Evolution Commons^™

A Balancing Act: Microrna Mediated Insect-Bacterial Homeostasis And The Tsetse Fly, Mason Hubbard Lee

Graduate Theses, Dissertations, and Problem Reports (ETD)

Microbial symbioses are ubiquitous across all kingdoms of life with broad and diverse impacts on the evolution of species. The sum of all microbes living in, on, or otherwise in close association with a host form the microbiota. In some cases, the development of a stable microbial association seems to have been necessary for the specialization of diet, as can be observed in numerous insect species, especially wood-eating, sap-feeding, and blood-feeding organisms. For the medically and economically tsetse fly (family Glossinidae), the mutualistic bacteria Wigglesworthia glossinidia is required for proper reproduction and supplementation of nutrients that the fly does not …

The Evolution Of The Metazoan Circadian Molecular Mechanism And The Conservation Of Canonical Circadian Elements, Olivia Waldridge

Theses and Dissertations--Biology

The temporal organization of biological activities through circadian rhythms is pivotal for the survival of organisms. Significant progress has been made in understanding the molecular foundations of animal circadian clocks through the characterization of key components such as Clock, Bmal1/Cycle(Cyc), Period (Per), Timeless, and Cryptochrome (Cry) in several model organisms. To determine the universality of this conservation, we investigated the sequences of these genes and their paralogs across 46 animal species that encompass multiple phyla in the metazoan kingdom to resolve the relative timing of duplication and loss events that have diversified core clock components in the metazoan kingdom. Using …

Functional Investigation Of Shaggy, An Inhibitor Of Canonical Wnt Signaling, In The Tardigrade Hypsibius Exemplaris, Raul A. Chavarria

UNF Graduate Theses and Dissertations

Tardigrades have a highly simplified anteroposterior (AP) axis. The mechanisms that regulate the development of this secondarily simplified AP axis are not known. In many animals, the canonical Wnt (cWnt) signaling pathway regulates primary axis establishment through antagonistic interactions with inhibitors of cWnt signaling. This study investigated the roles of shaggy, an inhibitor of cWnt signaling, in regulating development in the tardigrade Hypsibius exemplaris. Gene expression patterns of shaggy and other components of the cWnt signaling pathway were analyzed alongside markers of anterior and posterior identity using Hybridization Chain Reaction in situ in H. exemplaris. RNA interference …

Alfred Russel Wallace Notes 27. When Wallace Broke With Darwin., Charles H. Smith

Faculty/Staff Personal Papers

The year 1866 was the first year Alfred Russel Wallace showed definite signs of breaking with Darwin over the limits of natural selection. Attention is drawn to a July 1866 exchange of letters between the two, and how this foreshadowed what followed.

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 …

Morphological Trait Evolution In Solanum (Solanaceae): Evolutionary Lability Of Key Taxonomic Characters, Rebecca Hilgenhof, Edeline Gagnon, Sandra Knapp, Xavier Aubriot, Eric Tepe, Lynn Bohs, Leandro Giacomin, Yuri Gouvea, Andres Orejuela, Christopher T. Martine, Clara Ines Orozco, Iris E. Peralta, Tina Sarkinen

Faculty Journal Articles

Solanum is one of the world's largest and economically most important plant genera, including 1245 currently accepted species and several major and minor crops (e.g., tomato, potato, brinjal eggplant, scarlet eggplant, Gboma eggplant, lulo, and pepino). Here we provide an overview of the evolution of 25 key morphological traits for the major and minor clades of this giant genus based on stochastic mapping using a well-sampled recently published phylogeny of Solanum. The most evolutionarily labile traits (showing >100 transitions across the genus) relate to plant structure (growth form and sympodial unit structure), herbivore defence (glandular trichomes), pollination (corolla shape …

Pde Model For Protocell Evolution And The Origin Of Chromosomes Via Multilevel Selection, Daniel B. Cooney, Fernando W. Rossine, Dylan H. Morris, Simon A. Levin

Biology and Medicine Through Mathematics Conference

No abstract provided.

Reaction-Diffusion System On Irregular Boundaries Reproduces Multiple Generations Of Petal Spot Patterns In Monkeyflower Hybrids, Emily Simmons

Biology and Medicine Through Mathematics Conference

No abstract provided.

Analysis Of Gene Evolution In The Long-Lived Heliconius Butterfly Genus, Leann Ward

Theses and Dissertations

The butterfly genus Heliconius has an unusually long lifespan (six to eight months compared to only several weeks) and the unique ability to feed on pollen. The additional amino acids provided by a pollen diet seem intrinsically tied to longer lifespan in Heliconius. Because of these traits, Heliconius may be a valuable model species for future aging studies. As a preliminary analysis, we investigated differences in gene evolution between Heliconius and seven short-lived butterflies. We observed that the Heliconius genes had significant differences in evolutionary rates, in the direction of selection, and in the amounts of site-specific positive selection compared …

Mutual Aid: The Other Law Of The Jungle. Gauthier Chapelle And Pablo Servigne. Cambridge, Polity Press. 2022. 310 Pp, Tom P. Flower Dr

Emancipations: A Journal of Critical Social Analysis

In 1902, the anarchist Peter Kropotkin published Mutual Aid in which he promoted a radical perspective on evolution in which cooperation, as well as selfishness, drive the form, diversification and organization of life on earth. Despite initial recognition, Kropotkin’s contributions have been largely forgotten, even as modern evolutionary theory has recognized the central role of cooperation. In Mutual Aid: the other law of the jungle, Pablo Servigne and Gauthier Chappelle restore Kropotkin’s insights to their rightful place as foundational for our understanding of evolution. They further seek to overturn the pernicious misconception of the 20^th century, that nature is …

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

College of Arts & Sciences Senior 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

LSU 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 …

Alfred Russel Wallace Notes 25. Wallace And The 'Physical Environment'., Charles H. Smith

Faculty/Staff Personal Papers

Alfred Russel Wallace’s natural selection essay of 1858 has been held to frame a greater role for the physical environment in forcing selection regimes than we find in Darwin’s writings, but here that verdict is challenged by a re-examination of both the essay itself, and period usage of the term ‘physical.’

Why The Delay In Recognizing Terrestrial Obligate Cave Species In The Tropics?, Francis G. Howarth

International Journal of Speleology

“Nothing could possibly live there!” They believed. Indeed, until recently, few specialized cave- adapted animals were known from volcanic, tropical, or oceanic island caves, and plausible theories had been put forward to explain their absence. But assume nothing in science! One must illuminate, explore, and survey habitats before declaring them barren. Our understanding of cave biology changed dramatically about 50 years ago following the serendipitous discovery of cave-adapted terrestrial arthropods in Brazil and on the young oceanic islands of the Galápagos and Hawai‘i. These discoveries and subsequent studies on the evolutionary ecology of cave animals have revealed a remarkable hidden …

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, …

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 …

Alfred Russel Wallace Notes 22: Stumbling Blocks To An Understanding Of Wallace's Worldview, Charles H. Smith

Faculty/Staff Personal Papers

The writings of Alfred Russel Wallace (1823−1913) present a challenge to modern readers, both for the large range of subjects he entertained, and his unique point of view. In this short treatment, ten ‘stumbling blocks’ to an appreciation of Wallace’s thought are outlined which, it is suggested, have caused problems of interpretation in the past.

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

Dissertations and 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 …

The Biological Influence Of Stories & The Importance Of Reading Fiction, Elise N. Good, Katharine Schaab

The Kennesaw Journal of Undergraduate Research

Fictional narratives and stories have persisted throughout human history. However, perhaps due to a bias that stories offered nothing more than entertainment for the reader or perhaps that they are not useful outside of the realm of academia, the research within science academia has been lacking in literature on why these narratives have endured. Unfortunately, due to the lack of conversation across disciplines, particularly those of science and literature, this subject has not been thoroughly investigated through an interdisciplinary lens. Within this paper, the goal is to analyze the benefits of fictional narratives through biological, evolutionary, and neuropsychological perspectives. Research …

Plastic And Evolved Responses In The Eastern Oyster, Crassostrea Virginica, To Environmental Variation In The Northern Gulf Of Mexico, Kyle Sirovy

LSU Doctoral Dissertations

Climate change and other anthropogenic impacts are causing rapid alterations to many of the world’s most productive coastal ecosystems and there is an urgent need to understand how species will respond to these environmental changes. Organisms may respond through plasticity, evolution, or the evolution of plasticity. In this dissertation, I evaluate the role of plastic and evolved responses in the eastern oyster, Crassostrea virginica, to environmental variation in the northern Gulf of Mexico. I use comparative transcriptomics, physiology, and morphology to examine the relative contribution of plastic and evolved responses for oysters exposed to low salinity and outplant sites …

De-Coupling Cell-Autonomous And Non-Cell-Autonomous Fitness Effects Allows Solution Of The Fokker-Planck Equation For The Evolution Of Interacting Populations, Steph J. Owen

Biology and Medicine Through Mathematics Conference

No abstract provided.

Reconstructing The Ecological Relationships Of Late Cretaceous Antarctic Dinosaurs And How Functional Tooth Morphology Influenced These Relationships, Ian D. Broxson

2022 Symposium

The Sandwich Bluff Formation of the James Ross Basin of Antarctica has recently yielded a group of five late Cretaceous dinosaurs that lived contemporaneously with each other, a first for Antarctica. These five dinosaurs include fragmentary remains of two differently sized elasmarian ornithopods, a possible megaraptor, a hadrosaur, and a nodosaur. In this study we will construct a model of the ecological relationships of late Cretaceous Antarctica. Additionally, we will look at what specific factors allowed this group of four herbivores and a carnivore to coexist in a restricted locality and what niches were filled by each species. Methods to …

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 …

Phylogenomic Discordance Suggests Polytomies Along The Backbone Of The Large Genus Solanum, Edeline Gagnon, Rebeccca Hilgenhof, Andrés Orejuela, Angela J. Mcdonnell, Gaurav Sablok, Xavier Aubriot, Leandro Giacomin, Yuri Gouvêa, Thamyris Bragionis, João Renato Stehmann, Lynn Bohs, Steven Dodsworth, Christopher T. Martine, Péter Poczai, Sandra Knapp, Tiina Särkinen

Faculty Journal Articles

Premise of the study

Evolutionary studies require solid phylogenetic frameworks, but increased volumes of phylogenomic data have revealed incongruent topologies among gene trees in many organisms both between and within genomes. Some of these incongruences indicate polytomies that may remain impossible to resolve. Here we investigate the degree of gene-tree discordance in Solanum, one of the largest flowering plant genera that includes the cultivated potato, tomato, and eggplant, as well as 24 minor crop plants.

Methods

A densely sampled species-level phylogeny of Solanum is built using unpublished and publicly available Sanger sequences comprising 60% of all accepted species (742 spp.) …

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 …

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 …

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

College of Graduate Studies: Theses & 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 …

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 …

Phenotype Bias Determines How Natural Rna Structures Occupy The Morphospace Of All Possible Shapes, Fatme Ghaddar, Dr Kamaludin Dingle, Dr Petr Sulc, Prof Ard A. Louis

Undergraduate Research Symposium

The relative prominence of developmental bias versus natural selection is a long standing controversy in evolutionary biology. Here we demonstrate quantitatively that developmental bias is the primary explanation for the occupation of the morphospace of RNA secondary structure (SS) shapes. By using the RNAshapes method to define coarse-grained SS classes, we can measure the frequencies that non-coding RNA SS shapes appear in nature. Our main findings are firstly that only the most frequent structures appear in nature; the vast majority of possible structures in the morphospace have not yet been explored. Secondly, and perhaps more surprisingly, these frequencies are accurately …