Life Sciences Commons^™

Compsobuthus Hadeki Sp. N. From Iraq (Scorpiones: Buthidae), František Kovařík, František Šťáhlavský

Euscorpius

A new species, Compsobuthus hadeki sp. n. from Iraq is described and fully complemented with color photographs and compared with morphologically the most similar species, C. matthiesseni (Birula, 1905). The two species can be unequivocally separated by the following morphological features: in C. hadeki sp. n., movable finger of pedipalp bears 9 rows of granules; telson with aculeus shorter than vesicle, and metasoma III with 10 carinae. Cytogenetic analysis was performed, revealing a diploid chromosome count of 22 in C. hadeki sp. n.

Dr. Jonathan Velotta Faculty Spotlight, Katelyn Trimble

DU Undergraduate Research Journal Archive

An interview with Dr. Jonathan Velotta of the University of Denver's Department of Biological Sciences.

Phenotypic Plasticity In A Stochastic Environment: Modeling Three Phenotypes And Environments, Sarah P. Williams, Marissa C. K. Douglas, Stephen C. Adolph

Spora: A Journal of Biomathematics

Phenotypically plastic organisms are capable of adjusting their phenotypes in a variable environment. Padilla and Adolph (1996) modeled this process and included a time lag between detection of an environmental change and the responding change in phenotype. We extended the Padilla and Adolph model from two to three discrete environments and phenotypes and analyzed the model computationally. Our results were consistent with their findings: the fitness advantage of phenotypic plasticity is higher when (1) the lag time is shorter, (2) the probability of environmental change is lower, and (3) the fitness disadvantage of mismatched phenotypes and environments is more severe. …

The Effect Of The Chemical And Microbiological Structure Of Biofilms On The Growth Of Oyster Spats In The Hudson River, June L. Rahman

Student Theses and Dissertations

Eastern oysters (Crassostrea virginica) are sessile suspension feeding bivalves that improve water quality through filtration and reef formation, making them crucial to the health oftheir native ecosystems. Establishing oyster habitats is a priority in Hudson River restoration efforts following significant population declines due to over harvesting, habitat loss, and pollution. Oyster spat production and attachment are influenced by biofilms; however, it is not well known how biofilm properties, such as bacterial taxonomic composition and EPS content, affect oyster larval attachment in the Hudson River. We hypothesized that intertidal surfaces,which are more exposed sunlight, would develop photosynthetic biofilms that enhance oyster …

Popgenhelpr: An R Package To Streamline And Facilitate Informed Population Genomic Analyses And Visualization Of Genetic Ancestry, Diversity And Differentiation, Keaka Farleigh, Mason O. Murphy, Christopher Marie Blair, Tereza Jezkova

Publications and Research

Analysing large population genomic datasets requires an interdisciplinary skillset. Beyond a knowledge base in genetics and population biology, population genomic analyses involve computer science and statistics, representing a barrier for researchers without experience in those fields. PopGenHelpR seeks to lower this barrier by enabling researchers to perform population genomic analyses and generate near-publication quality figures in a streamlined and informed fashion. PopGenHelpR allows users to estimate genetic diversity within populations as well as differentiation among populations and individuals from single nucleotide polymorphism data. PopGenHelpR includes commonly used measures such as observed heterozygosity and FST. PopGenHelpR also provides five …

Improving Human-Wildlife Coexistence: An Ecological And Educational Approach To Rewilding Grizzly Bears (Ursus Arctos Horribilis) In California, Amanda C. D. Rosales

Master's Projects and Capstones

Megafauna extinction during the Holocene has been both caused and amplified by climatic changes and human influence. By the last half century, large carnivores were diminished in Europe and the United States, but policies increasingly addressed species decline and their territories expanded. This research examined large carnivore rewilding across the European Union and United States, specifically for rewilding brown bears, Ursus arctos, in historic habitat. Next, case studies for the health status of climate-impacted whitebark pine, Pinus albicaulis, a high energy food for bears, was assessed. Ultimately, research case studies, human perspective surveys, and the California Department of Education content …

Structure And Diversity Of Play Behavior In Juvenile Belding's Ground Squirrels, Paul O'Driscoll Ii

Master's Theses

Play behavior is ubiquitous among juvenile mammals and can promote motor, social, and cognitive development, providing multiple adaptive benefits to young animals in some cases. The structure of play can be linked to the benefits it confers on individuals. I evaluated the structure of play in juvenile Belding’s ground squirrels (Urocitellus beldingi), a species for which multiple adaptive benefits of play have been identified. I compared juvenile play in U. beldingi to adult sexual and aggressive behavior to determine and classify similarities between juvenile play and adult behavior. I evaluated diversity in the behaviors expressed during play interactions and diversity …

Investigating Cryptic Diversity In The Hawaiian Endemic Plant, Psychotria Mariniana (Rubiaceae), Uyen Thi Hoang Nguyen

Master's Theses

Islands, with their isolation and steep environmental gradients, serve as natural laboratories for studying speciation. Molecular phylogenetic and population genetic methods utilizing Next-Generation Sequencing (NGS) have revolutionized our ability to document patterns of genetic divergence and diversity. Cryptic diversity, genetically distinct populations that were previously unrecognized as unique, and cryptic speciation, where divergent genetic populations may be deserving of status as unique species, have been observed in many taxa. The Hawaiian Islands provide an ideal setting for studying divergence and speciation due to their extreme isolation, known ages, and volcanic origin. Previous work has investigated the evolutionary relationships of the …

Watershed Amendments: Assembling New Pervious Ground From Landscape Waste, Sophie Kaplan-Bucciarelli

Masters Theses

In Providence, Rhode Island, much of the downtown area is built over a vast historic tidal estuary. Though we no longer see the salt marshes, wooded bluffs, or meadows that once characterized this landscape, we recognize their absence in contemporary crises of urban heat, flooding, polluted soils and stormwater runoff, and habitat loss. These conditions are particularly acute along the city’s industrialized river corridors, where vacant lots and parking areas sit idle, their history paved over and potential constrained by limited imagination and resources.

These lots - already experiments in fill and land building after centuries of disturbance - can …

Insects And Arthropods And Their Role In Human Society, Emily Marie Perez-Medina

Whittier Scholars Program

With brightly colored exoskeletons, an excess of both eyes and legs, and seemingly  unpredictable behaviors, insects and arthropods come across as unusual and strange to general audiences. For this reason, they are often classified as “gross,” “ugly,” or “scary,” antagonists  in popular culture. What is not recognized when being represented to the masses is how much human society depends on their presence, and how a world without insects would be a world without most things humans know and love. In order to help reduce the stigma of these tiny, yet mighty creatures, this project serves as a call to action …

Somatic Prosthetics For Planetary Resonance, Disha Dharesh Kumar R

Masters Theses

This thesis investigates how industrial design can transcend extractive technological paradigms in favor of relational interfaces that foster planetary attunement. Framing the climate crisis as a 'crisis of imagination', the research challenges the Western bifurcation of nature and culture by drawing on Indic cosmologies- which recognize stones, plants, and ecosystems as conscious at different levels and participants in a shared cosmic field. By synthesizing research in Biosemiotics, Quantum Information Pansycishm, and Neuroscience, the project redefines intelligence as a distributed, more-than-human phenomenon.

The research materializes as a speculative design artifact: a device that functions as a somatic prosthetic for planetary resonance. …

Cyanogenesis Variation In White Clover Is Decoupled From Regional Climate And Human Footprint Across A Longitudinal Gradient, Philips O. Akinwole, Yangjie Tan, Victor L. Alfonso

Biology Faculty publications

Latitudinal clines in adaptive traits are well documented, yet how such patterns translate across longitudinal gradients, where climatic variation is reduced, remains poorly understood. We investigated spatial variation in hydrogen cyanide (HCN) - a well-characterized anti-herbivore defense polymorphism governed by two independently segregating loci (Ac and Li), in white clover (Trifolium repens) across nine Midwestern U.S. cities. A total of 269 populations (4,035 individuals) were sampled along urban-rural transects, and cyanotype (cyanogenesis phenotypes) frequencies were quantified alongside regional and site-level environmental variables, including vegetation cover (NDVI), land surface temperature (LST), snow cover, impervious surface intensity, aridity, …

The Concept 'Pollination' And Bee Pan-Trap Color And Uv Reflectance Determine The Taxonomic Compositions Of Bee Taxa Captures Across An Elevation Gradient And Seasons In The Jemez Mountains Of New Mexico, Esther A. Burton, Kelly B. Miller, Paul J. Watson, David C. Witherington, Steven Poe, David Lightfoot

Biology ETDs

This thesis examines the pollinator concept and tests how sampling methods shape bee communities. Chapter 1 provides a conceptual and philosophical analysis, arguing that pollination is a process and that pollinators are context-dependent functional roles rather than fixed taxonomic categories. It traces the concept’s development from natural history to ecological theory, introduces a dual-goal model separating plant reproduction from visitor foraging, and proposes a classification framework based on evidentiary certainty and pollination potential to resolve ambiguity in pollination research.

Chapter 2 applies these ideas empirically by evaluating how pan-trap color and ultraviolet (UV) reflectance influence bee assemblages across elevation and …

Characterizing A Potential Cbp/P300 Histone Acetyltransferase Homolog In Tardigrade Germline Specification And Development, Brittney Michelle Hartshorn

Honors Projects

Germline specification is a fundamental process that ensures the proper development of germ cells. Germline specification occurs either through germ cell determinants maternally inherited through the mechanism of preformation or through induction, where cell interaction and epigenetic modifications direct specification. Determining how these mechanisms evolved and diverged remains an important question in developmental biology. Despite research on germline regulation in model organisms such as Caenorhabditis elegans or Drosophila melanogaster, such regulation remains poorly understood in many other animal groups. Tardigrades are an emerging model system for investigating developmental mechanisms due to their phylogenetic placement and experimentally tractable embryos. CBP/P300 is …

Reassembling Riparian Ecosystems: Stream Restoration Effects On Vegetation, Arthropods, And Aquatic-Terrestrial Connectivity, Katelyn P. Driscoll

Biology ETDs

Riparian areas exist at the aquatic-terrestrial interface and provide disproportionate ecosystem services, yet multiple stressors have degraded these zones globally. Stream restoration seeks to reverse degradation, but rigorous evaluation of treatment effectiveness remains limited. I conducted a before-after-control-impact (BACI) study in the southern Rocky Mountains to evaluate two stream restoration treatments—beaver dam analogs (BDAs) and plug-and-ponds (P&Ps)—across three dimensions of riparian ecosystem response. Using Bayesian analysis, I quantified treatment effects on functional diversity and composition of riparian plant communities. Using generalized linear mixed models, I evaluated restoration effects on riparian arthropod abundance, richness and guild composition across lateral gradients and …

From Flight To Hatching: Adult Sexual Dimorphism, Life History, And Egg-Stage Ecology Of Pseudocotalpa Giulianii, Mandylene Mountain

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Nevada endemic dune beetle Pseudocotalpa giulianii is currently known only from two dune systems in Amargosa Valley, Nevada, yet much of its life cycle occurs below the sand surface and remains poorly documented. This thesis addresses key gaps in adult-stage biology and egg-stage development that are relevant to understanding reproduction, vulnerability, and habitat requirements in this dunerestricted species.

To characterize adult sexual dimorphism and life history, I quantified morphological differences between males and females and measured sex-specific adult survival under laboratory conditions relative to the aboveground flight season. Males and females overlapped broadly in external body size, but tarsal …

Ecological And Nutritional Drivers Of Floral Fidelity In Wild Pollinators, Adelaide Elise Ergastolo

Master's Theses

Plants must receive pollen from the same species in order to successfully reproduce. For most flowering plants, the transfer of pollen occurs via animal pollinators while they forage on plants to obtain food. Therefore, the fidelity of pollinators to individual plant species during foraging trips is directly related to the amount of conspecific pollen plants receive. Low floral fidelity of pollinators can reduce plant reproductive success, which in turn has the potential to lower food resources for pollinators in the future. While many factors can potentially influence pollinator floral fidelity, several important ones may be the nutritional resources provided by …

Thermal Physiological Ecology Of The Relict Leopard Frog At Hot And Cold Springs, Robert P. Pelletier Iii

UNLV Theses, Dissertations, Professional Papers, and Capstones

The relict leopard frog (Rana onca) once ranged across drainages in southern Nevada, northwestern Arizona, and southwestern Utah. Following a decline, the species only persisted in a few geothermally influenced hot springs, which led to the perspective that hot springs were high-quality habitat. Rana onca has been under intensive, multiagency management and the species has been translocated to establish additional populations, including at cold-water sites. Three research studies are presented into the thermal physiological ecology of R. onca with the aim of informing conservation strategy. The research was focused at a thermally influenced hot spring and a cold-water spring to …

Phase-Preserving Machine Learning Forecasting Of Nonlinear Predator–Prey Dynamics, Saira Batool, Muhammad Imran, Brett Mckinney

Biology and Medicine Through Mathematics Conference

No abstract provided.

Remote Sensing To Detect Crop Damage By An Invasive Species, Cole Butler

Biology and Medicine Through Mathematics Conference

No abstract provided.

A Reassessment Of “Tityus” Tenuimanus Banks, 1910, As A Misidentified Leiurus Sp. (Scorpiones: Buthidae), Mohamed Mousaid, Ersen A. Yağmur, Zoe Flores, Alana Rivera, Aziza Lansari, Abdellah Bouazza

Euscorpius

This study re-examines the holotype of “Tityus” tenuimanus Banks, 1910, previously synonymized with Buthus atlantis Pocock, 1889 by Lourenço & Francke (1984). Our results indicate that the specimen is a misidentified representative of Leiurus Ehrenberg, 1828, as it exhibits the diagnostic characters of this genus: the central lateral and posterior median carinae of the carapace fused into a lyre-shaped configuration, and tergites I–II bearing five granular carinae (a character absent in the genus Buthus Leach, 1815). Moreover, the holotype lacks one of the most distinctive characters of the genus Tityus Koch, 1836, namely the presence of a subaculear tubercle. The …

Incorporating Thermal Performance Curves Into Population Dynamic Models For The West Nile Vector, Culex Pipiens, Benjamin Bruncati, Helle Aronson, Chloé Lahondère, Michael A. Robert

Biology and Medicine Through Mathematics Conference

No abstract provided.

Assessing Vegetation Health Following The 2014 Carlton Complex Fire Using Remote Sensing, Rachael Sv Pentico

2026 Symposium

Climate change, combined with decades of altered fire regimes and fire suppression, has increased fuel accumulation across western U.S. forests, contributing to more frequent, larger, and more intense wildfires. Remote sensing offers an effective approach for analyzing these large-scale fire events and their ecological impacts, as satellite imagery enables affordable, accessible, and reproducible monitoring of vegetation change across broad spatial and temporal scales. This study examined the 2014 Carlton Complex Fire in the Methow Valley, Washington. Burning 265,108 acres, it was the largest wildfire in Washington State history at the time and caused extensive agricultural and forest damage. Post-fire vegetation …

Influence Of Pollinator Island Patch Size On Forb Establishment And Pollinator Networks In Palouse Prairie Restoration, Yaelle Esther Reeve

2026 Symposium

The Palouse Prairie Ecoregion is one of North America’s most endangered grassland ecosystems, with less than 1% retaining native vegetation. Restoration efforts have struggled to re-establish ecologically important native forbs and the plant–pollinator interactions necessary for long-term community stability. Spatial configuration of floral resources is known to influence pollinator foraging behavior and interaction network structure, yet few studies have evaluated how planting scale affects both plant establishment and pollinator community assembly in early-stage prairie restoration. My research aims to evaluate how variations in the size (0.1, 1, and 10 m²) of grouped wildflower plantings (pollinator islands) affect native forb establishment, …

Recognition Of The Spring Flight Of Celastrina (Tutt) (Lycaenidae: Polyommatinae) In Southern New England As An Introgressed Hybrid Species, Harry Pavulaan

The Taxonomic Report of the International Lepidoptera Survey

Populations of Celastrina (“Azure”) butterflies in southern New England have historically been referred to as either C. ladon (Cramer) or C. lucia (W. Kirby) by various authors. Following the discovery of elongated dorsal wing scales in males of C. ladon (D. Wright & Pavulaan, 1999; Ômura et al., 2015)—structures that replace the androconia that are typically present in most Celastrina species—it was believed that this trait was restricted to C. ladon, C. nigra (W. Forbes), and, more recently, C. iryna (Pavulaan, 2025). Microscopic examination of male “Spring Azure” specimens from across southern New …

Impact Of Land-Use Disturbances On The Composition Of Wetland Plant Communities Across The Conterminous United States, Maya Merchant

Undergraduate Honors Theses

Due to the threat of invasive species on wetland biodiversity, it is critical to assess factors driving their proliferation in wetlands. To address this growing need, this project analyzes relationships between non-native species and known anthropogenic disturbance types associated with increased biological invasions. Using the U.S. EPA’s 2021 National Wetland Condition Assessment, the relationship between non-native species (diversity, richness, and coverage) and surrounding land-use within 500, 1,000, and 3,000-meter buffers was evaluated. To explore patterns across larger spatial scales, mean non-native species diversity, richness, and coverage was calculated at the watershed level and compared to associated percentages of agricultural land …

Distribution Of Mussels In Tributary Systems Of The Lower Ouachita River Watershed, Zach R. Crain

ATU Theses and Dissertations 2021 - Present

Freshwater mussel communities in small tributary streams are poorly documented in Arkansas, limiting the understanding of how diversity is structured across river networks. To address this data gap, we surveyed 147 sites across five previously unsurveyed watersheds in the South-Central Plains Ecoregion (SCPE). We sampled 5,473 individuals representing 17 species, including four Arkansas Species of Greatest Conservation Need (SGCN). We evaluated patterns in community variation utilizing β-diversity based on both presence-absence and abundance data. Overall turnover (βsor and Bray) was partitioned into replacement (βsim and BrayBal) and nestedness (βsne and BrayGra) components. Replacement and nestedness each drove turnover in two …

Distribution, Habitat, And Fish Assemblages Associated With The Rocky Shiner In Arkansas, Savannah L. Wise

ATU Theses and Dissertations 2021 - Present

The Rocky Shiner (Notropis suttkusi) is a minnow species endemic to the Red River and its tributaries in southern Arkansas and Oklahoma. This species is petitioned for listing under the Endangered Species Act and is a species of greatest conservation need (SGCN) in Arkansas. However, there is little information for the species’ distribution, habitat use, and ecological niche, especially within the Arkansas portion of its range. Because of this data gap, my study provides an updated description of its distribution and habitat associations using conditional occupancy modeling and explores patterns of species co-occurrence within the community. I sampled …

Scorpions In Brazilian Caves And Other Subterranean Habitats, Jonas E. Gallão, Bruno D, Lenhare, Misael Oliveira-Neto, Maria E. Bichuette

Euscorpius

Arachnids have successfully colonized subterranean environments. Compared to spiders, harvestmen, and pseudoscorpions, scorpions have a moderate number of subterranean species, including troglophiles and troglobites. Among the four families and 184 species and three subspecies of scorpions found in Brazil, three families and at least 33 species and one subspecies have been documented in subterranean habitats. This study presents a faunistic list of scorpion occurrences in caves and other types of subterranean habitats in Brazil, along with distribution maps and an attempt to classify species based on their use of and dependence on subterranean environments.

Evolution Of Nematode Prey Chemotaxis Behavior Across Different Environments, Hailey R. Smith

Honors Theses

Climatic conditions in the near future are projected to be warmer, with more frequent and intense weather events. This will substantially alter the environments in which organisms must integrate specific information to find essential resources. Many organisms rely upon chemical signals to orient towards attractive resources through a mechanism called chemotaxis. How different environmental conditions, like temperature, impact this process will be important to understand as environments change. I conducted a laboratory evolution experiment with the model nematode Caenorhabditis elegans to see how success in chemotaxis assays changes over time when selected under different temperature regimes (normal laboratory temperature, increased …