Evolution Commons^™

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

Novel Adaptations In Iron Regulation Acquired During Chronic Fungal Cf Infections, Daniel R. Murante

Dartmouth College Ph.D Dissertations

Chronic fungal infections are highly recalcitrant to treatment; we postulated that as populations persist, increasing genetic diversity is reflected in phenotypic heterogeneity, contributing to treatment inefficacies. The study of evolutionary patterns is underrepresented in chronic fungal infections, and to supplement this body of knowledge, we leveraged isolates acquired from four individuals with chronic fungal-dominated cystic fibrosis infections. We evaluated in-host evolution through a whole-genome sequencing approach, comparing multiple isolates obtained from each subject's sputum and bronchoalveolar lavage fluid. Our analysis found non-synonymous mutations that arose in parallel across the independent infections in the gene MRS4, which encodes a mitochondrial …

Rewiring The Sex-Determination Pathway During The Evolution Of Self-Fertility., Yongquan Shen, Shin-Yi Lin, Jonathan Harbin, Richa Amin, Allison Vassalotti, Joseph Romanowski, Emily Schmidt, Alexis Tierney, Ronald E Ellis

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Although evolution is driven by changes in how regulatory pathways control development, we know little about the molecular details underlying these transitions. The TRA-2 domain that mediates contact with TRA-1 is conserved in Caenorhabditis. By comparing the interaction of these proteins in two species, we identified a striking change in how sexual development is controlled. Identical mutations in this domain promote oogenesis in Caenorhabditis elegans but promote spermatogenesis in Caenorhabditis briggsae. Furthermore, the effects of these mutations involve the male-promoting gene fem-3 in C. elegans but are independent of fem-3 in C. briggsae. Finally, reciprocal mutations in these genes show …

Evolution And Adaptation To Temperature In Thermotogota, Anne Amelia Farrell

Dartmouth College Ph.D Dissertations

Life thrives across incredibly diverse environmental conditions, yet most organisms are restricted to growing within a narrow range around their optimum growth temperature (OGT). The evolutionary events leading to changes in OGT are poorly understood, and it is uncertain if specific genes are required to thrive at a particular temperature. The bacterial phylum Thermotogota is an excellent model for the evolution of OGT. It comprises mesophilic, thermophilic, and hyperthermophilic members that collectively grow between 20°C and 90°C.

In this work, I analyze the history of OGT in the Thermotogota phylum and show how horizontal gene transfer contributes to the evolution …

Multi-Type Branching Processes In Time-Varying Environments, Arash Jamshidpey

Biology and Medicine Through Mathematics Conference

No abstract provided.

Bioinformatic Comparison And Salinity Tolerance Of Various Cyanobacterial Strains, Lucie Rowe

Honors Theses

Cyanobacteria are an abundant and diverse group of photosynthetic prokaryotes with a long evolutionary history, which presents challenges for comprehensive taxonomic classification. Phylogenies were traditionally constructed based on the highly conserved 16S rRNA gene, but research has increasingly relied upon whole genome sequencing to elucidate evolutionary relationships, despite increased cost and time. In this thesis, publicly available genome sequences of various cyanobacterial strains were utilized to determine if the whole rRNA region, which includes the 16S, 23S, and 5S genes as well as the spacer regions between, could provide accurate, yet cost/time efficient representations of their evolutionary relationships. From phylogenetic …

Connecting Genotype And Phenotype: Investigating The Functional Morphology And Molecular Architecture That Influences Craniofacial Divergence Using Lake Malawi Cichlid Fishes, Leah Delorenzo

All Dissertations

Connecting genotype and phenotype to better understand how species evolve has been a goal of evolutionary developmental biologists over the last 50 years. This dissertation aims to connect genotype and phenotype of the craniofacial skeleton within the adaptive radiation of Lake Malawi cichlids to fortify our understanding of the functional, genetic, and epigenetic factors that contribute to craniofacial divergence. I start with a functional approach using 2D geometric morphometrics to assess craniofacial shape across the Lake Malawi cichlid radiation to bolster our knowledge of the bone phenotypes that are important to niche specialization and are functionally relevant. Next, I use …

Examining Population Structure Of Cismontane And Desert Populations Of Zebra-Tailed Lizards (Callisaurus Draconoides) Using Mitochondrial And Nuclear Intron Dna., Lauren Nicole Morrison

Electronic Theses, Projects, and Dissertations

Callisaurus draconoides, also known as the Zebra-Tailed lizard, belongs to the family Phrynosomatidae family (Pianka, et al. 1972). C. draconoides is a widespread desert lizard found western North America. In California, this species can be found in the Mojave and Colorado Deserts. There are currently several populations that reside in the San Bernardino basin on the cismontane side of the Transverse and Peninsular ranges. These mountain ranges have the potential to have isolated the cismontane populations from their typical desert ranges. In addition, geological passes have the potential to serve as migration corridor between the Deserts and cismontane regions. The …

The Descent Of Anolis: Assemblages, Convergence, And Ecomorphological Evolution, Christopher G. Anderson

Biology ETDs

The evolutionary outcomes we observe in modern organisms, particularly associations between phenotypes and environments, have been and remain an invaluable tool in interpreting the biological phenomena that shape our world. In the following chapters, I leverage a comprehensive phylogenetic and morphological dataset for 351 species comprising a diverse group of arboreal lizards, the Anolis clade, to explore how communities and morphologies evolve. First, I characterized patterns among coexisting lineages of Anolis to reveal a general pattern of phylogenetic relatedness among lineages comprising assemblages and identify differences attributable to a biogeographic variable. Then I examined the morphological consequences associated with the …

Alfred Russel Wallace Notes 30. Wallace A Theist? Part I., Charles H. Smith

Faculty/Staff Personal Papers

Alfred Russel Wallace (1823−1913) has been portrayed as a ‘theist’ on a large number of occasions from his own time on to the present. In this, the first of a two part work, this assessment is questioned. In part one, the matter of Wallace’s personal philosophy and spiritual orientation is explored, the conclusion being that Wallace was a lifelong agnostic who can hardly be aligned with theism.

Exploring Ecological Drivers Of Evolution Of The Brain, Cognition, And Behavior, Meghan Korte

Biology Dissertations - Archive

Evolutionary theory proposes that increases in brain size confer cognitive and behavioral benefits that offset the expensive investment in brain tissue. However, few studies have examined the relationship between brain size, cognition, and behavior within species. The majority of research has focused on cross-species comparisons, thus there is a need for empirical research within species examining how contrasting ecological pressures select for cognitive and behavioral benefits and how these may evolve in tandem with changes in brain size. My dissertation addresses this gap by examining: 1) Whether selection on brain size is linked to improvements in cognitive ability; 2) How …

A Case Of Incipient Budding Speciation In The California Floristic Province, Infraspecific Divergence In Abronia Villosa, Eli J. Allen

Cal Poly Humboldt theses and projects

Physical barriers to gene flow are the traditional evidence for species divergence. Conversely, there has been increasing acknowledgment of speciation in the face of gene flow as an evolutionary process. Budding speciation involves peripheral populations adapting to local ecological conditions, thereby budding off from a widespread progenitor species. Budding speciation is distinguished by ecological divergence and is generally evidenced by asymmetrical range size and nested phylogenetic relationships of sister species. The narrow endemic Abronia villosa var. aurita is adapted to montane sandy washes adjacent to its widespread sister variety, the desert dwelling var. villosa. Here, I tested the hypothesis …

A Balancing Act: Microrna Mediated Insect-Bacterial Homeostasis And The Tsetse Fly, Mason Hubbard Lee

Graduate Theses, Dissertations, and Problem Reports (ETD)

Microbial symbioses are ubiquitous across all kingdoms of life with broad and diverse impacts on the evolution of species. The sum of all microbes living in, on, or otherwise in close association with a host form the microbiota. In some cases, the development of a stable microbial association seems to have been necessary for the specialization of diet, as can be observed in numerous insect species, especially wood-eating, sap-feeding, and blood-feeding organisms. For the medically and economically tsetse fly (family Glossinidae), the mutualistic bacteria Wigglesworthia glossinidia is required for proper reproduction and supplementation of nutrients that the fly does not …

The Evolution Of The Metazoan Circadian Molecular Mechanism And The Conservation Of Canonical Circadian Elements, Olivia Waldridge

Theses and Dissertations--Biology

The temporal organization of biological activities through circadian rhythms is pivotal for the survival of organisms. Significant progress has been made in understanding the molecular foundations of animal circadian clocks through the characterization of key components such as Clock, Bmal1/Cycle(Cyc), Period (Per), Timeless, and Cryptochrome (Cry) in several model organisms. To determine the universality of this conservation, we investigated the sequences of these genes and their paralogs across 46 animal species that encompass multiple phyla in the metazoan kingdom to resolve the relative timing of duplication and loss events that have diversified core clock components in the metazoan kingdom. Using …