Biology Commons^™

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 …

Historical And Topographic Drivers Of Tropical Insular Diversity: Comparative Phylogeography Of Eleutherodactylus Antillensis And E. Portoricensis, Two Ecologically Distinctive Frogs Of The Puerto Rican Bank, Brittany Suzanne Barker

Biology ETDs

Topographically complex islands present opportunities for in situ (within-island) allopatric speciation because of increased chances for isolation in separate mountain ranges, as well as greater opportunity for fragmentation by high sea levels and climate-driven changes in habitat distribution. Climatic oscillations of the Quaternary (Pleistocene - Holocene; ~2.5 million years ago to the present) may have influenced the severity of vicariant barriers among and within islands, yet how these events influenced evolution of tropical insular biota is not well understood. This dissertation explores the role of topographic complexity and climate-driven range shifts resulting from sea-level changes and habitat suitability in shaping …

Pattern And Process In Metabolic Ecology: From Biotic Interactions To Cultural Diversity Gradients, William R. Burnside

Biology ETDs

Many ecological patterns and processes are functions of metabolism (Brown 2004), meaning the acquisition, transformation, and allocation of energy, materials, and information within the bodies of individuals and among members of human and other animal societies. Individual metabolic rate should influence behavior by determining the energy available for action as well as the rate at which the body requires fuel. First, I test a key prediction of the metabolic theory of ecology (MTE), that biotic interaction rates are characteristic functions of temperature. Findings support this prediction and suggest that herbivory, predation, parasitism, parasitoidy, and competition increase exponentially with temperature and …

Diversification In Andean Tit-Tyrants (Aves, Tyrannidae), Shane G. Dubay

Biology ETDs

In my thesis I investigate evolution and diversification of montane birds that inhabit dramatic environmental and latitudinal gradients, specifically within the genus Anairetes (Aves, Tyrannidae). I use phylogenetic, population genetic, and physiological methods to examine patterns of diversification across environmental gradients. In the first chapter, I infer the phylogeny of Anairetes tit-tyrants to provide an essential phylogenetic framework to ask subsequent questions of biogeography and diversification within the group. In the second chapter, I investigated the role of differential adaptation to altitude in promoting diversification and maintaining species limits between A. reguloides and A. nigrocristatus. The phylogeny of the flycatcher …

Pollination Ecology Of Agave Palmeri In New Mexico, And Landscape Use Of Leptonycteris Nivalis In Relation To Agaves, Angela E. England

Biology ETDs

Where animals spend time can provide important clues to their ecological needs, but this information is very difficult to obtain for small volant animals. The research described in Chapter 1 was an attempt to discern how L. nivalis utilize the landscape in relation to the distribution of Agave havardiana in Big Bend National Park, Texas. I found that although the landscape use of Leptonycteris nivalis is centered on habitat with high concentrations of blooming A.havardiana, it is not restricted to those areas, and furthermore adults and juveniles may differ in their behavior. Adult females may remain near food sources in …

The Contribution Of Young-Of-Year Fishes To Aquatic Food Web Dynamics In An Arid-Land River System (Rio Grande, New Mexico), Corey Anne Krabbenhoft

Biology ETDs

1. Larval fishes have a rich history in ichthyological research. However, relatively little attention has been given to the role of young-of-year (YOY) fishes in ecosystem processes. Despite difficulties of sampling and identifying these small fishes, YOY may serve an important role in the dynamics of some aquatic communities. The specific role of YOY fishes in aquatic, desert food webs remains largely uncharacterized.

2. We hypothesize that YOY fishes may control abundance and community composition of lower trophic levels (i.e., aquatic invertebrates) because they are numerically dominant predators during the growing season. The goal of this study is to determine …

Effects Of Global Change On Savanna Grassland Ecosystems, Sally Elizabeth Koerner

Biology ETDs

Humans are altering the environment locally and globally through climate and land use change. Global temperature is increasing, precipitation patterns are becoming more variable, disturbance regimes are being altered, and ecosystems are being simplified as multi-species communities are replaced by monocultures of crops or livestock. Grasslands, which cover approximately a third of the terrestrial lands, are ecologically and economically significant, thus their responses to environmental change will have dramatic consequences for global patterns of productivity, biodiversity, and food production. This dissertation research investigates how the three main drivers of mesic grassland ecosystems — precipitation, grazing, and fire - interact to …

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 …

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, …

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 …

The Effect Of Increased Growth Temperature On Mid-Day And Mid-Night Co2 Fluxes In Populus Deltoids, Rachel Zulick

Biology ETDs

As global temperatures rise, understanding the effects of increased temperature on daily carbon dioxide fluxes is necessary to predict changes to the global carbon cycle. Using tunable diode laser spectroscopy, I measured CO2 fluxes and changes in isotopic composition of root respiration, leaf respiration and photosynthesis over a 12-hour night to day transition. I found that after a 10°C increase in growth temperature for four weeks, root CO2 fluxes acclimated to the higher temperature (i.e. they were not significantly different from controls). In contrast, both photosynthesis and respiration of leaves were higher at the elevated growth temperature. Though the root …

Cyclic Di-Gmp Phosphodiesterases Rmda And Rmdb Are Involved In Regulating Colony Morphology And Development In Streptomyces Coelicolor. Journal Of Bacteriology, Travis D. Hull, Min-Hyung Ryu, Matthew J. Sullivan, Ryan C. Johnson, Nikola T. Klena, Robert M. Gelger, Mark Gomelsky, Jennifer A. Bennett

Biology and Earth Science Faculty Scholarship

Cyclic dimeric GMP (c-di-GMP) regulates numerous processes in Gram-negative bacteria, yet little is known about its role in Gram-positive bacteria. Here we characterize two c-di-GMP phosphodiesterases from the filamentous high-GC Gram-positive actinobacterium Streptomyces coelicolor, involved in controlling colony morphology and development. A transposon mutation in one of the two phosphodiesterase genes, SCO0928, hereby designated rmdA (regulator ofmorphology and development A), resulted in decreased levels of spore-specific gray pigment and a delay in spore formation. The RmdA protein contains GGDEF-EAL domains arranged in tandem and possesses c-di-GMP phosphodiesterase activity, as is evident from in vitro enzymatic assays using the purified protein. …

Availability And Quality Of Vegetation Affects Reproduction Of The Gopher Tortoise (Gopherus Polyphemus) In Improved Pastures, Anna Louise Hathaway

USF Tampa Graduate Theses and Dissertations

As part of a state-funded Gopher Tortoise (Gopherus polyphemus Daudin) translocation project, I monitored actively grazed improved pastures to determine if they could serve as suitable recipient sites for the threatened Gopher Tortoise displaced by human development. For cattle ranches to be considered suitable recipient sites females must be able to acquire sufficient energy to produce a clutch of viable eggs, and sufficiently high quality vegetation must be available to support juvenile recruitment into the population. Vegetation surveys were conducted to determine the composition and percent cover of plant species, especially those containing high amounts of nutrients, specifically nitrogen. Resident …

Repeated Origin And Loss Of Adhesive Toepads In Geckos, Tony Gamble, Eli Greenbaum, Todd R. Jackman, Anthony P. Russell, Aaron M. Bauer

Biological Sciences Faculty Research and Publications

Geckos are well known for their extraordinary clinging abilities and many species easily scale vertical or even inverted surfaces. This ability is enabled by a complex digital adhesive mechanism (adhesive toepads) that employs van der Waals based adhesion, augmented by frictional forces. Numerous morphological traits and behaviors have evolved to facilitate deployment of the adhesive mechanism, maximize adhesive force and enable release from the substrate. The complex digital morphologies that result allow geckos to interact with their environment in a novel fashion quite differently from most other lizards. Details of toepad morphology suggest multiple gains and losses of the adhesive …

A Study Of The Eastern Oyster, Crassostrea Virginica, In Tampa Bay: Effects Of Perkinsus Marinus On Reproduction And Condition, Bridgit Melora Mccrickard

USF Tampa Graduate Theses and Dissertations

Abstract

Five sites in Tampa Bay, Florida, were sampled monthly from February 2006 to January 2007. These sites were located at the mouth of the Alafia River, in an inlet of Cross Bayou, on the easement of Gandy Bridge, near mangrove in Manatee County, and an inlet of Salt Creek, off Bayboro Harbor. Standard methods were used to determine shell height and Condition Index (CI). Intensity and prevalence of Perkinsus marinus were analyzed using Ray's Thioglycollate medium test, while Haplosporidium nelsoni was studied by histological examination. Histological methods were also used to determine sex ratios, reproductive phases, and egg diameters. …

The Role Of A And B Vitamins During Orofacial Development Of Xenopus Laevis, Allyson Kennedy

Theses and Dissertations

Orofacial anomalies make up about a third of the 120,000 birth defects each year in the United States. Children born with these abnormalities must undergo immense physical and emotional strain in order to correct the defects. In fact, about $697 million is spent every year surgically treating children with cleft lip and/or cleft palate (2011). In countries where surgery is not an option, this abnormality causes immense difficulties in eating, hearing, speech, and psychosocial development. The causes of cleft lip/palate are extremely complex. Genetics play a role in the anomaly; however, 95% of cleft palate cases are non-syndromic and likely …

Five Nuclear Loci Resolve The Polyploid History Of Switchgrass (Panicum Virgatum L.) And Relatives, Jimmy Triplett, Yunjing Wang, Jinshun Zhong, Elizabeth Kellogg

Biology Department Faculty Works

Polyploidy poses challenges for phylogenetic reconstruction because of the need to identify and distinguish between homoeologous loci. This can be addressed by use of low copy nuclear markers. Panicum s.s. is a genus of about 100 species in the grass tribe Paniceae, subfamily Panicoideae, and is divided into five sections. Many of the species are known to be polyploids. The most well-known of the Panicum polyploids are switchgrass (Panicum virgatum) and common or Proso millet (P. miliaceum). Switchgrass is in section Virgata, along with P. tricholaenoides, P. amarum, and P. amarulum, whereas P. miliaceum is in sect. Panicum. We have …

Human Breast Milk And Antiretrovirals Dramatically Reduce Oral Hiv-1 Transmission In Blt Humanized Mice, Angela Wahl, Michael D. Swanson, Tomonori Nochi, Rikke Olesen, Paul W. Denton, Morgan Chateau, J. Victor Garcia

Biology Faculty Publications

Currently, over 15% of new HIV infections occur in children. Breastfeeding is a major contributor to HIV infections in infants. This represents a major paradox in the field because in vitro, breast milk has been shown to have a strong inhibitory effect on HIV infectivity. However, this inhibitory effect has never been demonstrated in vivo. Here, we address this important paradox using the first humanized mouse model of oral HIV transmission. We established that reconstitution of the oral cavity and upper gastrointestinal (GI) tract of humanized bone marrow/liver/thymus (BLT) mice with human leukocytes, including the human cell types important for …

Traversing Swanton Road, 9th Ed., James A. West

Academic, Government & Associated Organizational Research Resources

Situated at the northwest end of Santa Cruz County and occupying circa 30 square miles of sharply contrasted terrain, the Scott Creek Watershed concentrates within its geomorphological boundaries, at least 10-12% of California's flora, both native and introduced. Paradoxically, the use/abuse that the watershed has sustained over the past 140+ years, has not necessarily diminished the biodiversity and perhaps parallels the naturally disruptive but biologically energizing processes (fire, flooding, landslides and erosion), which have also been historically documented for the area for +60 years. This is an early edition of an extensive document by James A. West. Please visit the …

Roosting Ecology And Survey Of Endangered And Species Of Special Concern Bats In The Mid-South Prior To The Arrival Of White Nose Syndrome, Tracy Lee Klotz

Student Theses and Dissertations

The proper management of any species requires baseline knowledge such as populations, diversity and habitat requirements. This thesis answers some of these vital questions about endangered (gray bat, Indiana bat and Ozark big-eared bat) and species of concern (Rafinesque's big-eared bat and southeastern myotis) bats in the mid-south. I conducted a mist net bat surveys at Donaldson Point Conservation Area (DPCA) in southeast Missouri and Rosson Hollow in west Arkansas. Both species of special concern were captured in DCPA and the species diversity of the area is consistent with similar habitat in northeast Arkansas. The species diversity in Rosson Hollow …

Bacteriophages Phi Mr299-2 And Phi Nh-4 Can Eliminate Pseudomonas Aeruginosa In The Murine Lung And On Cystic Fibrosis Lung Airway Cells, Aidan Coffey, Et. Al.

Department of Biological Sciences Publications

Pseudomonas aeruginosa is a common cause of infection in the lungs of patients with cystic fibrosis (CF). In addition, biofilm formation and antibiotic resistance of Pseudomonas are major problems that can complicate antibiotic therapy. We evaluated the efficacy of using bacteriophages to kill the pathogen in both biofilms and in the murine lung. We isolated and characterized two phages from a local wastewater treatment plant, a myovirus (ϕNH-4) and a podovirus (ϕMR299-2). Both phages were active against clinical isolates of P. aeruginosa. Together, the two phages killed all 9 clinical isolate strains tested, including both mucoid and nonmucoid strains. An …

A Genetic Study Of Ssv1, The Prototypical Fusellovirus, Eric Iverson, Kenneth M. Stedman

Biology Faculty Publications and Presentations

Viruses of thermophilic Archaea are unique in both their structures and genomic sequences. The most widespread and arguably best studied are the lemon-shaped fuselloviruses. The spindle-shaped virus morphology is unique to Archaea but widespread therein. The best studied fusellovirus is SSV1 from Beppu, Japan, which infects Sulfolobus solfataricus. Very little is known about the function of the genes in the SSV1 genome. Recently we have developed genetic tools to analyze these genes. In this study, we have deleted three SSV1 open reading frames (ORFs) ranging from completely conserved to poorly conserved: VP2, d244, and b129. Deletion of the universally conserved …

Transcendental Thermodynamics, Richard E. Morel, George Fleck

Kahn Institute Projects

Thermodynamics is often viewed as a narrow, introspective discipline, trapped by its origins in the 18th and 19th centuries. By dramatic contrast, we show that the Fourth Law of Thermodynamics provides explanations and interpretations of all natural events, extending across artificial boundaries of tradition- al academic disciplines. The Fourth Law of Thermodynamics states that far-from-equilibrium systems increase entropy at the maximum rate available to them. This broadly inclusive paradigm applies to systems from molecules, to organisms, to the biosphere. The Fourth Law is the Law of Evolution. All systems that communicate with their environment exhibit self-organization and self-optimization, enabling the …

Evolution Of A Sexually Dimorphic Trait In A Broadly Distributed Topminnow (Fundulus Olivaceus), Jacob F. Schaefer, David D. Duvernell, Brian R. Kreiser, Charles Champagne, Scott R. Clark, Melissa Gutierrez, Laura K. Stewart, Chazz Coleman

Biological Sciences Faculty Research & Creative Works

Understanding the interaction between sexual and natural selection within variable environments is crucial to our understanding of evolutionary processes. The handicap principle predicts females will prefer males with exaggerated traits provided those traits are indicators of male quality to ensure direct or indirect female benefits. Spatial variability in ecological factors is expected to alter the balance between sexual and natural selection that defines the evolution of such traits. Male and female blackspotted topminnows (Fundulidae: Fundulus olivaceus) display prominent black dorsolateral spots that are variable in number across its broad range. We investigated variability in spot phenotypes at 117 sites …

Modeling The Effect Of Environmental Factors On The Spread Of Bacterial Disease In An Economically Structured Population, Ram Naresh, Surabhi Pandey

Applications and Applied Mathematics: An International Journal (AAM)

We have proposed and analyzed a nonlinear mathematical model for the spread of bacterial disease in an economically structured population (rich and poor) including the role of vaccination. It is assumed that rich susceptible get infected through direct contact with infectives in the same class and with infectives from the poor class who work as service providers in the houses of rich people, living in much cleaner environment. The susceptible in the poor class are assumed to become infected through direct contact with infectives in the same class as well as by bacteria present in their own environment, degraded due …

A Mathematical Study On The Dynamics Of An Eco-Epidemiological Model In The Presence Of Delay, T. K. Kar, Prasanta K. Mondal

Applications and Applied Mathematics: An International Journal (AAM)

In the present work a mathematical model of the prey-predator system with disease in the prey is proposed. The basic model is then modified by the introduction of time delay. The stability of the boundary and endemic equilibria are discussed. The stability and bifurcation analysis of the resulting delay differential equation model is studied and ranges of the delay inducing stability as well as the instability for the system are found. Using the normal form theory and center manifold argument, we derive the methodical formulae for determining the bifurcation direction and the stability of the bifurcating periodic solution. Some numerical …

Analyzing The Interaction Between Melanocortin 5 Receptor, Melanocortin Receptor Accessory Protein 1, And Melanocortin 2 Receptor In Rainbow Trout, Domicinda M. Hill

Electronic Theses and Dissertations

Using CHO cells we sought to explore and characterize the functional relationship of rainbow trout MC5 receptor (rtMC5R) with zebrafish MRAP1 (zfMRAP1) and rainbow trout MC2 receptor (rtMC2R), as well as how the effect of such relationships may play a significant role in Hypothalamic-Pituitary-Adrenal/Interrenal axis activation. This research demonstrated that rtMC5R can be successfully expressed and functionally activated in CHO cells and, in a manner similar to mammals, α-MSH is the preferred ligand for rtMC5R. The presence of MRAP1 does not seem to inhibit the expression or function of rtMC5R, rather it appears that it may increase expression and total …

Connexin-32 And Connexin-43 Immunoreactivity In Rodent Taste Buds, Amanda E. Bond

Electronic Theses and Dissertations

Studies indicate that ATP is one of the primary neurotransmitters in taste transduction. ATP release occurs from taste cells via specific hemichannels such as pannexin/connexin hemichannels (Huang et al., 2007; Romanov et al., 2007). We hypothesize that Type II (receptor) and possibly Type III (presynaptic) cells release ATP at sites containing pannexin/connexin hemichannels. In this study, we examine the presence of connexin–32–LIR (Like Immunoreactivity) and connexin–43–LIR in rodent taste buds through immunocytochemical analysis and DAB (Di–amino–benzidine) immunoelectron microscopy. We observed that connexin–32–LIR co–localizes with P2X2–LIR in nerve fibers and in a small subset of NCAM–LIR cells. Connexin–32–LIR does not co–localize …

Dissection Of The Role Of The Stable Signal Peptide Of The Arenavirus Envelope Glycoprotein In Membrane Fusion, Emily L. Messina, Joanne York, Jack H. Nunberg

Biological Sciences Faculty Publications

The arenavirus envelope glycoprotein (GPC) retains a stable signal peptide (SSP) as an essential subunit in the mature complex. The 58-amino-acid residue SSP comprises two membrane-spanning hydrophobic regions separated by a short ectodomain loop that interacts with the G2 fusion subunit to promote pH-dependent membrane fusion. Small-molecule compounds that target this unique SSP-G2 interaction prevent arenavirus entry and infection. The interaction between SSP and G2 is sensitive to the phylogenetic distance between New World (Junin) and Old World (Lassa) arenaviruses. For example, heterotypic GPC complexes are unable to support virion entry. In this report, we demonstrate that the hybrid GPC …

A Revision Of The Genus Kaszabister Mazur (Histeridae, Histerinae, Exosternini), Michael S. Caterino, Nicolas Degalllier, Slawomir Mazur, Alexey K. Tishechkin

Publications

We revise the four species of Kaszabister Mazur, 1972, one of which, Kaszabister barrigai sp. n., is described as new. The other species in the genus are K. rubellus (Erichson, 1834), K. ferrugineus (Kirsch, 1873) and K. carinatus (Lewis, 1888). The species are principally known from the subtropics of South America, with one in Central America. Lectotypes are designated for K. rubellus and K. ferrugineus, and a key is provided for all the species. Ants of the genus Solenopsis Westwood, mainly S. invicta Buren and S. saevissima (Smith), are documented as hosts of three of the four species.