Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Central Africa (2)
- Climate change (2)
- Conservation (2)
- Africa (1)
- Amphibian (1)
-
- Biodiversity (1)
- Biogeography (1)
- Bottlenecks (1)
- C. virginica (1)
- Cephalophinae (1)
- Chromosome evolution (1)
- Clonal (1)
- Crassostrea virginica (1)
- Duikers (1)
- Dung beetles, species diversity, West and Central Africa, phylogeography, elevational gradient, intraspecific variation (1)
- Eastern oysters (1)
- Ecological modeling (1)
- Ecological niche modeling (1)
- Eichhornia crassipes (1)
- Evolution (1)
- Faeces (1)
- Feral horse behavior, equine behavior, harem stability, social stability, immunocontraception, activity budgets, harassment, PZP, Equus caballus (1)
- Genetic Diversity (1)
- Genetic differentiation (1)
- Genetic diversity (1)
- Growth (1)
- HSI (1)
- Habitat suitability (1)
- Herbarium (1)
- Invasive Species (1)
Articles 1 - 12 of 12
Full-Text Articles in Life Sciences
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 …
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 …
Documenting West And Central African Dung Beetle (Coleoptera: Scarabaeinae) Community Structures And Their Vulnerability To Climate Change, Christie A. Sukhdeo
Documenting West And Central African Dung Beetle (Coleoptera: Scarabaeinae) Community Structures And Their Vulnerability To Climate Change, Christie A. Sukhdeo
University of New Orleans Theses and Dissertations
The Guineo-Congolian (GC) region of West and Central Africa contains high levels of species richness (SR) and endemism. Within the GC region, the Cameroon Volcanic Line (CVL) is an important biodiversity hotspot in part due to montane habitats that constitute important ‘sky islands’ refugia during warm periods of the Pleistocene glacial cycles. However, little is known about the diversity of many taxa in the GC region, especially for insects. The main goals of this dissertation are to: 1) document dung beetle (Coleoptera: Scarabaeinae) species diversity across the GC region and assess the potential impacts of future climate change on species …
A Change In Grain? Diet Induced Plasticity In The Generalist Grasshopper Melanoplus Differentialis, Austin M. Culotta
A Change In Grain? Diet Induced Plasticity In The Generalist Grasshopper Melanoplus Differentialis, Austin M. Culotta
University of New Orleans Theses and Dissertations
Phenotypic plasticity is favored in heterogeneous environments in which alternative phenotypes can exploit alternative resources. However, it’s not clear whether phenotypic plasticity is useful in environments that become more homogenous over an organism’s life cycle. I studied a population of grasshopper Melanoplus differentialis that experiences high resource diversity as nymphs but low resource diversity as adults to determine if individuals can undergo diet-induced morphological plasticity in head shape to increase biting ability and ingestion of hard diets. Insects on a soft diet were larger and had greater bite force than those on a hard diet. Head structures related to chewing …
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 …
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 …
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 …
Analysis Of Temperature And Salinity Effects On Growth And Mortality Of Oysters (Crassostrea Virginica) In Louisiana, Troy Sehlinger
Analysis Of Temperature And Salinity Effects On Growth And Mortality Of Oysters (Crassostrea Virginica) In Louisiana, Troy Sehlinger
University of New Orleans Theses and Dissertations
Salinity (S) and temperature (T) control every facet of the eastern oyster (Crassostrea virginica) life cycle, principally reproduction, development, growth, and mortality. Previous studies conducted in in the Breton Sound (BR) and Barataria (BA) estuaries have reported differences in growth and mortality rates between the basins. In the present study, environmental conditions were synchronized to compare growth and mortality rates between basins at similar combinations of T and S. Results indicate that when T and S are the same (synchronized), seasonal oyster growth and mortality rates differ between BR and BA. Seasonal analyses revealed that as salinities increased …
The Origin And Expansion Of The Eastern Red Fox, Adrienne Egge Kasprowicz
The Origin And Expansion Of The Eastern Red Fox, Adrienne Egge Kasprowicz
University of New Orleans Theses and Dissertations
When new populations are first identified in a region there are multiple potential sources: introduction of a non-native species, extra-range expansion of a nearby population, or demographic growth of a previously unnoticed species. Red foxes were absent or rare in the mid-eastern portion United States until the late 1800s. Their origins potentially include natural population increase/expansion, translocations from Europe, and, eventually, 20th century fur farming. In this study I attempt to identify the relative impact of native expansion versus human mediated introductions of both colonial era European foxes and early 20th century fur-farm foxes on the establishment of red …
Comparative Phylogeography Of Central African Duikers Using Non-Invasive Sampling Methods, Stephan Ntie
Comparative Phylogeography Of Central African Duikers Using Non-Invasive Sampling Methods, Stephan Ntie
University of New Orleans Theses and Dissertations
The present study sets out to assess patterns of evolutionary diversification in central African duikers (subfamily Cephalophinae). The sampling strategy consisted of collecting geo-referenced duiker feces across 43 sites and seven countries. However, several challenges related to the use of non-invasive samples needed to be addressed prior to large scale DNA amplification. First, the best storage method for obtaining DNA from fecal samples needed to be established. Our study revealed that while silica is best for nuclear microsatellite analyses, RNAlater is the best storage medium for maximal mitochondrial amplification. Moreover, extracting DNA as early as possible always provided the …
Factors That Affect Harem Stability In A Feral Horse (Equus Caballus) Population On Shackleford Banks Island, Nc, Jessa Madosky
Factors That Affect Harem Stability In A Feral Horse (Equus Caballus) Population On Shackleford Banks Island, Nc, Jessa Madosky
University of New Orleans Theses and Dissertations
Mammal species often live in social groups, but the factors that promote group cohesion can be difficult to analyze due to the prevalence of strong group affiliations. Feral horses maintain stable harems of one or two males and several females, and harem stability is strongly related to individual fitness. Anecdotal evidence and an early study in the non-breeding season suggest that management of the Shackleford Banks island horses with immunocontraception reduces harem stability in the population, providing an opportunity to study the factors that influence harem stability. I investigated the effects of the immunocontraceptive PZP on harem stability during the …