Ecology and Evolutionary Biology Commons^™

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.

The Genus Nebo Simon, 1878 (Scorpiones: Diplocentridae) In Oman, Graeme Lowe

Euscorpius

No abstract provided.

Quantifying Genetic Diversity In Nematode Feeding Rate, Jacob King

Honors Theses

Understanding how populations persist under changing environmental conditions is a central question in ecology and evolutionary biology. Variation in traits related to resource acquisition may play a key role in determining population survival when resources are limited or fluctuate over time. In this study, I investigated how variation in feeding-related traits influences population persistence using a combination of computational modeling and laboratory experiments. I developed a stochastic, individual-based consumer–resource model to simulate population dynamics across varying levels of trait variance and resource regimes. Across 60,000 simulated populations, increased trait variation consistently reduced extinction risk and extended persistence time, although the …

I Lost My Number, Can I Have Yours? Body Image Satisfaction With Sexually Dimorphic Traits Is Associated With Men's Dating Anxiety And Confidence, David A. Frederick, Tania A. Reynolds, Nikoline L. Smart, Justin R. Garcia, David A. Puts

Psychology Faculty Articles and Research

Evolutionary scientists posit that sexual selection processes caused males to develop sexually dimorphic traits to aid them during intrasexual competition and increase their likelihood of being chosen as mates. Evolutionary social sciences have extensively examined women's preferences for traits such as muscle mass and voice pitch, reasoning that these traits serve as cues of men's ability to provide direct benefits (e.g., resources) and indirect (genetic) benefits passed on to offspring. At the same time, body image researchers have extensively focused on the social causes and consequences of men's dissatisfaction with their muscularity and body fat. We connected these two research …

Awe As Signpost: An Argument For The Consistency Of Lewis’S “Joy” And Psychological Awe, Audrey Hendricks

Senior Honors Theses

C.S. Lewis’s Surprised by Joy details Lewis’s autobiographical apologetic for the existence of God through his experiences of “Joy,” a technical term invented by Lewis. Upon close study, his experiences of Joy contain many similarities to psychological awe. This investigation compares Lewis’s Joy with psychological awe using the Awe Experience Scale (AWE-S) to determine consistency. Lewis’s Joy was found to be consistent with all six criteria of the AWE-S in addition to other recognized psychological characteristics of awe. In addition to qualitative consistency, this review also argues for the teleological consistency of the two concepts, contending for a Christian teleological …

Morphological Variation Of Lingual Glands In Wild American Alligator (Alligator Mississippiensis) Populations, Benjamin Angalet

Master's Theses

American alligators (Alligator mississippiensis) inhabit diverse aquatic ecosystems including freshwater wetlands, swamps, and estuarine rivers. As apex predators, their physiological resilience has implications for ecosystem stability and long-term conservation. With projected sea-level rise and increasing saltwater intrusion into coastal freshwater habitats, understanding the osmoregulatory capacity of alligators is increasingly important. Unlike marine-tolerant crocodilians such as the saltwater crocodile (Crocodylus porosus), which possess specialized salt-secreting lingual glands in addition to renal and cloacal mechanisms, the morphology and physiological significance of lingual glands in wild American alligators remain poorly understood. This study examined lingual gland morphology and plasma …

The Hitchhiker's Guide To The Host: Fleas And The History Of Pikas In North America, Josh Pletcher

All NMU Master's Theses

Parasite phylogenetics can offer windows into the cryptic evolutionary history of hosts, often highlighting events that are not recorded by the phylogenetics of the host. Pikas (small lagomorphs) host a diverse parasite community comprising endoparasites (e.g., coccidians, nematodes, and cestodes) and ectoparasites (e.g., fleas and mites). Phylogenetic analysis of pika endoparasites has revealed pikas evolved in Asia and colonized North America in two waves, and that contact between these two pika lineages allowed parasites to be transferred from one lineage to another and to survive the extinction of their original host. To uncover these cryptic histories, understanding the biogeography of …

Ontogeny And The Effects Of Perinatal Stress In The First Immature Skeleton Of Teleoceras Aepysoma (Perissodactyla, Rhinocerotidae), Joe Gajewski

Electronic Theses and Dissertations

Recovery of an immature fossil rhinoceros (Teleoceras aepysoma) skeleton (ETMNH 32999) from the Gray Fossil Site in Tennessee offers the first insights into the ontogeny of the species. ETMNH 32999 is interpreted to be a subadult male in an age class equivalent to ~17-20% of potential lifespan. Comparative analyses support the hypothesis that subadults of related taxa are typically ~91% of average adult size in most dimensions. However, certain cranial dimensions are substantially lower than expected in ETMNH 32999, averaging only ~74% of the average conspecific adult. Such departure from typical growth rates is suggested to be attributable …

Polydactyl Precursors: Insights Into Early Tetrapod Locomotion From Polydactyl American Alligators, Trevor P. Brewington

All Theses

Several of the earliest tetrapod lineages exhibited polydactyl limbs, with seven or eight digits per limb rather than the typical five or fewer seen in extant lineages. How these digit configurations might have been used during terrestrial locomotion is unclear, given the lack of living models in which their performance can be studied and limited evidence from fossil trackways. However, polydactyly occasionally appears in natural populations of American alligators (Alligator mississippiensis), animals with body plans that broadly resemble those of early tetrapods. To test how polydactyl limbs similar to those of early tetrapods might have functioned on land, …

Shape Variation In The Mandible Of The Borophagine Canids And Implications For Predatory Behavior, Benjamin Neavear

Theses, Dissertations and Culminating Projects

The borophagines are an extinct lineage of canids that inhabited North America for more than 20 million years. This group included genera such as Aelurodon, Borophagus, and Epicyon. Borophagines are commonly referred to as “bone-crushing dogs” because their skull morphology converged with that of extant hyenas, predators capable of consuming bone. The purpose of this study was to determine whether convergence was present in the mandible, an anatomical structure strongly correlated with feeding behavior, particularly in the genera Aelurodon and Borophagus. It was hypothesized that most borophagine taxa possessed mandibular shapes similar to those of hyenas. Numerous mandibular characters were …

Sex Or Survival: Does Wounding Elicit A Somatic Reproductive Tradeoff In Narnia Femorata Males?, Lillian E. Burbulis

Departmental Honors & Graduate Capstone Projects

Animals must partition resources into different life history traits resulting in tradeoffs because resources are finite. A tradeoff is the allocation of resources to one trait over another. Theory states that energy is allocated in a hierarchical fashion. For example, somatic maintenance should be a higher priority than reproduction, resulting in more resources being allocated to somatic maintenance compared to reproductive traits. The metabolic investment hypothesis states that energy must follow a hierarchical order prioritizing somatic maintenance over reproduction. Another hypothesis for energy allocation is the terminal investment hypothesis. This hypothesis states that energy will be allocated to reproduction over …

Aggression And Fish Welfare: Challenges And Opportunities, Christine M. Soper, Peter D. Dijkstra

Animal Sentience

Oldfield & Bonano’s (2024) [O&B] target article discusses the wellbeing and sociality of bony fishes. Many fish species, such as cichlids, are not only social but territorial. Aggression is normal, but territorial aggression in a captive environment can have a negative impact on welfare. Aggression-related injuries and deaths are prevalent in pet stores as well as research settings. We discuss the need to develop effective methods to minimize the negative consequences of aggression.

Variation In Infection Prevalence Of Splendidofilaria Pectoralis Across Alaskan Grouse Populations, Anahi Garcia Valdez, Diego Martinez

Create@State

In recent years, rapid climate change has altered species distributions worldwide and influenced parasite transmission dynamics in wildlife systems. Parasite infections play an important role in shaping patterns of disease distribution across species and populations. Understanding variation in infection prevalence across geographic regions and host demographic groups is essential for interpreting these patterns. Splendidofilaria pectoralis is a filarial nematode that infects the connective tissues of grouse (Aves: Tetraonini) in Alaska and has been moving northward as the climate warms. However, relatively little is known about the variation in prevalence of the nematode across geography and demography. This project examines variation …

An Integrative Description Of Euscorpius Diagorasi Sp. N. From Rhodes, Greece (Scorpiones: Euscorpiidae), Konstantinos Kalaentzis, Francesco Frigioni, Eliza Kaitetzidou, Alessio Iannucci, Alexandros Triantafyllidis

Euscorpius

The genus Euscorpius Thorell, 1876 comprises a diverse and taxonomically challenging group of scorpions in the Mediterranean, with Greece representing one of its principal centers of diversity. In this study, we provide an integrative description of Euscorpius diagorasi sp. n., a new species from Rhodes Island, Greece. The new species is described on the basis of adult male and female morphology and mitochondrial COI sequence data. It is a small oligotrichous species characterized by a total length of approximately 21–25 mm, pale yellow to light brown coloration with darker reddish-brown pedipalps, pectinal tooth count of 8 in the male …

Not Just Static: Evolutionary Throughlines In The Female Voice, Maria Hand '26

Honor Scholar Theses

Vocal communication is essential for many forms of human interaction and discourse. As such, the human voice has been the subject of extensive scientific research in a variety of contexts, including that of potentially evolved characteristics. Researchers have long studied the various changes that occur in direct relation to hormonal shifts across the ovulatory cycle, but one particularly interesting facet of this research is the voice. There are numerous acoustic parameters that are highly socially salient, and thus an ideal means with which to study potential ovulatory cycle related changes. Studies of this subject additionally provide further insight into the …

Intermediates Or Intermedius? An Examination Of Lotic Sternotherus In Baldwin And Mobile Counties, Al, Peyton A. Wilson

Theses

The Southeastern United States is a biodiversity hotspot, and turtles are no exception to the rule. This is particularly true for the genus Sternotherus. Alabama is the only state home to all six species of Sternotherus, including the recently described Intermediate Musk Turtle (Sternotherus intermedius). It was thought that the Perdido River was the western boundary of Sternotherus intermedius; however, surveys in recent years produced questionable individuals in several small watersheds feeding into the Mobile-Tensaw Delta, bringing the species true range into question, as well as the question of if this species has hybridized with its congener, …

Comparing Head Shape Of Polymorphic Subterranean E. Latitans And Subterranean E. Sp. 4, Brandon Chapa, Jordan Cosgrove, Lizzeth Holguin

Posters - 2026

Eurycea latitans (E. latitans) from Honey Creek Cave and unnamed Eurycea species from New Braunfels, Texas (E. sp. 4) are two paedomorphic subterranean species. E. latitans is polymorphic, meaning it also exists as a surface species. Similarities in morphology of subterranean salamander species may be due to convergent evolution as a result of living in similar environments. These similarities include having flatter, wider heads, and wider mouths than surface species (Tovar et al. 2025). Variation may also exist among different subterranean salamander species. Texas Eurycea salamanders display “complex patterns of morphological divergence”, suggesting that isolation and local environmental pressures can …

Comparing Gngt1 Expression In Eye Tissue Of Polymorphic Salamander Species Through Development, Fiona Coulbourne, Camila Cardozo, Macarena Machado, Ruben Tovar

Posters - 2026

The effect of the environment on organisms and their adaptations is widely studied. When exposed to different environmental niches, phenotypic adaptation is observed even within species. Animals that live in dark cave environments show a loss of their eyesight, since this sense is no longer useful to keep. Previous research has studied salamanders of the clade Eurycea and compared gene expression to subterranean and surface phenotypes1. E.pterophila is observed to express these two phenotypes depending on its environment, either Preserve Cave (subterranean) or Comal Springs (surface). Subterranean variant shows reduced eye volume and assumes to have decreased eyesight. Utilizing RNASeq …

Teeth That Tell Time: Elemental Analysis From Shark Teeth, Gisele-Elizabeth Perez

Posters - 2026

Sharks (Chondrichthyes) have hunted in the oceans for over 400 million years, their teeth leaving history behind, constantly becoming a part of the fossilization process (Worm et al. 2013). Their survival throughout 5 major extinctions is due to their ability to adapt easily with slow metabolism, a wide range of diet, and an efficient physiology. Shark teeth are vital to the hunting and consumption of their prey, making it a point for scientists to study them. Their tooth minerals contain fluorapatite in their enameloid, and dentin in the “root” of the tooth, with extinct species containing dentin and hydroxyapatite in …

Mapping Sensory Landscapes: Distribution And Arrangement Of The Anterior Lateral Line System In Texas Catfish, Tatiana Flores, Ruben Tovar

Research Papers

Fish have a system of sensory organs known as the lateral line system. This system contains numerous mechanoreceptive neuromasts and electroreceptive ampullary organs (Northcutt et al, 2000). Neuromasts are small, hair-like structures located within canals in the lateral line system just under the fish’s skin and are open to the environment through small pores visible on its skin (Parker, 2025). Water flows into these canals through the pores which stimulates the sensitive hair cells, resulting in electrical signals sent to the fish’s brain. The brain interprets these signals and creates “images” of the fish’s surroundings, helping it to see even …

Does Shape Matter?: How Salamander Head Morphology Shifts Based On Environment, Caitlyn Pinaga, Naomi Ramirez, Sonia Cerrillo

Posters - 2026

Groundwater salamanders of the genus Eurycea represent a diverse group of amphibians inhabiting the aquifer systems of central Texas, where both surface-dwelling and fully subterranean species coexist. Subterranean habitats impose extreme selective pressures, including complete darkness, limited nutrient availability, and stable environmental conditions, which drive convergent morphological traits such as eye reduction or loss, decreased pigmentation, and elongation of appendages. A key evolutionary pattern seen in these systems is sensory compensation, in which the reduction of one sensory modality, in this case vision, is accompanied by the enhancement of others. In aquatic salamanders, this often involves expansion of the lateral …

Smell Over Sight: Determining Levels Of Olfactory Gene Expression Between Surface And Subterranean Eurycea Salamanders, Sonia Cerrillo, Iliana Melendez, Naomi Ramirez

Posters - 2026

In the karst aquifers of central Texas, including the Edwards and Trinity systems, organisms live in an environment defined by constant temperatures, total darkness, and scarce food resources. These conditions have driven the evolution of salamanders in the genus Eurycea, particularly those that have adapted to subterranean life. Cave-dwelling species like Eurycea rathbuni exhibit hallmark “blind salamander” traits, including educed eyes, loss of pigmentation, and flattened head morphology. In contrast, surface-dwelling relatives such as Eurycea nana and Eurycea sosorum retain fully developed eyes and pigmentation, while some species like Eurycea latitans display both surface and subterranean forms across different populations.

The Missing Lynx: Investigating Passive And Active Rewilding With The Eurasian Lynx, Isaiah Charles, Tatiana Flores, Isabella Lopez

Conservation Biology

The Eurasian Lynx (Lynx lynx) is a wild cat native to the boreal forests, mountains and grasslands of Europe and Asia (Bhattacharyya, 2025). The Eurasian lynx keep ungulate populations in check which allow for forests to recover from overgrazing, promoting biodiversity and ecological balance. However, the Eurasian lynx had become locally extinct across Europe by the 1900s due to habitat loss, hunting by farmers in retaliation for predation of livestock and the illegal fur trade. Conservation and ecological restoration efforts to rebuild the lynx population have been underway. Rewilding is a form of ecological restoration involving the reintroduction of a …

Analysis Of Mitochondrial Dna Haplotype Groups For South Texas Canids, Canis Rufus, After Past Hybridization Events, Isabella Lopez

Presentations - 2026

mtDNA: mitochondrial DNA; passed from maternal parent to offspring (Haplotype)

Haplotype:  a group of genes or genetic markers inherited together from a single parent (Haplotype)

Mitochondrial DNA haplotypes specific sequences of mtDNA that is passed exclusively from maternal parent to offspring (Giles et al. 1980)

Pro's:

It is passed unchanged from mother to offspring, meaning it is fairly stable (Giles et al. 1980)

Each cell has multiple mitochondria vs one nucleus , which means mtDNA it is more likely to be recoverable from degraded samples like scat (Templeton et al. 2013)

Mapping Sensory Landscapes: Distribution And Arrangement Of The Anterior Lateral Line System In Texas Catfish, Tatiana K. Flores, Ruben Tovar

Posters - 2026

Fish have a system of sensory organs known as the lateral line system. This system contains numerous mechanoreceptive neuromasts and electroreceptive ampullary organs (Northcutt et al, 2000). Neuromasts are small, hair-like structures located within canals in the lateral line system just under the fish’s skin and are open to the environment through small pores visible on its skin (Parker, 2025). Water flows into these canals through the pores which stimulates the sensitive hair cells, resulting in electrical signals sent to the fish’s brain. The brain interprets these signals and creates “images” of the fish’s surroundings, helping it to see even …

Does Habitat Predict Head Shape? A Comparative Geometric Morphometric Analysis Of Eurycea Spp., Sarah Flores-Garza, Alexa Miner, Gianna Montelongo

Posters - 2026

Subterranean environments impose strong selective pressures, including complete darkness and reliance on non-visual sensory systems. In Eurycea salamanders, these conditions are associated with traits such as reduced eyes and expanded head regions that improve sensory detection (Tovar et al., 2025). Subterranean species are often expected to share similar head shapes due to convergent evolution. However, not all species experience these pressures equally. Eurycea latitans is a polymorphic species that inhabits both surface and cave environments. Eurycea sp._NB is an obligate subterranean species, while Eurcyea sosorum is a surface species. This study tests whether habitat predicts head shape in Eurycea, or …

Evolution Of Antibiotic Responses During Chronic P. Aeruginosa Infections In The Human Lung, David Frank Ritz

Dartmouth College Ph.D Dissertations

Typical antibiotic susceptibility testing (AST) of microbial samples is performed in homogeneous cultures in batch environments, which does not account for the highly heterogeneous and dynamic nature of antibiotic responses. The most common mutation found in P. aeruginosa lineages evolved during chronic cystic fibrosis infections in the human lung, a loss of function of repressor MexZ, increases basal levels of multidrug efflux MexXY, but does not increase resistance by traditional minimal inhibitory concentration (MIC) assays. Here, we use single cell microfluidics to show that P. aeruginosa’s response to aminoglycosides is highly heterogeneous, with only a subpopulation of cells surviving exposure. …

The Evolution Of Self-Awareness In Conscious Organisms, Robert A. Dielenberg

Journal of Conscious Evolution

Self-awareness in conscious organisms remains an enduring puzzle for philosophers and neuroscientists. This paper proposes a tripartite evolutionary model tracing its emergence through three sequential types: the sensory self (primitive egocentric, valence-tagged awareness of sensory states), the bodily self (external objectification of the body as a distinct entity, evidenced by mirror self-recognition in select species), and the cognitive self (internal objectification of the mind enabling recursive self-transformation). Adopting a monist framework, the model treats consciousness as the biological substrate of delayed neural apperception (the “Delayed Present”), within which selves emerge as increasingly sophisticated models. It distinguishes non-human metacognition—implicit, online regulation—from …

No Effect In Plasma Corticosterone Levels After Observation Of Diseased Conspecifics, B. M. Hardy, M. Chang, S. Mccallum, S. Santangelo, Patricia C. Lopes

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Organisms commonly respond to stressors in their environment by increasing the secretion of corticosterone (CORT). While increased CORT is acknowledged as a response to predation risk by organisms inhabiting a landscape of fear, new research raises the potential for changes in CORT as a response to the risk of infection by organisms in their environment. An increase in CORT of a healthy, uninfected individual in response to their perception of the risk of infection in their environment could change their susceptibility to infection, highlighting a significant role for CORT to alter host–pathogen dynamics. To investigate the effects of infection risk …

A Revision Of The Psammophilic Genus Liobuthus Birula, 1898 (Scorpiones: Buthidae), With A Description Of Four New Species From Central Asia, Victor Fet, František Kovařík, Graeme Lowe, Matthew R. Graham

Euscorpius

The rare Central Asian psammophilic scorpion genus, Liobuthus Birula, 1898 (Scorpiones: Buthidae), is revised. Five species are delineated according to results from three species delimitation approaches using mitochondrial DNA. Results are supported by diagnostic morphology, including an assessment of the distinctive neobothriotaxy. The type species, L. kessleri Birula, 1898, is confirmed for Iran (northeast), Turkmenistan and Uzbekistan (south). Four new species are described: L. atamuradovi sp. n. (Turkmenistan),  L. danovi sp. n. (Kazakhstan, northern Turkmenistan, Uzbekistan), L. shukurovi sp. n. (southwestern Tajikistan), and L. vachoni sp. n. (southern Kazakhstan), The unique additive neobothriotaxy (on both pedipalp femur and patella) …