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Ecology and Evolutionary Biology Commons™
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- Climate change (2)
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- Evolution (2)
- Africa (1)
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- Bottlenecks (1)
- C. virginica (1)
- Caligo (1)
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- Diversification (1)
- Eastern oysters (1)
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- Ecomorphology (1)
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- Eichhornia crassipes (1)
- Epibiont (1)
- Fish assemblages (1)
- Generalized linear models (1)
- Genetic Diversity (1)
- Genetic differentiation (1)
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- Genotyping-by-sequencing (1)
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- Gulf of Mexico (1)
- Gynodioecy (1)
Articles 1 - 16 of 16
Full-Text Articles in Ecology and Evolutionary Biology
Seagrass Epibiont Biodiversity In The Northern Gulf Of Mexico, Kathryn Wyssmann
Seagrass Epibiont Biodiversity In The Northern Gulf Of Mexico, Kathryn Wyssmann
University of New Orleans Theses and Dissertations
Epibionts on seagrass leaves contribute substantially to productivity and trophic interactions in seagrass ecosystems. Differences in epibiont assemblages and factors that contribute to epibiont diversity have been little studied on the seagrass Halodule wrightii in the northern Gulf of Mexico (nGoM). We used a metabarcoding approach to describe epibiont assemblages on H. wrightii leaves in four bays across the nGoM and to test whether epibiont assemblages differed spatially at local levels (within bays) or regional levels (from west to east). Furthermore, we tested if epibiont diversity was related to environmental conditions and/or seagrass productivity. Epibiont assemblages differed significantly between bays …
Past And Present Patterns Of Neutral And Adaptive Genetic Diversity In Wild Mandrills (Mandrillus Sphinx), Anna Weber
Past And Present Patterns Of Neutral And Adaptive Genetic Diversity In Wild Mandrills (Mandrillus Sphinx), Anna Weber
University of 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 …
Chromosome Number Evolution, Phylogeography, And The Effects Of Climate Change On Species Distributions In Polyploid Plant Systems, Courtney H. Babin
Chromosome Number Evolution, Phylogeography, And The Effects Of Climate Change On Species Distributions In Polyploid Plant Systems, Courtney H. Babin
University of New Orleans Theses and Dissertations
Polyploidy, a term used to describe organisms with cells having more than two paired sets of chromosomes, is a significant driver of diversification among land plants. Over a century of research has advanced our understanding of polyploidization in some taxa, but polyploid organisms remain understudied. In this dissertation, I investigate chromosome number evolution, phylogeographic structure, genetic differentiation, and the effects of climate change on ploidy level distribution using polyploid plant systems. In the first chapter, I inferred a molecular phylogeny of Allium, an economically important genus that includes cultivated crops and ornamentals, to investigate evolutionary transitions in chromosome number …
Co-Option Of The Yolkless Oocyte Receptor For Crispr/Cas9 May Induce Transient Sterility In Female Drosophila Grimshawi Flies, Bronwyn Miller
Co-Option Of The Yolkless Oocyte Receptor For Crispr/Cas9 May Induce Transient Sterility In Female Drosophila Grimshawi Flies, Bronwyn Miller
University of New Orleans Theses and Dissertations
Evolutionary developmental biology has historically used generalist model organisms like Drosophila melanogaster. The Hawaiian Drosophilidae radiation, which occurred just 25 million years ago, is an ideal lineage for work in Evo-Devo. Hawaiian flies make up 25% of the world’s Drosophila species and extreme diversity is seen throughout the group. D. grimshawi is a generalist Hawaiian picture-wing fly that has served as a model for the Hawaiian Drosophilidae radiation. However, D. grimshawi’s power and use as a model organism is constrained by our lack of ability to manipulate its genome. In this work, I attempted to edit the genome of …
Structure And Evolution Of Lizard Immunity Genes, Trent Santonastaso
Structure And Evolution Of Lizard Immunity Genes, Trent Santonastaso
University of New Orleans Theses and Dissertations
One of the most important gene families to play a role in adaptive immunity is the major histocompatibility complex (MHC). MHC class II loci are considered to be the most variable loci in the vertebrate genome, and studies have shown that this variability can be maintained through complex co-evolutionary dynamics between host and parasite. Despite the rich body of research into the MHC, there is comparatively little understanding of its genomic architecture in reptiles. Similarly, loci associated with innate immunity have received little attention in reptiles compared to other vertebrates. In the first chapter, we investigated the structure and organization …
Hind Wing Eyespots Of Brassolini Butterflies (Lepidoptera, Nymphalidae): Evolutionary Diversification And Functions In Anti-Predator Defense And Mating Behavior, Logan Crees
University of New Orleans Theses and Dissertations
Ventral hind wing eyespots are prominent pattern elements in Brassolini butterflies, likely functioning in predator-prey interactions and reproductive activities. Caligo and Opsiphanes differ in male mate-seeking behaviors and it has been suggested that Caligo females use the male cua1 eyespot as a mate-locating cue, but Opsiphanes females do not seem to do so. We predict Caligo males should have larger eyespots than congeneric females, but the sexes would not differ in eyespot size in Opsiphanes. Our analyses supported both these predictions. Displacing the eyespot to the center of the wing makes eyespots more conspicuous, we asked if eyespot position …
Understanding The Impacts Of Current And Future Environmental Variation On Central African Amphibian Biodiversity, Courtney A. Miller
Understanding The Impacts Of Current And Future Environmental Variation On Central African Amphibian Biodiversity, Courtney A. Miller
University of New Orleans Theses and Dissertations
Global climate change is projected to impact multiple levels of biodiversity by imposing strong selection pressures on existing populations, triggering shifts in species distributions, and reorganizing entire communities. The Lower Guineo-Congolian region in central Africa, a reservoir for amphibian diversity, is predicted to be severely affected by future climate change through rising temperatures and greater variability in rainfall. Geospatial modelling can be used to assess how environmental variation shapes patterns of biological variation – from the genomic to the community level – and use these associations to predict patterns of biological change across space and time. The overall goal of …
Legacy Habitat Suitability Of Eastern Oysters (Crassostrea Virginica) In Louisiana: A Prelude To Mississippi River Delta Freshwater Diversions, Tasia Mv Denapolis
Legacy Habitat Suitability Of Eastern Oysters (Crassostrea Virginica) In Louisiana: A Prelude To Mississippi River Delta Freshwater Diversions, Tasia Mv Denapolis
University of New Orleans Theses and Dissertations
The Louisiana oyster industry is greatly impacted by freshwater and sediment diversions that are part of the effort to restore the state’s coastline. A habitat suitability index (HSI) proposes species-habitat relationships that can be instrumental in creating impact assessments and suitability predictions for management as new diversions are implemented. An oyster (Crassostrea virginica) HSI was developed using three variables crucial to oyster sustainability: average annual salinity, minimum monthly salinity, and average salinity during the spawning season. These Legacy HSI visualizations show annual fluctuations in the distribution of zones suitable for oyster cultivation prior to proposed diversions in Pontchartrain …
Genetic Diversity In An Invasive Clonal Plant? A Historical And Contemporary Perspective, Elliot D. Weidow
Genetic Diversity In An Invasive Clonal Plant? A Historical And Contemporary Perspective, Elliot D. Weidow
University of New Orleans Theses and Dissertations
Introduced populations of Eichhornia crassipes (Pontederiaceae) possess extremely low levels of genetic diversity due to severe bottleneck events and clonal reproduction. While populations elsewhere have been well studied, North American populations of E. crassipes remain understudied. We used Amplified Fragment Length Polymorphism markers to assess genetic diversity and population structure in North American E. crassipes populations. Patterns of diversity over the past fifty years were analyzed using herbarium specimens. Furthermore, we sampled populations across the Gulf Coast of the United States throughout a year to determine contemporary genetic diversity and assess potential seasonal effects. Genetic diversity was found to be …
Phylogenetic Relationships And Evolution Of Snakes, Alex Figueroa
Phylogenetic Relationships And Evolution Of Snakes, Alex Figueroa
University of New Orleans Theses and Dissertations
Snakes represent an impressive evolutionary radiation of over 3,500 widely-distributed species, categorized into 515 genera, encompassing a diverse range of morphologies and ecologies. This diversity is likely attributable to their distinctive morphology, which has allowed them to populate a wide range of habitat types within most major ecosystems. In my first chapter, I provide the largest-yet estimate of the snake tree of life using maximum likelihood on a supermatrix of 1745 taxa (1652 snake species + 7 outgroup taxa) and 9,523 base pairs from 10 loci (5 nuclear, 5 mitochondrial), including previously unsequenced genera (2) and species (61). I then …
Determining The Pollination Mechanism Of A Problematic Invasive Species In The Gulf South: Triadica Sebifera, Jennifer Wester Clark
Determining The Pollination Mechanism Of A Problematic Invasive Species In The Gulf South: Triadica Sebifera, Jennifer Wester Clark
University of New Orleans Theses and Dissertations
Understanding the ecology of invasive species is vital to curb the homogenizing of ecosystems, yet the pollination mechanisms of the Chinese tallow tree (Triadica sebifera) in its introduced habitat remain ambiguous. This study examines self-pollination, wind pollination, and flower-visiting insects of tallow in a bottomland hardwood forest and Longleaf pine savannah in the U.S. Gulf South. These data suggest that self-pollination and airborne pollination are possible, but likely rare occurrences, although the possibility of apoxisis was not investigated. Seed production in exclusion experiments was significantly less than in open-pollinated flowers, and wind dispersal of tallow pollen dropped to …
Chasin’ Tail In Southern Alabama: Delineating Programmed And Stimulus-Driven Grooming In Odocoileus Virginianus, Kyle Heine
University of New Orleans Theses and Dissertations
This study examined variation in ectoparasite density and grooming behavior of naturally occurring white-tailed deer (Odocoileus virginianus) in southwest Alabama. Stimulus-driven grooming as well as the intraspecific body size and vigilance principles of programmed grooming were tested. During the rut, males had a higher average tick (Ixodidae) density than females and exhibited complete separation of tick parasitism between non-rutting and rutting periods, supporting the vigilance principle. Stimulus-driven grooming was supported, as both fawns and yearlings had significantly higher fly (Hippoboscidae) and combined fly/tick densities than adults, and fawns oral groomed at a significantly higher rate than adults, even …
Phylogenetics And Mating System Evolution In The Southern South American Valeriana (Valerianaceae), Lauren A. Gonzalez
Phylogenetics And Mating System Evolution In The Southern South American Valeriana (Valerianaceae), Lauren A. Gonzalez
University of New Orleans Theses and Dissertations
Species of Valerianaceae in South America represent one of the best examples of rapid diversification on a continental scale. The phylogeny of Valerianaceae has received a lot of attention within the last 10 years, but relationships among the South American species are fairly unresolved. Results from previous studies have not been well resolved with traditional genetic markers, most likely due to its recent and rapid radiation. Species in this clade exhibit a variety mating systems and inflorescence types. For the first part of this research I used several traditional plastid markers, and 3 new low copy nuclear markers to better …
Assessing The Responses Of Adult, Juvenile, And Larval Fish Assemblages To The Closure Of The Mississippi River Gulf Outlet, An Artificial Tidal Pass In Southeastern Louisiana, Rebecca Weatherall Cope
Assessing The Responses Of Adult, Juvenile, And Larval Fish Assemblages To The Closure Of The Mississippi River Gulf Outlet, An Artificial Tidal Pass In Southeastern Louisiana, Rebecca Weatherall Cope
University of New Orleans Theses and Dissertations
The creation of the Mississippi River Gulf Outlet (MRGO) in 1963 by the U.S. Army Corps of Engineers (USACE) represents one of the most catastrophic, anthropogenic stressors ever to impact the Lake Pontchartrain estuary in southeastern Louisiana, USA. The artificial tidal pass provided a direct route from the Gulf of Mexico to New Orleans. It allowed for high saline waters to enter Lake Pontchartrain, resulting in detrimental changes to the biotic community of the Lake and surrounding wetland areas. In July 2009, the USACE closed the MRGO in hopes of restoring natural ecosystems. This study assesses changes in the adult, …
Statistical And Comparative Phylogeography Of Mexican Freshwater Taxa In Extreme Aquatic Environments, Lyndon M. Coghill
Statistical And Comparative Phylogeography Of Mexican Freshwater Taxa In Extreme Aquatic Environments, Lyndon M. Coghill
University of New Orleans Theses and Dissertations
Phylogeography aims to understand the processes that underlie the distribution of genetic variation within and among closely related species. Although the means by which this goal might be achieved differ considerably from those that spawned the field some thirty years ago, the foundation and conceptual breakthroughs made by Avise are nonetheless the same and are as relevant today as they were two decades ago. Namely, patterns of neutral genetic variation among individuals carry the signature of a species’ demographic past, and the spatial and temporal environmental heterogeneity across a species’ geographic range can influence patterns of evolutionary change. Aquatic systems …
Occurrence And Genetic Diversity Of Lemon Sharks (Negaprion Brevirostris) At A Nursery Ground At The Chandeleur Islands, Louisiana., Jonathan F. Mckenzie
Occurrence And Genetic Diversity Of Lemon Sharks (Negaprion Brevirostris) At A Nursery Ground At The Chandeleur Islands, Louisiana., Jonathan F. Mckenzie
University of New Orleans Theses and Dissertations
Anecdotal evidence suggested that immature lemon sharks (Negaprion brevirostris) occur at the Chandeleur Islands in southeastern Louisiana. From May 2009 to August 2011, the Nekton Research Laboratory at the University of New Orleans regularly sampled habitats at the Chandeleur Islands to confirm the presence of immature individuals of this species. During these efforts, 147 immature lemon sharks (neonates, young-of-the-year, and juveniles) were collected. Each shark was PIT tagged and a tissue sample was taken for genetic analyses. Sizes ranged from 56 – 177 cm total length. Sharks showed a preference for sandy substrate and smaller individuals showed significant preference …