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Eco-Evolutionary Implications Of Environmental Change Across Heterogeneous Landscapes, Jared J. Homola

Electronic Theses and Dissertations

Species use a variety of mechanisms to adapt to environmental change. These range from spatially tracking optimal environments, to phenotypically plastic responses and evolutionary adaptation. Due to increases in anthropogenic influence on environments, characteristics of change such as their duration and magnitude are undergoing fundamental shifts away from the natural disturbance regimes that shaped species’ evolution. This dissertation uses empirical data and simulation models to examine the ecological and evolutionary consequences of environmental change across real, heterogeneous landscapes for multiple species, with an emphasis on anthropogenic changes. I used landscape genetics to evaluate the effects of urbanization on two native …

The Effect Of An Historical Geology Course On Students’ Attitudes Towards Science And Their Knowledge Of Deep Time As A Threshold To Their Knowledge Of Evolution, Allan Nolan

Dissertations

In America there exists a conflict between a small group of its citizens and the concept of evolution. Researchers have studied this conflict and the ways in which teachers might approach educational methodologies that not only address evolution in a sensitive manner, but also remain legally acceptable.

This research was designed to address teaching evolution in the context of deep time – the concept that time is vast and that geology and biology operate in a timescale of hundreds of millions to billions of years. In previous peer-reviewed works, it has been stated that deep time acts as a threshold …

Investigations On The Role Of The Immune System In Mammary Development And Maternal Immunity In The Marsupial, Monodelphis Domestica, Bethaney Fehrenkamp

Biology ETDs

All newborn mammals are highly dependent upon milk for nourishment and immune protection. This is especially true for marsupials, a lineage of mammals with a short gestation, limited placental development, and an increased reliance on an extended lactation period. Most newborn marsupials do not receive passive maternal immunity in utero and therefore are entirely dependent upon factors within the milk for immune protection until capable of mounting their own response. In this project we seek to characterize the complex lactation program utilized by marsupials, and seek greater understanding of the maternal role in the establishment of the developing immune system …

Digging Biomechanics In Geomyoid Rodents, Alexis Moore Crisp

UNLV Theses, Dissertations, Professional Papers, and Capstones

Subterranean digging behaviors provide opportunities for protection, access to prey, and predator avoidance for a diverse array of vertebrates, yet studies of the biomechanics of burrowing have been limited by the technical challenges of measuring kinetics and kinematics of animals moving within a substrate. Prior studies of burrowing have recorded a single axis of x-ray video and/or force. However, empirical observations show that burrowing is not restricted to a single axis or plane. I describe a new system called a ‘tunnel-tube’ for measuring 3D reaction force during burrowing. This tunnel-tube has two separate tubes, one ‘entry tube’ that has no …

Evolution Of Voltage-Gated Ion Channels, Kevin Gregory Bennett, Kevin Bennett

Master of Science in Integrative Biology Theses

Voltage-gated Ion Channels (VICs) form a superfamily of energy-independent membrane transporters that facilitate the transfer of charged sodium, calcium, and potassium ions across the cell membrane (Hodgkin & Huxley 1952). The channels contain a selective ion-conducting pore along with several other structural and gating features that come together to form a functional hetero- or homotetramer. A comprehensive phylogenetic study of all available proteins aimed at finding unknown distribution and illuminating evolutionary paths would be immensely useful in understanding relationships of structure, function, and organismal distribution. This phylogenetic analysis of VICs will be immensely useful in characterizing functional and structural distribution, …

Phylogeny And Evolutionary Genomics Of Non-Photosynthetic Diatoms, Anastasiia Onyshchenko

Graduate Theses and Dissertations

Diatoms are prolific photosynthesizers responsible for some 20% of global primary production. In real terms, the oxygen in one of every five breaths traces back to photosynthesis by marine diatoms. Among the tens of thousands of diatom species, a small handful of colorless diatom species in the genus Nitzschia have lost photosynthesis altogether and rely exclusively on extracellular organic carbon for growth. I used DNA sequence data to reconstruct the phylogeny of this group, and found that nonphotosynthetic diatoms are monophyletic, indicating that photosynthesis was lost just one time over the course of some 200 million years of diatom evolution. …

The Evolutionary Significance Of Body Size In Burying Beetles, Ashlee Nichole Momcilovich

Theses and Dissertations

Body size is one of the most commonly studied traits of an organism, which is largely due to its direct correlation with fitness, life history strategy, and physiology of the organism. Patterns of body size distribution are also often studied. The distribution of body size within species is looked at for suggestions of differential mating strategies or niche variation among ontogenetic development. Patterns are also examined among species to determine the effects of competition, environmental factors, and phylogenetic inertia. Finally, the distribution of body size across the geographic range of a species or group of closely related is looked at …

Impacts Of Genome And Nuclear Architecture On Molecular Evolution In Eukaryotes, Xyrus Maurer-Alcalá

Doctoral Dissertations

The traditional view of genomes suggests that they are static entities changing slowly in sequence and structure through time (e.g. evolving over geological time-scales). This outdated view has been challenged as our understanding of the dynamic nature of genomes has increased. Changes in DNA content (i.e. polyploidy) are common to specific life-cycle stages in a variety of eukaryotes, as are changes in genome content itself. These dramatic genomic changes include chromosomal deletions (i.e. paternal chromosome deletion in insects; Goday and Esteban 2001; Ross, et al. 2010), developmentally regulated genome rearrangements (e.g. the V(D)J system in adaptive immunity in mammals; Schatz …

Evolution Of Alu Elements In The Saimiri And Papio Lineages Of Primates, Jasmine Nicole Brown Baker

LSU Doctoral Dissertations

Alu elements are approximately 300 base pair (bp) primate specific non- autonomous retrotransposons. Alu elements, a short interspersed element (SINE), account for high copy numbers in all primate genomes. Numerous Alu element subfamilies have undergone varying degrees of activity and amplification within primates. Identification of these subfamilies has proved to be very informative in elucidating phylogenies and as phylogenomic markers. Squirrel monkeys, genus Saimiri, are one of the most well-known neotropical primates and the second most commonly used laboratory monkey. Squirrel monkey species diverged approximately 1.5 million years ago and are native to South America. Despite being well-known, there …

Redescription And Phylogenetic Analysis Of The Materials Assigned To The Taxon "Captorhinikos" Chozaensis, Jason Paul Jung

Electronic Theses, Projects, and Dissertations

“Captorhinikos” chozaensis is a multiple-tooth-rowed captorhinid reptile from the Lower Permian Clear Fork Group, undivided formation. Upon re-examination of the materials associated with the species from both the Chicago Field Museum of Natural History, and the Smithsonian United States National Museum, I reaffirm their affinity and collective identity as a valid taxon. “Captorhinikos” chozaensis does not, however, belong with either of the two members of its genus, C. valensis or “C.” parvus, instead occupying its own branch on the phylogenetic tree of the Captorhinidae. This conclusion is based in strong results from a combined phylogenetic parsimony analysis combined with …

Devonian Origin And Cenozoic Radiation In The Clubmosses (Lycopodiaceae), Weston Testo

Graduate College Dissertations and Theses

Together with the heterosporous lycophytes, the clubmoss family (Lycopodiaceae) is the sister lineage to all other vascular land plants. Given the family’s important position in the land-plant phylogeny, studying the evolutionary history of this group is an important step towards a better understanding of plant evolution. Despite this, little is known about the Lycopodiaceae, and a well-sampled, robust phylogeny of the group is lacking. The goal of this dissertation is to resolve the relationships among evolutionary lineages in the Lycopodiaceae and provide insight into the timing and drivers of diversification in the family.

First, to place the evolution of the …

Natural And Anthropogenic Drivers Of Tree Evolutionary Dynamics, Brandon M. Lind

Theses and Dissertations

Species of trees inhabit diverse and heterogeneous environments, and often play important ecological roles in such communities. As a result of their vast ecological breadth, trees have become adapted to various environmental pressures. In this dissertation I examine various environmental factors that drive evolutionary dynamics in threePinusspecies in California and Nevada, USA. In chapter two, I assess the role of management influence of thinning, fire, and their interaction on fine-scale gene flow within fire-suppressed populations of Pinus lambertiana, a historically dominant and ecologically important member of mixed-conifer forests of the Sierra Nevada, California. Here, I find evidence …

Biodiversity And Evolution In The Guiana Shield, South America, Andrew Michael Snyder

Electronic Theses and Dissertations

The neotropics are characterized as the most species rich region in the world. Unfortunately, the region's unparalleled biodiversity has not protected it from ongoing threats such as agriculture, mining, logging, oil extraction, and climate change. I studied the biodiversity and evolution of the herpetofauna of South America in order to investigate the influence of historical geological and climatological events in shaping extant neotropical diversity, particularly the Guiana shield. For my research, I set out to explore the processes involved in shaping the remarkable extant diversity using anuran amphibians as models. With my dissertation, I provide a comprehensive review of the …

Comparative Phylogeography, Taxonomy, And Neuroanatomy Of Montane Chameleons In The Albertine Rift, Central Africa, Daniel Hughes

Open Access Theses & Dissertations

How do traits vary across the tree of life? Our ability to address this question is diminished if: A taxonomic group has a poorly sampled phylogeny, a species goes extinct before their systematic position is resolved, or a trait is inadequately characterized for detailed studies. In the current era of mass extinction, it is imperative to not only accelerate species discovery through traditional studies in taxonomy and expeditionary research, but also to increase rescue efforts for all types of data before poorly understood species and potentially undescribed traits are lost. Here, an integrative taxonomic approach was used and novel methods …

Functional Variation In The Mitochondrial Genome Of The Yeast Saccharomyces Cerevisiae, John F. Wolters

Graduate Dissertations and Theses

Mitochondrial haplotypes contribute to functional diversity in natural populations. Uniparental inheritance makes it difficult to characterize the genetic architecture of mitochondrially driven phenotypes. In this work I explored the natural diversity of mitochondrial genomes in the yeast Saccharomyces cerevisiae. Few complete mitochondrial genomes were available for S. cerevisiae owing to challenges in high-throughput sequencing. I developed sequencing strategies using new technologies to generate complete high quality yeast mitochondrial genomes. Comparisons of 100 complete yeast mitochondrial genomes demonstrated extensive variation between populations in coding sequences and variable introns.

I demonstrated that these mitochondrial variants directly caused growth differences in strains with …