Ecology and Evolutionary Biology Commons^™

Ubiquitous Yet Inconspicuous: Quantifying Trophic Impact Of A Widespread Oceanic Comb Jelly (Ctenophore), Elizabeth Potter

USF Tampa Graduate Theses and Dissertations

The oceanic lobate ctenophore Ocyropsis spp. has a widespread distribution throughout the world’s tropical and sub-tropical oceans. While patchy, Ocyropsis spp. population densities are known to exceed one individual per m3. Studies of coastal ctenophores have shown that some species are capable of exerting strong predatory impacts on their ecosystems, but little is known about the potential trophic impacts of their oceanic relatives. Many oceanic genera such as Ocyropsis, Bolinopsis, and Eurhamphaea exhibit morphologies and prey capture mechanisms that are different from the more well-studied coastal species. Thus, existing data on coastal taxa may not apply to oceanic species due …

Ecological Genomics Of Two Coastal Foundation Plant Species, Jeannie Mounger

USF Tampa Graduate Theses and Dissertations

I was born and raised in rural Florida on a tributary of the Withlacoochee River. “Withlacoochee” comes from a series of Muscogee Creek words that together mean “big little water,” possibly owing to the seasonal fluctuations in the breadth and flow of the river or to the chain of lakes that in part form it. The name contains within it an understanding of the capacity of land and water to undergo great shifts. It conjures images of mutable boundaries, of water covering and receding across the landscape over and over again. Many of my clearest memories from childhood are related …

Evolutionary Mechanisms For Host Resistance To Tumor Growth And Subsequent Cancer Cell Counter-Adaptations, Arig Ibrahim Hashim

USF Tampa Graduate Theses and Dissertations

Cancer is well-recognized as an evolutionary system, as first proposed by Cairns and Nowell more than 60 years ago. In an evolutionary context, cancers growing in vivo typically consist of heterogeneous subpopulations of cells that interact with each other and with host cells through selection forces operating at many temporal and spatial scales. Moreover, the tumor environment comprises more than just cancer cells; it includes a rich cancer stroma and cancer-driving molecules such as cytokines and metabolites. The tumor’s environment comprises intratumoral heterogeneity that often leads to therapy resistance attributed to the essential roles of many genetic and nongenetic mechanisms. …

The Distribution In Native Populations From Mexico And Central America Of The C677t Variant In The Mthfr Gene, Lucio A. Reyes

USF Tampa Graduate Theses and Dissertations

Objectives: To explore evolutionary hypotheses for the high frequencies of a substitution in the methylenetetrahydrofolate reductase (MTHFR) gene, in Mexican and Central American Indigenous populations.

Materials and methods: We obtained allele frequencies for the C677T variant in the MTHFR gene and ecological information for 37 indigenous samples from Mexico and Central America. We calculated Hardy–Weinberg equilibrium and computed Fst statistics. We computed correlations between the samples' allele frequencies and ecological and geochemical variables.

Results: Many of the samples have extremely high frequencies of the T allele (q̄ = 0.62, median = 0.66). In this region, the frequency of the T …

Cross-Host Correlations And Multivariate Effects Of Herbivore Specialization, Daniel J. Zydek

USF Tampa Graduate Theses and Dissertations

The distribution of insect herbivores among plant hosts is largely nonrandom: most herbivores have limited sets of hosts within one or a few plant families. This host use specialization is reinforced by traits that confer differential fitness across host plant species. Classic explanations for herbivore specialization predict that evolutionary trade-offs reinforce these relationships by imposing costs in the form of reduced potential fitness on alternative hosts, due to negative genetic correlations in fitness across hosts. This prediction that trade-offs constrain host use in herbivores can be tested with experimental evolution, by showing the direct evolutionary effects of host manipulation on …

Reproduction And Parasite-Mediated Selection, Meredith A. Krause

USF Tampa Graduate Theses and Dissertations

Sexual reproduction generates genetic diversity that can help hosts respond to selection by parasites, and in this thesis, I test three predictions on how reproduction impacts predictions by the parasite theory of sex and the Red Queen hypothesis. In Chapter one, using a meta-analysis, I found that asexuals (lower genetic diversity) have more parasites than sexuals (higher genetic diversity), but this difference can be heavily mediated by the mode and origin of asexuality. Further, hybridization but not polyploidy can blunt predicted differences in parasite loads among sexual and asexual hosts. In Chapter two, I flip the perspective of Red Queen …

Effects Of Inter-Male Status Challenge And Psychopathic Traits On Sexual Aggression, Amy M. Hoffmann

USF Tampa Graduate Theses and Dissertations

Sexual aggression (SA) is a serious social problem that has been linked to a variety of negative physical and mental health outcomes for survivors and produces significant monetary costs to society. In the past five decades, a wealth of research has improved our understanding of the individual and sociocultural factors that contribute to SA perpetration; however, epistemological differences in theoretical approaches to the subject (i.e., evolutionary, feminist) have resulted in gaps in the empirical literature. Informed by both feminist and evolutionary perspectives, this study attempts to examine the ways in which same-gender interpersonal interactions and individual psychopathology interact to produce …

An Investigation Of The Effects Of The Parasitic Nematode Aplectana Hamatospicula On The Performance And Behavior Of Cuban Treefrogs (Osteopilus Septentrionalis), Kerri Surbaugh

USF Tampa Graduate Theses and Dissertations

Parasitic infections are ubiquitous in nature, and host-parasite dynamics can have powerful effects on wildlife populations. Many species have evolved behavioral responses to infection that can help mitigate damage from parasites. Anorexia is a common response to infection observed throughout the animal kingdom. Reducing nutrient intake can help shift host resources from digestion to immunity, as well as limit resources available to parasites. Reduced feeding can weaken the host, but in some host-parasite interactions, this cost is less than that of maintaining an infection. Here, I describe an experiment aimed to explore the effects of the parasitic nematode Aplectana hamatospicula …

Documenting Evolution: Comparing And Contrasting Late Mesozoic And Late Cenozoic Molluscan Patterns, Joshua Slattery

USF Tampa Graduate Theses and Dissertations

Despite major advances, evolutionary theory still has numerous shortcomings in terms of fully understanding the controls on speciation and diversification. A major factor limiting our knowledge is how biology and paleobiology view speciation from separate micro- and macro-evolutionary perspectives, respectively. Biologists typically examine microevolutionary changes within species from various biogeographic, behavioral, morphological, and genetic perspectives, which contrasts to the macroevolutionary approach of most paleobiologists, who have examined the same phenomena at larger scales but with the standpoint of time, have also concentrated on aspects of global or regional diversification (e.g., richness, origination rates, and extinction rates) over the long-term. Noticeably …

The Association Of Size Variation In The Dental Arch To Third Molar Agenesis For A Modern Population, Devin N. Williams

USF Tampa Graduate Theses and Dissertations

The frequency with which individuals do not develop their third molars, or wisdom teeth, is increasing worldwide. This current topic of human evolution is relevant to the research of anthropologists, geneticists, dentists, and other researchers involved in the study of human dentition. Many explanations have been offered to account for the prevalence of molar agenesis including, evolutionary, environmental, and genetic theories. The purpose of this research project is to determine the frequency of third molar agenesis and investigate the relationship between third molar agenesis and maxillomandibular jaw dimensions in a sample of orthodontic patients. This research tests the hypotheses that: …

Molecular Phylogenetics Of Floridian Boletes, Arian Farid

USF Tampa Graduate Theses and Dissertations

The boletes are macrofungi which have undergone extensive taxonomic revisions since the advent of molecular tools. To further our understanding of the boletes in peninsular Florida, we sequenced two common Floridian boletes, and analyzed them with molecular phylogenetic tools. Boletus rubricitrinus, a common Florida bolete often found in lawns under Quercus, and likely has a distribution that extends to Texas. Based on ITS and LSU sequences and morphological studies, this species belongs in the genus Pulchroboletus. As the holotype is in poor condition, an epitype is established here. A thorough description of macroscopic and microscopic features is also provided for …

Grooming Behaviors Of, Lauren N. Williams

USF Tampa Graduate Theses and Dissertations

The giant freshwater shrimp, Macrobrachium rosenbergii is a large species of prawn grown extensively in aquaculture settings. A social hierarchy exists within the males of this species, representing three distinct male morphotypes. These male morphotypes differ in their behavior, physiology, and morphology and include the largest blue-clawed males (BC males), moderately- sized orange-clawed males (OC males), and the undifferentiated small-clawed males (SM males). All individuals of this species perform grooming behaviors to rid themselves of body fouling which can impede important functions such as movement, respiration, chemoreception, and reproduction. Grooming behaviors in crustaceans often utilize specialized structures called setae, which …

Response To Nitrogen And Salinity Conditions In Rhizophora Mangle Seedlings Varies By Site Of Origin, Kristen L. Langanke

USF Tampa Graduate Theses and Dissertations

Many coastal plant species thrive across a range of environmental conditions, often displaying dramatic phenotypic variation in response to environmental variation. We characterized the response of the critical foundation species Rhizophora mangle L. to full factorial combinations of salt and nitrogen (N). We used seedlings collected from five populations and measured traits related to salt tolerance and N amendment. The response to increasing salt included significant plasticity in succulence, leaf mass area (LMA), and root to shoot ratio (R:S). Seedlings also showed overall reduced maximum photosynthetic rate in response to N amendment, but this response depended on the level of …

Molecular Response Of Spartina Alterniflora To The Deepwater Horizon Oil Spill, Mariano Alvarez

USF Tampa Graduate Theses and Dissertations

Although the “genome as a blueprint” metaphor has been pervasive in biology, recent advances in molecular biology have revealed a complex network of regulatory machinery that dynamically regulated molecular processes in response to environmental conditions. However, these patterns, as well as the evolutionary processes that underlie them, remain understudied in natural conditions. In 2010, the Deepwater Horizon oil spill released an estimated 4.9 million barrels of oil into the Gulf of Mexico, making landfall on salt marsh habitat dominated by the foundation species Spartina alterniflora. Despite the severe impacts to phenotype and fitness, S. alterniflora proved remarkably resilient in …

Pathways Of Embodiment: Drug Use Among Adolescents In Popay[Aacute]N Colombia, Sarah Louise Fishleder

USF Tampa Graduate Theses and Dissertations

This research examines the interrelated biological and cultural factors that determine pathways by which recreational drug use is manifest to addiction in the lives of youth aged 12-18 in Popay[aacute]n, Colombia. It utilizes existing data from mixed methods research conducted between 2004-2005 examining epidemiological risk factors, drug use, perceptions about drugs, and a biological phenomenon of the brain known as incentive salience. Perceptions and experiences related to drugs were gathered using structured methods. MDS and hierarchical plots of drug perceptions are presented in order to demonstrate the power of culture and expectation on perception and choice. Structural equation modeling was …

Comparative Developmental Transcriptomics Of Echinoderms, Roy Vaughn

USF Tampa Graduate Theses and Dissertations

The gastrula stage represents the point in development at which the three primary germ layers diverge. At this point the gene regulatory networks that specify the germ layers are established and the genes that define the differentiated states of the tissues have begun to be activated. These networks have been well characterized in sea urchins, but not in other echinoderms. Embryos of the brittle star Ophiocoma wendtii share a number of developmental features with sea urchin embryos, including the ingression of mesenchyme cells that give rise to an embryonic skeleton. Notable differences are that no micromeres are formed during cleavage …

Egyptian Body Size: A Regional And Worldwide Comparison, Michelle H. Raxter

USF Tampa Graduate Theses and Dissertations

Human body size and limb proportions can provide important information about adaptation, population movements, and health disparities. This study investigated changes in body size and limb proportions of adult Egyptians temporally and geographically in relation to climatological, sociopolitical and economic developments. It was predicted that Egyptian groups that experienced more environmental stress would be shorter and exhibit less sexual dimorphism. It was also predicted that Egyptians would be intermediate between higher and lower latitude populations in body form and limb length ratios. The main skeletal sample consisted of 492 males and 528 females, all adults from the Predynastic and Dynastic …