Matching Items (48)

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Cold populations of flies evolved larger bodies and larger wings made of larger cells

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We examined the evolutionary morphological responses of Drosophila melanogaster that had evolved at constant cold (16°), constant hot (25°C), and fluctuating (16° and 25°C). Flies that were exposed to the

We examined the evolutionary morphological responses of Drosophila melanogaster that had evolved at constant cold (16°), constant hot (25°C), and fluctuating (16° and 25°C). Flies that were exposed to the constant low mean temperature developed larger thorax, wing, and cell sizes than those exposed to constant high mean temperatures. Males and females both responded similarly to thermal treatments in average wing and cell size. The resulting cell area for a given wing size in thermal fluctuating populations remains unclear and remains a subject for future research.

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  • 2015-05

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Bayesian Biogeographical Analyses with Beast: Assessment Using Simulated Data

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Biogeography is the study of the spatial distribution of the earth's biota, both in the present and the past. Traditionally, biogeographical studies have relied on a combination of surveys of

Biogeography is the study of the spatial distribution of the earth's biota, both in the present and the past. Traditionally, biogeographical studies have relied on a combination of surveys of existing populations, fossil evidence, and the geological record of the earth. However, with the advent of relatively inexpensive methods of DNA sequencing, it is now possible to use information concerning the genetic relatedness of individuals in populations to address questions about how those populations came to be where they are today. For example, biogeographical studies of HIV-I provide strong support for the hypothesis that this virus arose in Africa through a host switch from chimpanzees to humans and only began to spread to human populations located on other continents some 60 to 70 years ago (Sharp & Hahn, 2010).

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  • 2015-05

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The Evolution of Social Media: Its Effect on Various Facets of Society

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Social media has evolved so quickly in the past two decades and continues to grow and change at a rapid pace. This way of connecting and communicating with others has

Social media has evolved so quickly in the past two decades and continues to grow and change at a rapid pace. This way of connecting and communicating with others has become so ingrained in daily life and can have a major influence on people's actions. Social media and social networking look vastly different today than it did in the past, and will continue to change for the future. The sports and travel industries are no exception to the integration of social media. Both entities understand the importance of being prominent in the online domain and connecting to the Millennial generation. It is crucial for young people to learn how to positively use social media in the classroom and in the workplace as their lives become consumed by this digital world. The emphasis on social media in different facets of society can bring both positive and negative connotations along with it, depending on how, when, and why people decide to use it. Social media is not meant to replace all interactions and forms of contact, but rather enhance these relationships. By analyzing the history of social media, current trends and effects, this project seeks to forecast the impact that social media will continue to have in the future. In the fast paced world today, social media and other forms of electronic communication will only continue to increase and be intensified. This project explores how social media has impacted society, most importantly, the travel industry and the sports industry. Social media will continue to expand knowledge, connect people all over the world, and enhance experiences as it inevitably becomes even more integrated into everyday life.

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Date Created
  • 2017-05

Evolutionary perspective suggests candidate genes for variation in Turner Syndrome phenotype

Description

Tremendous phenotypic variation exists across people with Turner syndrome (45,X). This variation likely stems from differential dosage of genes on the X chromosome. X-inactivation is the process whereby all X

Tremendous phenotypic variation exists across people with Turner syndrome (45,X). This variation likely stems from differential dosage of genes on the X chromosome. X-inactivation is the process whereby all X chromosomes in excess of one are silenced. However, about 15% of the genes on the silenced X chromosome escape this inactivation and are candidates for affecting phenotype in people with Turner syndrome. In this study we take an evolutionary approach to rank candidate genes that may contribute to phenotypic variation among people with Turner Syndrome. We incorporate analysis of patterns of DNA methylation from 46,XX and 45,X individuals, and estimates of variable X-inactivation status across 46,XX individuals, with patterns of gene expression conservation on the X chromosomes across five tissues and ten species. We find that genes that escape XCI are possible candidate genes for Turner syndrome phenotype, indicated by the constant levels of expression in escape genes and inactivated genes. Variation in these genes is expected to affect phenotype when dosage is altered from typical levels.

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Date Created
  • 2015-12

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Human Impacts on Evolution

Description

Humans have evolved in many ways. Just look at how life for mankind has changed over the past few decades. It is amazing how different life can be in just

Humans have evolved in many ways. Just look at how life for mankind has changed over the past few decades. It is amazing how different life can be in just a short amount of time. While it is evident that we have impacts of the environment, it should be just as evident that we impact the animals around us. However, there are a few subtle ways in which we impact the evolution of life.
Through man-made structures, human interference, artificial lights at night, and electromagnetic fields we have caused animals and insects to evolve and fit these new environments. While we tail the world around us to convince ourselves, the animals also living in these environments need to adapt to survive. In this essay, I will discuss how the affects mentioned above have cause crows, moths, snails, bobcats, blackbirds, mosquitoes, elephants, diurnal animals, fireflies, dung beetles, birds and bats to evolve. The adaptations these organisms made were caused by the subtle ways in which we have impact the landscapes around us.

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  • 2020-05

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Conservation of m6A in evolving long-term E. coli populations

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Many factors are at play within the genome of an organism, contributing to much of the diversity and variation across the tree of life. While the genome is generally encoded

Many factors are at play within the genome of an organism, contributing to much of the diversity and variation across the tree of life. While the genome is generally encoded by four nucleotides, A, C, T, and G, this code can be expanded. One particular mechanism that we examine in this thesis is modification of bases—more specifically, methylation of Adenine (m6A) within the GATC motif of Escherichia coli. These methylated adenines are especially important in a process called methyl-directed mismatch repair (MMR), a pathway responsible for repairing errors in the DNA sequence produced by replication. In this pathway, methylated adenines identify the parent strand and direct the repair proteins to correct the erroneous base in the daughter strand. While the primary role of methylated adenines at GATC sites is to direct the MMR pathway, this methylation has also been found to affect other processes, such as gene expression, the activity of transposable elements, and the timing of DNA replication. However, in the absence of MMR, the ability of these other processes to maintain adenine methylation and its targets is unknown.
To determine if the disruption of the MMR pathway results in the reduced conservation of methylated adenines as well as an increased tolerance for mutations that result in the loss or gain of new GATC sites, we surveyed individual clones isolated from experimentally evolving wild-type and MMR-deficient (mutL- ;conferring an 150x increase in mutation rate) populations of E. coli with whole-genome sequencing. Initial analysis revealed a lack of mutations affecting methylation sites (GATC tetranucleotides) in wild-type clones. However, the inherent low mutation rates conferred by the wild-type background render this result inconclusive, due to a lack of statistical power, and reveal a need for a more direct measure of changes in methylation status. Thus as a first step to comparative methylomics, we benchmarked four different methylation-calling pipelines on three biological replicates of the wildtype progenitor strain for our evolved populations.
While it is understood that these methylated sites play a role in the MMR pathway, it is not fully understood the full extent of their effect on the genome. Thus the goal of this thesis was to better understand the forces which maintain the genome, specifically concerning m6A within the GATC motif.

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  • 2020-05

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Characterization of Ions Found in Circumgalactic Clouds

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Galaxies in the universe are surrounded by a hot medium called the Circum-Galactic Medium (CGM). Present the CGM is gas that forms up clouds which travel within the CGM at

Galaxies in the universe are surrounded by a hot medium called the Circum-Galactic Medium (CGM). Present the CGM is gas that forms up clouds which travel within the CGM at speeds that approximately range between 100 km/s and 300 km/s. These gas clouds are very interesting because they play a crucial in the formation of stars within the galaxies and also in the overall evolution of galaxies. The clouds could in fact be thought of as mobile "gas stations" whose sole purpose is facilitate the ionization of elements and ultimately supply gas to galaxies. My thesis project is a follow-up study on CGM gas cloud observations that were made by Borthakur et. al. (2016). Using Cosmic Origins Spectrograph (COS) data from the Hubble Space Telescope (HST), Borthakur et. al. (2016) observed the presence of both Carbon IV (C IV) and Oxygen VI (O IV) but did not observe any Nitrogen V (N V) in the gas cloud when expected to be observable. Therefore, the ultimate goal of my research was to determine whether indeed CGM gas clouds have an actual shortage of the N V ion. My research involves the generation of cosmological simulations of a cold gas cloud that has a radius of 98 parsecs, relative velocity of 200 km/s, density range of 10-3 to -5 and a temperature in the range of ~104 to 5 K, and also a hot CGM that has density in the range of 10-4.5 to -6 particles/cm3 and temperature of approximately 106 K. Traces of N v are observed in my simulations.

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Date Created
  • 2018-05

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High School Biology Teacher Knowledge Governing the Laws Related to the Teaching of Evolution and Creationism

Description

This project examined the relationship of science teachers' knowledge about the laws relating to the teaching of creationism/evolution in public schools using multiple demographic factors. Overall, teachers correctly identified only

This project examined the relationship of science teachers' knowledge about the laws relating to the teaching of creationism/evolution in public schools using multiple demographic factors. Overall, teachers correctly identified only 7 out of 10 "yes" or "no" answers about the laws, this score is only slightly better than the expected 5 out of 10 that would be obtained from guessing. Statistically significant results in differences in the overall score on the survey were found for three major variables. Teachers who say creationism should be taught in the classroom have a lower score than those who say it should not be taught in the classroom, with a large effect size. Teachers who teach biology or a life science had significantly higher scores than those who do not, with a small/medium effect size. Older teachers had significantly higher scores than younger teachers, with a small effect size. Identifying the demographic variables that effect teacher knowledge about the laws is the first step to determining how to educate teachers on the legality teaching of creationism/evolution in public school classrooms to avoid violations of the First Amendment.

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  • 2018-05

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A Review of the Human Vermiform Appendix and its Proposed Function

Description

Since its discovery in 1524, many people have characterized the vermiform appendix. Charles Darwin considered the human appendix to be a vestige and a useless structure. Others at the time

Since its discovery in 1524, many people have characterized the vermiform appendix. Charles Darwin considered the human appendix to be a vestige and a useless structure. Others at the time opposed this hypothesis. However, Darwin's hypothesis became prevalent one until recently when there became a renewed interest in the appendix because of advancements in microscopes, knowledge of the immune system, and phylogenetics. In this review, I will argue that the vermiform appendix, although still not completely understood, has important functions. First, I will give the anatomy of the appendix. I will discuss the comparative anatomy between different animals and also primates. I will address the effects of appendicitis and appendectomy. I will give background on vestigial structures and will discuss if the appendix is a vestige. Following, I will review the evolution of the appendix. Finally, I will argue that the function of the appendix is as an immune organ, including discussion of gut-associated lymphoid tissue (GALT), development of lymphoid follicles in GALT and their comparison within different organs, Immunoglobulin A (IgA) function in the gut, biofilms as evidence that the appendix is a safe-house for beneficial bacteria, re-inoculation of the bowel, and protection against recurring infection. I will conclude with future studies that should be conducted to further our understanding of the vermiform appendix.

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  • 2018-05

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Bottom-Up Strategy Development: Evolving Metagames of Neural Network-Based Strategies

Description

In this paper, I describe the development of a unique approach to developing strategies for games in which success can only be measured by the final outcome of the game,

In this paper, I describe the development of a unique approach to developing strategies for games in which success can only be measured by the final outcome of the game, preventing the use of heuristics. I created and evaluated evolutionary algorithms, applying them to develop strategies for tic-tac-toe. Strategies are comprised of neural networks with randomly initiated weights. A population of candidate strategies are created, each strategy competes individually against each other strategy, and evolutionary operators are applied to create subsequent generations of strategies. The set of strategies within a generation of the evolutionary algorithm forms a metagame that evolves as the algorithm progresses. Hypothesis testing shows that strategies produced by this approach significantly outperform a baseline of entirely random action, although they are still far from optimal gameplay.

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  • 2020-05