Life Sciences Commons^™

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 …

Functional Morphology, Biomechanics, And Evolution Of Ruminant Mammals, Abby Vander Linden

Doctoral Dissertations

Ruminant mammals, including the families Bovidae, Cervidae, Tragulidae, Moschidae, Antilocapridae, and Giraffidae, display incredible past and present diversity in morphology, ecology, and behavior. They inhabit an impressive range of environments across North and South America, Europe, Asia, and Africa, and compel the fascination of naturalists and researchers alike with their charismatic social behavior and conspicuous cranial appendages. I explore the drivers and consequences of this spectacular diversity through a comparative morphological framework, biomechanical modeling approaches, and semi-parametric and likelihood-based methods for estimating state-dependent diversification rates across the ruminant phylogeny. Together, these investigations provide evidence for adaptation via correlated evolution of …

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 …

Phylogenomics And Population History Of Cichlid And Live-Bearing Fish Species In Lowland Neotropical Rivers, Konrad Taube

College of Science and Health Theses and Dissertations

Within Middle America, cichlids and poeciliids account for more than half of the fish biodiversity. This richness in fish fauna highlights the complexity of Middle American biogeography: no other continental area on earth contains within its range the unparalleled abundance of secondary freshwater fish species (fish that can tolerate both saltwater and freshwater). Research into the biogeography of widely distributed Middle American freshwater fish is essential to understanding this unique region.

Three species of freshwater fishes (Belonesox belizanus – Pike killifish, Vieja maculicauda – Black belt cichlid, and Gambusia nicaraguensis – Nicaraguan mosquitofish) are widely distributed across rivers on …

The Evolutionary History Of Camelina Crantz (Brassicaceae) And Domestication Of The Biofuel Crop, C. Sativa (L.) Crantz, Jordan Brock

Arts & Sciences Electronic Theses and Dissertations

The mustard family, Brassicaceae, is a large and economically important group of plants comprising ~350 genera and ~4060 species. Within the family, one genus, Camelina, has been neglected and nearly forgotten until recent decades. This genus comprises between 7 – 9 species, and includes Camelina sativa, an ancient oilseed crop cultivated for thousands of years in Europe. An allohexaploid, C. sativa contains high levels of omega-3 fatty acids and a seed oil composition amenable for production of aviation jet fuel. With a short generation time and ability to be cultivated on marginal soils with few inputs, C. sativa is set …

On The Relationship Of Diabetes And Sleep Apnea: Evolution And Epigenetics, Nancy Wilson

Undergraduate Honors Theses

This thesis gives an overview of the relationship between diabetes, sleep apnea, obesity, and heart disease. It then addresses evidence that the traditional understanding of this relationship is incomplete or misleading. In the process, there is a brief discussion of the evolutionary rationale for the development and retention of sleep apnea in light of blood sugar dysregulation, as an adaptive mechanism in response to environmental stressors, followed by a brief overview of the general concepts of epigenetics. Finally, this paper presents the results of a literature search on the epigenetic marks and changes in gene expression found in sleep apnea …

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 Evolution Of Sex Differences In Mandrills (Mandrillus Sphinx): Micro- And Macroevolution, Jerred Klint Schafer

Legacy Theses & Dissertations (2009 - 2024)

Primates show diverse patterns of adaptive color and body size dimorphism produced by inter- and intrasexual selection. However, the specific microevolutionary processes that produce variation in secondary sexual characteristics remain largely unexplored in primates. Furthermore, sexual conflict theory predicts that female and male secondary sexual traits can coevolve in an antagonistic manner and promote speciation. This dissertation explores the microevolution of secondary sexual characteristics in mandrills (Mandrillus sphinx) and the macroevolution of these characters in anthropoid primates. I address the microevolution of mandrill facial coloration and body mass by estimating the heritability, phenotypic selection, and genetic evolution of these traits …

Evolution Of Targeted Therapy Resistance In Eml4-Alk Positive Non-Small Cell Lung Cancer, Robert Vander Velde

USF Tampa Graduate Theses and Dissertations

Targeted therapies have emerged as potent treatments that lead to the remission of many tumors. However, they rarely cure cancers in advanced, metastatic settings. This is due to the evolution of resistance, which in turn can be ascribed to the survival of small subpopulations of tolerant and/or resistant cells. Here we investigated the evolution of resistance to EML4-ALK inhibitors in non-small cell lung cancer (NSCLC) and demonstrated that resistance evolves gradually, from unique pre-treatment sub-populations, as multiple resistance mechanisms accumulate in a Darwinian fashion. Despite accumulating multiple changes, cells evolved, in parallel, toward similar inhibitor specific phenotypes. Evolving cells have …

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 Diversity And Evolution Of Phenazine Biosynthesis Pathways In Enterobacterales, Christian Leise

Honors Theses

Enterobacterales is an order of Gram-negative bacteria that encompasses plant and animal pathogens and organisms of industrial importance. Some of these bacteria produce secondary metabolites classified as phenazines (Phz). Studies in other groups of microorganisms revealed that phenazines are redox-active and exhibit broad antibacterial, antifungal, and antiparasitic activity. Enterobacterales are known to produce phenazines, but details about the diversity, biochemistry, and function of phenazine metabolites in these organisms are missing. In this work, we screened the National Center for Biotechnology Information (NCBI) GenBank for genome sequences of phenazine-producing (Phz+) Enterobacterales. Additionally, genomes of Phz+ strains Pectobacterium carotovorum cc303 and …

On The Rocks: Changes In Substrate Alter Antipredator Behavior In Benthic Stream Fish, Sarah White

MSU Graduate Theses

Natural selection should strongly favor characteristics that make prey difficult for predators to distinguish from the background, including both morphological and behavioral crypsis. The Rainbow Darter (Etheostoma caeruleum) is a small, cryptic, benthic fish that inhabits gravel-bottomed streams and is preyed upon by predators such as the benthic Knobfin Sculpin (Cottus immaculatus) and the pelagic Longear Sunfish (Lepomis megalotis). In three experiments, I tested whether the behavior of darters was influenced by the opportunity for crypticity offered by their substrate and by the presence of cues from benthic and pelagic predators. First, darters in …

Evolution And Selection: From Suppression Of Metabolic Deficiencies To Bacteriophage Host Range And Resistance, Daniel Kurt Arens

Theses and Dissertations

The evolution and adaptation of microorganisms is so rapid it can be seen in the time frame of days. The root cause for their evolution comes from selective environmental pressures that see organisms with beneficial mutations survive otherwise deadly encounters or outperform members of its population who fail to adapt. This does not always result in strict improvement of the individual as in the case of antibiotic resistant bacteria who often display fitness tradeoffs to avoid death (see Reviews [1-3]). For example, when an ampicillin resistance gene (ampC) containing plasmid that is occasionally found in the wild was transformed into …

Dynamic Evolution In The Leucine-Rich Repeat Receptor-Like Kinase (Lrr-Rlk) Family Of Receptors, Jarrett Man

Doctoral Dissertations

Cells in multicellular organisms must gauge their environmental conditions, including neighboring cells, during development. In plants, the Leucine-Rich Repeat Receptor-like Kinases (LRR-RLKs) encode a family of membrane-bound receptors that transduce such cell-to-cell signals and are required for many aspects of plant development. Very little is known about the function of most of these genes, and the evolutionary history of the family is difficult to infer because of its size and complexity. Several factors contribute to this difficulty, including genetic redundancy, challenging bioinformatic detection, exceptionally large family size, and high copy number variation among species. In this dissertation, I characterize some …

Evolution And Development Of Staminodes In Paronychia (Caryophyllaceae), Andrea D. Appleton

Honors College Theses

Staminodes are infertile stamens that have evolved numerous times in flowering plants and exhibit a vast array of forms and functions. Variation in staminodes suggests that numerous evolutionary processes underlie their origins, but to understand their how and why they evolved, comparative studies are needed in groups of closely related species. Identifying structures as staminodes is not always straightforward and sometimes requires corroborating phylogenetic and developmental evidence. Staminodial structures in Paronychia (Caryophyllaceae), for example, vary in shape and size and have been referred to as both petals and staminodes, rendering their homology uncertain. The development of staminodes was compared across …

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 …

An Evaluation Of College Preparedness On Natural Selection Principles Following The Completion Of An Entry-Level Biology Course, Amy Bell

Murray State Theses and Dissertations

Abstract

Evolution education in secondary education has long been a topic of research. The level of knowledge and acceptance of students upon entering college has been studied using various methods; however, no study had provided the perception of preparedness from the student perspective nor had analyzed the individual Natural Selection principles. This study analyzed college freshmen (n=162) in an entry-level BIO 101 course. Participants were given the Conceptual Inventory of Natural Selection Instrument (CINSI) and perception survey questions upon completion of the course. The CINSI data was then analyzed for each of the four Natural Selection principles as well as …

Modeling Disorder In Proteins Yields Insights Into The Evolution Of Stability And Function, Jonathan Huihui

Electronic Theses and Dissertations

The central dogma of molecular biology dictates that a DNA sequence codes for an RNA sequence, which in turn codes for a sequence of amino acids that comprises a protein. Proteins are responsible with performing myriad functions within living organisms and most proteins require a folded structure in order to perform their function. The protein's structure is the direct link from sequence to function. This is known as the sequence - structure - function paradigm. However, this does not mean that the unfolded state is unimportant. In order to properly model the stability of the folded state, one needs to …

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 Origin Of Novel Trait Inferred From Transcriptomic Analysis And A Targeted Gene Approach In The Beetle Horns., Naureen Fatima

Graduate Theses, Dissertations, and Problem Reports

The origin of the evolutionary new trait (evolutionary novelty) and its subsequent evolution is of great interest for biologists in various fields, and beetle horns have been used to address this fundamental biological question. Previous studies on one of the horned beetle species, Onthophagus taurus, that utilized comparative gene expression analyses, suggested legs to be a strong candidate of the origin of horns. At the same time, their horns are secondary sexual traits whose development is regulated by the same gene (doublesex) as genitalia, which also originates from paired appendages such as legs. However, little is known …

Exploring Zosterophyll Relationships Within A More Broadly Sampled Character Space: A Focus On Anatomy, Megan Nibbelink

Cal Poly Humboldt theses and projects

Important constituents of Siluro-Devonian floras, zosterophylls gave rise to the lycophytes. I explore the relationships of 18 zosterophyll species from 16 genera, maximizing sampling of anatomy. Using phylogenetic and phenetic methods, I (1) assess the influence of tree rooting, taxon sampling, and morphological vs anatomical characters on the stability of relationships; and (2) compare phylogenetic and phenetic methods in terms of relationships recovered. Phenetic analyses show sensitivity to taxon sampling and support placement of Renalia among zosterophylls, but do not provide results that are strongly congruent with those of phylogenetic analyses. Phylogenetic analyses demonstrate that taxon and character sampling significantly …

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 …

Power Amplification Strategies Across Animals, Rayhan Asif

Williams Honors College, Honors Research Projects

Animals use muscles for movement, but some have evolved mechanisms to exceed maximum power used in a motion known as power amplification. In this literature review, I analyzed and compared the evolution of structures capable of power amplification between species. Structures capable of power amplification were broken down into the basic components of the engine, amplifier, and tool. The species analyzed were found to possess necessary structures for power amplification which were relatively similar to each other in morphology, but varied greatly in function. The ease with which these structures evolved was evaluated based on the amount of divergence which …

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

Honors Theses

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