Biology Commons^™

An Evolving Epigenome That Determines Tissue And Cell Specificity, Renee Louise Sears

Arts & Sciences Electronic Theses and Dissertations

Understanding the mechanisms driving phenotypic variation is a major goal of biology that unifies classical genetics with the emerging fields of genomics and epigenomics. Human and mouse share over 90% of genes and global tissue-specific patterns of expression are maintained between the species. Thus, it is hypothesized that gene expression is influenced through distinctive regulation among species in order to account for the unmistakable phenotypic divergence. DNA methylation, histone modifications, open chromatin patterns, transcription factor binding, and other epigenetic factors are all associated with shaping, maintaining, and repressing regulatory regions which in turn coordinate gene expression. It is vital to …

Trade-Offs Between Survival And Reproduction In Starvation-Selected Drosophila Melanogaster, Tammara Beeghly

UNLV Theses, Dissertations, Professional Papers, and Capstones

Evolutionary outcomes are demonstrated by traits that affect an organism’s schedule of reproduction and survival. These life history traits are reflected in an organism’s physiology, development and behavior. Environmental changes, such as availability of nutritional resources, can profoundly affect evolutionary outcomes of individuals and populations. When shortages arise, there will be trade-offs in the allocation of resources, where one trait prevails at the expense of another.

In the laboratory, we can mimic conditions in nature and study the specific effects of the conditions that we re-create. In our case, over 100 generations of Drosophila melanogaster have been selected for starvation …

Evolution - #0: Advanced Biological Systems, Jessica Amacher, Sowmya Anjur, Donald Dosch, Sarah O'Leary-Driscoll, Crystal Randall

Unit 1: Evolution

The first unit of Advanced Biological Systems is focused on the theory of evolution, the mechanisms of evolutionary change, and discussions of the biological species concept. We discuss briefly how biodiversity stabilizes ecosystems. A study of biological evolution is placed first in the sequence of our curriculum to establish a foundation that explains the diversity of organisms, as well as biochemical processes, and the ongoing change process we witness today. These concepts will later be utilized in our curriculum to highlight cellular and metabolic diversity, the development of cancers, the interactions of bacteria with the ecosystem of the human host, …

Evolution - #8: Ecosystem Disrupted, Jessica Amacher, Sowmya Anjur, Donald Dosch, Sarah O'Leary-Driscoll, Crystal Randall

Unit 1: Evolution

This is the culminating activity for the evolution unit. For this assignment, students must research into the impact human industry has on a small part of our world. Students have had a brief introduction to the history of the planet and the role that carbon dioxide concentration play in climate change. The role of climate and weather patterns is important in a discussion of a chosen place on the planet. Students have spent a large amount of effort in understanding evolutionary theory and mechanisms and seen it in practice as they read about speciation. With this assignment, students can synthesize …

Evolution - #3: Evolution On The Web, Jessica Amacher, Sowmya Anjur, Donald Dosch, Sarah O'Leary-Driscoll, Crystal Randall

Unit 1: Evolution

This lesson is a companion piece the previous one: Evolutionary Evidences and Inferences. It is completed supported by readings at an online site hosted by The University of California at Berkeley. The site is linked here:

http://evolution.berkeley.edu/evolibrary/article/0_0_0/evo_14

Evolution - #7: Speciation Jigsaw, Jessica Amacher, Sowmya Anjur, Donald Dosch, Sarah O'Leary-Driscoll, Crystal Randall

Unit 1: Evolution

This is a lesson intended to be complementary to the selection simulation. Whereas the simulation was used to develop a conceptual understanding of selection, the readings done here are used to allow students to see the application of their conceptualized understanding to researched examples of selection and speciation.

Evolution - #2: Evolutionary Evidence And Inferences, Jessica Amacher, Sowmya Anjur, Donald Dosch, Sarah O'Leary-Driscoll, Crystal Randall

Unit 1: Evolution

The theory of evolution articulates elegantly a series of inferences from a vast collection of observations and evidence. We present some of those evidences here to stimulate in our students the sorts of scientific reasoning necessary to understand the presence and origin of diversity of life on the planet.

Evolution - #1: History Of Life, Jessica Amacher, Sowmya Anjur, Donald Dosch, Sarah O'Leary-Driscoll, Crystal Randall

Unit 1: Evolution

From the perspective of a biologist, the history of life on the Earth is a recurring story. Although details may be different, what happens today has precedence in the occurrences of the past. Two underlying ideas are vital for students to understand a modern conception of the theory of evolution. First, over long periods of time, and due to natural events, the environment of the Earth has changed, sometimes dramatically. Second, each environmental change has created more favorable conditions for some species to live and reproduce, while producing less favorable conditions for others. This first lesson in our unit on …

Evolution - #4: Genetic Drift And Founder Effect, Jessica Amacher, Sowmya Anjur, Donald Dosch, Sarah O'Leary-Driscoll, Crystal Randall

Unit 1: Evolution

Genetic drift is a term used to describe chance fluctuations in the allelic frequencies in a population over time. The effects of genetic drift tend to be very minor in large populations, but they can be quite significant in small populations. Alleles are different functional forms in which a gene might exist. Humans have two alleles, sometimes the same but sometimes different, of most of their genes. In any population, it is possible to determine the frequency of all alleles. If these alleles get passed on to the next generation at random, then we should expect to see approximately the …

Evolution - #6: Selection Simulation, Jessica Amacher, Sowmya Anjur, Donald Dosch, Sarah O'Leary-Driscoll, Crystal Randall

Unit 1: Evolution

A modern understanding of the theory of evolution revolves around the selection of certain types within a population that over long time periods eventually leads to change of the species. This descent with modification is modeled with this activity, and leads to a subsequent lesson that has students reading about research into examples of speciation.

Evolution - #5: Globin Gene Evolution, Jessica Amacher, Sowmya Anjur, Donald Dosch, Sarah O'Leary-Driscoll, Crystal Randall

Unit 1: Evolution

For this lesson, students are guided through the steps necessary to compare nucleotide and amino acid sequences available at the National Center for Biotechnology Information that is maintained by the National Institutes of Health. The lesson starts with an examination of the alpha-globin gene. Alpha-globin is one of the proteins that constitutes hemoglobin. Student look at the various sequences of this gene that have been deposited at NCBI with a goal of determining alternative forms of the gene. The lesson then broadens the scope of comparison to include members of the globin protein family. Students create a phylogenetic tree that …

Dynamics Of Avian Elevational Ranges Reveal Hidden Evolutionary Forces, Chauncey Gadek

Biology ETDs

The distribution of life across the Andes mountains reflects historical elevational-range contraction and expansion. Whereas contraction implies specialization, expansion requires overcoming hidden barriers. Three eco-evolutionary phenomena may drive patterns in rates of elevational range evolution: (1) The Dobzhansky-MacArthur Phenomenon (DMP) predicts lower rates of upward expansion with harsher physical conditions, while downward expansion increases with lower diversity; (2) the evolutionary tendency toward specialization predicts contraction increases when ranges are broad; and (3) natural selection for respiratory performance could suppress expansion across mid-elevations due to gene-environment mismatch. We modeled elevational range shifts of Neotropical landbirds. Contrary to the DMP, upward expansion …

Evidence For Adaptive Introgression Of Exons Across A Hybrid Swarm In Deer, Emily Latch, Margaret Haines, Gordon Luikart, Stephen Amish, Seth Smith

Biological Sciences Faculty Articles

Background: Secondary contact between closely related lineages can result in a variety of outcomes, including hybridization, depending upon the strength of reproductive barriers. By examining the extent to which different parts of the genome introgress, it is possible to infer the strength of selection and gain insight into the evolutionary trajectory of lineages. Following secondary contact approximately 8000 years ago in the Pacific Northwest, mule deer (Odocoileus hemionus hemionus) and black-tailed deer (O. h. columbianus) formed a hybrid swarm along the Cascade mountain range despite substantial differences in body size (up to two times) and habitat preference. In this study, …

Evaluating The Effect Of Time Of Day On Singing Behavior In Anna’S Hummingbirds, Adrian D. Macedo, Maxine R. Mota

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

No abstract provided.

Systematics Of Carex Section Laxiflorae (Cyperaceae), Jenna Dorey

Dissertations, Theses, and Capstone Projects

Carex, with more than 2100 species, is the most species-rich genus of flowering plants in temperate regions of the world. Members of the family Cyperaceae are colloquially known as sedges, and members of the genus Carex are called “true sedges.” Carex occur on every continent except for Antarctica, they thrive in a panoply of habitats, and are ecologically important as a forage source for wildlife, carbon sequestration, prevention of soil erosion, and providing habitat for fresh water invertebrates. Despite their importance many sedges are still poorly known, such as the woodland sedges in Carex section Laxiflorae, which is …

The ‘Law Of Environmental Dependence’ - Biology And Ethics In The Work Of Ernest Everett Just: + Found – Some 251 Mostly Typed Pages, Theodore Walker

Perkins Faculty Research and Special Events

Abstract-

“The Origin of Man’s Ethical Behavior” (circa October 1941) by Ernest Everett Just and Hedwig A. Schnetzler Just - is an unpublished book manuscript about the biological origins and evolution of ethical behavior, and about “the law of environmental dependence.” Missing since Just’s death in October 1941, it was found and identified in May 2018 among the collected papers of Ernest Everett Just preserved at the Howard University Moorland-Spingarn Research Center in Washington, DC. In addition to the 1996 US postage with the caption “Ernest E. Just, Biologist,” we now have reason to add two new postage stamps with …

Mixing It Up: The Impact Of Episodic Introgression On The Evolution Of High-Latitude Mesocarnivores, Jocelyn P. Colella

Biology ETDs

At high latitudes, climatic oscillations have triggered repeated episodes of organismal divergence by geographically isolating populations. For terrestrial species, extended isolation in glacial refugia – ice-free regions that enable terrestrial species persistence through glacial maxima – is hypothesized to stimulate allopatric divergence. Alternatively, upon glacial recession, divergent populations expanded from independent glacial refugia and often contacted other diverging populations. In the absence of reproductive isolating mechanisms, this biogeographic process may trigger hybridization and ultimately, gene flow between divergent taxa. My dissertation research aims to understand how these episodic periods of isolation and contact have impacted the evolution of high latitude …

Solanum Plastisexum, An Enigmatic New Bush Tomato From The Australian Monsoon Tropics Exhibiting Breeding System Fluidity., Angela J. Mcdonnell, Heather B. Wetreich, Jason T. Cantley, Peter Jobson, Christopher T. Martine

Faculty Journal Articles

A bush tomato that has evaded classification by solanologists for decades has been identified and is described as a new species belonging to the Australian “Solanum dioicum group” of the Ord Victoria Plain biogeographic region in the monsoon tropics of the Northern Territory. Although now recognised to be andromonoecious, S. plastisexum Martine & McDonnell, sp. nov. exhibits multiple reproductive phenotypes, with solitary perfect flowers, a few staminate flowers or with cymes composed of a basal hermaphrodite and an extended rachis of several to many staminate flowers. When in fruit, the distal rachis may abcise and drop. A member of …

Evolutionary Expansions And Neofunctionalization Of Ionotropic Glutamate Receptors In Cnidaria, Ellen G. Dow

FIU Electronic Theses and Dissertations

Reef ecosystems are composed of a variety of organisms, transient species of fish and invertebrates, microscopic bacteria and viruses, and structural organisms that build the living foundation, coral. Sessile cnidarians, corals and anemones, interpret dynamic environments of organisms and abiotic factors through a molecular interface. Recognition of foreign molecules occurs through innate immunity via receptors identifying conserved molecular patterns. Similarly, chemosensory receptors monitor the environment through specific ligands. Chemosensory receptors include ionotropic glutamate receptors (iGluRs), transmembrane ion channels involved in chemical sensing and neural signal transduction. Recently, an iGluR homolog was implicated in cnidarian immunological resistance to recurrent infections of …

Differentiating Black Bears (Ursus Americanus) And Brown Bears (U. Arctos) Using Linear Tooth Measurements And Identification Of Ursids From Oregon Caves National Monument, Emily Bogner

Electronic Theses and Dissertations

North American black bears and brown bears can be difficult to distinguish in the fossil record due to similar dental and skeletal morphologies. Challenges identifying ursid material from Oregon Caves National Monument (ORCA) called for an accurate tool to distinguish the species. This study utilized a large database of lower tooth lengths and ratios in an attempt to differentiate black and brown bears in North America. Further, this project examined how these linear measurements differ geographically. Analysis of variance (ANOVA) found significant differences between black and brown bears from across North America for every variable studied. Stepwise discriminant analyses (DA) …

Lingering Impacts Of Hurricane Hugo On Rhizophora Mangle (Red Mangrove) Population Genetics On St. John, Usvi, Paul Ax Bologna, James J. Campanella, Dena J. Restaino, Zachary A. Fetske, Matthew Lourenco, John V. Smalley

Marine Biology and Coastal Sciences Faculty Scholarship and Creative Works

Stochastic events can have catastrophic effects on island populations through a series of genetic stressors from reduced population size. We investigated five populations of red mangrove (Rhizophora mangle) from St. John, USVI, an UNESCO Biosphere Reserve, which were impacted by Hurricane Hugo in 1989. Our goal was to determine diversity and to ascertain potential population bottlenecks two decades after the event. With the lowest observed heterozygosity, highest inbreeding coefficient, and evidence of a major bottleneck, our results demonstrated that the Great Lameshur mangroves, devastated by Hurricane Hugo, were the least diverse stand of trees. The other four populations from St. …

Phylogeny Of The Australian Solanum Dioicum Group Using Seven Nuclear Genes: Testing Symon’S Fruit And Seed Dispersal Hypotheses., Christopher T. Martine, Ingrid E. Jordon-Thaden, Angela J. Mcdonnell, Jason T. Cantley, Daniel S. Hayes, Morgan D. Roche, Emma S. Frawley, Ian S. Gilman, David C. Tank

Faculty Journal Articles

The dioecious and andromonoecious Solanum taxa (the “S. dioicum group”) of the Australian Monsoon Tropics have been the subject of phylogenetic and taxonomic study for decades, yet much of their basic biology is still unknown. This is especially true for plant-animal interactions, including the influence of fruit form and calyx morphology on seed dispersal. We combine field/greenhouse observations and specimen-based study with phylogenetic analysis of seven nuclear regions obtained via a microfluidic PCR-based enrichment strategy and high-throughput sequencing, and present the first species-tree hypothesis for the S. dioicum group. Our results suggest that epizoochorous trample burr seed …

Law, Evolution, And The Brain: Applications And Open Questions, Owen D. Jones

Owen Jones

This essay discusses several issues at the intersection of law and brain science. If focuses principally on ways in which an improved understanding of how evolutionary processes affect brain function and human behavior may improve law's ability to regulate behavior. It explores sample uses of such "evolutionary analysis in law" and also raises questions about how that analysis might be improved in the future. Among the discussed uses are: 1) clarifying cost-benefit analyses; 2) providing theoretical foundation and potential predictive power; 3) assessing comparative effectiveness of legal strategies; and 4) revealing deep patterns in legal architecture. Throughout, the essay emphasizes …

Proprioception, Non-Law, And Biolegal History, Owen D. Jones

Owen Jones

This Article explores several advantages of incorporating into law various insights from behavioral biology about how and why the brain works as it does. In particular, the Article explores the ways in which those insights can help illuminate the deep structure of human legal systems. That effort is termed "biolegal history."

Co-Occurrence Of Manganese Oxidase Genes Indicates Lateral Transfer Between Classes Of Proteobacteria, Jacob Olichney

Student Scholar Showcase

Pseudomonas putida GB-1 is a model organism for the study of manganese oxidation in bacteria, however, the frequency of co-localization of multiple known and suspected manganese oxidizing proteins, as well as their occurrence between species, is unknown. Eight different genes isolated from known manganese oxidizing bacteria (MnxG, MopA, McoA, PputGB1_2552, PputGB1_2553, MoxA, MofA, and Bacillus MnxG) were tested individually using BioPython and BLAST (Basic Local Alignment Search Tool) on multiple genomic databases. BLAST searches had an expect value cutoff of 1e-50, limiting gene homologs to those with high sequence similarity. The abundance of homologous genes across classes of proteobacteria point …

Comparing Feeding Accuracy Between High And Low Predation Trinidad Guppies, Lydia J. Bonnell

Honors College Theses

Efficient feeding accuracy could increase an organism’s survival. Although local adaptation in Trinidad guppies is common, the effects on accuracy are unknown. Guppies were wild caught in 2015 and 2017, filmed while capturing prey. Accuracy wasn’t different within samples but differed across samples, possibly due to the prey types used.

Plant Mitochondrial Genome Evolution And Structure Has Been Shaped By Double-Strand Break Repair And Recombination, Emily Wynn

School of Biological Sciences: Dissertations, Theses, and Student Research

Plant mitochondrial genomes are large but contain a small number of genes. These genes have very low mutation rates, but genomes rearrange and expand at significant rates. We propose that much of the apparent complexity of plant mitochondrial genomes can be explained by the interactions of double-strand break repair, recombination, and selection. One possible explanation for the disparity between the low mutation rates of genes and the high divergence of non-genes is that synonymous mutations in genes are not truly neutral. In some species, rps14 has been duplicated in the nucleus, allowing the mitochondrial copy to become a pseudogene. By …

A Phylogenetic Analysis Of Bostrichoidea (Coleoptera) And Revisions Of The Southern African Spider Beetle Genera Meziomorphum And Eutaphroptinus (Ptinidae: Coleoptera), Olivia M. Gearner

Masters Theses & Specialist Projects

Proposals for the internal relationships and classification of the bostrichoids are currently poorly supported, and almost all are based on morphology alone. This study improves upon on previous phylogenetic analyses of the group by including more taxa using the standard genes for many phylogenetic analyses. Cytochrome C oxidase subunit 1 (CO1), 28S small subunit rRNA, and 16S small subunit rRNA mitochondrial genes were sequenced or obtained from Genbank, then analyzed using parsimony and Bayesian analyses. Topologies differed depending on genes used. A three gene tree and a two gene (28S and CO1) tree both supported relationships in which a basal …

Genomics Based Approaches To Fungal Evolution, Aaron J. Robinson, Donald O. Natvig

Biology ETDs

Advances in DNA sequencing and data analysis make it possible to address questions in population genetics and evolution at the genomic level. Fungi are excellent subjects for such studies, because they are found in diverse environments, have short generation times, can be maintained in culture and have relatively small genomes. My research employed genetic approaches using a variety of sequencing technologies and methods of analysis to explore questions in fungal evolution.

In one study, I explored the genetics behind differences in thermotolerance between isolates of Neurospora discreta from Alaska and New Mexico. Isolates from the two states exhibited differences in …

Visual Attention In Jumping Spiders, Margaret Bruce

Masters Theses

The different ways that animals extract and analyze visual information from their environment is of interest to sensory ecologists. Jumping spiders, well-known for visually guided mating and hunting behavior, are an interesting model for the study of visual attention because they quickly and efficiently integrate information from eight eyes with a small brain. Stimuli in front of the spider are examined by two functionally and morphologically distinct pairs of forward-facing eyes. The principal eyes discern fine details and have small retinas and thus a small visual field. However, their position at the back of moveable tubes within the cephalothorax expands …