Ecology and Evolutionary Biology Commons^™

Morphological And Gene Expression Plasticity In Neotropical Cichlid Fishes, Sharon Fern Clemmensen

Doctoral Dissertations

Trophic divergence in cichlid fish is linked to morphological shifts in the pharyngeal jaw apparatus. For instance, in the Heroine cichlids of Central America, the ability to crush hard-shelled mollusks is a convergent phenotype with multiple evolutionary origins. These durophagous species often have very similar pharyngeal jaw morphologies associated with the pharyngeal jaw apparatus and some of these similarities could be due to phenotypically plastic responses to mechanical stress. I examined the durophagous cichlid Vieja maculicauda for differences in pharyngeal osteology, dentition, and soft tissues when exposed to different diet regimes. Here I discuss the effect on the morphology and …

Systematics And Biogeography Of The Cortinarius Violaceus Group And Sequestrate Evolution In Cortinarius (Agaricales), Emma Harrower

Doctoral Dissertations

Phylogenetics is a powerful tool used for illuminating the diversity of life on Earth, their evolution and their ecology. I created a multi-gene phylogenetic tree of Cortinarius section Cortinarius and uncovered five previously overlooked species, increasing the number of species in the section from seven to twelve. All members of the clade possess both cheilocystidia and pleurocystidia and possess a pigment known as (R)-39,49-dihydroxybphenylalanine. Ancestral state reconstruction estimated that the ancestral host was most likely an angiosperm, switching hosts when encountering novel host species in new lands, and only C. violaceus associating with the Pinaceae in North America. Biogeographic analysis …

Assessment Of Genetic And Education Recovery Plan Objectives For The Bog Turtle (Glyptemys Muhlenbergii), Cassie Marie Dresser

Doctoral Dissertations

Unprecedented declines in biodiversity are threatening the natural world as we know it. Without human intervention, two thousand species listed under the US Endangered Species Act are likely to disappear. Fortunately, these species receive federal protection and increased research effort is needed to create and satisfy the objectives outlined in the mandated Species Recovery Plan. In this dissertation, I address three conservation objectives outlined in the Recovery Plan for North America’s smallest and rarest turtle, the Bog Turtle (Glyptemys muhlenbergii): (1) investigate the potential genetic differentiation in southern portions of the species’ range, (2) investigate the genetic impacts …

Conservation Decisions: Designing, Financing And Fundraising For Protected Areas, Rachel Elizabeth Fovargue

Doctoral Dissertations

Establishing protection for conservation is a complicated process that involves many critical decisions, from spatial prioritization to garnering the necessary financial support to complete a project. In my research, I address questions that inform various components of this process. First, I ask questions about protected area design using a case study of a large reef system in Australia. I find that simple design rules can facilitate the pursuit of conservation and extractive management goals. Second, I address questions about costs incurred by the financing of new protection. I establish a unique dataset of projects financed by a conservation non-profit through …

Identifying Extinction Risk Patterns In Pollination Networks And Conservation Planning To Reduce The Cost Of Management-Necessitated Travel, Christine Elise Dumoulin

Doctoral Dissertations

Extinction rates are currently far above background levels, as a result of human activity. Although conservation spending is substantial, there is a shortfall between the cost of meeting biodiversity targets and the resources available to do so. Consequently, decision-makers are faced with the task of identifying which taxonomic groups and geographical regions are of greatest concern, and prioritizing approaches with the greatest conservation benefit. In this dissertation, I develop novel approaches in both of these areas.

First, I take a stochastic, community dynamic approach to modeling extinction risk patterns in pollination networks. Despite the ecological and agricultural importance of pollination …

Systematics, Diversification, And Functional Diversity Of Russulaceae (Russulales), Brian Patrick Looney

Doctoral Dissertations

The family Russulaceae is an iconic family of mushroom-forming Basidiomycetes both because of their importance as edible mushrooms in many parts of the world and their species richness in both temperate and tropical forested biomes. While much mycological research has been focused on this group, recent systematic and ecological research has failed to develop a comprehensive or cohesive organization by which to understand the evolutionary relationships, patterns of diversification, or functional importance of the group. Recently, interest in ectomycorrhizal fungi (EmF), of which Russulaceae is a key lineage, has greatly increased due to the recognition of the importance of EmF …

Biotic And Abiotic Drivers Of Plant Symbionts Determine Plant Performance, The Maintenance Of Diversity, And Response To Global Change, Jeremiah A. Henning

Doctoral Dissertations

Interactions among organisms regulate the structure and function of ecosystems and the response of ecosystems to global change. The outcome of species interactions is shaped by the partners involved in the interaction and the climate contexts of the systems in which they reside. Global change is altering the distributions of organisms as well as the climate contexts of the systems they reside within, shifting the biotic and abiotic factors shaping species interactions. Thus, predicting the response of ecosystem structure and function to global change remains unresolved. For my dissertation, I explored how the interactions among plants and their mutualistic communities …

Ecological And Evolutionary Dynamics Of Plant-Soil Feedbacks: Influences On Evolution And Range Dynamics, Michael E. Van Nuland

Doctoral Dissertations

Plants interact with, modify, and are affected by their soil environments. Though plant-soil interactions are well known to be important and active regulators of ecosystem function and community structure, much less is known about how these interactions affect plant evolution. The primary goal of my dissertation was to examine plant-soil interactions under a range of ecological and evolutionary contexts to better understand patterns of biodiversity, ecosystem function, and whole system responses to environmental change. Taking such an eco-evolutionary perspective allows for a holistic understanding of the causes and consequences of complex abiotic and biotic interactions that link ecosystem ecology and …

Molecular Phylogenetic Studies Of The Genera Of Tribe Polygonateae (Asparagaceae: Nolinoideae): Disporopsis, Heteropolygonatum, And Polygonatum., Aaron Jennings Floden

Doctoral Dissertations

The Polygonateae (Asparagaceae) are a subtribe of the Nolinoideae that is redefined here to include three genera which are investigated here: Disporopsis; Heteropolygonatum, and Polygonatum. This group of genera, characterized by their axillary-flowered habit, are closely related but differ greatly in their morphology, cytology, and diversity. A molecular phylogeny is presented to show their relationships to one another and to closely related outgroups based on data from whole chloroplast genomes with low taxonomic sampling. The results show that the genera of the Polygonateae are each monophyletic, and also show that a fourth genus, Maianthemum, that was …

Trait Evolution In Spiders: Perspectives On The Evolution Of Behavioral Syndromes And Web Structures, Jennifer Marie Bosco

Doctoral Dissertations

Organisms have evolved complex behavioral, morphological and physiological traits in response to various selection pressures. These phenotypes are usually composed of many traits that may or may not be genetically or phenotypically correlated. Correlations of both types can lead to evolutionary trade-offs, which may be broken over long evolutionary time periods through such mechanisms as the decoupling of genetic linkages and the development of phenotypic plasticity. Behavioral traits associated with temperament provide an excellent system in which to evaluate underlying mechanisms of the establishment and decoupling of genetic linkages. Other traits, such as the type of web that a spider …

Using Phylogenetic Comparative Methods To Understand Diversification And Geographic Range Evolution, Kathryn Aurora Massana

Doctoral Dissertations

Two key processes that have been modeled in a phylogenetic comparative framework are diversification and historical biogeography. Many questions arise on what process have shaped the abundance (or lack) of species we see today and what influences their survival and interconnectedness with other species. Many methods have been developed to answer these questions. Over the past several decades there has been a rise in parametric modeling and development of more adequate frameworks to answer biological questions of interest. However, many models still lack the incorporation of ecological, mainly biotic factors, which influence the evolution and ecology of species, while accounting …

Conservation Biology Of Bats: Invasive Threats, Research Effort, And Extinction Risk, Jessica Nicole Welch

Doctoral Dissertations

Global conservation for bats is needed: 15 percent of species are listed as extinct or threatened, signifying that they are at a high risk of extinction. An additional 17 percent are designated data-deficient, denoting that a threat category has not been assigned owing to insufficient knowledge on species abundance or distribution. In this dissertation, I use methods from both ecology and evolution to contribute to the study of bat conservation. Firstly, I review the impacts of biological invasion on bats, and provide examples of threats from each of four broad categories: predation, pathogens, competition, and indirect interactions. Overall, detailed accounts …