Ecology and Evolutionary Biology Commons^™

Understanding Context Dependent Responses To Climate Change In Arizona Tiger Salamanders (Ambystoma Mavortium Nebulosum), Kentrell Richardson

Masters Theses, 2020-current

Future emissions scenarios project climate change to increase average global temperatures by at least two ℃ in the next 50 years resulting in changes in local climate and causing increased variability within microclimates. Ectotherms are especially sensitive to climate change due to their dependence on environmental temperatures to regulate physiological functions. Changes in temperature are likely to impact thermally cued processes within amphibians and result in changes in variable magnitudes and directions within local populations.

Salamanders were placed in cups and partially submerged in a water bath and heated at a rate of ~0.27℃/ minute. Once salamanders were unable to …

Assessing The Utility Of High-Throughput Phenotyping For Ecological Applications, Annabree Corlew

Honors Theses

A phenotype describes the expressed traits of an organism. These traits can provide insight into interactions between an organism and its environment, making them a key focus of ecological research. But the process of phenotyping traits can be tedious to collect for large-scale experiments. High-throughput phenotyping software has the ability to speed up the phenotyping process by allowing multiple traits to be phenotyped at once. However, the utility of this relatively new and continually developing computational tool is still being assessed, especially beyond applications focused on agricultural crops and grasses. I investigated the accuracy and efficiency of the open-access high-throughput …

Intraspecific Potency Of Predation Risk Cues, Delbert Lee Smee, Benjamin Belgrad

Gulf and Caribbean Research

No abstract provided.

Parental Effects On Offspring Reaction Norms: Consequences For Complex Phenotypes In Variable Environments, Alexandra G. Cones

Theses and Dissertations--Biology

Organismal traits all exhibit some degree of environmental sensitivity, and both the strength and direction of these phenotypically plastic responses to the environment can evolve in adaptive ways. For example, parents can use information about their own environment to precondition the traits of their offspring so that they thrive in their future environment. This transgenerational plasticity can also alter the plasticity of offspring, but explicit investigations of this specific phenomenon are rare. I begin with a review of the literature and provide a quantitative genetic framework to investigate this phenomenon, which I then explore empirically using avian embryos. The metabolic …

The Potential Role Of Phenotypic Plasticity In The Ability Of Hydrocotyle Bonariensis To Occupy Two Different Habitats, Harold Ralph Parsons Iii

Honors College Theses

Phenotypic plasticity is the ability of an organism to change morphology and/or physiology in response to changes in the environment. Hydrocotyle bonariensis is a coastal perennial herb found in both coastal sand dunes and inland coastal plain habitats in Georgia. The purpose of this study was to determine if there were differences in leaf morphology for populations of H. bonariensis in coastal sand dune and inland coastal plain habitats. Leaf morphology and microenvironmental variables were compared between H. bonariensis populations at Tybee Island (TI), GA, representing the coastal sand dune habitat, and Georgia Southern University Armstrong Campus (GSU) in Savannah, …

Functional Trade-Offs Between Terrestrial And Aquatic Locomotion In The Amphibious Fish Kryptolebias Marmoratus, Erik Axlid

All Graduate Theses, Dissertations, and Other Capstone Projects

The mangrove rivulus (Kryptolebias marmoratus) is a phenotypically plastic teleost fish that can spend considerable time on land and traverse the terrestrial realm through a ballistic behavior termed the tail-flip jump. The tail-flip jump is a transitional stage between fully aquatic and terrestrial lifestyles. Therefore, understanding this behavior can provide insight into how organisms adapt to new environments over evolutionary time. Taxa that are successful tail-flip jumpers have a deep caudal peduncle and uniform body shape. Studies of K. marmoratus show that terrestrial acclimation and exercise improves tail-flip jumping performance due to muscle remodeling, but the implications of these muscular …

Susceptibility Of High-Elevation Forests To Mountain Pine Beetle (Dendroctonus Ponderosae Hopkins) Under Climate Change, David N. Soderberg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Across western North America, pine forests are important for timber, wildlife habitat, and at high elevations are important for water retention and yield from rain and snowmelt. The mountain pine beetle (MPB) is one of the most significant disturbance agents shaping pine forests, and like all insects, temperature is a major driver of its population success and the dynamics of the landscapes that they inhabit. Changing temperature regimes can therefore directly influence MPB population persistence at a particular location, in addition to potential shifts in the range boundaries that they inhabit. MPB is currently expanding its range northward in British …

Mutual Benefits Of Inducible Defenses To Crab Predators In The Blue Mussel Mytilus Edulis In A Multi-Predator Environment, Sophia Walton

Honors Projects

The blue mussel Mytilus edulis alters its phenotype in species-specific ways in response to either green crab (Carcinus maenus) or sea star (Asterias sp.) predation. Previous studies have shown that only sea stars induce changes in abductor muscle morphology, while green crabs generally alter the shape and thickness of shells. In the Western Gulf of Maine, Blue mussels collected from wave protected sites with abundant green crab predators were shown to have significantly thicker shells and larger adductor muscles than mussels collected from wave exposed sites with few green crab predators. The phenotypes of mussels originating …

Timing Of Predation Risk During Early Development Influences Oyster Shell Morphology, Armorel Eason, Andrew B. Powell, Sarah H. Roney, Carter Lin, Christa M. Russell, Benjamin A. Belgrad, Delbert Lee Smee

Gulf and Caribbean Research

No abstract provided.

The Evolutionary Consequences Of Human–Wildlife Conflict In Cities, Christopher J. Schell, Lauren Stanton, Julie K. Young, Lisa Angeloni, Joanna E. Lambert, Stewart W. Breck, Maureen H. Murray

USDA Wildlife Services: Staff Publications

Human–wildlife interactions, including human–wildlife conflict, are increasingly common as expanding urbanization worldwide creates more opportunities for people to encounter wildlife. Wildlife–vehicle collisions, zoonotic disease transmission, property damage, and physical attacks to people or their pets have negative consequences for both people and wildlife, underscoring the need for comprehensive strategies that mitigate and prevent conflict altogether. Management techniques often aim to deter, relocate, or remove individual organisms, all of which may present a significant selective force in both urban and nonurban systems. Managementinduced selection may significantly affect the adaptive or nonadaptive evolutionary processes of urban populations, yet few studies explicate the …

Local Adaptation Constrains Drought Tolerance In A Tropical Foundation Tree, Kasey E. Barton, Casey Jones, Kyle F. Edwards, Aaron B. Shiels, Tiffany Knight

USDA Wildlife Services: Staff Publications

1. Plant species with broad climatic ranges might be more vulnerable to climate change than previously appreciated due to intraspecific variation in climatic stress tolerance. In tropical forests, drought is increasingly frequent and severe, causing widespread declines and altering community dynamics. Yet, little is known about whether foundation tropical trees vary in drought tolerance throughout their distributions, and how intraspecific variation in drought tolerance might contribute to their vulnerability to climate changE.
2. We tested for local adaptation in seedling emergence and establishment with a full-factorial reciprocal transplant experiment including 27 populations and 109,350 seeds along a 3,500 mm precipitation gradient 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 …

Do Enallagma Exsulans From Streams And Lakes Show Patterns Of Divergence?, Savannah Rae Graham

Graduate Theses and Dissertations

Divergent selection across heterogenous environments could lead to adaptive divergence in populations resulting in potential local adaption. These populations have phenotypic differences that are fitness related and make native individuals more fit than non-native individuals. My research focuses on a species of damselfly, Enallagma exsulans, to explore local adaptation and morphological differences as a result of divergent selection or plasticity. My first study explored potential local adaptation of wild caught stream and lake E. exsulans using a reciprocal transplant design, a classic approach for this objective. The stream and lake sites chosen were on a small spatial scale allowing for …

Phenotypic And Genetic Variation Of The Brazilian Malaria Vector Nyssorhynchus Darlingi At Regional And Local Scales, Virginia Mildred Chu

Legacy Theses & Dissertations (2009 - 2024)

There have been major successes in the fight to eliminate malaria in the Americas, with 11

The Effects Of Diet And Mating System On Reproductive (And Post‐Reproductive) Life Span In A Freshwater Snail, Josh R. Auld

Biology Faculty Publications

The length of the reproductive life span, along with the number/frequency/magnitude of reproductive events, quantifies an individual’s potential contribution to the next generation. By examining reproductive life span, and distinguishing it from somatic life span, we gain insight into critical aspects of an individual’s potential fitness as well as reproductive and somatic senescence. Additionally, differentiating somatic and reproductive life spans can provide insight into the existence of a post‐reproductive period and factors that shape its duration. Given the known importance of diet and mating system on resource allocation, I reared individual freshwater snails (Physa acuta) from 22 full‐sib families under …

Thermal Physiology And Developmental Plasticity Of Pigmentation In The Harlequin Bug (Hemiptera: Pentatomidae), Carly D. Sibilia, Kelly A. Brosko, Christopher J. Hickling, Lily M. Thompson, Kristine L. Grayson, Jennifer R. Olson

Biology Faculty Publications

Traits that promote the maintenance of body temperatures within an optimal range provide advantages to ectothermic species. Pigmentation plasticity is found in many insects and enhances thermoregulatory potential as increased melanization can result in greater heat retention. The thermal melanism hypothesis predicts that species with developmental plasticity will have darker pigmentation in colder environments, which can be an important adaptation for temperate species experiencing seasonal variation in climate. The harlequin bug (Murgantia histrionica, Hemiptera: Pentatomidae, Hahn 1834) is a widespread invasive crop pest with variable patterning where developmental plasticity in melanization could affect performance. To investigate the impact of temperature …

Predators Modify The Temperature Dependence Of Life-History Trade-Offs, Thomas M. Luhring, Janna M. Vavra, Clayton E. Cressler, John Delong

School of Biological Sciences: Faculty Publications

Although life histories are shaped by temperature and predation, their joint influence on the interdependence of life-history traits is poorly understood. Shifts in one life-history trait often necessitate shifts in another—structured in some cases by trade-offs— leading to differing life-history strategies among environments. The offspring size–number trade-off connects three traits whereby a constant reproductive allocation (R) constrains how the number (O) and size (S) of offspring change. Increasing temperature and size-independent predation decrease size at and time to reproduction which can lower R through reduced time for resource accrual or size-constrained fecundity. We investigated how O, S, and R in …

Escaping The Arrhenius Tyranny: Metabolic Compensation During Exposure To High Temperature In Daphnia, Bret L. Coggins

Electronic Theses and Dissertations

Poikilothermic organisms experience trade-offs by differential physiological demands generated by temperature extremes. Many such organisms exhibit acclimatory effects, adjusting their metabolism and physiology to recently experienced temperatures. One such acclimatory effect is metabolic compensation, the deceleration of biological rates below Arrhenius expectations. Daphnia magna is eurythermal, and if acclimated to mildly stressful temperatures first, survives longer in lethal temperatures. This study examined the effect of ambient temperature (5°C-37°C) and acclimation history (lifetime at 10°C or 25°C) on the oxygen consumption rates of 8 genotypes of Daphnia with high or low acute temperature tolerance. There were decelerations of respiratory rates across …

Altered Spring Phenology Of North American Freshwater Turtles And The Importance Of Representative Populations, Fredric J. Janzen, Luke A. Hoekstra, Ronald J. Brooks, David M. Carroll, J Whitfield Gibbons, Judith L. Greene, John B. Iverson, Jacqueline D. Litzgus, Edwin D. Michael, Steven G. Parren, Willem M. Roosenburg, Gabriel F. Strain, John K. Tucker, Gordon R. Ultsch

Faculty & Staff Scholarship

Globally, populations of diverse taxa have altered phenology in response to climate change. However, most research has focused on a single population of a given taxon, which may be unrepresentative for comparative analyses, and few long-term studies of phenology in ectothermic amniotes have been published. We test for climate- altered phenology using long-term studies (10–36 years) of nesting behavior in 14 populations representing six genera of freshwater turtles (Chelydra, Chrysemys, Kinosternon, Malaclemys, Sternotherus, and Trachemys). Nesting season initiation oc- curs earlier in more recent years, with 11 of the populations advancing phenology. The onset of nesting for nearly all populations …

Morphological And Gene Expression Plasticity In Neotropical Cichlid Fishes, Sharon Fern Clemmensen

Doctoral Dissertations

Trophic divergence in cichlid fish is linked to morphological shifts in the pharyngeal jaw apparatus. For instance, in the Heroine cichlids of Central America, the ability to crush hard-shelled mollusks is a convergent phenotype with multiple evolutionary origins. These durophagous species often have very similar pharyngeal jaw morphologies associated with the pharyngeal jaw apparatus and some of these similarities could be due to phenotypically plastic responses to mechanical stress. I examined the durophagous cichlid Vieja maculicauda for differences in pharyngeal osteology, dentition, and soft tissues when exposed to different diet regimes. Here I discuss the effect on the morphology and …

Ecological Epigenetics Of Avian Range Expansions, Holly J. Kilvitis

USF Tampa Graduate Theses and Dissertations

In light of human-mediated environmental change, a fundamental goal for biologists is to determine which phenotypic characteristics enable some individuals, populations or species to be more adept at coping with such change, while rendering others more vulnerable. Studying ongoing range expansions provide a unique opportunity to address this question by allowing documentation of how novel environments shape phenotypic variation on ecological timescales. At range-edges, individuals are exposed to strong selective pressures and population genetic challenges (e.g. bottlenecks and/or founder effects), which make genetic adaptation difficult. Nevertheless, certain species, such as the house sparrow (Passer domesticus), seem to thrive in their …

Effects Of Plasticity And Hybridization On Life History Traits In Arabidopsis Thaliana Ecotypes, Kattia Paola Palacio Lopez

Graduate College Dissertations and Theses

Understanding the strategies that plant populations implement to increase evolutionary responsiveness to better survive environmental changes induced by climate change is a critical challenge for ecology and evolutionary studies. This dissertation investigates the role of hybridization, local adaptation, and phenotypic plasticity in plant population responses to environmental change. Specifically, I utilized meta-analysis techniques to investigate the prevalence of local adaptation and phenotypic plasticity as the two main mechanisms used to adapt to heterogeneous environments, and experimentally explored the genetic pathway of plasticity in phenology traits such as bolting time in Arabidopsis thaliana under high temperatures. Furthermore, A. thaliana was used …

Genetic Variation In Long-Term And Short-Term Physiological Changes In Daphnia Magna During Acclimation To High Temperature, Bret L. Coggins

Undergraduate Honors Theses

The aquatic zooplankton crustacean Daphnia magna must be able to tolerate thermal stress in order to survive their native shallow ponds that are susceptible to drastic seasonal and diurnal temperature fluctuations as well as to globally increasing temperatures. Survival in such variable environments requires plastic responses that must include fundamental aspects of Daphnia biochemistry and physiology. Adaptive response to selection favoring such plastic phenotypes requires the presence of genetic variation for plastic response in natural populations. Adverse effects of elevated temperature on aquatic organisms are diverse and so are their plastic responses; among the most severe challenges aquatic organisms face …

When An Invasive Plant Fails To Invade, Stephen L. Young

West Central Research and Extension Center, North Platte

In 2012, much of the US Midwest was gripped in one of the most severe droughts on record. While conducting experimental fieldwork at a site in Nebraska during June of that year, I noticed a single musk thistle (Carduus nutans; Figure 1) that appeared to be in the bolt or early flowering stage, which is typical for the species at that time. Here, however, two things were unusual: this plant was less than 1 meter tall (with adequate moisture and light, musk thistle typically grows to heights of 1–2.5 meters before flowering), and was only 3 months old (the bolt …

Diel Vertical Migration Of An Invasive Calanoid Copepod, Eurytemora Affinis, In Little Sturgeon Bay, Wisconsin, Alexandra N. Poli

Lawrence University Honors Projects

Eurytemora affinis, a calanoid copepod, is known to be a versatile, prolific invader of freshwater ecosystems across the globe. It has recently been documented in the Laurentian Great Lakes, including in Little Sturgeon Bay, an embayment of Lake Michigan. One survival mechanism that could make E. affinis a successful invader is diel vertical migration (DVM), a behavior in which animals move to different lakes depths at different times of day in order to avoid predation. Much is known about DVM of E. affinis, but primarily from studies in marine and brackish systems. Our goal was to investigate how …

The Ecology Of Phenotypic Plasticity In The Cabbage White Butterfly, Pieris Rapae, Isabella Thompson Lambert

Undergraduate Honors Thesis Collection

Phenotypic plasticity is the ability of an organism to alter its expressed phenotype in response to the environment in which it develops. There are many different environmental factors that can influence the phenotype of organisms such as photoperiod, temperature, mechanical strain, as well as nutrient availability (Stoehr and Goux 2008; Schneider et al. 2014). Adaptive plasticity allows organisms to cope with varying and complex environments and changing conditions. Along with these factors, the effects of changing environments caused from habitat alterations or climate change need to be studied more in depth. Understanding the ecology of plastic organisms is important for …

Switching Tactics: Phenotypic Plasticity In The Alternative Mate-Finding Tactics Of Burying Beetles, Theresa Mulrey

Theses and Dissertations

Male Nicrophorus burying beetles utilize two alternative mate-finding tactics, representing an ideal model system to test the influence of environmental cues on the expression of alternative tactics. The "searching" tactic involves flying in search of a carcass on which to mate. This tactic can result in high levels of paternity, but is risky in that carcasses are rare and competition for carcasses is fierce. The "signaling" tactic, which involves emitting pheromone in the absence of a carcass to attract females, is energetically less costly, but a signalling male must mate with multiple females to achieve the same reproductive returns as …

Evolutionary Change In Continuous Reaction Norms, Courtney J. Murren, Heidi J. Maclean, Sarah E. Diamond, Ulrich K. Steiner, Mary A. Heskel, Corey A. Handelsman, Cameron K. Ghalambor, Josh R. Auld, Hilary S. Callahan, David W. Pfennig, Rick A. Relyea, Carl D. Schlichting, Joel Kingsolver

Biology Faculty Publications

No abstract provided.

Body Size Variation In Two Adjacent Populations Of Black Kingsnakes (Lampropeltis Nigra) In East Tennessee, Jesse Weber, Joshua Ennen

Chancellor’s Honors Program Projects

No abstract provided.

Thermal Adaptation Of Life History Traits In The Drosophila Melanogaster Group, Christopher James Austin

Electronic Thesis and Dissertation Repository

Thermal adaptation is typically detected by examining the tolerance to extreme temperatures in a few populations within a single life stage. However, the extent to which adaptation occurs among many different populations might depend on the tolerance of multiple life stages and the average temperature range that the population experiences. Here, I examined adaptation to local temperature conditions in four species of fruit flies, including a cosmopolitan species, Drosophila melanogaster, and three species with geographically small-sized ranges, D. nepalensis, D. sechellia, and D. mauritiana. The cosmopolitan species showed adaptation to native temperatures during the larval and adult …