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Title: THE EFFECTS OF AGE ON REPRODUCTION IN A CITRUS ROOT WEEVIL DIAPREPES ABBREVIATUS.
Creator: Chasez, Heather, Fedorka, Kenneth, University of Central Florida
Abstract / Description: Understanding the factors influencing mate choice is a major focus of sexual selection. Many factors are potentially involved, including age of the individual. The good genes model and the youth advantage model both make predictions about the effect of age on mate choice. Under the good genes model older mates would be the more preferable due to their proven high survivability. The Ã‚Â"youth advantageÃ‚Â" model, predicts that young to intermediate age males...
Show moreUnderstanding the factors influencing mate choice is a major focus of sexual selection. Many factors are potentially involved, including age of the individual. The good genes model and the youth advantage model both make predictions about the effect of age on mate choice. Under the good genes model older mates would be the more preferable due to their proven high survivability. The Ã‚Â"youth advantageÃ‚Â" model, predicts that young to intermediate age males would be more advantageous as mates because of a decrease in sperm quality and the possibility of increased germ-line mutations in older animals. I examined the effects of age on behavioral and physiological factors in Diaprepes abbreviatus experimentally. Both males and females were found to be the least optimal as mates during the intermediate stage of their lives, with preferences for young and old age classes. Females had higher fertilization rates when young and fertilization steadily declined with age, consistent with the youth advantage model. Males overall had higher fertilization rate and procured matings faster when they were older, which was in accordance with the good genes model, though experience could also play a role in this result. These data here suggest that in D. abbreviatus age may play an important role in mate choice decisions.
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Date Issued: 2011
Identifier: CFE0003568, ucf:48924
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003568

Title: GEOGRAPHIC VARIATION IN POST-MATING IMMUNE GENE EXPRESSION INDROSOPHILA MELANOGASTER.
Creator: Pinzone, Cheryl, Fedorka, Kenneth, University of Central Florida
Abstract / Description: An organism's immune response may vary due to pathogen pressure in its environment, as well as due to interactions with other organisms. These factors, along with geographic rules (i.e. Gloger's rule) may influence the geographic distribution of the immune response within populations of a species. Here we use real-time quantitative PCR to measure the immune gene expression in six populations collected along the eastern U.S. of Drosophila melanogaster after mating. Antimicrobial genes...
Show moreAn organism's immune response may vary due to pathogen pressure in its environment, as well as due to interactions with other organisms. These factors, along with geographic rules (i.e. Gloger's rule) may influence the geographic distribution of the immune response within populations of a species. Here we use real-time quantitative PCR to measure the immune gene expression in six populations collected along the eastern U.S. of Drosophila melanogaster after mating. Antimicrobial genes did not show significant differences in expression due to location, whereas we did observe differences in anti-fungal and pro-phenoloxidase (anti-macromolecule) related genes. These differences in anti-macromolecule resistance are correlated with the latitude of the population opposite of which we would expect by Gloger's rule. We also determined that males and females from different populations tended to drive the differences we detected. Taken together, these results suggest that geographic factors influence genes involved in fungal and macro-pathogens defense post-mating.
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Date Issued: 2010
Identifier: CFE0003159, ucf:48617
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003159

Title: An examination of beta diversity indices and their predictors in two large-scale systems.
Creator: Schroeder, Philip, Jenkins, David, King, Joshua, Fedorka, Kenneth, Myers, Jonathan, University of Central Florida
Abstract / Description: Biodiversity is what conservation biology was developed to conserve. It is the physical manifestation of life as a concept and, be it for practical or idealistic reasons, all conservationists seek to protect or, in some cases, enhance it. Because of its monolithic importance to the field, much effort has been expended trying to better measure and understand it. Recently, greater attention has been paid to the partition of diversity; the observation that the total diversity of a system (?) can...
Show moreBiodiversity is what conservation biology was developed to conserve. It is the physical manifestation of life as a concept and, be it for practical or idealistic reasons, all conservationists seek to protect or, in some cases, enhance it. Because of its monolithic importance to the field, much effort has been expended trying to better measure and understand it. Recently, greater attention has been paid to the partition of diversity; the observation that the total diversity of a system (?) can be broken down into within-site diversity (?) and between-site diversity (?). In particular, it has been noticed that the ? component of diversity is not as well studied or understood as the ? component. In this study I attempt to address this shortfall, by examining two questions: (1) how is ? is best measured and (2) what drives ?? To answer the first question, I look to find the measure of ? that is most robust to sampling error. While many ? indices have been proposed, few have considered how our methods of data gathering might affect those indices. Datasets collected from the real world will all likely have some sort of error within them as a result of the way they were sampled. Those errors will affect some indices more than others, and the indices that are least affected will be the most reliable for actual data. Once robust indices were identified, I used them to identify possible predictors of ? in two large, national datasets. The first dataset was the National Lakes Assessment created by the USEPA, in which diatoms were sampled from over 1000 lakes across the country. The second was the eBird dataset from the Cornell Lab of Ornithology, which used citizen science to generate a continuous dataset spanning both the last decade and the boundaries of the conterminous United States. ? calculated from these sources was regressed against relevant environmental variables to create a clearer understanding of the effects of the environment on the ? of two very different ecological systems.
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Date Issued: 2018
Identifier: CFE0007367, ucf:52088
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007367

Title: Pine, aphids, and parasitoid wasps: patterns of cospeciation and host switches in a tri-trophic system.
Creator: Bass, Amber, Sharanowski, Barbara, Fedorka, Kenneth, Hoffman, Eric, University of Central Florida
Abstract / Description: Ecological interactions may drive speciation events, and the processes that drive these speciation events can leave behind patterns in the phylogenies of interacting taxa. These patterns have been studied extensively in herbivores and host plants, as well as parasites and their hosts, but rarely in tri-trophic systems. Here, we examine three closely related groups of interacting taxa, including parasitoid wasps (Pauesia), aphid herbivores (Cinara), and pine trees (Pinus) to determine if the...
Show moreEcological interactions may drive speciation events, and the processes that drive these speciation events can leave behind patterns in the phylogenies of interacting taxa. These patterns have been studied extensively in herbivores and host plants, as well as parasites and their hosts, but rarely in tri-trophic systems. Here, we examine three closely related groups of interacting taxa, including parasitoid wasps (Pauesia), aphid herbivores (Cinara), and pine trees (Pinus) to determine if the patterns between each interacting taxa indicate that cospeciation or host switches are more dominant. We create phylogenies of Cinara and Pauesia in the southeastern United States using ddRADseq data and analyze publicly available data for Pinus. Most Cinara and Pauesia were specialized, with no species utilizing more than three hosts, indicating that this system is well suited to cophylogenetic study, and host interactions likely play a role in the speciation of these taxa. Pauesia was slightly more specialized on Pinus, suggesting phytochemistry may constrain the host breadth of these wasps and lead to coevolutionary patterns between Pauesia and Pinus. Distance-based cophylogenetic analyses suggest that aphids and pine, and wasps and aphids have dependent phylogenies, but these analyses differ in regards to wasps and pine. However, event-based methods show that cospeciation events and host switches both present, often in nearly equal proportions, and duplications and sorting events occurred at a lower frequency if at all. Both Cinara and Pauesia require revisions and the development of updated taxonomic resources for identification. This system presents an ideal model group to study coevolutionary patterns and multi-trophic community dynamics across macro- and microevolutionary time scales.
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Date Issued: 2019
Identifier: CFE0007430, ucf:52707
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007430

Title: The ecology of central Florida's thief ants (Hymenoptera: Formicidae: Solenopsis).
Creator: Ohyama, Leo, King, Joshua, Jenkins, David, Fedorka, Kenneth, University of Central Florida
Abstract / Description: Thief ants of the genus Solenopsis are a diverse group of ants that are found in ant communities throughout the world. They have long been purported to practice lestobiosis, an interaction between small and larger-bodied ants, where small ants cryptically tunnel into larger-bodied ant nests within the subterranean environment and steal brood or eggs for consumption. Thief ants are extremely small, measuring 1-2 mm in length and many of the species within this group practice a subterranean...
Show moreThief ants of the genus Solenopsis are a diverse group of ants that are found in ant communities throughout the world. They have long been purported to practice lestobiosis, an interaction between small and larger-bodied ants, where small ants cryptically tunnel into larger-bodied ant nests within the subterranean environment and steal brood or eggs for consumption. Thief ants are extremely small, measuring 1-2 mm in length and many of the species within this group practice a subterranean life history, where they live the entirety of their lives exclusively belowground. Due to these key characteristics, the ecology and natural history of this group of ants has remained largely unknown despite their noted high abundance within the southeastern United States, especially in upland ecosystems. The purpose of this thesis is to improve our understanding of the ecology of this enigmatic group, providing a solid foundation for future work on their behavior, biology, and natural history. Therefore, this project first attempts to identify key abiotic environmental variables that potentially drive the diversity and distribution of this group in upland ecosystems. Next a field manipulation experiment was conducted in areas of high thief ant density to determine biotic effects between thief ants and the aboveground ant community. This was done by removing thief ants using belowground toxic baits and monitoring co-occurring ant worker abundances throughout a period of approximately 1 year. We found evidence that thief ants dominate belowground and diversity. Our field experiment also yielded evidence indicating that thief ants exert potential top-down regulation on entire ant communities.
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Date Issued: 2019
Identifier: CFE0007696, ucf:52408
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007696

Title: Fear and Loathing in the Super Organism: Foraging Strategy Doesn't Change Forager Response in a Landscape of Fear.
Creator: Schadegg, Philip, King, Joshua, De Bekker, Charissa, Fedorka, Kenneth, University of Central Florida
Abstract / Description: Understanding how predators impact keystone species, like ants, is very important for our understanding of ecology because of ants' importance in shaping community dynamics and ecosystem functions. In this thesis I present research investigating the role of the ant-specialized spider Anasaitis canosa in influencing the foraging behavior of four ant species (Formica pallidefulva, Odontomachus ruginodis, Pheidole obscurithorax (&) Solenopsis invicta). Collectively, these four species use...
Show moreUnderstanding how predators impact keystone species, like ants, is very important for our understanding of ecology because of ants' importance in shaping community dynamics and ecosystem functions. In this thesis I present research investigating the role of the ant-specialized spider Anasaitis canosa in influencing the foraging behavior of four ant species (Formica pallidefulva, Odontomachus ruginodis, Pheidole obscurithorax (&) Solenopsis invicta). Collectively, these four species use foraging strategies exhibited by most ants. I conducted two experiments to quantify the impacts of spider predation on ant prey. The first used forty colonies of four ant species to investigate how A. canosa changed foraging behavior at both the individual and colony level. The second used 27 lab-reared S. invicta colonies to see if there was any evidence for innate predatory avoidance in foragers and if predatory avoidance was influenced by learning. A field study observed the density and prey choices of A. canosa in 3 sites within the UCF arboretum. In sum, no consistent change in foraging occurred in the presence of A. canosa, over time scales sufficient to detect colony-level impacts and thus colonies as a whole appear to be risk insensitive. Na(&)#239;ve colonies had more ants beginning foraging before a single ant would return in their first trial compared to the second trial. This suggests forager learning occurs as foragers respond to the perception of a predator, and that S. invicta can reduce individual risk through increasing forager numbers. A. canosa predation rates and density were calculated and based on these estimates an approximate impact upon a colony was made. Most importantly, 13 foragers/m2 inside each foraging cohort can be expected to have prior experience with the spider.
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Date Issued: 2019
Identifier: CFE0007859, ucf:52792
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007859

Title: Life history response to infection and the potential for dishonest signals in the ground cricket, Allonemobius socius.
Creator: Copeland, Emily, Fedorka, Kenneth, Hoffman, Eric, Crampton, William, University of Central Florida
Abstract / Description: In order to maximize fitness, individuals must partition their limited resources among competing physiological processes, creating negative statistical associations between processes known as (")life-history trade-offs("). Evidence indicates that individuals tend to decrease their reproductive investment when confronted with a significant immunological challenge in order to increase investment in immune defense. This trade-off is often accompanied by a significant decrease in the sexual...
Show moreIn order to maximize fitness, individuals must partition their limited resources among competing physiological processes, creating negative statistical associations between processes known as (")life-history trade-offs("). Evidence indicates that individuals tend to decrease their reproductive investment when confronted with a significant immunological challenge in order to increase investment in immune defense. This trade-off is often accompanied by a significant decrease in the sexual signal, which provides an honest signal of the male's infection status to potential mates. However, if individual residual reproductive value is low, they may instead increase their reproductive investment to maximize reproductive success before the end of their life (a.k.a. terminal investment). Here, we investigate the potential for terminal investment in the ground cricket Allonemobius socius by inoculating males with varying dosages of an immune challenge. We predicted that both high dose and advanced male age would induce terminal investment. Furthermore, we predicted that terminally investing males would produce a dishonest signal by increasing their signaling effort. We found that upon infection We found that upon infection, young males and old males differentially alter their reproductive strategy. Young males exhibited the classic deceleration of reproductive effort. However, old males increased their calling song energetics and decreased their parental investment (nuptial gift size), suggesting that old males are dishonestly signaling their condition to the female.
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Date Issued: 2012
Identifier: CFE0004529, ucf:49249
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004529

Title: Effect of predation risk and food availability on parental care and nest survival in suburban and wildland Florida Scrub-Jays.
Creator: Niederhauser, Joseph, Jenkins, David, Fedorka, Kenneth, Bowman, Reed, University of Central Florida
Abstract / Description: Individual organisms often use cues from their natural environments to determine many behavioral and life-history (")decisions.(") These (")decisions(") are usually adaptive, i.e. a response to selection, because the environmental cues on which they are based reliably correlate with increased fitness over time. When the selected behavioral response to a natural cue no longer provides a fitness benefit, then selection for a new response may occur but individuals maintaining the previously...
Show moreIndividual organisms often use cues from their natural environments to determine many behavioral and life-history (")decisions.(") These (")decisions(") are usually adaptive, i.e. a response to selection, because the environmental cues on which they are based reliably correlate with increased fitness over time. When the selected behavioral response to a natural cue no longer provides a fitness benefit, then selection for a new response may occur but individuals maintaining the previously selected response may suffer reduced survival and reproduction. Especially in human-modified landscapes individuals making a maladaptive behavioral or life-history choice based on those formerly reliable environmental cues may be faced with an (")evolutionary trap("). In urban, or suburban, environments many factors have been altered in ways that could lead to evolutionary traps. Inappropriate behavioral responses by many individuals could lead to reduced demographic performance of urban populations relative to their wildland counterparts and to the decline of entire urban populations. In birds, maladaptive patterns of nest provisioning or vigilance may occur (a) when human-provided adult foods are easier to feed young because they are more abundant and predictable than foods appropriate for nestlings, or (b) when birds' perception of predation risk, which can be influenced by human disturbance, is greater than the real risk. By provisioning or attending their nests more or less than what is appropriate given the environmental level of resources and risks, the behavior of suburban parents may be contributing to high levels of nest failure during the nesting stage. To determine whether maladaptive parental care influences nest survival during the nestling stage, I conducted an experiment using Florida Scrub-Jays (Aphelocoma coerluscens). Suburban scrub-jays have lower nest survival during the nestling stage but higher survival during the incubation stage relative to wildland jays. Both predators and food abundance vary greatly between suburban and wildland scrub. The suburbs have a greater abundance of predators that may prey on both adult scrub-jays and their nests and more foods appropriate for adults but less nestling-appropriate food. This variation in risks and resources should affect the parental care behavior of suburban scrub-jays, which in turn may affect patterns of nest survival. In pre-treatment observations, I found that suburban females spent more time brooding than wildland birds but suburban males did not provision any more than wildland males. Experimentally increasing the perception of adult predation risk reduced parental care in both suburban and wildland females. Increasing the availability of nestling food reduced parental care in suburban females but had no effect in wildland females. Increasing food availability, but not predation risk, decreased call rates but increased call frequency in nestling scrub-jays from both habitats. However, neither parental care nor food availability had much influence on nest survival during the nestling stage. Instead, side nest concealment and the presence of helpers were the most important variables in nest survival analyses prompting other explanations besides maladaptive parental behavior or lack of nestling food resources for the habitat-specific difference in nest survival during the nestling stage.
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Date Issued: 2012
Identifier: CFE0004219, ucf:49015
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004219

Title: Testing for Isolation in Florida Raccoons (Procyon lotor) Using Phylogenetics and Population Genetic Structure.
Creator: Trujillo, Alexa, Hoffman, Eric, Fedorka, Kenneth, Parkinson, Christopher, University of Central Florida
Abstract / Description: Molecular data are useful in determining if populations are isolated and for species delimitation. Researchers and managers currently recognize five subspecies of raccoons (Procyon lotor) in Florida, based largely on perceived geographic isolation due to the island ranges of four subspecies. In this study, I provide the first estimate of phylogenetic relationships and population divergences within Florida raccoons using a molecular dataset. I analyze the mitochondrial control region,...
Show moreMolecular data are useful in determining if populations are isolated and for species delimitation. Researchers and managers currently recognize five subspecies of raccoons (Procyon lotor) in Florida, based largely on perceived geographic isolation due to the island ranges of four subspecies. In this study, I provide the first estimate of phylogenetic relationships and population divergences within Florida raccoons using a molecular dataset. I analyze the mitochondrial control region, cytochrome b gene, and eight nuclear microsatellite loci to test two hypotheses: 1) the five, morphologically and geographically-defined subspecies of raccoon in Florida represent genetically distinct populations and (2) due to differing range sizes and habitat variation between island and mainland subspecies, the four island populations should exhibit reduced levels of genetic diversity and smaller effective population sizes compared to the mainland population. My results indicate no evidence of historical differentiation between the subspecies, but suggest a recent restriction of gene flow among three clusters of raccoons. The three clusters do not correlate to traditional geographies for subspecies identification. I provide evidence of reduced genetic diversity in island populations of raccoons compared to their mainland counterparts. These data stress the importance of using multiple lines of evidence when naming taxa to avoid misinforming the taxonomy.
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Date Issued: 2015
Identifier: CFE0006233, ucf:51069
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006233

Title: Climate Change and the Evolution of Insect Immune Function.
Creator: Perry, Danae, Fedorka, Kenneth, Jenkins, David, Hoffman, Eric, University of Central Florida
Abstract / Description: Insects are ectothermic organisms that have physiological, behavioral and life-history traits directly influenced by their environment. Investigations have shown that many insects use melanin to permanently darken their cuticles in cooler or drier climates to improve thermoregulation and desiccation resistance. Melanin is a major component of pathogen defense in insects. This suggests that environmentally driven adaptive changes in cuticular melanin may non-adaptively shape insect immune...
Show moreInsects are ectothermic organisms that have physiological, behavioral and life-history traits directly influenced by their environment. Investigations have shown that many insects use melanin to permanently darken their cuticles in cooler or drier climates to improve thermoregulation and desiccation resistance. Melanin is a major component of pathogen defense in insects. This suggests that environmentally driven adaptive changes in cuticular melanin may non-adaptively shape insect immune function. This hypothesis has been referred to as climate-related Cuticle Dependent Immune Investment (climate-related CDII). Climate-related CDII also suggests that a warming climate could lead to the evolution of a weakened melanin-based immune response due to direct selection for lighter cuticles. Climate-related CDII has not been investigated with regard to climate change. Using Drosophila melanogaster, the first part of this study investigated if the documented pattern of lowered immune function in warmer temperatures offsets the expected gain in metabolic rate. The second part of this project investigated how a warming thermal environment will affect the evolution of insect immune function by quantifying changes in melanization and immune function over multiple generations in a changing thermal environment. In the first investigation there was evidence for weakened immune function in males, while females saw an offset by gaining a metabolic boost. The second investigation showed evidence that warming treatments evolved lowered overall immune function. This project gives evidence that insect immune function has the potential to be weakened by increasing temperatures. Insect immune function is a major contributing factor to insect abundances. A decrease in beneficial insects or an increase in harmful insects or pathogens they vector could have detrimental environment and human health consequences.?
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Date Issued: 2017
Identifier: CFE0006638, ucf:51256
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006638

Title: Genetic structure and demographic analysis of Key deer (Odocoileus virginianus clavium).
Creator: Villanova, Vicki, Hoffman, Eric, Parkinson, Christopher, Fedorka, Kenneth, University of Central Florida
Abstract / Description: Recent improvements in genetic analyses have paved the way in using molecular data to answer questions regarding evolutionary history, genetic structure, and demography. Key deer are a federally endangered subspecies assumed to be genetically unique (based on one allozyme study), homogeneous, and have a female-biased population of approximately 900 deer. I used 985bp of the mitochondrial cytochrome b gene and 12 microsatellite loci to test two hypotheses: 1) if the Moser Channel is a barrier...
Show moreRecent improvements in genetic analyses have paved the way in using molecular data to answer questions regarding evolutionary history, genetic structure, and demography. Key deer are a federally endangered subspecies assumed to be genetically unique (based on one allozyme study), homogeneous, and have a female-biased population of approximately 900 deer. I used 985bp of the mitochondrial cytochrome b gene and 12 microsatellite loci to test two hypotheses: 1) if the Moser Channel is a barrier to gene flow, I should expect that Key deer are differentiated and have reduced diversity compared to mainland deer and (2) if isolation on islands leads to a higher probability of extinction, I should expect that Key deer exhibit a small population size and a high risk of extinction. My results indicate that Key deer are genetically isolated from mainland white-tailed deer and that there is a lack of genetic substructure between islands. While Key deer exhibit reduced levels of genetic diversity compared to their mainland counterparts, they contain enough diversity of which to uniquely identify individual deer. Based on genetic identification, I estimated a census size of around 1,000 individuals with a heavily skewed female-biased adult sex ratio. Furthermore, I combined genetic and contemporary demographic data to generate a species persistence model of the Key deer. Sensitivity tests within the population viability analysis brought to light the importance of fetal sex ratio and female survival as the primary factors at risk of driving the subspecies to extinction.
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Date Issued: 2015
Identifier: CFE0006058, ucf:50981
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006058

Title: An Investigation of the Impacts of Face-to-Face and Virtual Laboratories in an Introductory Biology Course on Students' Motivation to Learn Biology.
Creator: Reece, Amber, Butler, Malcolm, Boote, David, Chini, Jacquelyn, Fedorka, Kenneth, University of Central Florida
Abstract / Description: The objective of this study was to evaluate and compare the effects of face-to-face and virtual laboratories in a large-enrollment introductory biology course on students' motivation to learn biology. The laboratory component of post-secondary science courses is where students have opportunities for frequent interactions with instructors and their peers (Seymour (&) Hewitt, 1997; Seymour, Melton, Wiese, (&) Pederson-Gallegos, 2005) and is often relied upon for promoting interest and...
Show moreThe objective of this study was to evaluate and compare the effects of face-to-face and virtual laboratories in a large-enrollment introductory biology course on students' motivation to learn biology. The laboratory component of post-secondary science courses is where students have opportunities for frequent interactions with instructors and their peers (Seymour (&) Hewitt, 1997; Seymour, Melton, Wiese, (&) Pederson-Gallegos, 2005) and is often relied upon for promoting interest and motivation in science learning (Hofstein (&) Lunetta, 2003; Lunetta, Hofstein, (&) Clough, 2007). However, laboratory courses can be resource intensive (Jenkins, 2007), leading post-secondary science educators to seek alternative means of laboratory education such as virtual laboratories. Scholars have provided evidence that student achievement in virtual laboratories can be equal to, if not higher than, that of students in face-to-face laboratories (Akpan (&) Strayer, 2010; Finkelstein et al., 2005; Huppert, Lomask, (&) Lazarowitz, 2002). Yet, little research on virtual laboratories has been conducted on affective variables such as motivation to learn science.Motivation to learn biology was measured at the beginning and end of the semester using the Biology Motivation Questionnaire (&)copy; (Glynn, Brickman, Armstrong, (&) Taasoobshirazi, 2011) and compared between the face-to-face and virtual laboratory groups. Characteristics of the two laboratory environments were measured at the end of the semester by the Distance Education Learning Environment Survey (Walker (&) Fraser, 2005). Interviews with 12 participants were conducted three times throughout the semester in the phenomenological style of qualitative data collection. The quantitative survey data and qualitative interview and observation data were combined to provide a thorough image of the face-to-face and virtual laboratory environments and their impacts on students' motivation to learn biology.Statistical analyses provided quantifiable evidence that the novel virtual laboratory environment did not have a differential effect on students' motivation to learn biology, with this finding being supported by the qualitative results. Comparison of the laboratory environments showed that students in the face-to-face labs reported greater instructional support, student interaction and collaboration, relevance of the lab activities, and authentic learning experiences than the students in the virtual labs. Qualitative results indicated the teaching assistants in the face-to-face labs were an influential factor in sustaining students' motivation by providing immediate feedback and instructional support in and out of the laboratory environment. In comparison, the virtual laboratory students often had to redo their lab exercises multiple times because of unclear directions and system glitches, potential barriers to persistence of motivation. The face-to-face students also described the importance of collaborative experiences and hands-on activities while the virtual laboratory students appreciated the convenience of working at their own pace, location, and time. According to social cognitive theory (Bandura, 1986, 2001), the differences in the learning environments reported by the students should have had ramifications for their motivation to learn biology, yet this did not hold true for the students in this study. Therefore, while these laboratory environments are demonstrably different, the virtual laboratories did not negatively impact students' motivation to learn biology and could be an acceptable replacement for face-to-face laboratories in an introductory biology course.
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Date Issued: 2015
Identifier: CFE0005872, ucf:50876
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005872

Title: The Effect of Parental Population Density on Offspring Immune Function.
Creator: Davis, Dana, Fedorka, Kenneth, Savage, Anna, Hoffman, Eric, University of Central Florida
Abstract / Description: It is well known that an individual's environment, genetic code, and gene by environment interactions have an effect on its overall phenotype. However, there is a growing body of work that shows that parents can have an effect on their offspring's phenotype beyond the inherited genetic code. Studies have shown that parents may affect their offspring through physiological mechanisms such as egg provisioning and epigenetic effects and through behavioral mechanisms such as maternal care. In many...
Show moreIt is well known that an individual's environment, genetic code, and gene by environment interactions have an effect on its overall phenotype. However, there is a growing body of work that shows that parents can have an effect on their offspring's phenotype beyond the inherited genetic code. Studies have shown that parents may affect their offspring through physiological mechanisms such as egg provisioning and epigenetic effects and through behavioral mechanisms such as maternal care. In many of these cases, the parental effect is triggered by an environmental cue. Previous work has shown that density can impact immune function and cuticle color in insects - two phenotypic traits that are pleiotropically linked. Additional work has shown that parental density can have impacts on offspring immune function, as well. However, previous studies utilized insect species that show a strict density dimorphic phenotype where individuals reared at high densities exhibit increased immune function and much darker cuticles than their low density counterparts, which is not an accurate representation of most insect systems as most insect systems show a more continuous response to density effects. Also, previous work has not determined the parental origin of density effects on offspring immune function and cuticle color. It has been suggested that parental density effects may be due to maternal egg provisioning and that paternal effects may be minimal. However, knowledge of parental origin would give us a better insight into the possible mechanisms of these density driven parental effects and provide a direction for future research. In my study, we used Drosophila melanogaster in order to determine (1) if density affects immune function and cuticle color in a species that shows a continuous response to density, (2) if parental density affects offspring immune function and cuticle color, and (3) if the source of these parental effects are of a maternal origin only or if these effects are of a paternal origin, as well. We found that there is an effect of density on immune function and cuticle color in the parents in a more common insect system and parental density had an effect on offspring phenotype, as well. Most notably, we found that, in addition to the effects of maternal density, these parental effects on offspring phenotype were a response to paternal density, as well.
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Date Issued: 2017
Identifier: CFE0006580, ucf:51355
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006580

Title: The Role of the Y-Chromosome in the Evolution of Autosomally Coded Traits.
Creator: Kutch, Ian, Fedorka, Kenneth, Vonkalm, Laurence, Hoffman, Eric, University of Central Florida
Abstract / Description: Recent work indicates that the Y-chromosome of the fruit fly Drosophila melanogaster can influence gene regulation on the autosomes and X chromosome. This newly discovered function of the Y has the potential to dramatically shape the regulatory evolution of numerous genes that reside throughout the genome; even for genes that code for both male and female traits. Given that the mechanism underlying the Y-linked influence on gene expression in D. melanogaster appears to exist in other...
Show moreRecent work indicates that the Y-chromosome of the fruit fly Drosophila melanogaster can influence gene regulation on the autosomes and X chromosome. This newly discovered function of the Y has the potential to dramatically shape the regulatory evolution of numerous genes that reside throughout the genome; even for genes that code for both male and female traits. Given that the mechanism underlying the Y-linked influence on gene expression in D. melanogaster appears to exist in other independently evolved heterogametic sex chromosomes, the evolutionary implications of Y-linked regulatory variation (YRV) deserves to be explored. These implications include the potential for Y-chromosomes to facilitate the adaptive evolution of sexually dimorphic gene expression, and the potential for the Y to constrain evolutionary rates in both males and females (depending on the nature of the YRV effect). Unfortunately, the evolutionary implications of this potentially widespread and significant phenomenon have yet to be explored. My dissertation addresses this knowledge gap by determining the influence YRV has on the evolution of autosomally coded traits in D. melanogaster. First, we address the potential for selection to shape YRV by determining if YRV (i) exists within natural populations (i.e. where natural selection operates), and (ii) has any influence on male fitness-related autosomal traits. Second, we address if YRV can facilitate the adaptive evolution of sexually dimorphic gene expression by testing for the presence of Y-linked additive genetic variation. To this end, we investigate the physiological properties of select Y-chromosomes across multiple genetic backgrounds. Third, we address if YRV can constrain adaptive evolution for autosomally coded traits by employing artificial selection on replicate populations that contain either multiple Y-chromosomes (i.e. contain YRV) or only a single Y-chromosome (no YRV). The following studies present evidence that YRV does exist within populations where natural selection operates. We show significant levels of YRV on X-linked and autosomal immune gene expression in wild caught D. melanogaster from a single natural population. Furthermore, YRV effects on immune related genes show a significantly positive correlation to a male fly's ability to fight an immune challenge (an important aspect of organismal fitness). Estimated physiological properties of YRV support previous interpopulation studies showing strong non-additive effect dependent on the autosomal genetic background with which Y-chromosome's are paired with. Physiological epistasis can manifest as additive genetic variation on a population level, but our experimental evolution study suggest that YRV constrains rather than facilitates the evolution of the autosomal coded geotaxis behavior. Ultimately, this dissertation provides evidence that YRV has the potential to influence how autosomal traits evolve and that population level studies of YRV indicate a potential constraint to the adaptive evolution of autosomal traits. If these trends are common and YRV is a wide spread phenomenon, Y-chromosomes have the potential to influence how autosomal traits evolve.
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Date Issued: 2017
Identifier: CFE0006756, ucf:51873
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006756

Title: A Time-Course Analysis of Behavioral Plasticity and Differential Gene Expression Patterns in Response to Density in Schistocerca americana (Orthoptera: Acrididae).
Creator: Gotham, Steven, Song, Hojun, Vonkalm, Laurence, Fedorka, Kenneth, University of Central Florida
Abstract / Description: Phenotypic plasticity is the ability of the genotype to express alternative phenotypes in response to different environmental conditions and this is considered to be an adaptation in which a species can survive and persist in a rapidly changing environment. Some grasshoppers and locusts are capable of expressing an extreme form of density-dependent phenotypic plasticity, known as locust phase polyphenism. At low population density, the individuals typically have a cryptic coloration as nymphs...
Show morePhenotypic plasticity is the ability of the genotype to express alternative phenotypes in response to different environmental conditions and this is considered to be an adaptation in which a species can survive and persist in a rapidly changing environment. Some grasshoppers and locusts are capable of expressing an extreme form of density-dependent phenotypic plasticity, known as locust phase polyphenism. At low population density, the individuals typically have a cryptic coloration as nymphs, are less active, and only seek out conspecifics for reproductive purposes. At high density, however, they develop a drastically different phenotype in which they have a conspicuous coloration, are much more active, and tend to stay together in large groups. The American Birdwing grasshopper, Schistocerca americana, is a non-swarming species related to the desert locust, S. gregaria, which shows density-dependent phenotypic plasticity in behavior, color, and morphology. In this thesis, I have identified the duration of crowding necessary for a 6th instar S. americana reared in the isolated condition to express the typical crowded behavior. The behavior changed after just one hour of crowding and the effect of crowding diminished after 48 hours to near-complete isolated behavior. In reverse, the crowded condition was isolated, but behavior did not significantly change over time. Gene expression of the following three genes suspected of having a role in behavior change were investigated based on studies of S. gregaria: protein kinase A (PKA), L-Tryptophan-5-monooxygenase (T-5), and Aromatic L-amino acid decarboxylase (Decarb). T-5 was up-regulated in the long-term isolated condition compared to the long-term crowded condition. T-5 and Decarb were up-regulated in isolated individuals that were crowded for 10 hours compared to the long-term isolated condition. This study represents a novel contribution in the study of phenotypic plasticity as it establishes the time course of behavioral and molecular plasticity in a non-swarming grasshopper for the first time.
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Date Issued: 2014
Identifier: CFE0005799, ucf:50049
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005799

Title: Character Evolution and Microbial Community Structure in a Host-associated Grasshopper.
Creator: Raszick, Tyler, Song, Hojun, Fedorka, Kenneth, Hoffman, Eric, University of Central Florida
Abstract / Description: The spotted bird grasshopper, Schistocerca lineata Scudder (Orthoptera: Acrididae), is a widely distributed species found throughout most of the continental United States and southern Canada. This species is known to be highly variable in morphology, with many distinct ecotypes across its native range. These ecotypes display high levels of association with type-specific host plants. Understanding the evolutionary relationships among different ecotypes is crucial groundwork for studying the...
Show moreThe spotted bird grasshopper, Schistocerca lineata Scudder (Orthoptera: Acrididae), is a widely distributed species found throughout most of the continental United States and southern Canada. This species is known to be highly variable in morphology, with many distinct ecotypes across its native range. These ecotypes display high levels of association with type-specific host plants. Understanding the evolutionary relationships among different ecotypes is crucial groundwork for studying the process of ecological differentiation. I examine four ecotypes from morphological and phylogeographic perspectives, and look for evidence of distinct evolutionary lineages within the species. I also begin to explore the potential role of the microbial community of these grasshoppers in ecological divergence by using 454 pyrosequencing to see if the microbial community structure reflects the ecology of the grasshoppers. I find support for a distinct aposematic lineage when approaching the data from a phylogeographic perspective and also find that this ecotype tends to harbor a unique bacterial community, different from that of a single other ecotype.
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Date Issued: 2014
Identifier: CFE0005540, ucf:50316
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005540

Title: Behavioral and disease ecology of Gopher Tortoises (Gopherus polyphemus) post exclusion and relocation with a novel approach to homing determination.
Creator: Napier, Johnathan, Savage, Anna, Moore, Sean, Vonkalm, Laurence, Fedorka, Kenneth, University of Central Florida
Abstract / Description: In the wake of human expansion, relocations and the loss of habitat can be stressful to an organism, plausibly leading to population declines. The gopher tortoise (Gopherus polyphemus) is a keystone species that constructs burrows it shares with 362 commensal species. Frequent exclusions and relocations and long generation times have contributed to G. polyphemus being State-designated as Threatened in Florida. Prior studies have indicated that G. polyphemus may possess homing behavior and...
Show moreIn the wake of human expansion, relocations and the loss of habitat can be stressful to an organism, plausibly leading to population declines. The gopher tortoise (Gopherus polyphemus) is a keystone species that constructs burrows it shares with 362 commensal species. Frequent exclusions and relocations and long generation times have contributed to G. polyphemus being State-designated as Threatened in Florida. Prior studies have indicated that G. polyphemus may possess homing behavior and thus be able to counteract stressors due to relocation and exclusion. I radiotracked a cohort of G. polyphemus for 11 months following excavation, relocation, and exclusion due to a pipeline construction project. In conjunction with analyzing G. polyphemus movement patterns post-release, I developed novel statistical methodologies with broad application for movement analysis and compared them to traditional analyses. I evaluated habitat usage, burrowing behavior, movements, growth, and disease signs among control versus relocated and excluded individuals and among sexes and size classes, forming predictors for behavior and disease risk. I found statistical support that my new methodology is superior to previous statistical tests for movement analyses. I also found that G. polyphemus engages in homing behavior, but only in males. Behavioral differences were also found between the sexes with respect to burrowing behavior. Overall health, disease prevalence, and immune response were unaffected by relocation and exclusion, nor were they statistically correlated. Signs were unreliable as etiological agents, outperformed by serological detection. I determined that the Sabal Trail pipeline as a potential stressor did not affect movement behavior, homing, nor the disease/immune profile of G. polyphemus in this study.
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Date Issued: 2018
Identifier: CFE0007581, ucf:52581
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007581

Title: Reproductive life history and signal evolution in a multi-species assemblage of electric fish.
Creator: Waddell, Joseph, Crampton, William, Fedorka, Kenneth, Quintana-Ascencio, Pedro, Stoddard, Philip, University of Central Florida
Abstract / Description: Animals that co-occur in sympatry with multiple closely-related species use reproductive mate attraction signals not only to assess the quality of a potential conspecific mate (sexual selection), but also to discriminate conspecifics from heterospecifics (species recognition). However, the extent to which sexual selection and species recognition may interact, or even conflict, is poorly known. Neotropical electric fish offer unrivaled opportunities for understanding this problem. They...
Show moreAnimals that co-occur in sympatry with multiple closely-related species use reproductive mate attraction signals not only to assess the quality of a potential conspecific mate (sexual selection), but also to discriminate conspecifics from heterospecifics (species recognition). However, the extent to which sexual selection and species recognition may interact, or even conflict, is poorly known. Neotropical electric fish offer unrivaled opportunities for understanding this problem. They generate simple, stereotyped mate attraction signals that are easy to record and quantify, and that are well-understood from the neurobiological perspective. Additionally, they live in electrically-crowded environments, where multiple congeners live and reproduce in close proximity. This dissertation reports an investigation of electric signal diversity and reproductive life history in a nine-species assemblage of the electric fish genus Brachyhypopomus from the upper Amazon. A year-long quantitative sampling program yielded a library of electric signal recordings from (>)3,000 individuals and an accompanying collection of preserved specimens from which suites of informative life history traits were measured. These data were used to understand basic reproductive biology, and to describe sexually dimorphic and interspecific diversity in electric signals. By integrating approaches from ecology, physiology, and evolutionary biology, novel perspectives are provided on: 1. how sexual selection and species recognition interact to shape signal diversity and the occupation of signal space in multi-species animal communities; 2. how extreme seasonal variation in Amazonian ecosystems influences trade-offs in the allocation of reproductive resources (-) including mate attraction signals, and; 3. how environmental variation shapes general life-history traits in a diverse tropical animal assemblage.
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Date Issued: 2017
Identifier: CFE0006925, ucf:51689
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006925

Title: Juvenile Ornamentation: Its Evolution, Genetic Basis, and Variation Across Habitats.
Creator: Tringali, Angela, Noss, Reed, Bowman, Reed, Fauth, John, Fedorka, Kenneth, University of Central Florida
Abstract / Description: Ornamental traits are considered honest advertisements of fitness, and their evolution is usually explained in terms of sexual selection. This explanation remains unsatisfactory in some instances, for example, juvenile birds whose plumage is molted prior to adulthood and breeding. I first evaluate whether juvenile plumage reflectance signals dominance status in the Federally Threatened Florida scrub-jay (Aphelocoma coerulescens) using a combination of observational and experimental methods....
Show moreOrnamental traits are considered honest advertisements of fitness, and their evolution is usually explained in terms of sexual selection. This explanation remains unsatisfactory in some instances, for example, juvenile birds whose plumage is molted prior to adulthood and breeding. I first evaluate whether juvenile plumage reflectance signals dominance status in the Federally Threatened Florida scrub-jay (Aphelocoma coerulescens) using a combination of observational and experimental methods. Then I estimate the heritability, non-genetic maternal and environmental effects, and strength of selection on juvenile plumage reflectance using archived feather samples and a pedigree constructed from historical nest records. Finally, I compare plumage reflectance and its use as a signal between a wildland and suburban population of scrub-jays. I conclude that plumage reflectance is a signal of dominance, and that social selection can also drive the evolution of sexually dimorphic traits. In this species, plumage reflectance is heritable and influenced by maternal effects, but environmental effects are inconsequential. Although this trait appears to have an important function, only mean brightness and female hue are associated with lifetime reproductive success. Plumage reflectance was more UV-shifted in the suburban birds, but there is no reason to believe that urbanization decreases the value of this plumage as a signal. However, these plumage differences may facilitate dispersal from suburban areas, contributing to the decline of suburban populations.
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Date Issued: 2013
Identifier: CFE0005431, ucf:50413
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005431

Drosophila (2)	+ -
reproductive effort (2)	+ -
Anasaitis canosa (1)	+ -
Ant Predators (1)	+ -
Ant foragers (1)	+ -

Behavior Time-Course (1)	+ -
Beta diversity (1)	+ -
Brachyhypopomus (1)	+ -
Cinara (1)	+ -
Communication (1)	+ -
Constraint (1)	+ -
Disposable Caste Hypothesis (1)	+ -
Drosophila melanogaster (1)	+ -
Electric organ (1)	+ -
Electrogenesis (1)	+ -
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Epistasis (1)	+ -
Evolutionary Genetics (1)	+ -
Evolutionary trap (1)	+ -
Florida Keys (1)	+ -
Florida Scrub-Jay (1)	+ -
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Fedorka, Kenneth (19)	+ -
University of Central Florida (19)	+ -
Hoffman, Eric (8)	+ -
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