Biology Commons^™

Reproductive Phenology Of Fishes Of The Rio Grande, New Mexico: A Genes-To-Community Approach, Trevor James Krabbenhoft

Biology ETDs

Reproductive phenology is a key life history attribute of long lived organisms that can strongly affect reproductive success and, ultimately, drive community composition. Understanding the ecological causes and consequences and genetic mechanisms shaping reproductive timing is key to predicting the outcome of environmental change (e.g., climate change). The three chapters that comprised this dissertation were focused on elucidating the ecological and genetic underpinnings of reproductive timing in the fish community of an arid-land river, the Rio Grande, New Mexico. In Chapter 1, we assessed reproductive phenology in the Rio Grande fish community with four years of young-of-year sampling data and …

Effects Of Translocation And Climatic Events On The Population Genetic Structure Of Black Bears In New Mexico, Frederic S. Winslow

Biology ETDs

Population structure of the American black bear (Ursus americanus) in New Mexico has been shaped by anthropogenic and natural forces. Black bears occur in habitat islands throughout New Mexico with natural movement among islands influenced by periodic drought, resource limitations and dispersal. Both natural movement and human mediated translocations primarily involve male black bears because of their tendency to move farther distances and more frequent conflict with human dominated landscapes than females. Using DNA microsatellite analysis to investigate the degree of differentiation between different population segments (Fst =0.025 across genetic loci, range = 0.018-0.032) we determined that black bear populations …

Linking Environment To Ecology In Arid Land Consumers: Two Case Studies, Ian White Murray

Biology ETDs

The physical environment has a profound influence over many aspects of animal ecology, such as governing the pace and timing of phenology and the patterns of activity across space and time. In extreme habitats such as deserts, the most important components of the physical environment are precipitation and temperature. Not only do these vary temporally and spatially, but this variation may influence the life history and ecology of species. My research examines how variance in temperature and precipitation influences the ecology of two species of desert dwelling consumers (desert woodrats and desert tortoises) over differing temporal scales. In Chapter 1, …

Identification Of The Wings Apart Transcriptional Unit In Drosophila Melanogaster, Ginny R. Morriss

Biology ETDs

Muscle development is an evolutionarily conserved process. Mechanisms that govern the development of specific muscles in invertebrates can inform our understanding of how vertebrate muscles form. Understanding these processes allows us to translate developmental mechanisms to disease pathogenesis, as similar genes and developmental processes are affected by these diseases. In this dissertation, CG14614 is identified as the gene responsible for the wings apart phenotype in Drosophila melanogaster. This mutation leads to a loss of the adult jump muscle (TDT) in most cases and a greater than 60% reduction in muscle fibers in its least severe form. wap mutants fail to …

Spectral Densities And Coherence Of Nm Hydrology; Nm Decomposition Analysis; Quantifying Science Education, Jennifer L. Tichy

Biology ETDs

Chapter 1: River discharge and montane snowpack play a central role in controlling processes at all levels of ecological organization, so the identification of dominant hydrological periods is an important issue in relating the physical system to the biological system. To quantitatively study the Rio Grande discharge along with the closely related snowpack, we determine the spectral densities as a function of frequency in addition to coherence estimates. This is quality-controlled through a signal to noise ratio, which also allows us to create a transfer function to model the relationship between river discharge and snowpack. By using frequency domain techniques, …

The Role Of Geological History, Topography, And Environmental Heterogeneity In The Diversification Of An Endemic Andean Radiation: The Metallura Hummingbirds, Phred M. Benham

Biology ETDs

A dynamic geological history, complex topography, and high species richness characterize the tropical Andes. Endemic radiations comprise a major component of this high diversity and evaluating the spatial and temporal context in which these radiations diversified provides an informative framework to understand the processes facilitating speciation in the Andes. Metallura hummingbirds are a diverse genus endemic to the Andes that are widely distributed geographically and ecologically making them well suited to investigating Andean speciation. In the first chapter I apply phylogenetic methods to address the relative roles of geological history, physical barriers, and environmental heterogeneity in the Metallura radiation. I …

Variation And Organization In Social Behavior: Infectious Disease And Human Intergroup Conflict And Warfare; And The Organization Of Foraging Behavior In Harvester Ants, Kenneth Letendre

Biology ETDs

Social behavior is an important contributor to the success of widely distributed animal taxa, including such distantly related taxa as humans and ants. There is variation in the features and organization of social systems based on ecological constraints and goals, as these alter the costs and benefits of social behaviors, and select for different optimal behaviors for social groups in different environments. I present two bodies of research: an effort to explain geographic variation in the frequency and intensity of human civil conflict; and an effort to describe and model the foraging behavior of colonies of harvester ants of the …

The Effects Of Precipitation Variability On C4 Photosynthesis, Net Primary Production And Soil Respiration In A Chihuahuan Desert Grassland, Michell L. Thomey

Biology ETDs

Although the Earths climate system has always been inherently variable, the magnitude and rate of anthropogenic climate change is subjecting ecosystems and the populations that they contain to novel environmental conditions. Because water is the most limiting resource, arid-semiarid ecosystems are likely to be highly responsive to future climate variability. The goal of my dissertation is to understand how precipitation variability affects primary productivity and soil respiration in desert grassland ecosystems. Initially, I reviewed the literature to understand how climate change affects net ecosystem exchange (NEE) across the warm deserts of North America (Chapter 2). Next, I examined the effects …

Lymphocyte Evolution And Ontogeny In Non-Eutherian Mammals, Xinxin Wang

Biology ETDs

Based on their different reproductive modes and evolutionary history, extant mammals are divided into three lineages: eutherians, marsupials and monotremes. Marsupials are the closest relatives to eutherians. They are born immune-incompetent. The characteristic that they develop their immune system postnatally makes them unique models to study newborn immune development and maternal immunology. As monotremes comprises the basal lineage of mammals, the study of monotreme immunology will provide unique insights regarding the origin of the mammalian immune system. Unfortunately, compared to our in-depth knowledge of eutherian immunology, especially humans and mice, knowledge of marsupial and monotreme immunology is scarce. The goal …

Infectious Disease And The Worldwide Distribution Of Iq, Christopher Guiles Eppig

Biology ETDs

We show that infectious disease is a major contributor to the worldwide distribution of human cognitive ability, as measured by psychometric IQ. In areas where infectious disease is high, average human intelligence tends to be lower, and in areas where infectious disease is low, average human intelligence tends to be higher. In separate studies, we tested this across world nations (chapter 2) and across states of the USA (chapter 3). In efforts to disseminate our research to wider audiences, I reviewed the findings contained in chapters 2 and 3 using language that is accessible to non-biologists (chapter 4). Although it …

Lateralization Of The Developing Rat Hippocampal Formation, Amanda Lynn Gross

Biology ETDs

Differences between the left and right hemisphere of the brain have been observed in humans and rodents (Broca, 1861; Wernicke, 1881), including the hippocampal formation, a region of the brain that is necessary for some forms of learning and memory (Olton and Samuelson, 1976; deToledo-Morrell et al., 1988; Bernasconi-Guastalla et al., 1994; Tabibnia et al., 1994; Poe et al., 2000; Lister et al., 2006; Hanlon et al., 2005; Sommer et al., 2005; Moskal et al., 2006; Thompson et al., 2008; Klur et al., 2009). Although lateralization of the hippocampal formation has been studied in the adult, few have sought to …

Mammalian Diversification Across The Holarctic: Spatiotemporal Evolution In Response To Environmental Change, Andrew G. Hope

Biology ETDs

The primary focus in this dissertation is on the processes of environmental change that drive evolution. We are currently witnessing unparalleled changes in climate and associated changes in biotic communities. With a growing understanding that climate and habitat change, coupled with natural variability, will have an increased influence on biota into the future, it is our responsibility to learn how best to manage and conserve the Earths natural resources. Among other things, this will require a firmer understanding of biodiversity, life histories, evolutionary relationships among species, and community dynamics over multiple species. One method of understanding how species will respond …

Transcriptional Analysis Of Schistosoma Mansoni Treated With Sub-Lethal Doses Of The Anthelmintic Drug Praziquantel, Jarrett Hines-Kay

Biology ETDs

Schistosoma mansoni is one of the most common etiological agents responsible for the disease schistosomiasis. More than 200 million people suffer from this disease making it the most severe tropical disease after malaria in terms of morbidity. Praziquantel (PZQ) is the treatment of choice for schistosomiasis and has been used almost exclusively to treat the disease since the 1970s. However, while the drug is lethal for sexually mature schistosomes, it is ineffective against juveniles. Thus, while morbidity can be eased, a cure is difficult to achieve. As a result there is an urgent need to develop a new generation of …

Substratum Interfacial Energetic Effects On The Attachment Of Marine Bacteria, Linnea Kathryn Ista

Biology ETDs

Biofilms represent an ancient, ubiquitous and influential form of life on earth. They are interesting both scientifically and because of their impacts on our environment, health and technology. Biofilm formation is initiated by attachment of bacterial cells from an aqueous suspension onto a suitable attachment substratum. While in certain, well studied cases initial attachment and subsequent biofilm formation is mediated by specific ligand-receptor pairs on the bacteria and attachment substratum, in the open environment, including the ocean, it is assumed to be non-specific and mediated by processes similar to those that drive adsorption of colloids at the water-solid interface. Colloidal …

Allometric Scaling And Metabolic Ecology Of Microorganisms And Major Evolutionary Transitions, Jordan G. Okie

Biology ETDs

My dissertation centers around investigating big-picture questions related to understanding the consequences of metabolism and energetics on the evolution, ecology, and physiology of life. The evolutionary transitions from prokaryotes to unicellular eukaryotes to multicellular organisms were accompanied by major innovations in metabolic design. In my first chapter, I show that the scaling of metabolic rate, population growth rate, and production efficiency with body size have changed across these transitions. Metabolic rate scales with body mass superlinearly in prokaryotes, linearly in protists, and sublinearly in metazoans, so Kleibers 3/4 power scaling law does not apply universally across organisms. This means that …

Stable Isotopes Provide Insight Into The Use Of Wildlife Water Developments By Resident And Migrant Birds In The Sonoran Desert Of Arizona, Theresa C. Hyde

Biology ETDs

Several studies have looked at the importance of man-made water resources to wildlife in desert regions. To our knowledge, however, none have attempted to directly quantify their importance to both resident and Neotropical migratory birds. During the spring and summer from 2007-2009, we enriched man-made water developments in the Sonoran Desert on the Kofa National Wildlife Refuge, Arizona. We enriched water developments using deuteriated water and sampled the body water pools of resident and migrant birds to quantify development use. We used a simple two end-point mixing model to estimate the proportion of an individual birds body water pool that …

Divergence In The Ecology Of Two Species Of Gambusia In Secondary Contact, Daniella Marilyn Swenton

Biology ETDs

Gambusia nobilis, a federally endangered species, and G. affinis (Poeciliidae) are small, livebearing fishes found in the southwestern U.S. The invasive G. affinis has been introduced globally to control mosquito populations. It is found in some populations of G. nobilis on Bitter Lake National Wildlife Refuge (BLNWR), the field site for this study. It is unclear to what extent the two species have diverged in behavior and ecology and how extensively they have hybridized on BLNWR, thereby threatening the endangered G. nobilis via genetic introgression. In this study I examined divergence in behavior and ecology between two species with four …

From Growth To Extinction: Explored By Life History And Metabolic Theory, Wenyun Zuo

Biology ETDs

The laws of energy and material conservation are fundamental principles across various scales and systems. Based on the conservation laws, I derive several theoretical models to understand mechanisms behind the energy budget of ontogenetic growth and the pattern of the late Pleistocene extinction of megafauna in the Americas. First, I present a model, empirically grounded in data from birds and mammals, that correctly predicts how growing animals allocate food energy between synthesis of new biomass and maintenance of existing biomass. Previous energy budget models have typically been based on rates of either food consumption or metabolic energy expenditure. The model …

Nf-Κb Translocation In Response To Different Lps Chemotypes In Murine Macrophages, Elizabeth L. Carles

Biology ETDs

Nuclear Factor κB (NF-κB) proteins make up a large family of eukaryotic transcription factors that regulate many important cellular functions, including cell signaling, cell growth, development, cell death by apoptosis, and immune and inflammatory responses, and has been shown to be involved in multiple human diseases. NF-κB proteins are subject to careful regulation in the cell, and are regulated at multiple levels. A family of inhibitory proteins exist (called IκB proteins) which bind to NF-κB and cause it to be localized in the cytoplasm. There are multiple signal transduction pathways that can lead to the activation of NF-κB. These signal …

The Spatial Ecology Of Galapagos Tortoises And New Mexico's Reptiles, Jacek Tomasz Giermakowski

Biology ETDs

The analysis of spatial processes and spatial heterogeneity is an important part of ecology because distribution of organisms in space partly defines ecology as a discipline. In addition, advances in analysis of DNA, geographical computing and the availability of vast amounts of environmental data obtained by satellites provide new opportunities for studying ecology at different spatial and phylogenetic scales. My research takes advantage of information gathered by satellites and adds modeling and data collected on the distribution of different reptiles to examine processes at various spatial and temporal scales. In Chapter 1 I describe how juvenile Galapagos tortoises change their …

The Isotopic Composition Of Light-Enhanced Dark Respiration (Ledr) In C3 And C4 Plants, Susan Christy Mirabal

Biology ETDs

Light-enhanced dark respiration (LEDR) has been studied in C3 plants as a method to elucidate the careful balance between photosynthesis and respiration yet little is known about the metabolic properties by which it occurs in C4 plants. Using a tunable diode laser gas exchange system, we analyzed transient isotopic shifts in leaf-respired CO2 associated with LEDR at 10Hz frequency from Populus deltoides (C3), Amaranthus hypochondriacus (C4 NAD-ME), and Zea mays (C4 NADP-ME). The results suggest that:

(1) Post-photosynthetic fractionations are different between C3 and C4 (and within C4) plants, where A. hypochondriacus exhibited an unexpected LEDR response (Fig. 3, Table …

Biogeography Of Alien Vertebrates In The Galapagos Islands: Patterns, Processes, And Conservation Implications, Reese Brand Phillips

Biology ETDs

Alien species are one of the principal threats to global biodiversity. Insular ecosystems have proven exceptionally susceptible to invasion by aliens and vulnerable to their negative effects. Some of the most destructive alien species are vertebrates, in part due to their having been introduced to islands worldwide. Rodents (Rattus spp. and Mus musculus) are among the most widespread and devastating invasive species for insular flora and fauna. In this research I investigate the biogeographic patterns and processes of alien vertebrates in the Galapagos Islands, focusing on the mechanisms that influence their dispersal and colonization within the archipelago. In the first …

Nutrient Cycling In Impacted Stream Ecosystems: From Microbes To Watersheds, David James Van Horn

Biology ETDs

The conditions found in stream ecosystems are an integration of watershed characteristics and processes. Anthropogenic disturbances are part of this integration and include direct inputs to streams, alteration of riparian areas, and modification of catchment properties which affect material inputs. Impacts to discrete portions of terrestrial watersheds combine as water moves down gradient, transporting the byproducts of catchment disturbances to streams including, nutrients, organic materials, particulates, and toxins. This dissertation explores the effects of disturbance on nutrient cycling in stream ecosystems at three spatial scales: the patch scale includes localized processes and assemblages, the reach scale encompasses tens to hundreds …

High-Throughput Genomic/Proteomic Studies: Finding Structure And Meaning By Similarity, George Sidney Davidson

Biology ETDs

The post-genomic challenge was to develop high-throughput technologies for measuring genome scale mRNA expression levels. Analyses of these data rely on computers in an unprecedented way to make the results accessible to researchers. My research in this area enabled the first compendium of microarray experiments for a multi-cellular eukaryote, Caenorhabditis elegans. Prior to this research approximately 6% of the C. elegans genome had been studied, and little was known about global expression patterns in this organism. Here I cluster data from 553 different microarray experiments and show that the results are stable, statistically significant and highly enriched for specific biological …

Female Perception Of Testeronized Male Facial Images: Evidence Of A Co-Evolutionary Tradeoff Responsive To Conditions For Both Competition And Cooperation, Melissa L. Franklin

Biology ETDs

Theorists and researchers who examine the evolutionary ecology of mating dynamics consider two primary forces, intrasexual and intersexual, as important pressures of selection. Bilateral symmetry and, more controversially, hormone markers in many species, impart information that has been found to influence some aspects of intersexual selection. Both symmetry, as a sign of developmental stability, and hormone markers (i.e., testosteronized traits as cues of immunocompetence) have been classically treated as signals of genetic fitness (Moller & Swaddle, 1997; Hamilton & Zuk, 1982), although neither are consistently shown to correlate with increased mating success. Indeed, results between studies on either trait independently …

Genome Architecture In The Fungal Kingdom, Diego Antonio Martinez

Biology ETDs

Previous studies have suggested that the location of genes in genomes is not random; instead they may be organized in a way that is beneficial to cellular processes and the organism. While a few studies have investigated the organization of genes on a whole genome scale, they were limited in the functions of genes used in the search and in the number and type of genomes searched. With the recent explosion of available fungal genomes and tools to automatically annotate many genes in a short period of time, it is now possible to obtain a global view of the level …

Temporal Dynamics And Spatial Analysis Of Competing Dengue 2 Virus Strains In The Americas, Stacy O'Neil Scholle

Biology ETDs

The dengue virus is the causative agent of an important re-emerging infectious disease that has become increasingly significant in tropical America and the Caribbean due to the infiltration of a more pathogenic Asian/American strain of dengue serotype 2 into the population. This invading strain is responsible for epidemics of dengue hemorrhagic fever, a life-threatening disease that was not previously a large public health concern in the region. Here, I create a historical map of the invasion and replacement of the endemic American strain of dengue 2 by the Asian/American strain, showing that the timing of invasion spans 25 years, and …

Comparison Of Microbial Communities On Roots, Ceilings And Floors Of Two Lava Tube Caves In New Mexico, Jessica R. Snider

Biology ETDs

Lava tube caves possess a rich and patchy mosaic of nutrients and water that fosters a wide variety of microbial life. Water percolating past vegetation and through surface soils introduces dissolved carbon and nitrogen into caves. Roots provide even higher levels of carbon, nitrogen and microorganisms as they grow into the cave environment from surface vegetation. I hypothesized that this mosaic of nutrients and energy resources has a direct effect on the distribution and composition of microbial communities within caves. To test this hypothesis, I selected two lava tube caves in New Mexico, USA and identified six zones consisting of …

Always Read The Introduction: Integrating Regulatory And Coding Sequence Evolution In Yeast, Annette M. Evangelisti

Biology ETDs

We analyze duplicate genes in a yeast, Saccharomyces cerevisiae with the aim of determining a genes history and to observe that gene in its genomic context. In Chapter 2 we show that the fate of a duplicate gene pair is in part determined by its genome location. Moreover, we show that for two classes of duplicate genes, resulting from either small-scale duplication or whole-genome duplication, this fate can often be assessed by measuring the patterns of asymmetry in the sequence divergence of the genes in question. In Chapter 3 we study duplicate genes in the context of their local environments …

Tracing Deuterium Through The Food Web And Into Birds And Mammals Along An Elevational Gradient In The Southern Rocky Mountains, Matthew J. Baumann

Biology ETDs

Animals incorporate local δ2H values from available water and dietary sources during tissue synthesis, which can provide evidence of elevational movements if multiple tissues with different turnover times are examined. Here we test the applicability of using δ2H as an indicator of altitudinal movements by examining multiple tissues (δ2Hbw (body water), δ2Hfeather, δ2Hfur, and δ2Hclaw) in birds and mammals in the Sangre de Cristo Mountains. Additionally, we measured δ2Hsw (stem water) and insect δ2bw and δ2wb (whole body) values to assess changes with elevation. We sampled 15 species of birds and two small mammal species along with potential food sources …