Evolution Commons^™

Sexual Di(Et)Morphism: Using Experimental Evolution To Test Whether Resource Partitioning Promotes Divergence Of The Sexes In Drosophila Melanogaster, Owen A. Jamieson

Theses and Dissertations (Comprehensive)

Sexual dimorphism has been a long-studied phenomenon in the field of evolutionary biology. Usually, these differences in morphology, physiology and/or behaviour between the sexes are studied through the parsimonious lens of sexual selection. However, there are natural history cases where this lens does not seem applicable. Some species show sex specific morphological traits whose presence may not be due to a direct benefit to reproduction, but a difference in how each sex interacts with the environment and differing selective pressures from the environment on either sex. Darwin even brought up examples of this kind of dimorphism and pondered their existence, …

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 …

A Simple And Affordable Protocol To Assess Censer Seed Dispersal: First Confirmation Of The Mechanism In The Genus Solanum, Abigail J. Motter, Christopher T. Martine, Melody P. Sain

Faculty Journal Articles

The censer seed dispersal mechanism, whereby mature fruits are retained on plants and seeds dispersed by mechanical shaking, is among the most specialized wind-aided seed dispersal strategies employed by the flowering plants. An efficient, affordable, and easily repeatable protocol for determining whether a species uses this unusual mechanism of seed dispersal is lacking. Our focal species, Solanum tudununggae, is one of just two Solanum species (in a fleshy-fruited genus of ca. 1200 species) hypothesized to use this dispersal mechanism as a means to move seeds farther from parent plants than would gravity alone.

Analysis Of Alternative Oxidase In Non-Angiosperm Plants, Anissa M. Francis

Theses and Dissertations (Comprehensive)

Alternative oxidase (AOX) is a mitochondrial terminal oxidase that provides an alternative pathway for electron transport, allowing plants to maintain respiratory flexibility under environmental stress conditions. While AOX has been extensively studied in angiosperms (flowering plants), little is known about its distribution and conservation in non-angiosperms. Based on gaps identified in the literature, this thesis investigated the distribution of AOX across non-angiosperm plant lineages. Although AOX is present in many green algae and is therefore considered to be an ancient protein that originated before the existence of non-angiosperm plants, it remains unclear whether the protein is uniformly distributed across these …

Sex In Plants: Birth, Death, And Trying To Survive In Changing Climates, Elena M. Meyer

Theses and Dissertations

Plant mating systems are key determinants of fitness. Angiosperms exhibit a wide variety of reproductive strategies, including self-fertilization (or selfing), outcrossing, and mixed mating. It has been estimated that up to 43% of plant species are capable of selfing, and selfing has been hypothesized to provide reproductive assurance where opportunities for mating may be limited, such as in marginal environments. However, questions regarding the overall distribution of selfing rates across angiosperms, the maintenance of mixed mating in the face of inbreeding depression, and the impact of self-fertilization on diversification rates remain incompletely resolved. Here, we explore the dynamics of self-fertilization …

Systematics Of Disk-Winged Bats (Thyroptera), Courtney L. Klumpp

Capstone Showcase

This thesis investigates the evolutionary relationships among disk-winged bats in the genus Thyroptera, a small group of Neotropical bats known for the adhesive suction disks on their wings and feet that allow them to roost inside tightly rolled leaves. The distinctive morphology and behavior of these bats have not been extensively documented, and their phylogenetic relationships remain only partially resolved. The goal of this research is to better understand how these species are related to one another and to determine whether the five recognized species of Thyroptera form a single monophyletic group. To address this question, morphological and genetic …

A New Dioecious Bush Tomato, Solanum Nectarifolium (Solanaceae), From The Northern Tanami Desert, Northern Territory, Australia, With Reassessment Of S. Ossicruentum And A Change In The Circumscription Of S. Dioicum, Christopher T. Martine, Kym Brennan, Jason T. Cantley, Aiden Webb, Geoffrey Newton

Faculty Journal Articles

A new species of functionally dioecious bush tomato from the “Solanum dioicum + S. echinatum group” of Solanum subgenus Leptostemonum is described. Solanum nectarifolium Martine & Brennan, sp. nov., is a member of the taxonomically challenging Solanum dioicum W.Fitzg. species complex in Australia and differs from other species in the group by the presence of prominent and conspicuous extrafloral nectaries on the abaxial leaf surfaces, a tinge of purple on the new growth and young fruiting calyces, and curved prickles on young stems. Although fairly well represented in herbarium collections, this new taxon has historically been treated as a …

The Inherent Values Of Observation And Description: A Case Study In The Spiny Solanums Of Australia, Christopher T. Martine

Faculty Journal Articles

The basic exploratory effort of doing descriptive biology is an avenue by which we can deepen our knowledge about taxa and the natural phenomena that drive their diversification. As Conniff (2011) wrote in The species seekers, “we still live in the great age of discovery”, and much like that historically recognized period of the eighteenth and nineteenth centuries there remains today a distinct need for the sort of work that might have been attributable to the naturalists of that time. The careful observation of how organisms go about their lives, including how they interact with one another …

Evaluating The Environmental Determinants Of Tadpole Mouthpart Deformities, Nicholas J. Canfield

Research from the Berry Summer Thesis Institute, 2025

Amphibians are among the most threatened group of animals on the planet, with over 40% of living species facing an extinction risk. These organisms are highly sensitive to environmental change due to their highly permeable skin and complex life cycle that exposes them to stressors in both aquatic and terrestrial ecosystems. Amphibian populations that are closely monitored can serve as valuable bioindicators of environmental health because they typically respond rapidly to habitat degradation, decreased water quality, and changes in climate. Tadpoles in particular may act as a “canary in a coal mine” for aquatic ecosystems because they easily develop anatomical …

A Phylogenomic Investigation Of The Historical Biogeography Of Livebearers (Cyprinodontiformes: Poeciliidae), Sheila Rodríguez Machado

LSU Doctoral Dissertations

The Neotropics contain several biodiversity hotspots and harbor the highest diversity of freshwater fishes globally. Yet, recognizing the patterns and processes driving this richness remains a challenge. Similarly, all groups and subregions have not received the same attention, especially in the genomics era. Addressing these knowledge gaps will help us to better understand the region’s evolutionary and biogeographic complexity. The goal of this dissertation is to examine phylogenetic and biogeographic patterns of Neotropical freshwater fishes, with emphasis on the Greater Antilles, across multiple taxonomic and geographic scales. To achieve this goal, I generated a genomic dataset of hundreds of ultraconserved …

Diversification Of Avifauna In The Darién Highland Region: Ecological Niche Modeling, Phylogeography And Morphology To Explore Speciation In The Montane Species Myadestes Coloratus, Chlorospingus Tacarcunae And Margarornis Bellulus., Jorge L. Garzon Vasquez Mrs

Theses and Dissertations

Montane regions in the Neotropics are hotspots of endemism and biodiversity, yet their species are especially vulnerable to the impacts of climate change and geographic isolation. This thesis investigates the evolutionary and ecological dynamics of three bird species endemic to the Darién Highlands of eastern Panama: Myadestes coloratus, Chlorospingus tacarcunae, and Margarornis bellulus. Through an integrative approach combining ecological niche modeling, morphometric analysis, and genomic data from ultraconserved elements (UCEs) and mitochondrial DNA, the study explores the historical biogeography, current distribution patterns, population structure, and phenotypic differentiation of these montane taxa. Ecological niche models revealed that suitable habitat …

Molecular Characterization Of Fungus-Arthropod Associations, Angie M. Martin

Graduate Theses, Dissertations, and Problem Reports (ETD)

Arthropods, or phylum Arthropoda, are the largest group of animals, accounting for over three quarters of all animal records on NCBI Taxonomy. And yet, only 40% of all deposited sequences on NCBI Nucleotide come from arthropods. Clearly, arthropods are an understudied group of animals: they are small, often drab, and lead lives very alien to our own. Arthropods have chitinous exoskeletons, segmented bodies, and jointed appendages, and include crabs, barnacles, insects, spiders, and millipedes. Since the era of DNA based studies took off in the 1980s, DNA and other small molecules have been integral to our understanding of the Earth …

The Influence Of Environmental Change On Genetic Diversity Across Spatial And Taxonomic Scales, Connor M. French

Dissertations, Theses, and Capstone Projects

The spatial distribution of genetic diversity is of interest to biodiversity scientists and conservationists and is a fundamental metric of biodiversity. Genetic diversity patterns across spatial and taxonomic scales contain information about population and assemblage dynamics that can convey their resilience to environmental change. Ectotherms are especially linked to their environments and may be especially sensitive to fluctuations in the environment over time. Herein, I investigate global and regional patterns of genetic diversity in two groups of ectotherms, insects and lizards, to understand the relationship between environmental change and genetic diversity, from populations to assemblages. Overall, my research aims to …

The Role Of Elevation In The Migration, Physiology, And Genomic Diversification Of Birds, Jessie L. Williamson

Biology ETDs

Elevational gradients cause profound eco-climatic variation across short distances. Partial pressure of oxygen (PO₂) is a severe challenge that organisms face at high elevations; due partly to specialization on PO₂, most Neotropical bird species have narrow elevational ranges. However, a small fraction are elevational generalists that span sea level to high elevations, and a subset undertake extreme migratory journeys from low to high elevations biannually. My dissertation combines diverse approaches across levels of biological organization to understand how elevation impacts the ecology, evolution, physiology, and migration of montane birds. I examined ‘extreme’ elevational …

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 …

Omani Camels From A Cultural And Genomics Perspective, Al Muatasim Al Zadjali

Electronic Theses and Dissertations

The Dromedarian camel, Camelus dromedarius, is native to the Arabian Peninsula, including the Sultanate of Oman. These camels are used for food, milk, as well as show and racing competitions. Despite their economic and cultural importance research on camels in Oman is limited. The goal of this study was to examine their genomic variation, relationship with camels in other parts of the Arabian Peninsula, and to determine if selective breeding has led to the establishment of distinct breeds in Oman. Information was compiled from multiple sources to produce a comprehensive review on the breeding, management, economic and cultural use, …

Cross-Pollination: Building A Co-Taught Course To Examine Art And Sex Through The Lens Of Botany, Christopher T. Martine, Diamanda A. Zizis, Anna K. Kell

Faculty Journal Articles

Driven by overlapping interests in plants, art, and diversity in sex expression, Anna Kell (Department of Art and Art History) and Chris Martine (Department of Biology) developed a course that integrates the perspectives of a visual artist and a botanist. Art & Sex Through the Lens of Botany seeks to impart the importance of making connections across disciplines and the value of visual literacy across academic lines. The course introduces foundational concepts in each field and encourages students to integrate and explore these different systems of knowledge and their intersections. In addition to developing fluencies related to both general botany …

Parental Environnement Influences Offspring Gene Expression In The Olympia Oyster, Ostrea Lurida., Mark S. Yeats

LSU Master's Theses

The Olympia Oyster is the only native oyster species on the Pacific coast of North America. Seasonality in water temperatures across this threatened species’ broad and fragmented range has been linked to its development, reproductive timing, reproductive activity, growth, and survival rates. Recent evidence suggests parental environments can have carry-over effects on larval growth and respiration rates in response to temperature. In this study, we utilized transcriptomic methods to identify the underlying mechanisms of this cross-generation plasticity. Sequence libraries of adult ctenidia tissue and pooled larval replicates were extracted and spawned from hatchery raised oysters of the same parentage immediately …

The Morphological Evolution Of The Inner Ear In Lacertoidea (Squamata), Cristian Hernandez

Biology Dissertations - Archive

The popularization of high-resolution computed tomography(HRCT) has produced a revolution in the field of comparative anatomy. This technology allows us to reach a level of morphological detail in our observations that has never been possible previously. Now we can perform digital dissections isolating structures of interest such as individual bones, soft tissue organs, and even generate 3D models of body cavities (endocasts) such as the braincase and inner ear. Encompassed with the progress of the HRCT, 3D geometric morphometrics have emerged as a common tool to address morphological questions in a statistical context that outperforms the traditional 2D geometric morphometrics. …

Functional Investigation Of Shaggy, An Inhibitor Of Canonical Wnt Signaling, In The Tardigrade Hypsibius Exemplaris, Raul A. Chavarria

UNF Graduate Theses and Dissertations

Tardigrades have a highly simplified anteroposterior (AP) axis. The mechanisms that regulate the development of this secondarily simplified AP axis are not known. In many animals, the canonical Wnt (cWnt) signaling pathway regulates primary axis establishment through antagonistic interactions with inhibitors of cWnt signaling. This study investigated the roles of shaggy, an inhibitor of cWnt signaling, in regulating development in the tardigrade Hypsibius exemplaris. Gene expression patterns of shaggy and other components of the cWnt signaling pathway were analyzed alongside markers of anterior and posterior identity using Hybridization Chain Reaction in situ in H. exemplaris. RNA interference …

High-Quality Dietary Protein (Essential Amino Acids Matched To Reproductive Needs) Partially Breaks The Lifespan And Reproduction Trade-Off In Lubber Grasshoppers, Emma Kordek

UNF Graduate Theses and Dissertations

Finding interventions to break the trade-off between reproduction and lifespan can provide insight into physiological limitations of animals. Effects of dietary protein quality on the trade-off are currently unclear, but clarity could lead to better designed diets that match animal needs. Dietary amino acid blends matching yolk proteins support reproduction and extend lifespan in fruit flies. To test if this is conserved across species, we matched dietary amino acids to vitellogenin to test reproduction and lifespan in adult females of the lubber grasshopper. Specifically, we compared varying degrees of protein quality by manipulating dietary essential amino acids. We identified a …

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

Master of Science in Integrative Biology Theses

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

Morphological Trait Evolution In Solanum (Solanaceae): Evolutionary Lability Of Key Taxonomic Characters, Rebecca Hilgenhof, Edeline Gagnon, Sandra Knapp, Xavier Aubriot, Eric Tepe, Lynn Bohs, Leandro Giacomin, Yuri Gouvea, Andres Orejuela, Christopher T. Martine, Clara Ines Orozco, Iris E. Peralta, Tina Sarkinen

Faculty Journal Articles

Solanum is one of the world's largest and economically most important plant genera, including 1245 currently accepted species and several major and minor crops (e.g., tomato, potato, brinjal eggplant, scarlet eggplant, Gboma eggplant, lulo, and pepino). Here we provide an overview of the evolution of 25 key morphological traits for the major and minor clades of this giant genus based on stochastic mapping using a well-sampled recently published phylogeny of Solanum. The most evolutionarily labile traits (showing >100 transitions across the genus) relate to plant structure (growth form and sympodial unit structure), herbivore defence (glandular trichomes), pollination (corolla shape …

Development Of A 16s Reference Library For Edna Metabarcoding The Freshwater Fishes Of Western Ecuador., Hannah M. Willis, Olivia G. Schweikart, Windsor E. Aguirre

DePaul Discoveries

This project examines the use of the 16S locus to amplify neotropical freshwater fishes native to Western Ecuador in a newly created 16S reference library for DNA barcoding and eDNA metabarcoding applications. Among the orders Characiformes, Siluriformes, Cichliformes, Gobiiformes, Cryprinodontiformes, Gymnotiformes, and Perciformes, a compendium of 105 specimens were sequenced, with 43 representing new 16S sequences previously unavailable on Genbank.

Fluidity And Inconstancy: Australian Bush Tomatoes As An Exemplar Of Non-Normative Sex Expression, Christopher T. Martine

Faculty Journal Articles

Solanum, a genus of ~1500 global species, is one of the more interesting plant groups in which to study reproductive biology and ecology. Overwhelmingly, species in this group express full cosexuality, where individual plants have flowers containing both fully-functioning “male” (staminate) and “female” (carpellate) organs. However, there have been multiple and widespread evolutionary transitions within the genus to non-normative variations on this ancestral condition. Australian bush tomatoes (ca. 40 species) are especially diverse in this regard, with uncommon variation and combinations of unisexuality and cosexuality -- including, most notably, two sexual systems known as dioecy (unisexual male or female …

Past And Present Patterns Of Neutral And Adaptive Genetic Diversity In Wild Mandrills (Mandrillus Sphinx), Anna Weber

LSU New Orleans Theses and Dissertations

Although primates have fascinated researchers and the public alike for generations, one species that has remained enigmatic is the mandrill (Mandrillus sphinx), a large Cercopithecine monkey endemic to Central Africa. Mandrills are currently in decline due to bushmeat hunting, urbanization, and habitat loss. Neutral and adaptive genetic diversity are important tools for understanding evolutionary history and future viability, since diversity influences a species’ ability to adapt to a changing environment. However, thus far, minimal genetic information has been available for wild mandrills. Because of the dense vegetation in their tropical forest habitat, studying wild mandrills has proven to …

Does The Genome Of A Putatively Specialist Moth (Schinia Gracilenta) Contain A Signal Of The Indigenous Cultivation Of Its Host Plant (Iva Annua), Wren Renquist

2023 Midwest Ecology & Evolution Conference

When one species depends on one another for survival, they may have shared demographic histories. Further, when symbionts have shorter life spans, their rate of evolution may be quicker than that of their hosts. For this reason, detecting a recent demographic signal in a symbiont’s genome may often be easier than directly studying the host.

Here I study the slender flower moth (Schinia gracilenta) and its host plant, sumpweed (Iva annua). Sumpweed is thought to have been cultivated in North American ca. 5000 BC - AD 1700 and its range may have been expanded during this time. I collected S. …

Biomechanics Of Mantis Prey Capture, Danielle S. Taylor

Honors Theses

Mantis species have a variety of different morphologies, so do the extreme forms of mantis limbs trade prey catching capability for camouflage? We hypothesize that some extreme forms of mantis limbs that are associated with cryptic species may be associated with a tradeoff of the capability of those limbs. Previous research has developed 2D morphologies of several hundred species of mantises. We are creating a 3D morphology by using micro dissection, micro CT imaging to construct our 3D biomechanical model. We found the attachment points of the ligaments and muscles from a Tenodera forearm and have constructed a 2D biomechanical …

Investigation Of The Segment Polarity Network In The Tardigrade Hypsibius Exemplaris, Taylor R. Harrison

UNF Graduate Theses and Dissertations

Segmentation has facilitated the evolution of the many forms of the panarthropods. Downstream regulation of segmentation is controlled by the highly conserved segment polarity network which includes the genes engrailed (en), hedgehog (hh), wingless (wg), cubitus interruptus (ci), patched (ptc), and smoothend (smo). While a high level of conservation has been seen in both the arthropods and onychophorans, only en has been described in any representatives of Tardigrada. Previous work had already established the loss of wg, which encodes for a Wnt ligand, in the tardigrade H. exemplaris …

Insect Availability And Parental Care Behavior In A Common Bird, Cole Bourque

Symposium of Student Scholars

Populations of aerially insectivorous birds are declining throughout North America. Urbanization may indirectly contribute to this decline through its negative effects on populations of insects, an important food source in insectivores' diets, where low insect availability may be especially challenging for birds during breeding. How fluctuations in insect populations impact various species at higher trophic levels is an important area of current study for future conservation biology. Here, we examine whether nestling provisioning, brooding and guarding behaviors in a breeding bird—the European starling (Sturnus vulgaris)—may be altered depending on the relative insect availability in the environment. We found …