phenotypic plasticity in a commonly found and important species of epizoic barnacle, Chelonibia testudinaria. Limited research has been published regarding how phenotypic expression is mediated the spatial distribution of barnacles on a mobile host. To investigate this potential relationship, barnacles were collected from the backs of turtles along the beaches of Fort Lauderdale Florida. These barnacles were assessed for various phenotypic traits as well as their corresponding spatial distribution on the turtle carapace. Barnacles were safely removed from the carapace using a chisel before their preservation in ethanol. Barnacles were then numbered …

Factors Influencing Primate Hair Microbiome Diversity, Catherine Kitrinos

Masters Theses

Primate hair is both a substrate upon which essential social interactions occur and an important host-pathogen interface. As commensal microbes provide important immune functions for their hosts, understanding the microbial diversity in primate hair could provide insight into primate immunity and disease transmission. While studies of human hair and skin microbiomes show differences in microbial communities across body regions, little is known about the nonhuman primate hair microbiome. In this study, we collected hair samples (n=159) from 8 body regions across 12 nonhuman primate species housed at 3 US institutions to examine 1) the diversity and composition of the primate …

Coevolution Of Hosts And Pathogens In The Presence Of Multiple Types Of Hosts, Evan J. Mitchell

Electronic Thesis and Dissertation Repository

How will hosts and pathogens coevolve in response to multiple types of hosts? I study this question from three different perspectives. First, I model a scenario in which hosts are categorized as female or male. Hosts invest resources in maintaining their immune system at a cost to their reproductive success, while pathogens face a trade-off between transmission and duration of infection. Importantly, female hosts are also able to vertically transmit an infection to their newborn offspring. The main result is that as the rate of vertical transmission increases, female hosts will have a greater incentive to pay the cost to …

Landscape Population And Evolutionary Genomics Of Several Closely Related Species Of Mallard-Like Ducks, Joshua Brown

Open Access Theses & Dissertations

Divergence and speciation proceed through three major evolutionary forces (i.e., selection, genetic drift, and gene flow) that are often spatially and temporally heterogeneous across the landscape. Moreover, these forces can have differing but subtle effects within the genomes of diverging taxa, and therefore, disentangling the effects of these evolutionary mechanisms throughout the speciation process can be challenging. Here, I use a recent species radiation, the mallard complex, to investigate how strong, yet varied, evolutionary pressures influence the speciation process. The mallard complex consists of 14 mallard-like waterfowl species around the world that have some of the highest rates of hybridization …

The Role Of Nutrition And Hormone Signaling In Extended Larval Development And Obesity In Starvation-Selected Drosophila Melanogaster, Jennifer M. Clark

UNLV Theses, Dissertations, Professional Papers, and Capstones

Brief periods of starvation are a common stressor that most animals encounter in the wild and must be able to survive in order to maximize their fitness. Starvation resistance of the adult fruit fly, Drosophila melanogaster, is thought to be primarily conferred by adult fat stores, body size, metabolic rate, behavior, and activity levels. Additionally, flies selected for starvation resistance also often show delayed pupariation, which is usually indicative of altered hormone signaling. How starvation selection extends development and if it contributes to adult starvation resistance remains incompletely studied. Identifying the targets of starvation selection that cause extended development and …

The Distribution In Native Populations From Mexico And Central America Of The C677t Variant In The Mthfr Gene, Lucio A. Reyes

USF Tampa Graduate Theses and Dissertations

Objectives: To explore evolutionary hypotheses for the high frequencies of a substitution in the methylenetetrahydrofolate reductase (MTHFR) gene, in Mexican and Central American Indigenous populations.

Materials and methods: We obtained allele frequencies for the C677T variant in the MTHFR gene and ecological information for 37 indigenous samples from Mexico and Central America. We calculated Hardy–Weinberg equilibrium and computed Fst statistics. We computed correlations between the samples' allele frequencies and ecological and geochemical variables.

Results: Many of the samples have extremely high frequencies of the T allele (q̄ = 0.62, median = 0.66). In this region, the frequency of the T …

Functional Genetic Approaches To Provide Evidence For The Role Of Toolkit Genes In The Evolution Of Complex Color Patterns In Drosophila Guttifera, Mujeeb Olushola Shittu

Dissertations, Master's Theses and Master's Reports

Toolkit genes are set of genes that orchestrate the development of basic body plan of animals, and they are highly conserved in all animals. The co-option of the toolkit genes into the pigmentation pathway has led to the evolution of novel species. This study focuses on understanding how the complex color patterns in animals develop by using the Drosophila species in the quinaria group as models. We developed an mRNA in situ hybridization (ISH) protocol, which allowed us to study gene expression patterns in the abdomen of developing pupae of non-model Drosophila species (Chapter 2). Through ISH, we found that …

The Evolution Of Technology, Kelly Cooper

Williams Honors College, Honors Research Projects

As per outlined by Dr. Quinn, this literature review will be a comprehensive review paper including an overview of current and previous research done in the field of Memetics. This will further include sifting through literature to hone in on a specific, new area of memetics Dr. Weeks is focused on, the evolutionary change of abiotic factors through purchasing. This is to be completed with the help of the library worshops designed to teach the skills necessary to undergo a literature review of this size. I will also participate in weekly reading groups to discuss papers and work closely with …