Ecology and Evolutionary Biology Commons^™

The Role Of Gene Expression Noise In Mammalian Cell Survival, Kevin Farquhar

Dissertations and Theses (Open Access)

Drug resistance and metastasis remain obstacles to effective cancer treatment. A major challenge contributing to this problem is cellular heterogeneity. Even in the same environment, cells with identical genomes can display cell-to-cell differences in gene expression, also known as gene expression noise. Gene expression noise can vary in magnitude in a population or in fluctuation time scales, which is influenced by gene regulatory networks.

Currently, it is unclear how gene expression noise from gene regulatory networks contributes to drug survival outcomes in mammalian cells. An isogenic cell line with a noise-modulating genetic system tuned to the same mean is required. …

Using Molecular Diet Analysis To Inform Invasive Species Management: A Case Study Of Introduced Rats Consuming Endemic New Zealand Frogs, Bastian Egeter, Cailín Roe, Sara Peixoto, Pamela Puppo, Luke J. Easton, Joana Pinto, Phillip J. Bishop, Bruce C. Robertson

Biological Sciences Faculty Research

The decline of amphibians has been of international concern for more than two decades, and the global spread of introduced fauna is a major factor in this decline. Conservation management decisions to implement control of introduced fauna are often based on diet studies. One of the most common metrics to report in diet studies is Frequency of Occurrence (FO), but this can be difficult to interpret, as it does not include a temporal perspective. Here, we examine the potential for FO data derived from molecular diet analysis to inform invasive species management, using invasive ship rats (Rattus rattus) …

Characterization Of Microtubule Organizing Centers In The Genus Protostelium, Including Evolutionary Implications, Ethan Taylor Ozment

Graduate Theses and Dissertations

Microtubule organizing centers (MTOCs) are cellular regions of microtubule nucleation. The best known MTOCs are those associated with the centrosome, but several non-centrosomal MTOCs are known in eukaryotes, especially in land plants. MTOCs are poorly characterized across the breadth of amoebozoan diversity, but are well-known in certain amoebozoan lineages, including the genus of protosteloid slime molds Protostelium. The structure of the MTOC is known for two non-ciliated species, P. nocturnum and P. mycophaga, as well as P. aurantium, which can reversibly become ciliated under appropriate conditions. P. nocturnum and P. mycophaga have acentriolar centrosomal MTOCs while P. aurantium has a …

Stabilizing Forces In Acoustic Cultural Evolution: Comparing Humans And Birds, Daniel C. Mann

Dissertations, Theses, and Capstone Projects

Learned acoustic communication systems, like birdsong and spoken human language, can be described from two seemingly contradictory perspectives. On one hand, learned acoustic communication systems can be remarkably consistent. Substantive and descriptive generalizations can be made which hold for a majority of populations within a species. On the other hand, learned acoustic communication systems are often highly variable. The degree of variation is often so great that few, if any, substantive generalizations hold for all populations in a species.

Within my dissertation, I explore the interplay of variation and uniformity in three vocal learning species: budgerigars (Melopsittacus undulatus), …

The Functional Morphology Of Ingestion In The Platyrrhine Sclerocarpic Harvesters (Platyrrhini, Primates), Zachary Stoffel Klukkert

Dissertations, Theses, and Capstone Projects

The identification of anatomical correlates of diet and feeding behavior in nonhuman primates is an important area of research in biological anthropology. The morphology of the jaws and teeth reflects the phylogeny and adaptations that distinguish taxa and their different ecological niches. Studying the form-function relationships of jaws and teeth in modern species provides a framework for interpreting the diets of extinct species and for inferring the ecological pressures that may have contributed to the evolutionary diversification of primate craniodental morphology. Previous work on modeling primate jaw mechanics has focused largely on the functional context of a closed jaw. Little …

Impacts Of Cattle Grazing As A Tool To Control Phragmites Australis In Wetlands On Nitrogen, Phosphorus, And Carbon, Brittany L. Duncan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Phragmites australis is a plant that is causing problems in wetlands by outcompeting native plants that provide food and shelter for millions of migratory birds. Currently, managers try to control Phragmites australis by spraying herbicide, burning, and mowing, but these methods are costly, time consuming, and have low levels of success. Adding grazing as a tool to control Phragmites australis provides a cheap and low labor alternative. However, there are many concerns regarding if grazing will cause nutrient loading in our wetlands that will decrease water quality and alter beneficial functions of wetlands.

To better understand the effects of grazing …

Fire - Herbivory Interactions In An East African Savanna: Effects On Acacia Drepanolobium Trees, Eric M. Lamalfa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Globally, changes in plant community structure have occurred in ecosystems where humans have altered natural disturbance regimes. Many plants have adaptive life histories and morphological traits that have coevolved with fire and herbivory, which allows them to thrive despite repeated tissue losses. Therefore, altering the type, frequency, or severity of disturbance affects individual plant growth and competition among species. When these changes benefit or disadvantage different plant functional groups (i.e., grasses, shrubs, trees) it alters ecosystem structure and function. Understanding and predicting these vegetation changes, is critical for conservation and management of biodiversity, wildlife habitat, livestock forage, and water.

Savannas …

Monitoring Desert Ungulates Via Fecal Dna-Based Capture Recapture, Stephen S. Pfeiler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Estimates of population abundance and survival are critical for effective wildlife management. Obtaining estimates of these kind using traditional wildlife monitoring techniques (i.e. ground and aerial surveys) has proven to be difficult, especially for species that are wide ranging and exist in small, patchily distributed populations.

My objective was to implement fecal DNA-based capture-recapture surveys to estimate abundance and survival of two different ungulate populations that inhabit the deserts of southeastern California. I also compared fecal DNA-based capture-recapture techniques to traditional methods by evaluating the costs and precision associated with both methods. Using artificial water sources as focal sampling sites, …

Effects Of Ecological Restoration Techniques In Glen Canyon National Recreation Area, Simone Ka-Voka Jackson

UNLV Theses, Dissertations, Professional Papers, and Capstones

A better understanding of key ecological restoration techniques can inform land management in the Southwest on restoration options for areas infested by invasive grasses that can pose threats to ecosystems, from changes in nutrient cycling to altered fire regimes. In the semi-arid desert of Glen Canyon National Recreation Area (GLCA), several exotic grasses pose risks to local ecosystems: Saccharum ravennae, a relatively new invasive perennial grass, and Bromus rubens and Bromus tectorum, widespread annual grasses. In this study, multiple ecological restoration techniques were implemented to assess their effects on native and nonnative vegetation on sites invaded by the non-native grasses …

Assessing Minimal-Input Restoration Strategies For Desert Soil And Vegetation Restoration, Audrey Jean Rader

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Mojave and Sonoran Deserts have been negatively impacted by anthropogenic disturbances. Considering that these ecosystems may recover on millennial timescales, research has shown that restoration techniques can be fairly successful in initiating long-term recovery processes in these sensitive environments. However, uncertainty remains as to which techniques are effective in different circumstances, such as in different climates or across different soil properties, and which techniques may best avoid unintended consequences, such as facilitating non-native plants. To reduce fugitive dust as a human health hazard, increase soil stability, and enhance wildlife habitat, further work is necessary to develop restoration techniques for …

Long-Term Monitoring Of Rare Gypsum Communities In The Eastern Mojave Desert: A Study In Science And Art, Tiffany Jane-Marie Pereira

UNLV Theses, Dissertations, Professional Papers, and Capstones

For land managers, reliable estimates of soil seed banks, and more specifically, change in seed banks over time, provide insight into the restoration and regeneration potential of the landscape, site history and disturbance mapping, and, invasive and rare plant management. To understand the intricacies of desert soil seed banks in relation to aboveground vegetation change, my research evaluated long-term change in soil seed banks, fertile islands, and plant communities of conservation-priority gypsum rare plant habitat of the eastern Mojave Desert. Research found significant spatial and temporal differences in seed bank composition and density over an 11-year period; however, the gypsum …

Effects Of Disturbance And Restoration Treatment On Fertile Islands In Lake Mead National Recreation Area, Camille Traylor

UNLV Theses, Dissertations, Professional Papers, and Capstones

Disturbances by humans are one of the main drivers of change in contemporary desert ecosystems. Restoration treatments such as topsoil application and outplanting can be implemented in response to disturbances in order to maintain soil stability and a diverse plant community. Fertile islands - nutrient enriched areas beneath perennial shrubs - are fundamental features of deserts that can facilitate annual plant growth. A major uncertainty in desert ecology is how much time is required for fertile islands and nurse plant effects (the facilitation of one plant by another) to develop below maturing perennial plants. By studying naturally recruited perennial plants …

Understanding Wetlands And Irrigation In The Little Snake River Basin, Wyoming, Lindsey Washkoviak

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The Little Snake River Basin (LSRB) is a managed basin in South-central Wyoming located within the Colorado River watershed facing severe water shortages. There is increased pressure on water resource managers and agricultural producers to adopt water efficiency practices that could negatively affect wetland resources. However, studies have begun to quantify the importance of irrigation for recharging groundwater, maintaining late season instream flows, and maintaining and creating wetlands that provide wildlife habitat and ecosystem services.

In the LSRB there are 11,636 acres of wetlands; 56% of which overlap with irrigation. Conversion to more efficient irrigation could reduce water availability to …

Review Of Carnivores Of The World, Second Edition, By Luke Hunter, Shannon M. Barber-Meyer

The Prairie Naturalist

Cracking open this fully revised field guide invites a new appreciation for the diversity of carnivores (members of the order Carnivora) in the world. Dig a little deeper and you’ll uncover just how little we know about so many of them. This second edition of the Carnivores of the World features 250 mammalian species—from a species so tiny it can squeeze through a wedding ring to one weighing thousands of times more, the polar bear (Ursus maritimus). Each detailed species account includes an illustration of the species (and sometimes varying forms or subspecies), information on morphological and identifying features, distribution …

Beyond Genetics: Addressing Activity In Microbial Ecology, Scott Christopher Thomas

UNLV Theses, Dissertations, Professional Papers, and Capstones

The field of microbial ecology is on the cusp of another revolution, one that uses synergy to address the limitations of previous studies. My dissertation is representative of the new era of research to come, through combining the latest technological advances with established classical methods to provide a more complete understanding of microbial ecosystems. In my first study, I evaluate the conservation of central carbon metabolic pathways and activity along a temperature and diversity gradient (60-95 ℃) through the use of 16S rRNA gene amplicon data, metagenome sequencing, and position-specific 13C-labeled metabolite probing. In my second study, I provide the …

Cognitive Models Of Defense Behaviors In Hosts Of Brood Parasites, Thomas J. Manna

Dissertations, Theses, and Capstone Projects

Social parasites exploit the behavioral repertoire of their hosts for their own benefit, thereby reducing host reproductive success. Whether and how hosts respond to prevent, reduce, or eliminate the costs of parasitism requires the characterization of host cognitive algorithms in response to parasites. In this dissertation, I review the suite of the defense behaviors and decision rules of hosts targeted by avian and insect brood parasites, and present new experimental data on the detection of parasitism through the visual system of focal host species. In Chapter 1, I review extensive data already accumulated to isolate the cognitive mechanisms used by …

Amphibian And Reptile Community Responses To Forest And Riparian Disturbance, Jacquelyn Christine Guzy

Graduate Theses and Dissertations

Riparian zones are transitional, semi-terrestrial areas regularly influenced by freshwater. These areas serve as dispersal corridors for many animal and plant species and ultimately function as important reservoirs of biodiversity in altered landscapes. While much of the riparian habitat in the United States has been affected by anthropogenic activities, management actions may mitigate potentially negative influences of these activities. For example, Streamside Management Zones (i.e., riparian buffers; SMZs) are commonly implemented within managed forests to protect water quality, but may also provide habitat for riparian-associated wildlife. Yet, little research has rigorously addressed the value of SMZs for wildlife, particularly cryptic …

Cool And Warm Season Climate Signals In Tree Rings From North America, Max Carl Arne Torbenson

Graduate Theses and Dissertations

Earlywood (EW) and latewood (LW) ring-width chronologies have become an increasingly important proxy in paleoclimate reconstructions. These subannual variables can provide estimates of past hydroclimate variability for seasonal windows that total ring-widths cannot resolve. The strength of the relationship between EW and LW series may influence what type of paleoclimate information is embedded within the tree-ring series. High correlations (> 0.70) between EW and LW are recorded for much of the continent but the magnitude of correlation varies greatly across space and species boundaries. Using four LW chronologies from shortleaf pine, the North American conifer species displaying the lowest EW-LW …

Do Enallagma Exsulans From Streams And Lakes Show Patterns Of Divergence?, Savannah Rae Graham

Graduate Theses and Dissertations

Divergent selection across heterogenous environments could lead to adaptive divergence in populations resulting in potential local adaption. These populations have phenotypic differences that are fitness related and make native individuals more fit than non-native individuals. My research focuses on a species of damselfly, Enallagma exsulans, to explore local adaptation and morphological differences as a result of divergent selection or plasticity. My first study explored potential local adaptation of wild caught stream and lake E. exsulans using a reciprocal transplant design, a classic approach for this objective. The stream and lake sites chosen were on a small spatial scale allowing for …

Biogeography Of Endemic Dragonflies Of The Ozark-Ouachita Interior Highlands, Wade Alexander Boys

Graduate Theses and Dissertations

A common pattern across many taxonomic groups is that relatively few species are widespread while the majority are restricted in their geographic ranges. Such species distributions are used to inform conservation status, which poses unique challenges for rare or cryptic species. Further, priority status is often designated within geopolitical boundaries, which may include only a portion of a species range. This, coupled with lack of distributional data, has resulted in species being designated as apparently rare throughout some portions of their range, which may not accurately reflect their overall conservation need. The Interior Highlands region of the central United States …

Phylogenomics And Geometric Morphometrics Define Species Flocks Of Snowtrout (Teleostei: Schizothorax) In The Central Himalayas, Binod Regmi

Graduate Theses and Dissertations

Schizothorax (Snowtrout) is a genus of medium-sized minnows (Cypriniformes) inhabiting glacier-fed streams, rivers, and lakes in the Himalayas. There are more than 30 species of Schizothorax across the region. The speciation and diversity of the Snowtrout in the vast hinterlands of the Himalayan Region has not been fully explored. Three species in Lake Rara, Western Nepal are considered a species flock, comprising endemic ecotypes that are morphologically differentiated and reproductively isolated.

My dissertation research examined the diversity of Schizothorax in the Central Himalayan region and evolutionary relationships among species distributed in the Tibet, Central and Southeast Asia. Chapter I describes …

Effects Of Experimental Forest Management On Avian Communities In The Missouri Ozarks, David R. Hollie

Electronic Theses & Dissertations

In recent decades, concern for migratory birds has stimulated research assessing the relationships between forest management and bird populations. The Missouri Ozark Forest Ecosystem Project (MOFEP) is a long-term, landscape-scale experiment designed to examine the effects of even-aged (i.e. clearcutting), uneven-aged (i.e. selection cutting), and no harvest forest management on ecosystem level processes. The management systems were randomly assigned to three sites each (mean area = 400 ha) under a 100-year rotation with a 15-year re-entry period.

In the first chapter, we used non-metric multidimensional scaling and generalized linear mixed models to investigate the effects of silvicultural treatment and year-since-harvest …

Play Behavior And The Development Of Boldness And Caution In Juvenile Ground Squirrels, Madelene Shehan

Creative Activity and Research Day - CARD

We evaluated the relationship between play behavior and the development of boldness in juvenile Belding’s ground squirrels (Urocitellus beldingi). We observed the play behavior of juvenile U. beldingi, and conducted boldness tests at the beginning and toward the end of the developmental period during which play primarily occurs. Behavioral tests consisted of a researcher acting as an intruder, walking toward a juvenile, and noting the distance between the squirrel and intruder at which the juvenile first became aware of the intruder, and the distance at which the squirrel fled. The age of mothers was a significant predictor …

Ecomorphological Variation Among Redbreast Sunfish Populations Of The South-Eastern United States, Grayson Ariel Walker

Honors College Theses

Individual populations of a species will morphologically adapt to their surrounding environment. It has been noted in the past that when species are placed under similar environmental conditions, they will evolve similar morphological structures and shape variation to overcome those obstacles. Redbreast sunfish (Lepomis auritus) were sampled from three different ecoregions (mountainous, Piedmont, and coastal plain) of 4 different isolated river basins in the southeastern North America. It was hypothesized that across basins, populations would show convergent morphological adaptations to mountain, piedmont, and coastal plain condition. I indexed using site elevation as an independent variable, serving as a …

Presence And Distribution Of Leptodactylus Guianensis Heyer And De Sa, 2011 In Colombia: Comparisons With Other Species In The L. Latrans Group., Mariela Osorno Muñoz, Doris L. Gutiérrez-Lamus, Rafael O. De Sá

Biology Faculty Publications

Leptodactylus guianensis is reported for the first time for Colombia along with a distributional map of the species. The species is the fifth species of the L. latransspecies group documented in the country. Males possess a single, conical and slightly chisel-shaped thumb spine; only three species in the group have a single thumb spine. In collections, specimens of L. guianensis are misidentified as L. macrosternum, L. latrans or L. bolivianus. We provide morphological, colouration and habitat descriptions for where the species occurs in Colombia.

Multi-Trophic Species Interactions Shape Seascape-Scale Coral Reef Vegetation Patterns, Elizabeth M. P. Madin, Kristin Precoda, Alastair R. Harborne, Trisha B. Atwood, Chris M. Roelfsema, Osmar J. Luiz

Ecology Center Publications

How species interactions shape habitat structure is a longstanding question in ecology. A curious phenomenon reflecting ecological self-organization around reef habitat structures exists on coral reefs: large-scale (hundreds to hundreds of thousands of m2) halo-like patterns surrounding patch reefs, i.e., individual coral reefs that are often separated by seagrass or macroalgal meadows. These “halos,” long known to occur in various locations worldwide, reflect a distinct band of unvegetated sediments surrounding coral patch reefs. However, the full suite of mechanisms controlling them have never been rigorously explored, perhaps due to the common assumption dating back nearly 50 years that they arise …

Marine Reserves Shape Seascapes On Scales Visible From Space, Elizabeth M. P. Madin, Alastair R. Harborne, Aaron M. T. Harmer, Osmar J. Luiz, Trisha Brooke Atwood, Brian J. Sullivan, Joshua S. Madin

Watershed Sciences Faculty Publications

Marine reserves can effectively restore harvested populations, and ‘mega-reserves’ increasingly protect large tracts of ocean. However, no method exists of monitoring ecological responses at this large scale. Herbivory is a key mechanism structuring ecosystems, and this consumer–resource interaction's strength on coral reefs can indicate ecosystem health. We screened 1372, and measured features of 214, reefs throughout Australia's Great Barrier Reef using high-resolution satellite imagery, combined with remote underwater videography and assays on a subset, to quantify the prevalence, size and potential causes of ‘grazing halos’. Halos are known to be seascape-scale footprints of herbivory and other ecological interactions. Here we …

Spatial And Temporal Distribution Of The Forensically Significant Blow Flies Of Los Angeles County, California, United States (Diptera: Calliphoridae), Royce T. Cumming

School of Natural Resources: Dissertations, Theses, and Student Research

Forensic entomology although not a commonly used discipline in the forensic sciences, does have its niche and when used by investigators is respected in crinimolegal investigations (Greenberg and Kunich, 2005). With many species of forensically significant insects being regionally specific, it is often difficult for forensic entomologists to as confidently translate regionally specific studies across drastically differing geographic regions (Brundage, et al., 2011).

The purpose of this study is to help create a better temporal and geographic distributional understanding of the blow fly species present in Los Angeles County, California, United States. Twenty-five locations from four ecoregions (coastal mountains, urban, …

Abiotic And Landscape Factors Constrain Restoration Outcomes Across Spatial Scales Of A Widespread Invasive Plant, Christine B. Rohal, Chad R. Cranney, Karin M. Kettenring

Ecology Center Publications

The natural recolonization of native plant communities following invasive species management is notoriously challenging to predict, since outcomes can be contingent on a variety of factors including management decisions, abiotic factors, and landscape setting. The spatial scale at which the treatment is applied can also impact management outcomes, potentially influencing plant assembly processes and treatment success. Understanding the relative importance of each of these factors for plant community assembly can help managers prioritize patches where specific treatments are likely to be most successful. Here, using effects size analyses, we evaluate plant community responses following four invasive Phragmites australis management treatments …

Phenological Mismatch Between Season Advancement And Migration Timing Alters Arctic Plant Traits, Ryan T. Choi, Karen H. Beard, A. Joshua Leffler, Katharine C. Kelsey, Joel A. Schmutz, Jeffrey M. Welker

Ecology Center Publications

1. Climate change is creating phenological mismatches between herbivores and their plant resources throughout the Arctic. While advancing growing seasons and changing arrival times of migratory herbivores can have consequences for herbivores and forage quality, developing mismatches could also influence other traits of plants, such as above‐ and below‐ground biomass and the type of reproduction, that are often not investigated.
2. In coastal western Alaska, we conducted a 3‐year factorial experiment that simulated scenarios of phenological mismatch by manipulating the start of the growing season (3 weeks early and ambient) and grazing times (3 weeks early, typical, 3 weeks late, or no‐grazing) …