Ecology and Evolutionary Biology Commons^™

Adapting Population Genetics, Practice, And Policy For Plant Conservation In A Changing World, Cooper M. Kimball-Rhines

Graduate Doctoral Dissertations

Biodiversity conservation is an inherently interdisciplinary goal that requires effective collaboration among academics, ecosystem managers, policymakers, and other stakeholders. Codesigning research with these groups ensures experiments are useful and improves adoption of policy and practice recommendations while advancing our understanding of basic science. This dissertation explores the power of codesigned research in shaping plant conservation strategies using stakeholder engagement, causal inference, demographic modeling, and multi-omic sequencing techniques. In chapter 1 I discuss the history of New England ecosystems and the need for research-driven changes to plant conservation policy and practice in the face of global change. In chapter 2, I …

Patents And Technology Evolution: Altering Innovations And Innovators Via Patent Influences, Richard Gruner

Georgia Journal of Law & Technology

Technologies improve primarily through evolutionary change not rational optimization. New technologies emerge as attempts to solve practical problems, the technologies are tested in marketplaces to determine if they are superior in cost and function to alternatives, and those that fare well in the testing gain widespread adoption.  Widely adopted technologies, and their problems, form the basis for the next round of technology improvements and evolution.  Through these steps, evolutionary processes lacking rational direction can generate changing technologies matched to the desires and problems of present society.

As they operate to advance diverse technologies, evolutionary processes governing technology change are subject …

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 …

Hidden Diversity In A Clonal Endemic: Insights Into Clematis Socialis From A Population Genetics Perspective, Joanna M. Lapoint

Theses

Clematis socialis (Kral) is a rare, federally endangered perennial species restricted to a small number of fragmented populations in Alabama and Georgia. The species exhibits extensive clonality and limited sexual recruitment, characteristics that complicate expectations regarding genetic diversity and population connectivity. Despite its conservation significance, genome-wide assessments of population structure have been lacking. We used genotyping-by-sequencing (GBS) to generate a genome-wide SNP dataset for 170 individuals sampled from six natural populations. Population structure and genetic differentiation were evaluated using Bayesian clustering, analysis of molecular variance (AMOVA), pairwise FST estimates, and network-based visualization. Analyses revealed strong genetic structuring among populations and …

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.

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 …

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

Research Papers

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 …

The Presence Of Predators Moderates Evolutionary Responses Of Trinidadian Killifish To A Novel Parasite, Anne E. Christian

Biology Dissertations

The Healthy Herds Hypothesis suggests the idea that prey populations derive a benefit from their predators: predators reduce the exposure of their prey to infectious disease, both by limiting prey population densities and by eliminating sick individuals. Much research has focused on the balancing effect that predators have on ecosystems. There is a current need for research into whether these effects cause evolutionary shifts in prey populations, where strong predation pressure prevents prey species from evolving physiological tolerance or resistance to infectious agents. Parasites especially often have rapid effects on host evolution, due to exploitative interactions.

I seek to address …

Phylogeography, Fungal Host Specificity, And Fitness In The Corallorhiza Maculata Species Complex, Hana Thixton-Nolan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Mycoheterotrophic plants exploit fungi for most or all nutritional needs, providing a compelling system to address the evolutionary consequences of genome reduction, population-level variation, and germination requirements. I am using the widespread Corallorhiza maculata species complex to address questions of genomic variation, fungal host specificity, morphological variation, and germination requirements across the broad geographic range from Mexico to northern North America. This complex contains C. bulbosa, C. macrantha, and C. mertensiana, the latter with three varieties (maculata, occidentalis, and mexicana). These taxa vary in flowering time, floral morphology, and fungal associations. However, the degree …

Are There Ecological Consequences Of Urban Adaptation? A Test Of Eco-Evolutionary Dynamics In A Terrestrial Isopod (Oniscus Asellus), Aaron Yilmaz, Grace Bellino, Ryan A. Martin

Faculty Scholarship

Urbanization affects many aspects of the environment with the potential to alter both ecological and evolutionary processes. However, while examples of urban evolution are accumulating, tests of urban eco-evolutionary dynamics are rare. We carried out a reciprocal transplantation experiment using the terrestrial isopod Oniscus asellus to test how adaptation to the urban heat island influenced ecological processes. As isopods are important decomposers, we asked if leaf-litter decomposition differed among reciprocal transplant treatments and used a separate laboratory experiment to isolate the effects of temperature on rates of isopod leaf consumption. We found that leaf-litter decomposition was greater in urban habitats, …

Dosage Sensitivity And The Evolution Of Dosage Compensation: Tests Of The Insensitive Sex Chromosome Hypothesis In Flour Beetles, Shana Pau

Biology Dissertations

Sex chromosome evolution generates imbalances in gene dosage that can disrupt gene expression and organismal function. These imbalances are often resolved through dosage compensation mechanisms, yet the factors that drive the emergence and diversity of these systems remain poorly understood. This dissertation addresses a central question in evolutionary genomics: what governs the evolution of dosage compensation?

Focusing on dosage sensitivity as a potential driver, I evaluate the Insensitive Sex Chromosome Hypothesis (ISCH), which predicts that chromosome-wide compensation is more likely to evolve in genomic contexts that are not depleted of dosage-sensitive genes. Using flour beetles (Tribolium spp.) as a …

Genomic Variation, Adaptive Evolution, And Invasive And Evolutionary History Of Microstegium Vimineum, Cameron William Corbett

Graduate Theses, Dissertations, and Problem Reports (ETD)

Invasive species can cause environmental and economic damage, but can offer unique opportunities to study rapid evolution and adaptation in novel environments. Microstegium vimineum (stiltgrass) is a prolific invasive grass in the eastern United States. Historical herbaria collections were used to identify patterns of invasion history and population dynamics over a spatial and temporal scale. Analyses of plastid genomes reveal a complex invasion history, including a single introduction in the southern United States linked to Japan and multiple repeated introductions in the northern United States from various source populations. Spread of introduced populations provide evidence of admixture among previously geographically …

Comparative Analysis Of Six New Chloroplast Genomes In Platanthera (Orchidaceae) Enhances Understanding Of Its Diversification, Lisa E. Wallace, Martin I. Batalla, Matthew Maisonave

Biological Sciences Faculty Publications

Platanthera is among the most diverse genera of orchids in north temperate regions, with high species diversity in Asia and North America. Despite many ecological studies in this group, little is known about its genomic diversity. Here, we report the newly annotated chloroplast genomes from six species in subgenus Limnorchis from North America and compare them with plastomes published for Platanthera species from Asia and Europe. We found that the plastomes of species in subg. Limnorchis are among the smallest reported for Platanthera thus far. While major structural differences were not detected in the newly sequenced species, ndh genes were …

Phylogenetic Comparative Vocal Evolution, Casper W. Buchanan

Master's Theses

Vocal learning is a trait unique to humans, bats, cetaceans, primates, and birds (Jarvis & Nottebohm, 1997; McComb & Semple, 2005; Wilbrecht & Nottebohm, 2003). Although there has been extensive research on vocal learning in songbirds, parrots are an even closer proxy to human learning, as they are social, intelligent, and lifelong learners, with some having repertoires of over 300 sounds (Benedict et al., 2022; Péron et al., 2011; Thomsen et al., 2019; Toft & Wright, 2015). Elevated vocal learning can be attributed to the need for parrots to have strong communication skills through the sharing of information over foraging, …

Functional Morphology Of The Primate Knee And Its Implications For Hominin Bipedal Mechanics, Catherine K. Miller

Dartmouth College Ph.D Dissertations

Bipedal locomotion is central to the human condition, having shaped our evolutionary trajectory since its early emergence in the hominin lineage. Despite its importance, key questions remain about its origins and evolutionary trajectory. While many studies have focused on locomotor-related anatomies, comparatively less attention has been paid to the knee joint – a structure critical to the primate locomotor repertoire. This dissertation aims to clarify the form-function relationship of the knee in extant primates to better infer the locomotor behaviors of Miocene hominoids and Plio-Pleistocene hominins. To address these questions, this research employs a multifaceted analytical approach, integrating linear measurements, …

Elucidating The Role Of Transposable Element Derived Gene, Dplg3, In Drosophila Melanogaster, Kaisy A. Martinez

2025 Spring Honors Capstone Projects - Archive

A big fraction of most eukaryotic genomes is comprised of transposable elements (TEs). TEs are mobile genetic sequences often causing deleterious effects as they increase in copy number. On rare occasions, TEs can undergo molecular domestication, where the TE proteins are co-opted by the host to serve cellular functions. In Drosophila melanogaster, domestication from PIF/Harbinger TEs has resulted in five Drosophila PIF-Like Genes (DPLG1-4 and 8). This study focuses on investigating the function of DPLG3. In DPLG3 knock out lines, DPLG3-KO, a fraction of the progeny shows an abnormal gonad phenotype. We sought to confirm …

Ediacaran Paleocommunity Structure, Body Size Evolution, And The Rise Of Complex Animals, Matthew Philip Craffey

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The Ediacaran period (635-538ma) is a key interval in the evolution of life as it records the first macroscopic animal communities. Major extinction pulses appear to have altered the composition of the global marine biosphere between each sub-interval of the Ediacaran Period: the Avalon, White Sea, and Nama assemblage Zones. While considerable attention has been paid to the causes of these extinction pulses, less has been afforded to the consequences of Ediacaran biotic turnover for community organization and function. Moreover, it is unclear how body size - the defining trait of macrofauna - affected the transition between animal groups across …

Robust Sex Determination In The Caenorhabditis Nigoni Germ Line, Jonathan P Harbin, Yongquan Shen, Shin-Yi Lin, Kevin Kemper, Eric S Haag, Erich M Schwarz, Ronald E Ellis

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Sexual characteristics and reproductive systems are dynamic traits in many taxa, but the developmental modifications that allow change and innovation are largely unknown. A leading model for this process is the evolution of self-fertile hermaphrodites from male/female ancestors. However, these studies require direct analysis of sex-determination in male/female species, as well as in the hermaphroditic species that are related to them. In Caenorhabditis nematodes this has only become possible recently, with the discovery of new species. Here, we use gene editing to characterize major sex-determination genes in C. nigoni, a sister to the widely studied hermaphroditic species C. briggsae. These …

Learning In Nonleafcutting Fungus-Gardening Ants, Elizabeth D. Boshers

Biology Theses

Social complexity influences learning and other cognitive behaviors, but for insects, this influence is not well understood. Delayed rejection is an aversive learning behavior previously studied exclusively in leafcutting ant species, the most socially complex of the fungus-gardening ants. Fungus-gardening ants are unique in that they do not directly consume the material they forage, using it instead as substrate to cultivate a symbiotic fungus on which the ants are obligately dependent. Here, I attempt to induce delayed rejection in several fungus-gardening ant species that exhibit a range of social complexity, then compare the characteristics of delayed rejection behavior among species. …

How Individual Traits Predict Distribution Patterns And Community Convergence, Zachary K. Lange

Biology Dissertations - Archive

One of the fundamental questions in biology is whether natural conditions lead species and communities toward predictable outcomes. Answering this question requires understanding how traits of individual organisms are connected to species- and community-level patterns. In Chapter 2, I examined how thermal physiology and environmental temperatures interact to determine the distribution patterns of Anolis lizards on the Greater Antilles. I combined lab-measured thermal traits (critical thermal minimum: CT_min, critical thermal maximum: CT_max, thermal preference: T_pref) with occurrence and abundance data from 21 species of Anolis lizards collected from extensive mark-resight surveys of communities across …

The Evolution Of The Stress Response In The Trinidadian Killifish: Ecological Drivers And Maternal Mediation, Mikaela E. Feder

Biology Dissertations - Archive

Ecological variables can induce the stress response in organisms. Yet, few studies have tested for evolutionary shifts in stress responses across ecological gradients. In these studies, we used Trinidadian killifish found in sites with predators (high predation, HP) and sites where they are the only fish present (killifish only, KO). HP and KO populations differ in a suite of behavioral and life-history traits, making the Trinidadian killifish an excellent model to examine evolutionary physiology. My dissertation addresses the knowledge gap by examining: (1) how baseline cortisol differs in wild-caught Trinidadian killifish found in HP and KO sites, (2) the influence …

Karyotyping As A Method To Verify Phylogenetic Relationships Among The Enneacanthus Species, Ophelia A. Anderson

Theses and Dissertations

The Enneacanthus genus consists of three species of freshwater fish endemic to eastern North America: E. obesus (Banded Sunfish), E. gloriosus (Blue Spotted Sunfish), and E. chaetodon (Black Banded Sunfish). Previous studies using molecular data suggest that E. obesus and E. gloriosus are more closely related, with E. chaetodon as the most distantly related species in the genus. This study investigates the phylogenetic relationship among the Enneacanthus species, using karyotype characteristics - chromosome number, morphology and fundamental number - as comparative metrics. Chromosome spreads were obtained from scale and gill epithelium samples collected between 1993 and 1994. Prepared slides …

Divergent Floral And Vegetative Trait Responses To Abiotic Factors Drive Phenotypic Diversity In Platanthera Dilatata (Orchidaceae) Across Alaska, Marlin L. Bowles, Lisa E. Wallace

Biological Sciences Faculty Publications

Multiple traits make up an integrated phenotype, but traits may be shaped by differing drivers. It is often assumed that selection by biotic agents drives floral variation, but abiotic factors are also known to influence floral traits. Understanding trait covariations and their association with diverse environmental factors is a central question in evolution and ecology. Here, we studied covariation in floral and vegetative traits in relation to climate and topo-edaphic variation in the orchid Platanthera dilatata. In Platanthera, nectar spur length is associated with pollinator tongue length, but much variation exists in other traits too, likely to be …

Study Of The Brain Anatomy Of Three Extinct Marsupials: Thylacinus Cynocephalus, Thylacoleo Carnifex, And Silvabestius Johnnilandi, Francisco Garcia

Honors Program Theses and Research Projects

Marsupials are pouched mammals that today are mainly found in Australasia and South America. Marsupials have proven to be quite intriguing to evolutionary biologists who note how some marsupials resemble placentals in anatomy due to convergent evolution, with both marsupials and placentals filling similar niches in their respective environments. As of today, studies interested in marsupial brain evolution have published descriptions of cranial endocasts for several species of marsupials, with the number of descriptions seeing a massive boost over the last 20 years with the arrival of CT imaging technology. However, no comprehensive study of brain evolution in marsupials has …

Alfred Russel Wallace Notes 33. The Story In Evolution., Charles H. Smith

Faculty/Staff Personal Papers

Alfred Russel Wallace (1823-1913) is best known for his independent formulation of the principle of natural selection. In this work I first review my understanding of Wallace’s intellectual development on this subject, including the notion that he had no model for the evolution of higher consciousness as of his first treatment of natural selection in 1858. This leads to some conclusions about his approach to the subject, and links to parallel ideas inherent in the philosophy of Baruch de Spinoza (1632-1677).

What Drives Gut Microbial Diversity And Community Structure Among Closely-Related Host Species?, Rylee Jensen

All NMU Master's Theses

The gut microbiome (GMB) of mammals hosts an important community of microbes that perform countless micro-ecosystem services for the host and are influenced by numerous factors including host physiology, environment, and phylogeny. Phylogeny may have a unique effect on GMB diversity and community structure (i.e., a GMB profile) via phylosymbiosis, a theory in which the evolution of hosts matches the evolution of their associated microbiota. Elucidating phylosymbiosis in mammals is difficult because multiple intrinsic and extrinsic factors collectively drive individual GMB variation. Thus, there is a need to simultaneously analyze the role of physiology, environment, and phylogeny on shaping host …

A Comparative Analysis Of Extant Oceanic Shark Species Using Trait-Based Ecology, Elizabeth A. Johnson

All HCAS Student Capstones, Theses, and Dissertations

Over the past few decades, scientists have been working together to mitigate human impacts on global shark populations, but deciding which species need the most immediate attention can be difficult. This study uses a newly emerging approach to ecology, trait-based ecology, to identify trends in trait expression with depth and determine which species have the most unique sets of traits. While trait-based ecology has already been applied to numerous fields, a trait-based approach to shark research is still in its infancy. A total of 15 traits across 337 oceanic shark species were examined to identify trends in trait expression and …

The Evolution Of A Response To Smoke Within The Arthropoda, Adam Miles

Masters Theses & Specialist Projects

Many animals have a survival instinct to flee in response to fire, but do they respond to smoke alone? Many arthropods respond to fire or smoke by moving in the opposite direction (a negative taxis) to obtain shelter. At the species level, taxa that have adapted a behavioral response to fire increase their fitness. This response behavior has been observed in many terrestrial arthropods. Still, the behavior is currently unknown for marine, aquatic, or cave arthropods, which are atypically exposed to smoke or fire. This project assesses how often behavioral adaptation to smoke avoidance may have evolved within Arthropoda. Twenty-two …

Venom Complexity Within Garter Snakes And The Role Of Diet In Toxin Diversification, Tucker Heptinstall

All Theses

Complex traits, such as body size and venom, are often under strong selection by

dietary ecology and can increase efficiency of prey capture and processing. To investigate relationships between ecology and trait evolution in Thamnophis, we amassed nearly 10,000 diet records for 32/35 Thamnophis species and classified each species’ dietary repertoire. We categorized 15/32 species as generalist predators and 17/32 species as specialist predators of varying prey groups and investigated the hypothesis that generalist predators have larger body size. However, we found no significant relationship between body size and dietary specialization. Venom has evolved over 100 times across the Tree …

Antimicrobials Produced By Ants: Chemical Properties And Microbe Specificity, Katy Chon

Master's Theses

Antibiotic resistance is a growing public health concern worldwide, and for over a decade, we have been witnessing the growth of difficult to treat infectious diseases caused by bacteria that are becoming resistant to antibiotics. This resistance can be mostly related to the misusing and improper use of antibiotics in both humans and animals. To restore this problem, humans have turned to new sources for the production of antibiotics. In this study, we focused on using ants. Social insects, including ants and bees, have faced strong disease pressures during their evolution and have developed a range of methods to fight …