Biology Commons^™

Thermal Ecology And Swimming Performance Of Native Tadpoles Dryophytes Femoralis In Central Florida, Jessalyn Aretz

USF Tampa Graduate Theses and Dissertations

Urbanization and climate warming have contributed to global amphibian declines in recent decades. Amphibians are particularly vulnerable to climate and urban-induced warming because their physiological processes are dependent on temperature across all life stages, but few studies have been done on tadpole responses to warming in comparison to adult responses. The study objective was to determine how the thermal ecology and swimming performance of a native Florida tadpole varied with rearing temperature and urban level, and whether these traits are plastic or adaptive. We collected eggs from wild populations of pine woods treefrog (Dryophytes femoralis) tadpoles at an urban and …

The Effect Of Urbanization And Temperature On Thermal Tolerance, Foraging Performance, And Competition In Cavity-Dwelling Ants, Brooke A. Harris, Dale Stevens, Kaitlyn A. Mathis

Biology

Human disturbance including rapid urbanization and increased temperatures can have profound effects on the ecology of local populations. Eusocial insects, such as ants, have adapted to stressors of increasing temperature and urbanization; however, these evolutionary responses are not consistent among populations across geographic space. Here we asked how urbanization and incubation temperature influence critical thermal maximum (CT_max) and various ecologically relevant behaviors in three ant species in urban and rural locations in Worcester, MA, USA. We did this by incubating colonies of three species of cavity dwelling ant (Aphaenogaster picea, Tapinoma sessile, and Temnothorax longispinosus) from 2 habitat …

Complex Dynamics Of Coral Gene Expression Responses To Low Ph Across Species, Veronica Z. Radice, Ana Martinez, Adina Paytan, Donald C. Potts, Daniel J. Barshis

Biological Sciences Faculty Publications

Coral capacity to tolerate low pH affects coral community composition and, ultimately, reef ecosystem function. Low pH submarine discharges (‘Ojo’; Yucatán, México) represent a natural laboratory to study plasticity and acclimatization to low pH in relation to ocean acidification. A previous >2‐year coral transplant experiment to ambient and low pH common garden sites revealed differential survivorship across species and sites, providing a framework to compare mechanistic responses to differential pH exposures. Here, we examined gene expression responses of transplants of three species of reef‐building corals (Porites astreoides, Porites porites and Siderastrea siderea) and their algal endosymbiont communities …

Diversity, Function, And Phenotypic Plasticity Of Cryptophyte Phycobiliproteins, Kristiaän Merritt

Theses and Dissertations

Cryptophytes are a group of unicellular eukaryotic algae that can be found in a wide range of underwater habitats. Part of their ecological success can be attributed to their diverse array of cryptophyte phycobiliproteins (Cr-PBPs), a pigment class that captures wavelengths of light that are poorly absorbed by chlorophylls. Cryptophytes gained photosynthesis via secondary endosymbiosis in which their ancestor engulfed a red algal endosymbiont. Following endosymbiosis, they deconstructed the red algal photosynthetic machinery to form the Cr-PBP. Since then, the Cr-PBPs have diversified into at least 9 spectrally distinct forms. I investigated the diversity of Cr-PBP light absorption across 76 …

Gabaergic Synaptic Scaling Is Triggered By Changes In Spiking Activity Rather Than Transmitter Receptor Activation, Carlos Gonzalez-Islas, Zahraa Sabra, Ming-Fai Fong, Pernille Bülow, Nicholas Au Yong, Kathrin Engisch, Peter Wenner

Biological Sciences Faculty Publications

Homeostatic plasticity represents a set of mechanisms that are thought to recover some aspect of neural function. One such mechanism called AMPAergic scaling was thought to be a likely candidate to homeostatically control spiking activity. However, recent findings have forced us to reconsider this idea as several studies suggest AMPAergic scaling is not directly triggered by changes in spiking. Moreover, studies examining homeostatic perturbations in vivo have suggested that GABAergic synapses may be more critical in terms of spiking homeostasis. Here we show results that GABAergic scaling can act to homeostatically control spiking levels. We find that increased or decreased …

Multilevel Phenotypic Integration Of Metabolism And Behavior In House Sparrows And Mice, Tim Salzman

Theses and Dissertations--Biology

Patterns of multilevel variation in behavior, both within and among individuals, raise challenging questions about underlying mechanisms and the selective pressures acting on them. One intriguing hypothesis is that physiology shows parallel multilevel variation, and so might represent a latent trait that integrates multilevel behavioral responses. For example, foraging acquires the fuel needed to maintain metabolism, and in turn, an individual’s metabolism affects expression of foraging, and other, behaviors. Metabolism and behavior thus might coevolve to become integrated traits. Despite the appeal of this hypothesis, numerous investigations into the link between metabolism and behavior have yielded largely equivocal results.

To …

Global Population Divergence Of A Cosmopolian Desert Plant, Victor Ryan Alfaro

Biology ETDs

Genetic and phenotypic variation can have different patterns within a species if it has populations with contrasting histories. Populations can have discrete differences that are shaped by different evolutionary scenarios, but within each population, range, or region, traits and association with fitness can also be affected by both edaphic and landscape variation. For my dissertation, I surveyed and experimentally analyzed variation and adaptive potential in Sahara mustard (Brassica tournefortii), a desert annual that has endemic, invasive, and agricultural populations in Africa, Asia, and the Americas. Although my multi-trait analysis generated complex results, my findings can be applied to …

Most Published Selection Gradients Are Underestimated: Why This Is And How To Fix It, Niels Jeroen Dingemanse, Yimen G. Araya-Ajoy, David F. Westneat

Biology Faculty Publications

Ecologists and evolutionary biologists routinely estimate selection gradients. Most researchers seek to quantify selection on individual phenotypes, regardless of whether fixed or repeatedly expressed traits are studied. Selection gradients estimated to address such questions are attenuated unless analyses account for measurement error and biological sources of within-individual variation. Estimates of standardized selection gradients published in Evolution between 2010 and 2019 were primarily based on traits measured once (59% of 325 estimates). We show that those are attenuated: bias increases with decreasing repeatability but differently for linear versus nonlinear gradients. Others derived individual-mean trait values prior to analyses (41%), typically using …

The Evolution Of Life Histories And Phenotypic Plasticity Across Environmental Gradients In Daphnia Sp., Michelle Renee Swan Packer

Biology Dissertations

Understanding how environmentally-induced variation ultimately leads to speciation is a main component of evolutionary ecology. This dissertation uses Daphnia in experimental and comparative studies to address several theoretical questions concerning the role of phenotypic plasticity in the evolutionary process. Specifically, I explore novel environmental factors which induce plasticity and investigate the plastic response across systems to determine general hypotheses for understanding the mechanisms which may be involved. Additionally, this dissertation provides empirical results which add to the body of research investigating the transition between environmentally induced phenotypes and genetic adaptation. The results of this body of work show that ancestral …

Combined Opportunistic And Equilibrium Life-History Traits Facilitate Successful Invasions Of The Shimofuri Goby (Tridentiger Bifasciatus), Jiao Qin, Miao Xiang, Meixiang Jia, Fei Cheng, Bjorn V. Schmidt, Jian Liu, Songguang Xie

Faculty Publications

The life-history traits of a non-native population of Shimofuri goby (Tridentiger bifasciatus) were investigated in Nansi Lake, which is a storage lake on the East Route of the South-to-North Water Transfer Project, China. The results were analyzed in combination with data from other non-native populations of this species to reveal the life-history traits that caused its successful invasions. Mature gonads in April and May suggest that the species spawns in this period, and cohort tracking and age analysis revealed that individuals had a one-year lifespan. The relative fecundity was 2,825 ± 614 eggs/g. A short lifespan and high fecundity are …

A Comparison Of Low Temperature Biology Of Pieris Rapae From Ontario, Canada, And Yakutia, Far Eastern Russia, Natalia G. Li, Jantina Toxopeus, Martin Moos, Jesper G. Sørensen, Brent J. Sinclair

Biology Publications

Low temperatures limit the distribution and abundance of ectotherms. However, many insects can survive low temperatures by employing one of two cold tolerance strategies: freeze avoidance or freeze tolerance. Very few species can employ both strategies, but those that do provide a rare opportunity to study the mechanisms that differentiate freeze tolerance and freeze avoidance. We showed that overwintering pupae of the cabbage white butterfly Pieris rapae can be freeze tolerant or freeze avoidant. A population of P. rapae in northeastern Russia (Yakutsk) froze at c. -9.3 °C and were freeze-tolerant in 2002-2003 when overwintered outside. However, P. rapae from …

Direct And Indirect Effects Of Sex Steroids On Gonadotrope Cell Plasticity In The Teleost Fish Pituitary, Romain Fontaine, Muhammad Rahmad Royan, Kristine Von Krogh, Finn-Arne Weltzien, Dianne M. Baker

Biological Sciences Research

The pituitary gland controls many important physiological processes in vertebrates, including growth, homeostasis, and reproduction. As in mammals, the teleost pituitary exhibits a high degree of plasticity. This plasticity permits changes in hormone production and secretion necessary to meet the fluctuating demands over the life of an animal. Pituitary plasticity is achieved at both cellular and population levels. At the cellular level, hormone synthesis and release can be regulated via changes in cell composition to modulate both sensitivity and response to different signals. At the cell population level, the number of cells producing a given hormone can change due to …

What Role Does Age-Associated Neuroplasticity Play In The Efficacy Of Cochlear Implantation?, Jacob Fliegelman

The Science Journal of the Lander College of Arts and Sciences

Bilateral, profound-severe, congenital deafness causes widespread structural and functional changes of the auditory system. In humans, the consequences of these changes are extensive and often include detriments to language acquisition and auditory perception. Fortunately, early intervention methods, such as cochlear implantation, can significantly mitigate inevitable auditory deficiencies. This review begins by briefly addressing early stages of brain development and associated anatomical discrepancies observed in congenitally deaf subjects. Considering the deleterious effects of congenital deafness, neuroplasticity, the ability of the brain to rewire itself, is of paramount importance in reversing the auditory impairments. Hence, its incorporation into the methods required for …

Plasticity And The Impact Of Increasing Temperature On A Tropical Ectotherm, Adam A. Rosso

Electronic Theses and Dissertations

Organisms may respond to climate change through behavior, genetic adaptation, and/or phenotypic plasticity. Tropical ectotherms are thought to be especially vulnerable to climate change because most have a narrow range of thermal tolerance while living close to their upper thermal tolerance limits. Additionally, many tropical species live in closed-canopy forests, which provide homogenous thermal landscapes that prevent behavioral compensation for stressfully warm temperatures. Finally, tropical ectotherms are thought to have decreased capacity for phenotypic plasticity because they have evolved in thermally stable environments. We tested gene expression patterns and phenotypic plasticity in the Panamanian slender anole by a) measuring changes …

Synaptic Plasticity In A Visual Cortical Region Induced By Early-Deafness, John M. Kay

Theses and Dissertations

When organisms learn and adapt to their environment or lose a sensory modality, neurons in the brain undergo a cellular process called ‘plasticity.’ This thesis explores the loss of a non- visual system (early deafness) and how it can affect visual plasticity. To examine this question, Golgi-stained cortical neurons were studied from the visual region PLLS from early-deaf cats and their hearing controls. Dendritic spine density and dendritic spine diameter are well-known indicators of synaptic plasticity and these neuronal features were measured using light microscopic techniques and Neurolucida. Within the visual PLLS, the mean spine density for the deaf cats …

Plasticity Of Foot Muscle And Cardiac Thermal Limits In The Limpet Lottia Limatula From Locations With Differing Temperatures, Terrance Wang, Richelle L. Tanner, Eric J. Armstrong, David R. Lindberg, Jonathon H. Stillman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Species distributions are shifting in response to increased habitat temperatures as a result of ongoing climate change. Understanding variation in physiological plasticity among species and populations is important for predicting these distribution shifts. Interspecific variation in intertidal ectotherms’ short-term thermal plasticity has been well established. However, intraspecific variation among populations from differing thermal habitats remains a question pertinent to understanding the effects of climate change on species’ ranges. In this study, we explored upper thermal tolerance limits and plasticity of those limits using a foot muscle metric and 2 cardiac metrics (Arrhenius breakpoint temperature, ABT, and flatline temperature, FLT) in …

Translational Control Of Stress Induced Breast Cancer Plasticity, Michael Jewer

Electronic Thesis and Dissertation Repository

Cancer cell plasticity, whereby stem-cell-like properties are acquired in response to stress, represents a major challenge in cancer treatment. Using cell line and patient-derived xenograft (PDX) models, we demonstrate that translational reprogramming occurs in response to stresses such as hypoxia and chemotherapy which elicits stem cell properties in breast cancer. Other stresses like chemotherapy demonstrate the translational inhibition that has been well characterized as an integral hypoxic cellular response. The inhibition of translation is primarily regulated at initiation by mTOR/4E-BP1 and PERK/eIF2α signalling. We identify previously undescribed 5’ untranslated regions (5’UTRs) of plasticity-associated genes like NANOG, SNAIL and NODAL. …

Extended Adolescence: The Ecology And Endocrinology Of Facultative Paedomorphosis, Jason R. Bohenek

Electronic Theses and Dissertations

Phenotypic plasticity is an adaptation to unpredictable environments whereby an organism of a single genotype may express more than one phenotype under differing environmental conditions. Phenotypic plasticity can manifest as polyphenisms, which is an extreme form of phenotypic plasticity that produces two or more discrete, alternative phenotypes. The expression of alternative phenotypes is controlled by biotic and abiotic environmental factors, which variably affect the strength and direction of phenotypic outcomes. Using a model polyphenic salamander, I sought to understand the ecological and hormonal processes that regulate alternative phenotype expression. The mole salamander (Ambystoma talpoideum) and eastern newt ( …

Cold Acclimation Response Of Non-Native Italian Wall Lizard (Podarcis Siculus) Populations From New York And California, Daniel Haro

Master's Theses

Understanding how organisms respond to climatic variability and novel conditions is becoming an increasingly important task for ecologists. For ectotherms in the northern hemisphere, the response to cold is of special interest, considering that poleward range expansion events and increasing variability of temperatures during winter are already being observed as consequences of a warming planet. Though direction of change in physiological variables in response to cold is well studied in ectotherms, the extent to which traits can change and the rate at which they can change is not.

We compared the extent and rate of change in cold tolerance (CT …

Phenotypic Plasticity In Light-Induced Flavonoids Varies Among Tissues In Silene Littorea (Caryophyllaceae), José Carlos Del Valle, Mª Luisa Buide, Justen B. Whittall, Eduardo Narbona

Biology

Plants respond to environmental stimuli in a diversity of ways including the production of secondary metabolites. Biosynthesis of plant phenolics, including flavonoids, is frequently activated in response to a variety of abiotic and biotic stressors (e.g. extreme temperatures, high radiation, pathogens, etc.). This induced reaction is typically assumed to be a plastic response, but the components attributable to plasticity vs genetic variance in these components are poorly understood. Here, we investigate the variation in flavonoid production (anthocyanins and flavones) in petals and in photosynthetic tissues (calyces, leaves and stems) of Silene littorea. We performed a common garden experiment with …

Identification Of Genes That Maintain Behavioral And Structural Plasticity During Sleep Loss, Laurent Seugnet, Stephane Dissel, Matthew S. Thimgan, Lijuan Cao, Paul J. Shaw

Biological Sciences Faculty Research & Creative Works

Although patients with primary insomnia experience sleep disruption, they are able to maintain normal performance on a variety of cognitive tasks. This observation suggests that insomnia may be a condition where predisposing factors simultaneously increase the risk for insomnia and also mitigate against the deleterious consequences of waking. To gain insight into processes that might regulate sleep and buffer neuronal circuits during sleep loss, we manipulated three genes, fat facet (faf), highwire (hiw) and the GABA receptor Resistance to dieldrin (Rdl), that were differentially modulated in a Drosophila model of insomnia. Our results indicate …

Mechanisms Of Invasion And Competition In Anolis Sagrei And Anolis Carolinensis Lizards In Southeastern Louisiana, Jessica R. Edwards

University of New Orleans Theses and Dissertations

Invasive species can have a variety of effects on the behavior and ecology of native species. Currently in New Orleans, Louisiana, both A. sagrei and A. carolinensis lizards are relatively abundant, but the A. sagrei population is expanding rapidly. I used a combination of laboratory and field studies to investigate factors that might be influencing local dominance of invasive A. sagrei over native A. carolinensis populations, including habitat use, display behavior, interspecific aggressive interactions, and plasticity. When comparing display behavior and habitat use in anole populations across three field sites in southern Louisiana, I found differences in male display behavior …

Thermal Biology Of Insect Immunity And Host-Microbe Interactions, Laura V. Ferguson

Electronic Thesis and Dissertation Repository

The influence of temperature on interactions with pathogenic or symbiotic microbes is a driving force behind the survival of insects under climate change. However, we know little of how insects physiologically respond to these pressures. In temperate climates, winter dominates the thermal landscape; thus, I am particularly interested in how cold interacts with insect responses to microbes. Here I explore the thermal biology of the insect immune system and the impacts of cold on host-microbe interactions. First, I demonstrate that acute exposure to cold activates selective components of immunity in Drosophila melanogaster, as a compensatory response to trade-offs or …

Positional Plasticity In Regenerating Amybstoma Mexicanum Limbs Is Associated With Cell Proliferation And Pathways Of Cellular Differentiation, Catherine D. Mccusker, Antony Athippozhy, Carlos Diaz-Castillo, Charless Fowlkes, David M. Gardiner, S. Randal Voss

Biology Faculty Publications

BACKGROUND: The endogenous ability to dedifferentiate, re-pattern, and re-differentiate adult cells to repair or replace damaged or missing structures is exclusive to only a few tetrapod species. The Mexican axolotl is one example of these species, having the capacity to regenerate multiple adult structures including their limbs by generating a group of progenitor cells, known as the blastema, which acquire pattern and differentiate into the missing tissues. The formation of a limb regenerate is dependent on cells in the connective tissues that retain memory of their original position in the limb, and use this information to generate the pattern …

On Flavonoid Accumulation In Different Plant Parts: Variation Patterns Among Individuals And Populations In The Shore Campion (Silene Littorea), José C. Del Valle, Mª Luisa Buide, Inés Casimiro-Soriguer, Justen B. Whittall, Eduardo Narbona

Biology

The presence of anthocyanins in flowers and fruits is frequently attributed to attracting pollinators and dispersers. In vegetative organs, anthocyanins and other non-pigmented flavonoids such as flavones and flavonols may serve protective functions against UV radiation, cold, heat, drought, salinity, pathogens, and herbivores; thus, these compounds are usually produced as a plastic response to such stressors. Although, the independent accumulation of anthocyanins in reproductive and vegetative tissues is commonly postulated due to differential regulation, the accumulation of flavonoids within and among populations has never been thoroughly compared. Here, we investigated the shore campion (Silene littorea, Caryophyllaceae) which exhibits …

Monoaminergic Tone Supports Conductance Correlations And Stabilizes Activity Features In Pattern Generating Neurons Of The Lobster, Panulirus Interruptus, Wulf-Dieter C. Krenz, Anna R. Parker, Edmund William Rodgers, Deborah J. Baro

Biology Faculty Publications

Experimental and computational studies demonstrate that different sets of intrinsic and synaptic conductances can give rise to equivalent activity patterns. This is because the balance of conductances, not their absolute values, defines a given activity feature. Activity-dependent feedback mechanisms maintain neuronal conductance correlations and their corresponding activity features. This study demonstrates that tonic nM concentrations of monoamines enable slow, activity-dependent processes that can maintain a correlation between the transient potassium current (IA ) and the hyperpolarization activated current (Ih ) over the long-term (i.e., regulatory change persists for hours after removal of modulator). Tonic 5 nM DA acted through an …

A Tale Of Two Morphs: Genetic And Genotypic Structure Between Macrocystis Pyrifera And Macrocystis Integrifolia, Heidi Hargarten

Theses and Dissertations

Organisms living along environmental gradients often utilize phenotypic plasticity to maximize their survival across a range of conditions. Wherever gradients occur, there is potential for divergence through isolation-by-adaptation (IBA) to build-up between genotypes experiencing different selective pressures. Plasticity in traits pertaining to mating systems in particular are likely to constitute an interesting and revealing model for the study of the underlying mechanisms behind parapatric speciation. Giant kelp, Macrocystis spp., shows striking plasticity in holdfast morphology and reproductive strategy when colonizing intertidal (M. integrifolia morph) versus subtidal (M. pyrifera morph) areas along temperate rocky coastlines of the eastern Pacific Ocean. In …

Non-Adaptive Phentypic Plasticity: Morphology, But Not Swim Speed, Of Spotted Salamander Larvae Is Affected By "Terrestrial" And "Aquatic" Herbicides, Mitchell Schooler

Mahurin Honors College Capstone Experience/Thesis Projects

1. Phenotypic plasticity, although ubiquitous, may not always be advantageous. In cases where individuals expressing an induced phenotype outperform non-induced individuals, the phenotypic plasticity is considered adaptive. Conversely, if the individuals with an induced phenotype underperform relative to non-induced individuals, then the plasticity is maladaptive. A final possibility is that both induced and non-induced individuals perform equally well (or poorly). This would be a case of non-adaptive (i.e. neutral) phenotypic plasticity.
2. We investigated the mode of phenotypic plasticity induced by four glyphosate-based herbicides in larvae of the spotted salamander, Ambystoma maculatum (Shaw, 1802), by determining whether the herbicides induced different morphologies, …

Consequences Of Life History Switch Point Plasticity For Juvenile Morphology And Locomotion In The Túngara Frog, Julie Charbonnier, James R. Vonesh

Biology Publications

Many animals with complex life cycles can cope with environmental uncertainty by altering the timing of life history switch points through plasticity. Pond hydroperiod has important consequences for the fitness of aquatic organisms and many taxa alter the timing of life history switch points in response to habitat desiccation. For example, larval amphibians can metamorphose early to escape drying ponds. Such plasticity may induce variation in size and morphology of juveniles which can result in carry-over effects on jumping performance. To investigate the carry-over effects of metamorphic plasticity to pond drying, we studied the Túngara frog, Physalaemus pustulosus, a …

Consequences Of Life History Switch Point Plasticity For Juvenile Morphology And Locomotion In The Túngara Frog, Julie Charbonnier, James R. Vonesh

Biology Publications

Many animals with complex life cycles can cope with environmental uncertainty by altering the timing of life history switch points through plasticity. Pond hydroperiod has important consequences for the fitness of aquatic organisms and many taxa alter the timing of life history switch points in response to habitat desiccation. For example, larval amphibians can metamorphose early to escape drying ponds. Such plasticity may induce variation in size and morphology of juveniles which can result in carry-over effects on jumping performance. To investigate the carry-over effects of metamorphic plasticity to pond drying, we studied the Túngara frog,Physalaemus pustulosus, a …