Evolution Commons^™

Systematics Of African River Frogs (Anura: Pyxicephalidae: Amietia) In Central Africa, With The Description Of Two New Species, Jesus Manuel Reyes

Open Access Theses & Dissertations

Amietia is a pyxicephalid anuran genus that is prevalent throughout central, southern, and eastern portions of sub-Saharan Africa. Recent phylogenetic studies have been in conflict regarding the validity and composition of several Amietia species in the Albertine Rift region. The goals of this study are to: (1) generate an updated molecular phylogeny for Central African Amietia with new sampling; (2) clarify the relationship between the previously unsampled taxa A. amieti and A. chapini; (3) clarify the status of A. desaegeri; and (4) confirm the taxonomic status of potentially new species. Maximum likelihood and Bayesian inference methods were used to generate …

Phylogenetics And Integrative Taxonomy Of The Lang's Reed Frog Species Complex (Anura: Hyperoliidae: Hyperolius Langi), Dominic Troiani

Open Access Theses & Dissertations

The genus Hyperolius (Rapp, 1842) is the most speciose amphibian genus in sub-Saharan Africa. The genus has a complex taxonomic history because of its extensive intraspecific and interspecific morphological variation, large geographic distribution of many taxa, gaps in sampling, and the discovery of significant cryptic diversity within many species. The goal of this study is to understand the relationships and taxonomy of Hyperolius langi via an integrative taxonomic approach that combines molecular, morphological, and bioacoustics data to clarify the systematics of the geographically widespread species Hyperolius langi. Two mitochondrial (16S and cyt b) and one nuclear (RAG1) gene were used …

Association Between Gene Family Expansion And The Rapid Diversification Of Pleurocarpous Mosses, Meredith A. Cobb

All Theses

Mosses are the second most species-rich group of land plants. They represent a critical group for understanding the evolution and diversity of land plants. Mosses comprise two major groups, acrocarps and pleurocarps. Despite having a more recent evolutionary origin than acrocarps, pleurocarps are exceptionally diverse. The difference in species richness reflects a rapid species diversification, roughly coincident with the origin and diversification of flowering plants. The speciation events giving rise to pleurocarp diversity happened so rapidly, making it historically difficult to produce strongly supported phylogenies with which to test evolutionary hypotheses. One such hypothesis is whether large-scale changes at the …

Linked Lives In The Riverbed: Integrating Fish Host Dynamics, Community Structure, And Demography For Freshwater Mussel Conservation., Jonathan Patrick Frommeyer

Electronic Theses and Dissertations

Freshwater mussels are long-lived benthic invertebrates that play key roles in nutrient cycling, water filtration, and habitat stability in rivers and streams. Despite their ecological importance, they are among the most imperiled faunal groups in North America, with their persistence increasingly threatened by environmental degradation and disruptions to host–parasite dynamics. This dissertation integrates host ecology, community structure, and demographic modeling to assess population viability and guide conservation priorities for mussel species in Kentucky river systems. The first chapter introduces the ecological context and conservation urgency surrounding freshwater mussels. In particular, emphasizing the need for multi-scale approaches to understand how parasitic …

Ecomorphological Diversification Of Tooth Complexity In The Oral Jaws Of Marine Teleostean Fishes, Keiffer L. Williams

All Dissertations

Teeth are essential biological tools that function as a direct interface between predator and prey, thus providing essential insights into the evolutionary history and ecological diversity of vertebrates. Historically, studies on vertebrate dentitions have been qualitative and focused on mammals. More recently, quantitative methods have been developed that can reliably measure tooth surface complexity. These methods have been applied across both mammals and saurian reptiles to test for correlations with diet, leading to the conclusion that herbivorous species generally possess higher overall tooth complexity than any other dietary group. Surprisingly, the relationship between tooth complexity and diet in the most …

The Island Biogeography Of Mangrove-Dwelling Vertebrates: Isolation, Specialisation, And Extinction, Jian Xiong David Tan

Biology ETDs

Mangroves are highly dynamic ecosystems that are widely distributed across the coastlines of the tropics and subtropics. Despite their low plant diversity, mangroves host a disproportionately high number of terrestrial vertebrate taxa. However, mangrove specialists — taxa that only occur in mangrove habitats — exhibit a global distribution that is incongruous with the broader background distribution patterns of mangrove-associated fauna, exhibiting higher diversity in Australia and Southeast Asia. This dissertation therefore aims to assess how the diversity and distribution of mangrove specialist fauna may have been shaped by the historical biogeography of mangroves, and the effects of mangrove specialisation on …

Scorpions Of The Horn Of Africa (Arachnida: Scorpiones). Part Xli. Pandinops Sahil Sp. N. From Somaliland (Scorpionidae), František Kovařík

Euscorpius

Pandinops sahil sp. n. from Somaliland is described and compared with other species of the genus, fully complemented with color photos of specimens of both sexes of the new species, as well as of their habitat. Pandinops bambii Rossi, 2017 is synonymyzed with Pandinops turieli Kovařík, 2016, syn. n. A key for the species of Pandinops and a map of the distribution of the genus are provided.

Scorpions Of The Horn Of Africa (Arachnida: Scorpiones). Part Xl. Barbaracurus Lowei Sp. N. From Ethiopia (Buthidae), František Kovařík, Hassan Sh A. Elmi

Euscorpius

Barbaracurus lowei sp. n. from Ethiopia is described and compared with other species of the genus, fully complemented with color photos of specimens of both sexes of the new species, as well as of their habitat. Included is a key for Barbaracurus and a map of the distribution of the genus in the Arabian Peninsula and the Horn of Africa.

Niche Conservatism And Sympatric Parallel Evolution May Help To Maintain Eight Nascent Tree Taxa Along A Sharp Elevation Gradient, Elizabeth A. Stacy, Rebecca Ostertag

Life Sciences Faculty Research

1. Patterns of niche partitioning among closely related taxa, such as those in incipient adaptive radiations, can provide clues into how niches are created, partitioned, and integrated over ecological and evolutionary time scales. Hawaiian Metrosideros is a ~3-MYO adaptive radiation of trees that dominates the Hawaiian Islands in continuous stands within islands and allows examination of niche partitioning at the early stages of adaptive radiation.
2. We monitored growth and survivorship over 2 years of seedlings derived from open-pollinated fruits of eight Metrosideros taxa distributed along the elevation gradient of Koʻolau Volcano, Oʻahu, under four combinations of light and phosphorus. We included …

The Astrobiological Figure Of Humboldt As Pioneer In The Rock Varnish Research, Jose Jordan-Soria

Homage to Alexander von Humboldt: Travels to and from Spain Throughout the Centuries / Homenaje a Alexander von Humboldt: Viajes hacia y desde España de todos los siglos

From Humboldt is particularly interesting -and little know- his description of mineral coatings on rocks 200 years ago, reported in his book Personal Narrative of Travels to the Equinoctial Regions of the New Continent during the years 1799-1804, co-written with Aimé Bonpland, for which is considerate the father of rock coating research. On June 5th 1799 set sail from A Coruña -Spain- to Cumaná -Venezuela- beginning five years of expedition. While they explored the Orinoco River system, in th eriver basin waterfalls, Humboldt observed the presence of dark coating depositions. He ascertained a manganese-rich accretion, reporting similar structures in other …

First Case Of Sexual Cannibalism In Leiurus Abdullahbayrami Yağmur, Koç & Kunt, 2009 (Scorpiones: Buthidae) From Lebanon, Rami Khashab

Euscorpius

This study presents the first report of sexual cannibalism in the medically significant scorpion Leiurus abdullahbayrami Yağmur, Koç & Kunt, 2009, that was recorded during a herpetological field trip to the semi-desert area in northern Lebanon. It broadens the understanding of sexual cannibalism in scorpions and adds a new prey item to the dietary spectrum of the scorpion.

Scorpions Of The Horn Of Africa (Arachnida: Scorpiones). Part Xxxix. Buthus Pygmaeus Sp. N. From Somaliland (Buthidae), František Kovařík, Graeme Lowe, František Šťáhlavský, Hassan Sh A. Elmi

Euscorpius

New data are presented on the distribution of the genus Buthus Leach, 1815 in the Horn of Africa, mainly in Somaliland. B. pygmaeus sp. n. is described, fully complemented with color photographs of live and preserved specimens, as well as their habitats. In addition to the analysis of external morphology and hemispermatophors, we provide a description of the karyotype of B. pygmaeus sp. n. (2n=22). A key and distribution map of Buthus in the Horn of Africa (six species) are included

​​Site Fidelity Is Associated With The Social Experience Of Forked Fungus Beetles (Bolitotherus Cornutus), Joo Yeon Kim , '22, C. W. Wood, E. D. Brodie Iii, Vincent A. Formica

Biology Faculty Works

Consistently returning to or remaining within a specific location, a behavior known as site fidelity, is a useful metric for quantifying animal space use. When multiple individuals display similar site fidelity patterns, they are likely to interact, shaping the degree and quality of their social interactions. However, the link between the expression of site fidelity behavior and an individual’s social experience has not been thoroughly investigated. In this study we examined (1) how intrinsic individual properties (body size and sex) predicted variation in site fidelity and (2) whether site fidelity was linked to the social experience of individuals in wild …

Evolutionary Dynamics Of Artificial Agents: Exploration And Learning In Games, Brian Mintz

Dartmouth College Ph.D Dissertations

The natural world abounds with examples of complex behavior in humans and many other species. Evolutionary game theory is a powerful mathematical framework to understand the origins of many such behaviors like cooperation. Since these behaviors are often selected against initially, understanding why they are so widespread has been a longstanding question. Rather than assuming agents' rationality, like in traditional game theory, this approach studies the mutation and selection of strategies themselves. However most behavior is neither perfectly rational nor entirely determined by genetics. This dissertation works to bridge the gap between these two perspectives by analyzing models where individuals …

Changes In Morphology, Phenology, And Demography Of Several Avian Species Over 18 Years At A Restored Grassland, Ashley Mcmahon, Katie Stumpf

Georgia Journal of Science

In response to a changing climate and the loss of habitat, avian species are displaying changes in body size, migration phenology, and demography. Several species have adhered to Allen’s and Bergmann’s rules by displaying increased wing length and decreased mass, respectively, over time in response to higher temperatures. Climate change has also resulted in earlier spring migration and depending on species, either earlier or later fall migration. Finally, species affected by habitat loss often display male-skewed sex ratios and juvenile skewed age ratios. Our goal was to determine how body size, migration phenology, and demography have changed for grassland birds …

Field Journal: The Excluded Middle, Carrie E. Kouts

Masters Theses

What does it look like to engage with organisms and landscapes at the periphery of anthropocentric value structures? How does one break the internalized myth that the “built” environment is excluded from the natural world? When does a hyper-mobile and hyper-commodified society confront the exponential crisis of animal death? Within this series of journal entries, field notes, collection observations, weird prose, and sensory musings, one will find questions on the nature of being human and the complex narratives of care we encounter in a world shared with more-than-humans. Each handwritten vignette and photograph from daily life weaves a non-linear and …

Cost-Effective Solutions For High-Throughput Enzymatic Dna Methylation Sequencing, Amy Longtin, Marina M. Watowich, Baptiste Sadoughi, Rachel M. Petersen, Sarah F. Brosnan, Kenneth Buetow, Qiuyin Cai, Cayo Biobank Research Unit, Vanderbilt University, Michael D. Gurven, James P. Higham, Heather M. Highland, Yi-Ting Huang, Hillard Kaplan, Thomas S. Kraft, Yvonne A. L. Lim, Jirong Long, Amanda D. Melin, Michael J. Montagne, Jamie Roberson, Kee Seong Ng, Michael L. Platt, India A. Schneider-Crease, Jonathan Stieglitz, Benjamin C. Trumble, Vivek Venkataraman, Ian J. Wallace, Jie Wu, Noah Snyder-Mackler, Angela Jones, Alexander G. Bick, Amanda J. Lea

ESI Publications

Characterizing DNA methylation patterns is important for addressing key questions in evolutionary biology, development, geroscience, and medical genomics. While costs are decreasing, whole-genome DNA methylation profiling remains prohibitively expensive for most population-scale studies, creating a need for cost-effective, reduced representation approaches (i.e., assays that rely on microarrays, enzyme digests, or sequence capture to target a subset of the genome). Most common whole genome and reduced representation techniques rely on bisulfite conversion, which can damage DNA resulting in DNA loss and sequencing biases. Enzymatic methyl sequencing (EM-seq) was recently proposed to overcome these issues, but thorough benchmarking of EM-seq combined with …

Network Analysis Of Antimicrobial Resistance In Staphylococcus Aureus: Characterization Of Hub Genes And Their Functional Implications, Md Imran Hasan, Davida Smyth, Jeong Yang, Ashley Teufel

Masters Theses (Archived)

Antimicrobial resistance is a major cause of morbidity and mortality in patients with S. aureus infections. In this study, we analyzed genes, molecular mechanisms, and pathways driving drug resistance in S. aureus using network analysis. Using whole-genome sequencing (WGS) data and systems biology approaches, we identified 229 AMR-associated genes and constructed a protein-protein interaction network among these genes. Through network topology and functional enrichment analyses, we not only confirmed their association with resistance, but also highlighted the central roles of these genes in resistance pathways, such as efflux, target replacement, and target protection, which are directly linked to multiple drug …

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 …

Scorpions Of The Horn Of Africa (Arachnida: Scorpiones). Part Xxxviii. Parabuthus Puntlandus Sp. N. From Somalia (Puntland) (Buthidae), František Kovařík, František Šťáhlavský, Hassan Sh A. Elmi, Roman Štarha

Euscorpius

A new species Parabuthus puntlandus sp. n. from Somalia (Puntland) is described. Combination of five characters; metasoma V black; pectine teeth number 39–42 in both sexes; pedipalp chela length/width ratio 3.05–4.26 in both sexes; metasoma and telson sparsely hirsute; smooth inner side of the base of fingers of pedipalp chela (tubercle absent) distinguish P. puntlandus sp. n. from all other species in the region. In addition to the analyses of external morphology, we have provided descriptions of the karyotype of P. puntlandus sp. n. (2n=16). Included is also a map of distribution of Parabuthus species in Horn of Africa.

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 …

Uncovering The Evolutionary Origins Of Neo-Sex Chromosomes In The Insect Family Membracidae, Mary Kumah

2025 Spring Honors Capstone Projects - Archive

This research explores the evolution of the neo-XX/XY sex chromosome system of Amblyophallus exaltatus, a treehopper insect in the family Membracidae. Neo-XX/XY sex chromosome systems can evolve from an XX/X0 sex chromosome system via fusion events between the X chromosome and an autosome. Although cytological work has indicated the presence of a neo-XX/XY system within A.exaltatus, the chromosomal identity of the fused autosome and the molecular drivers behind this chromosomal fusion remain poorly understood. By performing a coverage analysis with whole genome sequence data, the parts of the A.exaltatus genome that fused with the X chromosome will be better …

Morphology Of Smallmouth Bass (Micropterus Dolomieu) In Arkansas, Robert Laroche

Biological Sciences Undergraduate Honors Theses

The Smallmouth Bass, Micropterus dolomieu, is one of the most important game fishes in Arkansas. Three distinct lineages are recognized from different river basins: the Northern, Neosho, and Ouachita Smallmouth Bass. Understanding the biodiversity within this species complex inhabiting different water bodies in Arkansas is important for effective management of the fisheries resource and to guide conservation efforts. But current data on distribution of distinct forms are insufficient to guide management. The primary goals of the study presented here was to quantify morphological characteristics to identify distinct lineages of Smallmouth Bass, and to determine their specific locations within Arkansas streams …

Maggot Mass Effect On The Development And Survival Of Forensic Blow Flies, Akomavo Fabrice Gbenonsi

School of Natural Resources: Dissertations, Theses, and Student Research

Forensic entomology scientists use blow flies' developing patterns to estimate the postmortem interval (PMI). However, larval aggregations produce metabolic heat, resulting in complex microclimates that may change growth timetables. This study investigates how larval density and associated temperature changes affect the development and survival of two forensically essential blow fly species, Lucilia sericata and Calliphora vicina.

This study examined how larval density and associated thermal profiles affect the development of both blow fly species. Using a split-plot design, we tested four larval densities at 25°C and 30°C, with temperature gradients measured via thermocouple at four mass positions three times …

Chromosome Evolution Model Reveals Hidden Variation In Karyotype-Driven Speciation In Ferns, Thomas Buchloh

All Theses

Because karyotype change commonly generates reproductive isolation between diverging species, rapid karyotype evolution, like that seen in plants, may increase the total rate of diversification. However, few studies have investigated this predicted relationship. Tests of this prediction have identified a positive correlation between the rate of karyotype change (specifically whole genome duplications) and diversification, but tests have been restricted to relatively small and young clades. Fortunately, novel macroevolutionary models have recently become available to investigate patterns of karyotype evolution in large phylogenies, providing new opportunity to investigate variation in karyotype driven diversification. Ferns are one of the most karyotype rich …

A Redescription Of Leiurus Libycus (Birula, 1908), Stat. N. (Scorpiones: Buthidae), Ersen A. Yağmur, František Kovařík, Victor Fet

Euscorpius

Buthus quinquestriatus libycus was described by Birula (1908) from the Libyan Desert, based on a subadult male specimen. This taxon was later synonymized with Leiurus quinquestriatus (Ehrenberg, 1828) by Vachon (1949). In this study, we re-evaluate this taxon and recognize it as Leiurus libycus (Birula, 1908), stat. n., providing a redescription based on the holotype. The type locality of this species is clarified as western Egypt (between Alexandria and Fayum). We synonymize Leiurus aegyptiacus Lourenço & El-Hennawy, 2021 with L. libycus, stat. n., syn. n.

A New Centruroides Species And First Record Of C. Tapachulaensis Hoffmann, 1932 (Scorpiones: Buthidae) From Honduras, Luis F. De Armas, Alex M. Cubas-Rodríguez

Euscorpius

A new species of striped bark scorpions, Centruroides lenca sp. n. is described, based on both sexes, from the Pacayita Volcano Biological Reserve (2,385 m a. s. l.), Ocotepeque Department, in the southwestern Honduras. By its general pattern, the new species resembles C. thorellii (Kraepelin, 1891), from which it clearly differs by having stronger and very darker pedipalp chelae, minute subaculear tubercle and basal pectinal plate with a large central pit in the female, among other diagnostic characters. Also, Centruroides tapachulaensis Hoffmann, 1932 is recorded for the first time from Honduras, on the basis of two observed or collected specimens …

Scorpions Of The Horn Of Africa (Arachnida, Scorpiones). Part Xxxvii. The Genus Hemiscorpius (Hemiscorpiidae), František Kovařík, Hassan Sh A. Elmi, František Šťáhlavský

Euscorpius

Occurrence of the rare in the Horn of Africa genus Hemiscorpius Peters, 1861 (Scorpiones: Hemiscorpiidae) is summarized, including a distribution map. A male of Hemiscorpius lipsae Kovařík & Lowe, 2022 from Djibouti is described for the first time. A new species Hemiscorpius huluul sp. n. from Somaliland is described, fully complemented with color photographs.

An Injury Healing On The Carapace Of Hottentotta Saulcyi (Simon, 1880) (Scorpiones: Buthidae), Fatih Yeşilyurt, Ersen A. Yağmur

Euscorpius

A new case of injury healing on the carapace is reported in a female Hottentotta saulcyi (Simon, 1880). An asymmetrical indentation was observed on the anterior part of the carapace, resulting from the healing of an old injury. The indentation is relatively deep, with muscle tissue visible inside it. Scar tissue is present at the end of indentation and healing tissue is present along its margins.