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Full-Text Articles in Life Sciences

Illuminating The Drivers Of Genomic Diversification In Lamprologine Cichlids Of The Lower Congo River, Naoko P. Kurata Jun 2023

Illuminating The Drivers Of Genomic Diversification In Lamprologine Cichlids Of The Lower Congo River, Naoko P. Kurata

Dissertations, Theses, and Capstone Projects

Freshwater fishes are extraordinarily diverse, considering their available habitats represent a tiny proportion of the earth’s surface. Rivers connect heterogeneous habitats in a linear form and provide excellent simplified models to understand how aquatic biodiversity evolves. In particular, the lower Congo River (LCR) in west Central Africa consists of a dynamic hydroscape exhibiting extraordinary aquatic biodiversity, endemicity, and morphological and ecological specialization. This system is thus an excellent natural laboratory for understanding complex speciation and population diversification processes. In my research, I explore various drivers of diversification, and adaptive evolution in rheophilic lamprologine cichlids endemic to the LCR, including Lamprologus …


Metagenomic Identification And Classification Of The Mercury-Methylating Gene Hgca In Response To Water Table And Plant Functional Group Manipulations In Peat Soil, Madeline Peterson Jan 2021

Metagenomic Identification And Classification Of The Mercury-Methylating Gene Hgca In Response To Water Table And Plant Functional Group Manipulations In Peat Soil, Madeline Peterson

Dissertations, Master's Theses and Master's Reports

Methyl-mercury (MeHg) is a potent neurotoxin that threatens the health of humans and wildlife alike. Climate warming threatens to shift regional precipitation and climate regimes in peatland environments, which could destabilize northern peatlands and accelerate both Hg release from soil and MeHg production. Peatlands are among the leading hotspots for MeHg, yet little is known about the community composition or functional relationship of mercury-methylating microbes in response to varying environmental conditions. The recognized mercury-methylating genes responsible for this activity are the obligatory gene pair hgcA and hgcB. Metagenomic data from the full-factorial peatland mesocosm experiment PEATcosm was obtained to …


Natural Variation And Evolutionary Responses To Climate Change Stressors In Marine Invertebrates, Joanna Sarah Griffiths Mar 2020

Natural Variation And Evolutionary Responses To Climate Change Stressors In Marine Invertebrates, Joanna Sarah Griffiths

LSU Doctoral Dissertations

Our rapidly changing climate is putting many species at risk of extinction and there is an urgent need to understand how species will respond to these changes. In this dissertation, I evaluate how three species of marine invertebrates (corals, oysters, and copepods) respond to stressful conditions in their current environments and how plasticity and evolutionary adaptation could alter their response to future climate change stressors. I first employed a space for time study to elucidate population differences in the response of cold-water corals, Balanophyllia elegans, to future ocean acidification. I found evidence that upwelling history (natural low pH exposure) influences …


Understanding The Impacts Of Current And Future Environmental Variation On Central African Amphibian Biodiversity, Courtney A. Miller Dec 2018

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 …


Multi-Stress Proteomics: The Global Protein Response To Multiple Environmental Stressors In The Porcelain Crab Petrolisthes Cinctipes, Michael A. Garland Sep 2015

Multi-Stress Proteomics: The Global Protein Response To Multiple Environmental Stressors In The Porcelain Crab Petrolisthes Cinctipes, Michael A. Garland

Master's Theses

Global climate change is increasing the number of hot days along the California coast as well as increasing the incidence of off-shore upwelling events that lower the pH of intertidal seawater; thus, intertidal organisms are experiencing an increase in more than one stress simultaneously. This study seeks to characterize the global protein response of the eurythermal porcelain crab Petrolisthes cinctipes to changes in thermal, pH, and tidal regime treatments, either combined or individually. The first experiment examined temperature stress alone and sought to determine the effect of chronic temperature acclimation on the acute heat shock response. We compared the proteomic …