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Articles 301 - 330 of 890

Full-Text Articles in Entire DC Network

Asymmetric Interference Competition Between Herbivorous Gastropods, Introduced Littorina Littorea And Indigenous L. Obtusata, Alysha B. Putnam, Paulette Peckol Apr 2018

Asymmetric Interference Competition Between Herbivorous Gastropods, Introduced Littorina Littorea And Indigenous L. Obtusata, Alysha B. Putnam, Paulette Peckol

Biological Sciences: Faculty Publications

Competitive interactions may affect distribution and abundance of mobile organisms, such as the intertidal herbivorous gastropods Littorina littorea and L. obtusata, in areas of resource overlap. We examined intra- and interspecific competition between US New England populations by measuring effects of snail density and food availability on growth rates and abundances. We investigated mechanisms of interference, including resistance (phlorotannin) induction of fucoid algae, and impacts of snail presence, waterborne cues, and mucus on herbivory. L. obtusata density increased significantly within fucoid canopies following repeated (every 12 h for 3 d) removal of L. littorea at both study sites. In the …

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Using Δ13c, Δ15n, And Δ2h To Better Understand The Ecology Of Green Sea Turtles, Laura Pagès Barceló Apr 2018

Using Δ13c, Δ15n, And Δ2h To Better Understand The Ecology Of Green Sea Turtles, Laura Pagès Barceló

Biology ETDs

Many green sea turtle populations are slowly recuperating from a recent severe decline due to anthropogenic factors including human consumption and mortality related to the fishing industry. Despite being charismatic animals that have been extensively studied, there is still a limited understanding of their feeding strategies and diet plasticity. This research explores the use of hydrogen isotopes in marine ecosystems to better understand green sea turtle ecology. This study is presented in two chapters: I first examined the trophic discrimination factor (D2HNET) for hydrogen isotope (d2H) as a tool to correct hydrogen isotope data …

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Small Mammal Diversity, Rattlesnake Demographics, And Resource Utilization In The Great Basin: Implications For Management And Stable Isotope Proxies, Bryan T. Hamilton Apr 2018

Small Mammal Diversity, Rattlesnake Demographics, And Resource Utilization In The Great Basin: Implications For Management And Stable Isotope Proxies, Bryan T. Hamilton

Theses and Dissertations

Plant carbon isotopes were used to track assimilation of riparian resources by small mammals. Voles and shrews derived significant portions of their carbon from riparian vegetation. Deer and harvest mice were abundant in riparian habitat but assimilated little riparian vegetation indicating that the riparian corridor provided resources other than food. This is first use of stable carbon isotopes to trace riparian resources into a vertebrate community. Conifer encroachment in sagebrush ecosystems negatively affects many wildlife populations. Conifer removal is recommended across millions of hectares in the Great Basin. However the effects of conifer encroachment and conifer removal are unknown for …

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Killi-Data News (Spring), Tyrone Genade Mar 2018

Killi-Data News (Spring), Tyrone Genade

Killifish Research Review

This is the start of Killi-Data News’ second year. In this first issue of the year we have the usual review of research pub- lications as well as input from Martin Reichard on his lab’s Nothobranchius research. Martin is responding to my reviews of his lab’s work in the previous edition. I am serious about making sure the content in this newsletter is reliable but I erred in the previous edition and Martin has written extensively to correct my mistake in the section “Erratum”. This reply is welcomed and owed to readers. I must confess that I don’t know everything …

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Killi-Data News (Spring), Tyrone Genade Mar 2018

Killi-Data News (Spring), Tyrone Genade

Killifish Research Review

This is the start of Killi-Data News’ second year. In this first issue of the year we have the usual review of research pub- lications as well as input from Martin Reichard on his lab’s Nothobranchius research. Martin is responding to my reviews of his lab’s work in the previous edition. I am serious about making sure the content in this newsletter is reliable but I erred in the previous edition and Martin has written extensively to correct my mistake in the section “Erratum”. This reply is welcomed and owed to readers. I must confess that I don’t know everything …

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Ecomorphological Variation In Three Species Of Cybotoid Anoles, A. F. Kahrl, Brittney M. Ivanov, K. C. Wollenberg Valero, Michele A. Johnson Mar 2018

Ecomorphological Variation In Three Species Of Cybotoid Anoles, A. F. Kahrl, Brittney M. Ivanov, K. C. Wollenberg Valero, Michele A. Johnson

Biology Faculty Research

Caribbean Anolis lizards exhibit a complex suite of ecological, morphological, and behavioral traits that allow their specialization to particular microhabitats. These microhabitat specialists, called ecomorphs, have independently evolved on the four islands of the Greater Antilles, and diversification among anole ecomorphs has been the focus of many studies. Yet, habitat specialization has also occurred among species within the same ecomorph group. Here, we examined ecological, morphological, and behavioral divergence in three Hispaniolan trunk-ground species, the cybotoid anoles: Anolis cybotes, A. marcanoi, and A. longitibialis. We found differences in limb morphology, locomotor behavior, and perch use among the three cybotoid species …

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Monitoring Of Dung Beetle (Scarabaeidae And Geotrupidae) Activity Along Maryland's Coastal Plain, Patrick Simons, Michael Molina, Mallory A. Hagadorn, Dana L. Price Mar 2018

Monitoring Of Dung Beetle (Scarabaeidae And Geotrupidae) Activity Along Maryland's Coastal Plain, Patrick Simons, Michael Molina, Mallory A. Hagadorn, Dana L. Price

Biology Faculty Publications

Our understanding of how human activities impact insect communities is limited. Dung beetles, well known for the ecosystem services they provide, are faced with many conservation threats, particularly from deforestation and agriculture. Here we used 200-m transects and human-dung—baited pitfall traps to examine dung beetle populations in 7 forests of Maryland's Coastal Plain. We set traps once a month, from May 2014 to April 2015, to determine species presence, abundance, range, and seasonality. We collected 6463 individuals representing 22 species; Janes Island State Park (JISP) had the highest abundance (2705 individuals) and Martinak State Park (MSP) had the highest species …

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Population Dynamics Of Off-Host Rhipicephalus (Boophilus) Microplus (Acari: Ixodidae) Larvae In Response To Habitat And Seasonality In South Texas, Brenda Leal, Donald B. Thomas, Robert K. Dearth Mar 2018

Population Dynamics Of Off-Host Rhipicephalus (Boophilus) Microplus (Acari: Ixodidae) Larvae In Response To Habitat And Seasonality In South Texas, Brenda Leal, Donald B. Thomas, Robert K. Dearth

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

The cattle tick, Rhipicephalus microplus (Canestrini), is an economically destructive arthropod because of its ability to vector bovine babesiosis. It is known that cattle ticks can spend 80–90% of their lifecycle as questing larvae, yet the effect of climatic factors on their off-host behavior and survival is unclear. The goal of this study was to measure the effects of specific ecological factors on off-host questing larvae in nature. The study was conducted in a south Texas pasture over a two-year period, during which time larval populations were surveyed. Simultaneously, weather variables—precipitation, relative humidity, and ambient temperatures—were recorded. Larval survival rates …

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Mode And Rate Of Evolution Of Haemosporidian Mitochondrial Genomes: Timing The Radiation Of Avian Parasites, Patricia Parker, M Pacheco, Nubia Matta, Gediminas Valkiūnas, Beatriz Mello, Craig Stanley, Miguel Lentino, Maria Garcia-Amado, Michael Cranfield, Sergei Pond, Ananias Escalante Feb 2018

Mode And Rate Of Evolution Of Haemosporidian Mitochondrial Genomes: Timing The Radiation Of Avian Parasites, Patricia Parker, M Pacheco, Nubia Matta, Gediminas Valkiūnas, Beatriz Mello, Craig Stanley, Miguel Lentino, Maria Garcia-Amado, Michael Cranfield, Sergei Pond, Ananias Escalante

Biology Department Faculty Works

Haemosporidians are a diverse group of vector-borne parasitic protozoa that includes the agents of human malaria; however, most of the described species are found in birds and reptiles. Although our understanding of these parasites’ diversity has expanded by analyses of their mitochondrial genes, there is limited information on these genes’ evolutionary rates. Here, 114 mitochondrial genomes (mtDNA) were studied from species belonging to four genera: Leucocytozoon, Haemoproteus, Hepatocystis, and Plasmodium. Contrary to previous assertions, the mtDNA is phylogenetically informative. The inferred phylogeny showed that, like the genus Plasmodium, the Leucocytozoon and Haemoproteus genera are not monophyletic groups. Although sensitive to …

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Using Environmental Dna And Occupancy Modeling To Examine Drivers Of Eastern Hellbender Extirpation And Sampling Method Efficiency In West Virginia, Sean Michael Wineland Jan 2018

Using Environmental Dna And Occupancy Modeling To Examine Drivers Of Eastern Hellbender Extirpation And Sampling Method Efficiency In West Virginia, Sean Michael Wineland

Theses, Dissertations and Capstones

Amphibian population declines and range constrictions are widespread but poorly understood. Effective conservation planning relies on accurate distribution data to develop a fundamental understanding of causal changes in species distributions. However, conventional detection methods for cryptic and elusive amphibians suffer from imperfect detection. Environmental DNA (eDNA) has emerged as an innovative and powerful conservation tool for detecting aquatic species presence; however comparative studies aimed at fully understanding eDNA detection probabilities are lacking. In this study, I used environmental DNA (eDNA) sampling methods and detailed historical records to identify drivers of extirpation and sampling method efficiency for an imperiled, long-lived giant …

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Ontogeny Of Juvenile Freshwater Pearl Mussels, Margaritifera Margaritifera (Bivalvia: Margaritiferidae), Louise Lavictoire, Andrew D. Ramsey, Evelyn A. Moorkens, Graham Souch, M. Christopher Barnhart Jan 2018

Ontogeny Of Juvenile Freshwater Pearl Mussels, Margaritifera Margaritifera (Bivalvia: Margaritiferidae), Louise Lavictoire, Andrew D. Ramsey, Evelyn A. Moorkens, Graham Souch, M. Christopher Barnhart

College of Natural and Applied Sciences

The gills of juvenile freshwater bivalves undergo a complex morphogenesis that may correlate with changes in feeding ecology, but ontogenic studies on juvenile mussels are rare. Scanning electron microscopy was used to examine the ultrastructure and ontogeny of 117 juvenile freshwater pearl mussels (Margaritifera margaritifera) ranging in age from 1-44 months and length from 0.49-8.90 mm. Three stages of gill development are described. In Stage 1 (5-9 inner demibranch filaments), only unreflected inner demibranch filaments were present. In Stage 2 (9-17 inner demibranch filaments), inner demibranch filaments began to reflect when shell length exceeded 1.13 mm, at 13-16 months old. …

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Sparsorythus Sescarorum, New Species From Mindoro, Philippines (Ephemeroptera, Tricorythidae), Jhoana Garces, Ernst Bauernfeind, Hendrik Freitag Jan 2018

Sparsorythus Sescarorum, New Species From Mindoro, Philippines (Ephemeroptera, Tricorythidae), Jhoana Garces, Ernst Bauernfeind, Hendrik Freitag

Biology Faculty Publications

A new mayfly species, Sparsorythus sescarorum sp. n. (Tricorythidae) is described from Mindoro Island, Philippines. Nymphs are characterized by the combination of the following characters: compound eyes of approximately equal size in both sexes, shape and setation of legs, presence of rudimentary gills on abdominal segment VII, and some details of mouthparts. Male imagines are characterized by the coloration pattern of wings and details of genitalia. The developmental stages are matched by DNA barcodes.

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The Effects Of Acidic Conditions And Tannins On The Survival, Development, And Behavior Of Cope’S Gray Treefrog (Hyla Chrysoscelis), Caleb E. Dodd Jan 2018

The Effects Of Acidic Conditions And Tannins On The Survival, Development, And Behavior Of Cope’S Gray Treefrog (Hyla Chrysoscelis), Caleb E. Dodd

Electronic Theses and Dissertations

As amphibians decline around the world, freshwater acidification resulting from pollutants and acid rain may be a contributor. The ability of organisms to cope with environmental changes is greatly mediated by behavior, and recent studies indicate that anthropogenic acidification impairs behavioral responses by impacting olfactory abilities of aquatic organisms. Responding appropriately to novel stimuli is important for individual performance and survival, and pollutants may cause organisms to behave maladaptively. In this study I sought to: a) determine whether the oviposition site choices of adult female frogs correspond with the pH and tannin conditions that maximize tadpole survival and performance in …

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Do The Lifetime Prevalence And Prognosis Of Schizophrenia Differ Among World Regions?, Cheryl Lynn Smith Jan 2018

Do The Lifetime Prevalence And Prognosis Of Schizophrenia Differ Among World Regions?, Cheryl Lynn Smith

CMC Senior Theses

Much cross-cultural research has been done on the topic of schizophrenia, but few studies thus far have focused on lifetime prevalence and prognosis together, grouped by world region. Additionally, there has been severe bias in which countries and regions have been studied both historically and currently. Any study that had statistics on lifetime prevalence per 1000 people and/or DALYs, from a specified country or region, was included in this thesis. Results showed that lifetime prevalence of schizophrenia does not differ among WHO regions, but DALYs and thus prognosis do differ. Several major conclusions can be drawn from these results. One …

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Identification And Characterization Of Tri-Colored Bat Hibernaculum In Russell County, Kansas, Angelica Sprague Jan 2018

Identification And Characterization Of Tri-Colored Bat Hibernaculum In Russell County, Kansas, Angelica Sprague

Master's Theses or Doctor of Nursing Practice

Caves are often essential during hibernation, a sensitive stage in the life cycle of bats. Caves offer more stable conditions, such as temperature and relative humidity, during the changing seasons when food supply is limited, and weather is unstable. As caves in North-Central Kansas are sparse, the hibernating status of tri-colored bat (Perimyotis subflavus) is not well known. Bats are experiencing substantial population declines within the United States, caused primarily by white nose-syndrome, as well as habitat loss and degradation, and increased wind-power facilities. In the winter seasons of 2015 and 2016, I studied tri-colored bat hibernacula. A man-made “cave” …

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Patterns Of Trematode Distribution From Hosts Collected At Lake Winnibigoshish, Minnesota, Scott Malotka Jan 2018

Patterns Of Trematode Distribution From Hosts Collected At Lake Winnibigoshish, Minnesota, Scott Malotka

All Graduate Theses, Dissertations, and Other Capstone Projects

A comparative and seasonal study was performed on trematode populations and communities within waterfowl definitive hosts in order to determine important factors in the structuring of these communities. Furthermore, larval trematode populations were also sampled in order to compare larval stages found within snail hosts to adult stages found within collected waterfowl in order to determine where infections could have occurred with the trematode species. 52 birds including 18 blue-winged teal (Anas discors), 5 bufflehead (Bucephala albeola), 4 common goldeneye (Bucephala clangula), 1 greater scaup (Aythya marila), 1 green-winged teal (Anas carolinensis), 11 lesser scaup (Aythya affinis), 1 northern pintail …

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The Effects Of Temperature On Batrachochytrium Dendrobatidis Resistance And Heart Rate In The Polymorphic Eastern Red-Backed Salamanders, Plethodon Cinereus, Joseph Alan Demarchi Jan 2018

The Effects Of Temperature On Batrachochytrium Dendrobatidis Resistance And Heart Rate In The Polymorphic Eastern Red-Backed Salamanders, Plethodon Cinereus, Joseph Alan Demarchi

Masters Theses

No abstract provided.

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Evidence For Trait-Based Dominance In Occupancy Among Fossil Taxa And The Decoupling Of Macroecological And Macroevolutionary Success, Peter Wagner, Roy E. Plotnick, S. Kathleen Lyons Jan 2018

Evidence For Trait-Based Dominance In Occupancy Among Fossil Taxa And The Decoupling Of Macroecological And Macroevolutionary Success, Peter Wagner, Roy E. Plotnick, S. Kathleen Lyons

School of Biological Sciences: Faculty Publications

Biological systems provide examples of differential success among taxa, from ecosystems with a few dominant species (ecological success) to clades that possess far more species than sister clades (macroevolutionary success). Macroecological success, the occupation by a species or clade of an unusually high number of areas, has received less attention. If macroecological success reflects heritable traits, then successful species should be related. Genera composed of species possessing those traits should occupy more areas than genera with comparable species richness that lack such traits. Alternatively, if macroecological success reflects autapomorphic traits, then generic occupancy should be a by-product of species richness …

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An Examination Of Beta Diversity Indices And Their Predictors In Two Large-Scale Systems, Philip Schroeder Jan 2018

An Examination Of Beta Diversity Indices And Their Predictors In Two Large-Scale Systems, Philip Schroeder

Electronic Theses and Dissertations

Biodiversity is what conservation biology was developed to conserve. It is the physical manifestation of life as a concept and, be it for practical or idealistic reasons, all conservationists seek to protect or, in some cases, enhance it. Because of its monolithic importance to the field, much effort has been expended trying to better measure and understand it. Recently, greater attention has been paid to the partition of diversity; the observation that the total diversity of a system (γ) can be broken down into within-site diversity (α) and between-site diversity (β). In particular, it has been noticed that the β …

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Conflicting Hydraulic Effects Of Xylem Pit Structure Relate To The Growth-Longevity Tradeoff In A Conifer Species, Beth Roskilly Jan 2018

Conflicting Hydraulic Effects Of Xylem Pit Structure Relate To The Growth-Longevity Tradeoff In A Conifer Species, Beth Roskilly

Graduate Student Theses, Dissertations, & Professional Papers

Consistent with a ubiquitous life history tradeoff, trees exhibit a negative relationship between growth and longevity among and within species. However, the mechanistic basis of this life history tradeoff is not well understood. In addition to tradeoffs among multiple traits based on resource allocation conflicts, life history tradeoffs may arise from tradeoffs based on single traits under opposing selection. While a myriad of factors likely contribute to the growth-longevity tradeoff in trees, we hypothesized that conflicting functional effects of xylem structural traits contribute to the growth-longevity tradeoff. We tested this hypothesis by examining the extent to which xylem morphological traits …

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Vocalizations Influence Roost-Site Selection In Overwintering Cavity-Nesting Birds In Eastern Washington, Shelby M. Hunter Jan 2018

Vocalizations Influence Roost-Site Selection In Overwintering Cavity-Nesting Birds In Eastern Washington, Shelby M. Hunter

EWU Masters Thesis Collection

Primary cavity-nesting birds are keystone species because the annual tree cavities they excavate become critical habitat for other species. In eastern Washington, most primary cavity-nesting birds are year-round residents. They increase overwinter survival by night roosting in cavities and forming flocks. The timing of roost site selection can impact the quality of a roost site, thus selecting a roost site too late reduces the odds of selecting the most favorable microclimate available. Birds in flocks use alarm calls to warn of threats and contact calls to promote group cohesion. My study asks if timing of roost site selection and vocalizations …

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Quantitative Acoustic Differentiation Of Cryptic Species Illustrated With King And Clapper Rails, Lydia L. Stiffler, Katie M. Schroeder, James T. Anderson, Susan B. Mcrae, Todd E. Katzner Jan 2018

Quantitative Acoustic Differentiation Of Cryptic Species Illustrated With King And Clapper Rails, Lydia L. Stiffler, Katie M. Schroeder, James T. Anderson, Susan B. Mcrae, Todd E. Katzner

Faculty & Staff Scholarship

Reliable species identification is vital for survey and monitoring programs. Recently, the development of digital technology for recording and analyzing vocalizations has assisted in acoustic surveying for cryptic, rare, or elusive species. However, the quan- titative tools that exist for species differentiation are still being refined. Using vocali- zations recorded in the course of ecological studies of a King Rail (Rallus elegans) and a Clapper Rail (Rallus crepitans) population, we assessed the accuracy and effective- ness of three parametric (logistic regression, discriminant function analysis, quadratic discriminant function analysis) and six nonparametric (support vector machine, CART, Random Forest, k-nearest neighbor, weighted …

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Diet And Activity Patterns Of Five Bat Species In North-Central Kansas, Holly G. Wilson Dec 2017

Diet And Activity Patterns Of Five Bat Species In North-Central Kansas, Holly G. Wilson

Master's Theses or Doctor of Nursing Practice

My study focuses on six bat species that occur in north-central Kansas. Although each species is widely distributed, information about their diet and activity patterns is lacking, especially within Kansas. Increased knowledge about bat species in Kansas can provide a baseline for future studies and conservation efforts for the species included in my study; big brown bat (Eptesicus fuscus), eastern red bat (Lasiurus borealis), hoary bat (Lasiurus cinereus), northern myotis (Myotis septentrionalis), evening bat (Nycticeius humeralis), and tricolored bats (Perimyotis subflavus) were captured and fecal samples were examined for diet diversity. I captured bats in mist nets in the Kansas …

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The Cost Of Roaming Free: Assessing The Effects Of Plant Secondary Metabolites On Diet Selection And Nutritional Condition In A Free-Ranging Generalist Herbivore, Daniel Patrick Melody Dec 2017

The Cost Of Roaming Free: Assessing The Effects Of Plant Secondary Metabolites On Diet Selection And Nutritional Condition In A Free-Ranging Generalist Herbivore, Daniel Patrick Melody

Boise State University Theses and Dissertations

Large vertebrate herbivores have a wide variety of browsing options available. However, most plants contain a suite of plant secondary metabolites (PSMs) that can have toxic effects when ingested. Herbivores must therefore make dietary choices that minimize the potentially harmful effects of PSM ingestion and maximize the use of available nutrients and protein. During winter months, in northern latitudes, climatological factors restrict browsing options and many populations of herbivores must subsist primarily on forage that is relatively poor in nutritional quality and high in PSMs. Many species of herbivores have developed a suite of behavioral and physiological adaptations to cope …

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Behavioral Ecology And Associated Virology Of Mosquito-Host Interactions In Southern California, Oliver Eshun Dec 2017

Behavioral Ecology And Associated Virology Of Mosquito-Host Interactions In Southern California, Oliver Eshun

Loma Linda University Electronic Theses, Dissertations & Projects

Elucidating characteristics of mosquito-host interactions are critical for understanding the ecology and epidemiology of mosquito-borne diseases. In this dissertation, I conducted three studies to explore potential mosquito-host interactions and associated virus infection rates. I first demonstrated that mosquito captures at CO2-baited traps decreased most markedly with height above ground, and also decreased with distance from water at a riparian area but not at an open water source lacking a vegetated border. Birds might therefore prefer elevated nests or roosts to avoid mosquitoes. The second study examined the anti-mosquito behaviors of budgerigars (Melopsittacus undulatus) in a laboratory study. The birds defended …

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Ecology Of Greater Sage-Grouse Inhabiting The Southern Portion Of The Rich-Morgan-Summit Sage-Grouse Management Area, M. Brandon Flack Dec 2017

Ecology Of Greater Sage-Grouse Inhabiting The Southern Portion Of The Rich-Morgan-Summit Sage-Grouse Management Area, M. Brandon Flack

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greater sage-grouse (Centrocercus urophasianus; sage-grouse) are sagebrush obligates and are therefore considered to be key indicators of sagebrush ecosystem health. Sage-grouse populations have declined range-wide over the last century due to loss and fragmentation of sagebrush (Artemisia spp.) habitats. Sage-grouse populations found in large intact sagebrush landscapes are considered to be more resilient, however, some small isolated populations persist and thrive in fragmented landscapes. Because of Utah’s unique topography and geography, sage-grouse habitat is discontinuous and populations are naturally dispersed throughout the state in suitable intact blocks or in disconnected islands of sagebrush habitat. Thus, Utah populations …

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Ecological And Oceanographic Influences On Leatherback Turtle Behavior And Scyphozoan Jellyfish Distributions In The Gulf Of Mexico, Katrina Aleksa Dec 2017

Ecological And Oceanographic Influences On Leatherback Turtle Behavior And Scyphozoan Jellyfish Distributions In The Gulf Of Mexico, Katrina Aleksa

Dissertations

Leatherback turtles (Dermochelys coriacea) are a wide-ranging, oceanic species that feed exclusively on gelatinous zooplankton. Leatherback have been spotted in the Gulf of Mexico (GoM) for several decades and consistently had a high level of interactions with longline fisheries. However, no quantitative studies have been performed to address the spatiotemporal distribution of these turtles in the GoM. This research determines 1) leatherback movements and high-use areas in the GoM, 2) their association with oceanographic features, 3) the distribution and density of two abundant medusae in the northern GoM and any association with biophysical parameters, and 4) the body …

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Polyploidy And Hybridization Have A Role In Plant Distribution In The United States: A Bioinformatics Study, Andrea Ortiz Nov 2017

Polyploidy And Hybridization Have A Role In Plant Distribution In The United States: A Bioinformatics Study, Andrea Ortiz

Biology Theses

Introduction: Polyploidy is the doubling of a genome. Autopolyploidy and allopolyploidy are two different modes of genome duplication. These events are common in angiosperms and usually involve diploids and tetraploids, a resulting polyploid species. Both cytotypes exhibit competitive exclusion and environmental adaptation according to their spatial distributions. My research focuses on how abiotic environmental factors affect the range and the amount of range overlap of the taxon within the Callisia graminea and Allium canadense systems over time. Niche modeling determines whether there is substantial niche overlap between the Callisia graminea diploid and tetraploid, whether range shifts occur between the Callisia …

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Bacterial Siderophore Production In Lechuguilla And Spider Caves, Carlsbad National Park (Ccnp) Carlsbad, New Mexico, Tammi R. Duncan Nov 2017

Bacterial Siderophore Production In Lechuguilla And Spider Caves, Carlsbad National Park (Ccnp) Carlsbad, New Mexico, Tammi R. Duncan

Biology ETDs

Lechuguilla and Spider caves, Carlsbad Caverns National Park, contain a rich microbial diversity. Despite oligotrophic conditions, the microorganisms in these caves have developed strategies to acquire essential nutrients. I hypothesized that cave bacteria use siderophores, a ferric iron chelating compound, to acquire iron for essential life processes. To understand the backdrop against which the cave bacteria would produce siderophores, I examined the bacterial physiological characteristics, determined whether cave bacteria have an ability to produce siderophores, and investigated a possible correlation between iron and manganese concentrations in cave deposits and siderophore production by bacteria cultured from the same site. I carried …

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Assessment Of Intra And Interregional Genetic Variation In The Eastern Red-Backed Salamander, Plethodon Cinereus, Via Analysis Of Novel Microsatellite Markers, Alexander C. Cameron Oct 2017

Assessment Of Intra And Interregional Genetic Variation In The Eastern Red-Backed Salamander, Plethodon Cinereus, Via Analysis Of Novel Microsatellite Markers, Alexander C. Cameron

Biology

The red-backed salamander (Plethodon cinereus) has long-served as a model system in ecology, evolution, and behavior, and studies surveying molecular variation in this species have become increasingly common over the past decade. However, difficulties are commonly encountered when extending microsatellite markers to populations that are unstudied from a genetic perspective due to high levels of genetic differentiation across this species’ range. To ameliorate this issue, we used 454 pyrosequencing to identify hundreds of microsatellite loci. We then screened 40 of our top candidate loci in populations in Virginia, Pennsylvania, and Ohio—including an isolated island population ~ 4.5 km off the …

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