Life Sciences Commons^™

Reef Fish Wariness Behavior: Fish Flight Initiation Distance Mediated By Territoriality And Body Size In Three Reef Sites Off The Western Coast Of Isla Colón, Bocas Del Toro, Panamá, Alina G. Irvine

Independent Study Project (ISP) Collection

Coral reefs are highly productive and diverse underwater ecosystems, providing a variety of environmental services including sand generation, nutrient processing, fish supply, and tourism. However, coral reefs have been increasingly impacted by natural and anthropogenic disturbances, which has negatively affected fish security within their environment. A significant observation is the reduction in evasive behaviors among reef fish in marine reserves compared to those exposed to anthropogenic threats. The present research aims to investigate the factors mediating fish wariness behavior through an exploration of the roles of territoriality and body size on fish flight initiation distance (FID). FID is the distance …

Body Size And Habitat Shading Influence The Consumptive And Non-Consumptive Effects Of Wood Frog (Lithobates Sylvaticus) Tadpoles On Aquatic Invertebrate Communities, Brady Patrick Parlato

Online Theses and Dissertations

Consumptive (direct) effects of predation have been well-studied in most aquatic systems, but non-consumptive (indirect) effects on prey have only recently received limited attention in some groups. As aquatic consumers, tadpoles have traditionally been considered strict herbivores, leaving their predatory impacts via consumptive and non-consumptive interactions on aquatic invertebrates largely unexplored. The objectives of this study were to quantify omnivory among wood frog (Lithobates sylvaticus) tadpoles, determine their consumptive and non-consumptive effects on invertebrate communities, and investigate whether such effects are mediated by habitat shading and tadpole body size. Lithobates sylvaticus tadpoles and egg masses were randomly sampled from 11 …

Maternal Drivers Of Reproductive Output In The Lizard Family Scincidae: A Phylogenetic Comparative Approach, William Zang

West Chester University Master’s Theses

Scincidae is one of the most diverse families of squamates, comprising over 1,300 species of lizards with a variety of life history and ecological traits. This diversity includes three reproductive modes, where some species reproduce via oviparity (egg-laying), viviparity (live birth) or use of a mixed strategy (females switch modes). In this study, it was sought whether reproductive output differs between scincid species using these reproductive modes. Reproductive output is defined as the average product of offspring abundance and size per reproductive event, representing the reproductive effort of an individual. Additionally, the importance of phylogeny (evolutionary relatedness) and a suite …

The Evolution Of Sex Differences In Mandrills (Mandrillus Sphinx): Micro- And Macroevolution, Jerred Klint Schafer

Legacy Theses & Dissertations (2009 - 2024)

Primates show diverse patterns of adaptive color and body size dimorphism produced by inter- and intrasexual selection. However, the specific microevolutionary processes that produce variation in secondary sexual characteristics remain largely unexplored in primates. Furthermore, sexual conflict theory predicts that female and male secondary sexual traits can coevolve in an antagonistic manner and promote speciation. This dissertation explores the microevolution of secondary sexual characteristics in mandrills (Mandrillus sphinx) and the macroevolution of these characters in anthropoid primates. I address the microevolution of mandrill facial coloration and body mass by estimating the heritability, phenotypic selection, and genetic evolution of these traits …

Patterns Of Recent Natural Selection On Genetic Loci Associated With Sexually Differentiated Human Body Size And Shape Phenotypes, Audrey M. Arner, Kathleen E. Grogan, Mark Grabowski, Hugo Reyes-Centeno, George H. Perry

Anthropology Faculty Publications

Levels of sex differences for human body size and shape phenotypes are hypothesized to have adaptively reduced following the agricultural transition as part of an evolutionary response to relatively more equal divisions of labor and new technology adoption. In this study, we tested this hypothesis by studying genetic variants associated with five sexually differentiated human phenotypes: height, body mass, hip circumference, body fat percentage, and waist circumference. We first analyzed genome-wide association (GWAS) results for UK Biobank individuals (~194,000 females and ~167,000 males) to identify a total of 114,199 single nucleotide polymorphisms (SNPs) significantly associated with at least one of …

The Role Of Plasticity In Bumble Bee Responses To Environmental Variability, Matthew Austin

Dissertations

An aim of contemporary biology is elucidating the causes and consequences of phenotypic plasticity. Here, I approach this aim by exploring the eco-evolutionary dynamics of phenotypic plasticity and environmental variability in bumble bees (Apidae: Bombus), a congeneric clade of eusocial pollinating insects. Throughout their evolution, bumble bees have encountered spatiotemporal variability imposed by dynamic floral environments. Today, bumble bees additionally encounter spatiotemporal variability imposed by anthropogenic environmental change. In this dissertation, I explore how phenotypic plasticity affects how successfully bumble bees respond to environmental variability imposed by anthropogenic global change (Chapters 1 and 2) and their floral resources (Chapters …

Investigating The Dynamics Of Elk Population Size And Body Mass In A Seasonal Environment Using A Mechanistic Integral Projection Model, Shelly Lachish, Ellen E. Brandell, Meggan E. Craft, Andrew P. Dobson, Peter J. Hudson, Daniel R. Macnulty, Tim Coulson

Wildland Resources Faculty Publications

Environmentally mediated changes in body size often underlie population responses to environmental change, yet this is not a universal phenomenon. Understanding when phenotypic change underlies population responses to environmental change is important for obtaining insights and robust predictions of population dynamics in a changing world. We develop a dynamic integral projection model that mechanistically links environmental conditions to demographic rates and phenotypic traits (body size) via changes in resource availability and individual energetics. We apply the model to the northern Yellowstone elk population and explore population responses to changing patterns of seasonality, incorporating the interdependence of growth, demography, and density-dependent …

Mammal Community Structure Through The Paleocene-Eocene Thermal Maximum, Danielle Fraser, S. Kathleen Lyons

School of Biological Sciences: Faculty Publications

Human-mediated species invasion and climate change are leading to global extinctions and are predicted to result in the loss of important axes of phylogenetic and functional diversity. However, the long-term robustness of modern communities to invasion is unknown, given the limited timescales over which they can be studied. Using the fossil record of the Paleocene- Eocene Thermal Maximum (PETM; ~ 56 Ma) in North America, we evaluate mammalian community-level response to a rapid global warming event (5° to 8°C) and invasion by three Eurasian mammalian orders and by species undergoing northward range shifts. We assembled a database of 144 species …

Functional Responses Are Maximized At Intermediate Temperatures, Stella F. Uiterwaal, John Delong

School of Biological Sciences: Faculty Publications

Functional responses describe how consumer foraging rates change with resource density. Despite extensive research looking at the factors underlying foraging interactions, there remains ongoing controversy about how temperature and body size control the functional response parameters space clearance (or attack) rate and handling time. Here, we investigate the effects of temperature, consumer mass, and resource mass using the largest compilation of functional responses yet assembled. This compilation contains 2,083 functional response curves covering a wide range of foragers and prey types, environmental conditions, and habitats. After accounting for experimental arena size, dimensionality of the foraging interaction, and consumer taxon, we …

Rapid Evolution Of Testis Size Relative To Sperm Morphology Suggests That Post-Copulatory Selection Targets Sperm Number In Anolis Lizards, A. F. Kahrl, Michele A. Johnson, R. M. Cox

Biology Faculty Research

Post-copulatory sexual selection is thought to be responsible for much of the extraordinary diversity in sperm morphology across metazoans. However, the extent to which post-copulatory selection targets sperm morphology versus sperm production is generally unknown. To address this issue, we simultaneously characterized the evolution of sperm morphology (length of the sperm head, midpiece and flagellum) and testis size (a proxy for sperm production) across 26 species of Anolis lizards, a group in which sperm competition is likely. We found that the length of the sperm midpiece has evolved 2–3 times faster than that of the sperm head or flagellum, suggesting …

Correlates Of Snake Entanglement In Erosion Control Blankets, Sarah E. Ebert, Kasey L. Jobe, Christopher M. Schalk, Daniel Saenz, Cory K. Adams, Christopher E. Comer

Faculty Publications

In road construction projects across the United States, erosion control methods (e.g., erosion control blankets [ECBs]), are mandated to stimulate seedbed regeneration and prevent soil loss. Previous reports have suggested that snakes are vulnerable to entanglement in ECBs. We conducted a literature review, field surveys, and an entanglement experiment to examine what factors increase a snake’s risk of ECB entanglement. Our literature review produced reports of 175 reptiles entangled in mesh products, 89.1% of which were snakes, with 43.6% of snake entanglements occurring in erosion control products. During our field surveys, we found 10 entangled snakes (n = 2 alive; …

How Do Trait-Mediated Non-Lethal Effects Of Predation Affect Population-Level Performance Of Mosquitoes?, Karthikeyan Chandrasegaran, Steven A. Juliano

Faculty Publications – Biological Sciences

Non-lethal, trait-mediated effects of predation impact prey behavior and life-history traits. Studying how these effects in turn influence prey demography is crucial to understand prey life-history evolution. Mosquitoes are important vectors that claim several million lives every year worldwide by transmitting a range of pathogens. Several ecological factors affect life-history traits of both larval and adult mosquitoes, creating effects that cascade to population-level consequences. Few studies have comprehensively explored the non-lethal effects of predation and its interactions with resources and competition on larval, adult, and population traits of mosquitoes. Understanding these interactions is important because the effects of predation are …

Top-Down And Bottom-Up Effects On Collembola Communities In Soil Food Webs, Jordan Kustec

Electronic Thesis and Dissertation Repository

Anthropogenic changes are causing shifts within soil food web communities, which may alter ecosystem processes such as nutrient cycling, carbon storage and decomposition. I quantified ecological stressor effects on the abundance, richness, community composition and body size of a soil-dwelling microarthropod (Collembola: Hexapoda). I quantified the effects of warming and nitrogen deposition in two separate field studies and demonstrated that warming shifts Collembola community structure and decreases community body size. I quantified the interactive effects of top-down and bottom-up forces mediated by warming as ecological stressors in Collembola communities. I found that bottom-up effects of nutrient addition did not affect …

Morphological Changes In American Kestrels (Falco Sparverius) At Continental Migration Sites, Gregory S. Kaltenecker

Intermountain Bird Observatory Publications and Presentations

Many American kestrel (Falco sparverius) populations are declining across North America. Potential causes include mortality from reduction in food availability, a changing climate, habitat degradation, an increase in avian predators, disease, and toxins. We analyzed American kestrel count and banding data from seven raptor migration sites throughout North America with at least 20 years of migration data. We used count data to determine the year at which the kestrel population began a significant decline and then used banding records to determine whether body mass and wing chord declined after this point. We found reductions in kestrel body mass …

The Evolutionary Significance Of Body Size In Burying Beetles, Ashlee Nichole Momcilovich

Theses and Dissertations

Body size is one of the most commonly studied traits of an organism, which is largely due to its direct correlation with fitness, life history strategy, and physiology of the organism. Patterns of body size distribution are also often studied. The distribution of body size within species is looked at for suggestions of differential mating strategies or niche variation among ontogenetic development. Patterns are also examined among species to determine the effects of competition, environmental factors, and phylogenetic inertia. Finally, the distribution of body size across the geographic range of a species or group of closely related is looked at …

Does Body Size Affect Fitness The Same Way In Males And Females? A Test Of Multiple Fitness Components, Ashlee N. Smith, Mark C. Belk

Faculty Publications

Body size generally has an important relationship with fitness, whereby larger body size leads to an increase in fitness through competition, reproductive output and survivorship. However, the traits through which body size increases fitness often differ between the sexes. We tested for the effects of body size on fitness in both sexes using three separate experiments on competitive ability, reproductive output and starvation resistance in the burying beetle Nicrophorus marginatus. Results varied between sexes as follows: (1) larger body size increased competitive ability differentially between sexes; (2) female body size, but not male body size, significantly affected reproductive output …

Intrasexual Selection Drives Sensitivity To Pitch, Formants And Duration In The Competitive Calls Of Fallow Bucks, Benjamin J. Pitcher, Elodie Briefer, Alan G. Mcelligott

Alan G. McElligott, PhD

Background: Mammal vocal parameters such as fundamental frequency (or pitch; fo) and formant dispersion often provide information about quality traits of the producer (e.g. dominance and body size), suggesting that they are sexually selected. However, little experimental evidence exists demonstrating the importance of these cues in intrasexual competition, particularly fo. Male Fallow deer (bucks) produce an extremely low pitched groan. Bucks have a descended larynx and generate fo well below what is expected for animals of their size. Groan parameters are linked to caller dominance, body size and condition, suggesting that groans are the product of sexual selection. Using a …

Field Evidence Challenges The Often-Presumed Relationship Between Early Male Maturation And Female-Biased Sexual Size Dimorphism, Marie Claire Chelini, Eileen Hebets

Eileen Hebets Publications

Female-biased sexual size dimorphism (SSD) is often considered an epiphenomenon of selection for the increased mating opportunities provided by early male maturation (i.e., protandry). Empirical evidence of the adaptive significance of protandry remains nonetheless fairly scarce. We use field data collected throughout the reproductive season of an SSD crab spider, Mecaphesa celer, to test two hypotheses: Protandry provides fitness benefits to males, leading to female-biased SSD, or protandry is an indirect consequence of selection for small male size/large female size. Using field-collected data, we modeled the probability of mating success for females and males according to their timing of …

Body Size Predicts Cardiac And Vascular Resistance Effects On Men's And Women's Blood Pressure, Joyce M. Evans, Siqi Wang, Christopher Greb, Vladimir Kostas, Charles F. Knapp, Qingguang Zhang, Eric S. Roemmele, Michael B. Stenger, David C. Randall

Biomedical Engineering Faculty Publications

Key Points Summary

• We report how blood pressure, cardiac output and vascular resistance are related to height, weight, body surface area (BSA), and body mass index (BMI) in healthy young adults at supine rest and standing.
• Much inter-subject variability in young adult's blood pressure, currently attributed to health status, may actually result from inter-individual body size differences.
• Each cardiovascular variable is linearly related to height, weight and/or BSA (more than to BMI).
• When supine, cardiac output is positively related, while vascular resistance is negatively related, to body size. Upon standing, the change in vascular resistance is positively related to size. …

Geographical Variation In Community Divergence: Insights From Tropical Forest Monodominance By Ectomycorrhizal Trees*, Tadashi Fukami, Mifuyu Nakajima, Claire Fortunel, Paul V. Fine, Christopher Baraloto, Sabrina E. Russo, Kabir G. Peay

School of Biological Sciences: Faculty Publications

Convergence occurs in both species traits and community structure, but how convergence at the two scales influences each other remains unclear. To address this question, we focus on tropical forest monodominance, in which a single, often ectomycorrhizal (EM) tree species occasionally dominates forest stands within a landscape otherwise characterized by diverse communities of arbuscular mycorrhizal (AM) trees. Such monodominance is a striking potential example of community divergence resulting in alternative stable states. However, it is observed only in some tropical regions. A diverse suite of AM and EM trees locally codominate forest stands elsewhere. We develop a hypothesis to explain …

Where The Wild Things Are: Investigating Body Size As A Mechanism For Persistence, Meghan A. Balk

Biology ETDs

Body size is a trait under selection. Genetic drift, climate, diet quality, and biotic interactions all select upon body size at the population, species, and community levels. These factors can be important in the context of rapidly changing climate. One of the ways an animal can persist in its environment is through morphological adaptation in situ. Here, I investigate four questions relating to the evolution of body size: (1) what is the limit in body size change in response to climatic change; (2) how does body size influence the thermal tolerances of animals; (3) how does body size evolve …

Ecological Pleiotropy Suppresses The Dynamic Feedback Generated By A Rapidly Changing Trait, John Delong

School of Biological Sciences: Faculty Publications

Population dynamics may carry a signature of an ecology- evolution-ecology feedback, known as eco-evolutionary dynamics, when functionally important traits change. Given current theory, the absence of a feedback from a trait with strong links to species interactions should not occur. In a previous study with the Didinium-Paramecium predator-prey system, however, rapid and large-magnitude changes in predator cell volume occurred without any noticeable effect on the population dynamics. Here I resolve this theory-data conflict by showing that ecological pleiotropy—when a trait has more than one functional effect on an ecological process—suppresses shifts in dynamics that would arise, given the links between …

Biometric Variation In Martes Foina From Mainland Greece And The Aegean Islands, Malamati Papakosta

Turkish Journal of Zoology

The geographical morphometric variations in the stone marten (Martes foina) from mainland Greece, the Aegean Islands, and Crete were analyzed. Samples taken from the three areas were compared regarding 18 craniometrical and 5 body size variables. According to univariate statistics, 13 skull measurements from males and 15 from females (72% and 83% of total skull variables for males and females, respectively) did not differ significantly among mainland Greece, the Aegean Islands, and Crete. The morphological differences among mainland and insular populations showed a tendency for separation (63% overall correct classification from skull measurements of males, 72.5% and 73.6% for body …

Examining The Combined Effects Of Dissolved Oxygen, Temperature, And Body Size On The Physiological Responses Of A Model Macrobenthic Polychaete Species, Capitella Teleta, Kelsey Burns Gillam

Dissertations

While the scientific community is in consensus that coastal systems are threatened by climate change, few climate change studies test the effects of more than one variable directly related to climate change. The dissolved oxygen (DO) levels of the ocean are currently subject to both global warming and eutrophication; 94% of all hypoxia zones are expected to experience >2°C increase by 2035. This dissertation aims to examine how a model organism responds to simultaneous thermal and DO stress involving four levels of DO (100%, 70%, 50%, and 20%) saturation and three temperatures (15°C, 20°C, and 25°C).

The polychaete, Capitella teleta …

Intrasexual Selection Drives Sensitivity To Pitch, Formants And Duration In The Competitive Calls Of Fallow Bucks, Benjamin J. Pitcher, Elodie Briefer, Alan G. Mcelligott

Elodie Briefer, PhD

Background: Mammal vocal parameters such as fundamental frequency (or pitch; fo) and formant dispersion often provide information about quality traits of the producer (e.g. dominance and body size), suggesting that they are sexually selected. However, little experimental evidence exists demonstrating the importance of these cues in intrasexual competition, particularly fo. Male Fallow deer (bucks) produce an extremely low pitched groan. Bucks have a descended larynx and generate fo well below what is expected for animals of their size. Groan parameters are linked to caller dominance, body size and condition, suggesting that groans are the product of sexual selection. Using a …

Morphological Variation Among Herring Gulls (Larus Argentatus) And Great Black-Backed Gulls (Larus Marinus) In Eastern North America, Gregory J. Robertson, Sheena Roul, Karel A. Allard, Cynthia Pekarik, Raphael A. Lavoie, Julie C. Ellis, Noah G. Perlut, Antony W. Diamond, Nikki Benjamin, Robert A. Ronconi, Scott G. Gilliland, Brian G. Veitch

Environmental Studies Faculty Publications

Herring Gull (Larus argentatus) and Great Black-backed Gull (L. marinus) morphometric data from various eastern North American locations was collected to examine the sources of variation in body size within and among geographic regions. For Herring Gulls, significant differences in all commonly taken measurements at local and regional scales were found. However, most of the variation in measurements was due to sex differences and the natural variance seen within local populations. Herring Gulls breeding in the Arctic did not show any evidence of being morphologically different from other groups. A discriminant function derived from a Newfoundland, …

Body Size Distributions Signal A Regime Shift In A Lake Ecosystem, Trisha L. Spanbauer, Craig R. Allen, David G. Angeler, Tarsha Eason, Sherilyn C. Fritz, Ahjond S. Garmestani, Kirsty L. Nash, Jeffery R. Stone, Craig A. Stow, Shana M. Sundstrom

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Communities of organisms, from mammals to microorganisms, have discontinuous distributions of body size. This pattern of size structuring is a conservative trait of community organization and is a product of processes that occur at multiple spatial and temporal scales. In this study, we assessed whether body size patterns serve as an indicator of a threshold between alternative regimes. Over the past 7000 years, the biological communities of Foy Lake (Montana, USA) have undergone a major regime shift owing to climate change. We used a palaeoecological record of diatom communities to estimate diatom sizes, and then analysed the discontinuous distribution of …

Body Size Affects Individual Winter Foraging Strategies Of Thick-Billed Murres In The Bering Sea, Rachael Orben, Rosana Paredes, Daniel Roby, David Irons, Scott A. Shaffer

Faculty Publications, Biological Sciences

Foraging and migration often require different energetic and movement strategies. Though not readily apparent, constraints during one phase might influence the foraging strategies observed in another. For marine birds that fly and dive, body size constraints likely present a trade-off between foraging ability and migration as smaller bodies reduce flight costs, whereas larger bodies are advantageous for diving deeper. This study examines individual wintering strategies of deep diving thick-billed murres (Uria lomvia) breeding at three colonies in the south-eastern Bering Sea: St Paul, St George and Bogoslof. These colonies, arranged north to south, are located such that breeding birds forage …

The Evolutionary History Of Cetacean Brain And Body Size, Stephen H. Montgomery, Jonathan H. Geisler, Michael R. Mcgowen, Charlotte Fox, Lori Marino, John Gatesy

Lori Marino, PhD

Cetaceans rival primates in brain size relative to body size and include species with the largest brains and biggest bodies to have ever evolved. Cetaceans are remarkably diverse, varying in both phenotypes by several orders of magnitude, with notable differences between the two extant suborders, Mysticeti and Odontoceti.We analyzed the evolutionary history of brain and body mass, and relative brain size measured by the encephalization quotient (EQ), using a data set of extinct and extant taxa to capture temporal variation in the mode and direction of evolution. Our results suggest that cetacean brain and body mass evolved under strong directional …

The Evolution Of Body Size In The Order Siluriformes, D Cooper Campbell

Honors Theses

The evolution of body size has long been a topic of interest to biologists due to the close link between size and various aspects of an organism’s biology. Adult body size is influenced by the underlying tradeoff in energy allocation between maintenance, somatic growth and reproduction. I studied the evolution of a large group of globally distributed (primarily freshwater with some marine forms) fishes to test some basic hypotheses about the evolution of adult body size. Catfish (Siluriformes) are an excellent group for this type of research as they represent approximately 11% of fishes and species range in size from …