Digital Commons Network^™

Leveraging Eco-Evolutionary Models For Gene Drive Risk Assessment, Matthew A. Combs, Andrew J. Golnar, Justin M. Overcash, Alun L. Lloyd, Keith R. Hayes, David A. O'Brochta, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Engineered gene drives create potential for both widespread benefits and irreversible harms to ecosystems. CRISPR-based systems of allelic conversion have rapidly accelerated gene drive research across diverse taxa, putting field trials and their necessary risk assessments on the horizon. Dynamic processbased models provide flexible quantitative platforms to predict gene drive outcomes in the context of system-specific ecological and evolutionary features. Here, we synthesize gene drive dynamic modeling studies to highlight research trends, knowledge gaps, and emergent principles, organized around their genetic, demographic, spatial, environmental, and implementation features. We identify the phenomena that most significantly influence model predictions, discuss limitations of …

Tropical Understory And Canopy Twig Ants (Pseudomyrmex): Natural History, Sensory Homing, And Neuroecology., Daniella Prince

Electronic Theses and Dissertations

In this dissertation, I examined the behavior of foraging twig ants, explored the sensory profile of their homing behavior, and investigated the role of habitat use in shaping the sensory neurobiology of species within the genus Pseudomyrmex (Hymenoptera: Formicidae). In chapter one, I reviewed the ecology of Pseudomyrmex, and introduced the focal species, P. boopis, a neotropical understory-dwelling twig ant. In chapter two, I described the natural history of P. boopis on Barro Colorado Island, Panama—specifically, their nesting habits, activity rhythm, and foraging behavior on understory surfaces. Pseudomyrmex boopis colonies were diurnal and nested in dead twigs in …

Western Pearlshell (Margaritifera Falcata) Extirpation In The Smith River, Montana, With A Possible Link To Warming Water Temperatures, David M. Stagliano

Western North American Naturalist

Western pearlshell (Margaritifera falcata) populations are in decline across the species’ range in western North America. In 2008, Montana categorized the western pearlshell as an imperiled species of concern (S2) based on reduced detections at historically occupied sites and few viable populations. Between 2004 and 2014, we surveyed 24 Smith River reaches (61 total sites in the watershed) for the presence of western pearlshell populations. Despite historical and anecdotal descriptions of abundant western pearlshell in the Smith River, intensive structured surveys between 2004 and 2007 documented only 4 sections with low-density, nonviable western pearlshell populations (<10 individuals, large size classes [average total length = 70 mm], with no signs of recruitment). In 2014, we revisited these occupied sites to repeat surveys (expending significantly more search time) and observed no live individuals. This was surprising given that, although those populations would certainly die out without recruitment, older individuals can oftentimes persist for decades. Therefore, we consider the western pearlshell mussel extirpated from the Smith River watershed. We reviewed long-term USGS gage discharge and temperature data near the western pearlshell populations to evaluate the potential causal factors for, and timing of, the extirpation. From 3 July to 3 August 2007, water temperatures were at or above the thermal stress levels of the western pearlshell (>25 °C, …

Fishing Out Nutrients: The Spatiotemporal And Ecological Dynamics Of Fishery-Based Nutrient Extraction, Adrián A. González Ortiz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Marine fisheries are one of the most impactful human activities on the planet. Since the 1950s, marine fisheries have removed billions of metric tons of marine biomass leading to substantial declines in many fish populations. Among their impacts, we have begun to investigate the role of fisheries in disrupting marine nutrient cycles. Specifically, removing biomass can change nutrient cycles by reducing the amount of nutrients stored within animal biomass.

No studies have investigated the large-scale geographical and ecological contexts of nutrient removal by fisheries over a large timescale. For my thesis, we compiled data on fishery-targeted organisms' carbon, nitrogen, and …

Sequestered Sequences: A Bioinformatic Approach To The Forgotten Genome, Dylan Barth

UNLV Theses, Dissertations, Professional Papers, and Capstones

As high throughput sequencing generates ever increasing amounts of genetic and epigenetic data new lines of inquiry open up in the field of genomic research. In this thesis, we discuss three ways in which we can utilize public databases of next generation genomic data in order to study areas of the genome previously ignored by traditional approaches. These include the study of linker regions between domains of proteins, indirect enhancers that do not strongly contact promoters of genes they regulate, and transposon-derived enhancer elements. The work uncovers many exceptions to known biological principles, and adds nuance to our understanding of …

Emergence, Evolution, And Outcomes Of Community-Based Conservation Behaviors In Coastal Systems, Matthew C. Clark

Boise State University Theses and Dissertations

This body of work leverages a variety of quantitative and theoretical approaches to advance our understanding of why individuals adopt community-based conservation behaviors, the impacts those decisions have on natural resources and human wellbeing, and how these insights can be used for practical conservation planning. The first chapter makes a theoretical contribution by fitting data produced from a stylized, agent-based simulation of conservation adoption over time with a set of probabilistic differential equations derived from the theory of diffusion of innovations and cultural evolutionary theory broadly. We use these methods to demonstrate that such a statistical approach can provide accurate …

Informing Management Strategy For The Relict Leopard Frog (Rana Onca): Insights Into Breeding Biology And An Attempt To Improve Augmentation Success Through Pre-Exposure And Clearance Of An Emerging Amphibian Pathogen, Rebeca Rivera

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Relict Leopard Frog, Rana onca, is a species of conservation concern that suffered a decline sometime during the 20th century. Even after two decades of intensive management, the species currently only occupies 20 spring sites in southern Nevada and northwestern Arizona. The causes for the historical decline are mostly speculative, but relate to habitat loss, introduced predators, and emergent disease. Since 2001, R. onca has been under an intensive conservationprogram managed by a multiagency conservation team. There are several objectives specified in the program including the need to investigate the biology of the species and incorporate findings into …

Precipitation And Soil Properties Determine Long-Term Consequences Of Disturbance And Invasion In Drylands, Tyson Terry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Disturbance and invasive species have dramatic effects on desert plant communities, often resulting in degradation or shifts to alternative plant communities. Climate and soil properties determine water availability to plants, and have been thought to drive patterns of recovery following disturbance and potential for invasion.

In chapter II we used a combination of natural gas pipelines and satellite imagery to understand how recovery from a uniform disturbance differs across precipitation and soil gradients. We used a recovery ratio (disturbed/undisturbed) of pipeline pixels and their undisturbed nearest neighbor pixel to quantify recovery in a comparable way across precipitation gradients. We found …

Opening The Black Box: Soil Microbial Communities In Field-Based Plant-Soil Feedback Experiments, Julia Kate Aaronson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plant-soil feedback is a process through which plants modify the properties of their associated soils, affecting their growth. PSF can play a key role in regulating plant growth and communities including altering plant invasion, rarity, and abundance. However, our understanding of the soil organisms that drive these plant growth responses is limited. Most studies treat soils as a ‘black box’ and do little to reveal which specific microbes or microbial communities may be responsible. This chapter examines two recent large PSF field experiments conducted in Minnesota, USA, and Jena, Germany. These experiments revealed that plants altered their soils, changing subsequent …

A Statewide Evaluation Of Fuel Treatment Effectiveness In Altering Wildfire Outcomes On Public Lands In Utah, Jamela Charmaine Thompson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fuel treatments are land management activities that reduce living and dead flammable materials on the landscape to mitigate undesirable wildfire behavior and effects. Common treatments in the western United States include mechanical methods such as thinning and mastication, prescribed burns, and chemical methods, such as herbicide application. Treatments usually have multiple objectives, including reducing fire intensity, protecting natural and cultural resources, slowing or disrupting a potential future fire’s path, supporting ecosystem health, and reestablishing low to mid severity fire cycles in ecosystems. Although treatments can potentially modify fire behavior and ecological health, they generally cannot prevent fires from igniting, eliminate …

Evaluating Beaver Translocation Methods For Desert River Restoration, Christine E. Sandbach

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wildlife translocation, or moving wild animals from their original home to a new location, is a common conservation practice; however, translocation programs have variable success rates. Beaver translocation is often used in stream restoration projects due to beavers’ role as ecosystem engineers—beavers enhance riparian habitat by building dams that hold water and create more diverse channels. Beaver translocation success is often limited by high mortality and long distance movement after release, and improvement in translocation methods is needed. My objective was to evaluate two methods of improving beaver translocation success in a degraded desert river in east-central Utah: beaver dam …

Mountain Lion (Puma Concolor) And Feral Horse (Equus Ferus) Interactions: Examining The Influence Of A Non-Native Ungulate On Predator Behavior In A Semi-Arid Environment, Peter C. Iacono

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A non-native is a species that evolved in one ecosystem and has established within another. Non-native species can thrive in new ecosystems as they can spread quickly, outcompete and replace native species, and disrupt food webs. Domestic horses were brought to North America by Europeans in 1493. They are now found in 11 states across the western United States. Feral horses can negatively impact vegetation, endangered species habitat, compete with native species, and be important prey for mountain lions under certain conditions. But do feral horses affect the food web? Feral horses are managed by large removals to reduce the …

Influence Of Abiotic Drivers And Plant Community Interactions On Bald Cypress (Taxodium Distichum) Seedlings: Implications For Restoration, Victoria Ellis

Biological Sciences Theses & Dissertations

Forested freshwater wetlands are valuable ecosystems that provide habitat for numerous species, sequester carbon, and act as sinks for excess water and nutrients. Historically, these ecosystems have been heavily degraded by anthropogenic activities leading to loss of ecosystem services and a desire to restore freshwater forested wetland habitat. Thus, science-backed approaches for the restoration of freshwater forested wetlands are necessary to ensure restoration goals are met. This body of research employed the Stress Gradient Hypothesis to test whether a multi-species planting approach using Juncus effusus (L.) (soft rush) could facilitate the survival of Taxodium distichum (L.) Rich. (bald cypress) seedlings …

An Ecological Survey Of East Texas Salamanders Across The Camp Tyler Outdoor Field School In Smith County, Texas, Justin C. Hunt

Biology Theses

Amphibians are a unique class of organisms with a very long and storied evolutionary history of survival. Many modern amphibian clades occupy several vital ecological roles within their native freshwater environments. One of these roles, typically includes functioning as an ecological indicator species, whereby the presence of stable and diverse populations of many amphibian species, including salamanders, within a freshwater ecosystem have long been considered ecological indicators of good habitat quality and stable ecosystem health. Similarly, salamanders also function as important members of their local food webs and act as valuable mediators of complex trophic hierarchies to facilitate nutrient cycling …

Monitoring The Effects Of Poultry Waste On Fishes And Macroinvertebrates In The Sabine River, Karley R. Parker

Biology Theses

Freshwater is a vital resource that provides life and sustainability for almost all organisms on Earth. It is important to maintain its health and protect it from emerging pollutants that pose a threat to the organisms that use it. Pollution continues to threaten the well-being of the environment’s freshwater sources all around the world that could lead to damaging effects in the future. The Sabine River is a major freshwater resource in the east Texas and western Louisiana areas that provides a habitat for thousands of organisms as well as other domestic uses for humans. In 2019, a waste discharge …

Commercial Fishing Identification Guide 2023, Department Of Primary Industries And Regional Development, Western Australia

Fisheries Occasional Publications

Throughout this guide you will see all or some of the marine bioregion symbols with each fish illustration, indicating where the species is most likely to occur.

This guide has been developed to help you identify the more common species in Western Australia you may encounter. The purpose of this guide is to enhance consistent and accurate species identification.

If you are unsure about a particular species (or if it is not in this guide), please discuss it with a representative of the Department of Primary Industries and Regional Development, Western Australia.

Historical Trends Of Aquatic Invasive Species Introduction And Establishment In Illinois, Usa, Carter S. Cranberg, Reuben Keller

School of Environmental Sustainability: Faculty Publications and Other Works

Tracking the introduction and establishment of aquatic invasive species (AIS) is important for monitoring the biological and economic health of freshwater environments. The state of Illinois (USA) is a critical region for understanding the threats of AIS because it possesses the only continuous aquatic habitat connecting the Laurentian Great Lakes and Mississippi River Basins. In this study, we update a previous effort to catalogue and evaluate historical AIS records from Illinois. Our updated database shows that there are now at least 92 nonindigenous aquatic species established in Illinois and a further 51 have been recorded as introduced but not established. …

Beef Color And Tenderness Response To Production Systems Utilizing Additive Combinations Of Growth-Promotant Technologies, Megan J. Webb, Janna J. Block, John R. Jaeger, R. Funston, Michael G. Gonda, Keith R. Underwood, Judson K. Grubbs, Kenneth C. Olson, Amanda D. Blair

West Central Research and Extension Center, North Platte

The objective of this study was to compare the influence of beef production systems using additive combinations of growth-promotant technologies on meat quality. Steer calves (n = 120) were assigned to 1 of 4 treatments: 1) no technology (NT; control), 2) antibiotic treated (ANT; NT plus therapeutic antibiotics, monensin, and tylosin), 3) implant treated (IMP; ANT plus a series of three implants), and 4) beta-agonist treated (BA; IMP plus ractopamine-HCl). Muscle biopsy samples from the longissimus lumborum were extracted from a subset (n = 4 per treatment) of steers to evaluate expression of calpain-1, calpain-2, and calpastatin using …

Annotation Of Non-Model Species’ Genomes, Taiya Jarva

Master's Theses

The innovations in high throughput sequencing technologies in recent decades has allowed unprecedented examination and characterization of the genetic make-up of both model and non-model species, which has led to a surge in the use of genomics in fields which were previously considered unfeasible. These advances have greatly expanded the realm of possibilities in the fields of ecology and conservation. It is now possible to the identification of large cohorts of genetic markers, including single nucleotide polymorphisms (SNPs) and larger structural variants, as well as signatures of selection and local adaptation. Markers can be used to identify species, define population …

Pronghorn Survival And Resource Selection In Western Nebraska's Agriculturally Dominated Landscape, Katie Piecora

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

Nebraska’s pronghorn population has been stable over the last decade, yet their presence on the landscape remains a contentious subject amongst private landowners. Conversion of grassland for crop production and increased anthropogenic activity has drastically altered pronghorn behavior throughout their current range, however basic ecology and resource use by pronghorn in Nebraska remains poorly understood. Establishing baseline population metrics and seasonal patterns of resource use for this population at the eastern periphery of the species range is critical to guide management actions. We deployed GPS collars on 110 adult pronghorn to quantify survival, mortality risk, and seasonal resource selection in …

Neutral Theory And Beyond: A Systematic Review Of Molecular Evolution Education, Desiree Forsythe, Jeremy L. Hsu

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Molecular evolution—including the neutral theory of molecular evolution—is a major sub-discipline of evolution and is widely taught in undergraduate evolution courses. However, despite its ubiquity, there have not been any previous attempts to compile and review the molecular evolution education literature. Here, we draw upon the framework proposed in a past literature review examining the broader evolution education landscape to conduct a literature review of papers related to molecular evolution education, classifying the contributions of such papers to evolution pedagogy as well as evolution education research. We find that there remains very limited coverage of molecular evolution in the education …

Exploring The Relationships Between Mammalian Functional Trait Distributions And Regional Biomes, With Application To Miocene Paleoecology, Devra Hock-Reid

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Paleoecology relies on understanding relationships between modern animals and their environment. Animals are adapted to niches in their environments, and those physical adaptations, or functional traits, are utilized as proxies to interpret aspects of paleo-ecosystems. Much is known about individual functional traits in extant mammals and their relationship to the environment. Less is known about how multiple functional traits across a community can be utilized for paleoecological interpretations. I develop models utilizing traits in mammalian communities at the biome level. For Chapter 1, I build a model for North American regional biomes using mammalian trait frequencies. I quantify changes in …

2023 Coordinated Spring Survey Of Mid-Continent Sandhill Cranes, Terry Liddick

United States Fish and Wildlife Service: Publications

The aerial transect portion of the coordinated spring survey of mid-continent Sandhill cranes was conducted on March 22, 2023 in Nebraska’s Central Platte and North Platte River valleys (United States). The 2023 photo-corrected aerial estimate is 1,259,000 birds. Outside the traditional aerial transect portion, observers conducted ground surveys during the period March 20–22. From these regions, observers in the Official Survey Area (OSA) of Nebraska, Kansas, Texas, Oklahoma, and Wyoming reported an additional 25,363 cranes. The 2023 total estimate (1,284,500) increased 43.1% from 2022. The current three-year average (2021–2023 with no photo correction in 2021), based on photo corrected estimates …

Variable Synchrony In Insect Outbreak Cycling Across A Forest Landscape Gradient: Multi-Scale Evidence From Trembling Aspen In Alberta, Barry J. Cooke, Jens Roland

Aspen Bibliography

Using multi-scale trembling aspen tree-ring width data from Alberta, we show that scaling has a profound influence on dendroecological inferencing. At all scales of sampling, there is a significant climatological signal whose strength is nevertheless superseded by the pervasive effect of insect herbivory. At the smallest spatial scale, 20 km x 20 km, we demonstrate a quasi-periodic pattern of sharp growth reductions and the existence of negative spatial correlations among successive outbreaks. At the intermediate spatial scale of 20 km x 80 km, we show that the period 1930-1963 was marked by extremely low correlations in aspen ring widths, with …

Phylogeny And Taxonomy Of Genus Physaria In North America, Binoshi Hettihewa

Theses

Physaria is a genus of ~108 species belonging to family Brassicaceae that is predominantly distributed in Western North America, but one species occurs in Arctic Russia and Northern Canada and several species occur in South America. Regardless of the vast number of species in the genus, the genus lacks a well-resolved phylogeny representing many taxa, partially because phylogeny reconstruction is complicated by the fact that many species of Physaria vary in chromosome numbers and ploidy levels. In chapter 1, we review how polyploids are formed and become established and summarize what is known about variation in chromosome number and ploidy …

Testing The Urban Dulling Hypothesis In An Iridescent Passerine Bird, Joanna Gresham

Master of Science in Integrative Biology Theses

Urbanization has brought grave consequences that lead to declines in many species; however, some species thrive in urban ecosystems. This allows us the opportunity to study evolution in real time, as species adapt and change in a new setting. Novel urban ecosystems have led to phenotypic divergence between urban and rural populations. There is a rich body of literature on how songbirds are affected by urbanization, however divergent signaling behaviors are less well understood. Urban color homogenization is well-documented in carotenoid-colored species. However, iridescent plumage is understudied in general, and little is understood about how environmental changes shape iridescent plumage. …

Phylogeographic History Of The Leaf-Eared Mouse, Phyllotis Xanthopygus Complex, Tabitha R. Mcfarland

Biology ETDs

Museum collections provide essential biodiversity sampling needed to understand the species limits, phylogeny, and biogeographic history of mammals, all key features of the foundation for comparative analyses in ecology and evolution. We add to this framework a diverse assemblage of species of leaf-eared mice (genus Phyllotis) in South America and then focus on the Phyllotis xanthopygus complex by combining available mitochondrial sequence (cytochrome b; cytb) data (351 GenBank samples) with 52 newly sequenced museum samples from the northern extent of this complex’s range (51 from Bolivia and 1 from northern Chile) to reconstruct evolutionary relationships using maximum …

Assessing Ecological Relationships Among Late Triassic Vertebrates In Petrified Forest National Park, Alexandra Davis Apgar

Earth and Planetary Sciences ETDs

The complex vertebrate ecosystem of the Late Triassic has not yet been fully understood, largely due to oversimplification of hypothesized trophic hierarchies and limited preservation of direct evidence of faunal interaction. Paleocommunity reconstruction attempts can also fall victim to taphonomic biases, time-averaging inaccuracies, and non-analogue paleoecologies. Utilizing a combination of PAIRS analysis and NMDS ordination, we highlight vertebrate faunal relationships within the Adamanian and Revueltian faunachrons of Petrified Forest National Park, assess the likelihood that these patterns have ecological rather than preservational drivers, and examine how these potential interactions may have been impacted by the Adamanian-Revueltian turnover event. We are …

Mitogenomes Revealed The History Of Bison Colonization Of Northern Plains After The Last Glacial Maximum, Igor V. Ovtchinnikov, Blake Mccann

Biology Faculty Publications

American bison demonstrated differential patterns of extinction, survival, and expansion since the terminal Pleistocene. We determined population dynamics of the Northern Great Plains bison using 40 mitochondrial genomes from radiocarbon dated remains with the age ranging from 12,226 to 167 calibrated years before present. Population dynamics correlated with environmental and anthropogenic factors and was characterized by three primary periods: terminal Pleistocene population growth starting 14,000 years ago, mid Holocene demographic stability between 6700 and 2700 years ago, and late Holocene population decline in the last 2700 years. Most diversification of mtDNA haplotypes occurred in the early Holocene when bison colonized …

Wave Attenuation Through Mangrove Forest Using Lidar Representation, Elizabeth Bogan

LSU Master's Theses

Mangrove forests can be found along the world’s intertidal tropical and sub-tropical coastlines. These forested wetlands provide many ecosystem services, including supporting coastal food chains, trapping sediment, and shoreline stabilization. Mangroves are also known for flood damage mitigation by dissipating waves and surge during flooding events. Thus, coastal communities declare a vested interest in the performance of the forest to mitigate flood damage. Physical models using artificial mangrove structures have shown that red mangrove-dominated fringe forests can protect built infrastructure by reducing wave height due to increased drag. One way to estimate the contribution of red mangrove (Rhizophora mangle) prop …