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Articles 1 - 30 of 79
Full-Text Articles in Biology
The Effects Of Prescribed Fire On Ant-Mediated Seed Dispersal In Missouri, Eva M. Colberg
The Effects Of Prescribed Fire On Ant-Mediated Seed Dispersal In Missouri, Eva M. Colberg
Dissertations
Many aspects of animal-mediated seed dispersal are vulnerable to disturbance, including partner identity and dispersal quantity and quality. This dissertation explores ant-mediated seed dispersal of the herb Sanguinaria canadensis in Missouri Ozark oak forests, where prescribed fire is a common land management tool. In Chapter 1, I test the definition of a keystone seed disperser using absolute and relative contributions of different ant species to the quantity and distance of seed dispersal, based on field observations of S. canadensis seed dispersal. I demonstrate that the ant Aphaenogaster rudis is better described as a numerically dominant rather than keystone seed disperser, …
Cognitive Ecology Of Color Vision In Orchid Bees, Andreia Queiroz Santos A Figueiredo
Cognitive Ecology Of Color Vision In Orchid Bees, Andreia Queiroz Santos A Figueiredo
Dissertations
Animals interact with their environment and acquire information from it. Information can be processed by their sensory systems and influence behavior, often mediated through mechanisms of decision-making and learning. Animal pollinators acquire information from flowers and use this information to make decisions about the flowers they visit. My research aimed to understand the role of color vision in a tropical pollinator, the orchid bee Euglossa dilemma. Chapter 1 is a review exploring pollination through the lens of prepared learning. Prepared learning proposes that animals learn some associations better than others due to an evolved match with the environment. I …
Identification And Characterization Of Novel Genes And Genetic Interactions That Influence Iba Metabolism, Vanessica Jawahir
Identification And Characterization Of Novel Genes And Genetic Interactions That Influence Iba Metabolism, Vanessica Jawahir
Dissertations
Indole-3-butyric acid (IBA) is an endogenous storage auxin important for maintaining appropriate indole-3-acetic acid (IAA) levels that influences primary root elongation and lateral root development. IBA is metabolized into free IAA in the peroxisome in a multistep process similar to fatty acid β-oxidation. Although many components specific to IBA metabolism and peroxisome function have been identified, our understanding is incomplete. I sought to identify novel components of IBA metabolism or peroxisome function by conducting a forward genetic screen for Arabidopsis thaliana plants with enhanced resistance to IBA. I identified Long chain acyl-CoA synthetase 4 (LACS4) as a novel gene functioning …
Vines In The Neotropics: Phylogenomics, Biogeography And Systematics In Passion Flowers (Passiflora Subgenus Decaloba Section Decaloba), Serena Acha
Dissertations
With 600 species, Passiflora is a large, morphologically complex and broadly distributed genus in Passifloraceae that represents a major challenge to scientists interested in understanding the evolutionary history of tropical vines. Passiflora has been divided into subgenera, super sections and sections. One of the most enigmatic and species-rich (~120 spp.) groups in Passiflora is section Decaloba, which occurs in the Neotropics and is particularly diverse in Andean montane forests. In this study, we used phylogenomic and population genomic approaches to investigate the evolutionary history, biologeography, species boundaries, and taxonomy of Passiflora section Decaloba. We sampled herbarium specimens, extracted …
The Role Of Multidrug Resistance Regulators Mara, Soxs, Rob And Rama In Regulating Virulence Traits In Salmonella Enterica, Srinivas Thota
The Role Of Multidrug Resistance Regulators Mara, Soxs, Rob And Rama In Regulating Virulence Traits In Salmonella Enterica, Srinivas Thota
Dissertations
Enteric pathogens sense numerous signals specific to the anatomical location in the intestine and integrate them with the complex regulatory networks to temporally and spatially regulate their virulence genes. MarA, SoxS, Rob and RamA are homologous transcription factors that belong to AraC family of proteins in Salmonella enterica that primarily were thought to be involved in rendering antibiotic resistance to bacteria by up regulating efflux pumps and down regulating outer membrane porins. The fact that these transcription factors respond to the same intestinal compounds that regulate virulence genes in Salmonella motivated us to look for other roles of these transcription …
Taxonomy, Species Limits, And Phylogenetic Relationships Of Anoura Gray 1838 (Chiroptera: Phyllostomidae), Camilo Andres Calderon Acevedo
Taxonomy, Species Limits, And Phylogenetic Relationships Of Anoura Gray 1838 (Chiroptera: Phyllostomidae), Camilo Andres Calderon Acevedo
Dissertations
This dissertation addresses several aspects of the diversity and species limits in the nectarivorous bat genus Anoura Gray 1838(Chiroptera: Glossophaginae). Based on morphometric approaches, the current taxonomic arrangement for Anoura includes 8 to 10 species; however, previous taxonomic revisions did not include all closely related species in the genus. In Chapter 1, I investigate the identity of Anoura carishina and its position in the morphospace of the large-bodied Anoura using craniodental and external variables. I analyze traits thought to be diagnostic for these species, including 1) an elliptical Fourier transformation analysis of the shape of the third upper premolar …
Peroxisomal Protein Defects Disrupt Coordinated Peroxisomal Processes And Affect Early Seedling Development Through Accumulating Toxic Catabolic Intermediates, Ying Li
Dissertations
Many peroxisomal proteins act in β-oxidation processes on a range of substrates. It is unclear how these proteins are coordinated to determine the flux of peroxisomal processes and meet the requirements for plant growth and development. Using mutant analysis and metabolic profiling, I examined proteins predicted to act in fatty acid and indole-butyric-acid (IBA) β-oxidation. ECH2 confers enoyl-CoA hydratase activity for the auxiliary β-oxidation of fatty acids with an even cis-unsaturated bond. ECH2 was suggested to function in IBA β-oxidation, as ech2 seedlings have altered IBA response. ech2 seedlings have reduced root length and cotyledon area. ech2 seedlings accumulate 3-hydroxyoctenoate …
Achilles Is A Circadian Clock-Controlled Gene That Regulates The Immune System And Its Rhythmicity In Drosophila, Jiajia Li
Dissertations
Circadian clock is a transcriptional/translational feedback loop that drives the rhythmic expression of downstream mRNAs. Termed “clock-controlled genes,” these molecular outputs of the circadian clock orchestrate cellular, metabolic, and behavioral rhythms. As part of our on-going work to characterize key upstream regulators of circadian mRNA expression, we have identified a novel clock-controlled gene in Drosophila melanogaster, Achilles (Achl), which is rhythmic at the mRNA level in the brain and represses expression of immune response genes, especially anti-microbial peptides in the immune system. Achl knock-down in the brain dramatically elevates expression of crucial immune response genes, including IM1 …
In Vivo Characterization Of The Drosophila Mrna 3’-End Processing Core Cleavage Complex: Poly(A) Mrna & Histone Mrna 3’-End Processing, Daniel Michalski
In Vivo Characterization Of The Drosophila Mrna 3’-End Processing Core Cleavage Complex: Poly(A) Mrna & Histone Mrna 3’-End Processing, Daniel Michalski
Dissertations
A core cleavage complex (CCC) consisting of CPSF73, CPSF100 and Symplekin is required for co-transcriptional 3’ end processing of all metazoan pre-mRNAs, yet little is known about the in vivo molecular interactions within this complex. The CCC is a component of two distinct complexes, the cleavage/polyadenylation complex and the complex that processes non-polyadenylated histone pre-mRNAs. RNAi-depletion of CCC factors in Drosophila culture cells causes reduction of CCC processing activity on histone mRNAs, resulting in read through transcription. In contrast, RNAi-depletion of factors only required for histone mRNA processing allows use of downstream cryptic polyadenylation signals to produce polyadenylated histone mRNAs. …
Anthropogenic Disturbance Modulates Mammal Community Diversity, Assembly, & Abundance: Emerging Infectious Disease Risk In The Greater Yellowstone Ecosystem, Leticia Andrea Gutiérrez Jiménez
Anthropogenic Disturbance Modulates Mammal Community Diversity, Assembly, & Abundance: Emerging Infectious Disease Risk In The Greater Yellowstone Ecosystem, Leticia Andrea Gutiérrez Jiménez
Dissertations
This dissertation examines the role of mammalian biodiversity in maintaining overall ecosystem health in the Greater Yellowstone Ecosystem (GYE). The study explores the pathways by which anthropogenic disturbance prevents or promotes the emergence of human infectious diseases. I studied two paramount research questions: Question 1: What are the direct effects of anthropogenic disturbance on rodent community assemblages and the consequent indirect effects on public health? I first surveyed the GYE rodent community and their pathogens by using land use as a measure of anthropogenic disturbance (e.g., human settlements, horseback ranches, pastures, undisturbed). I identified pathogens in rodent blood samples by …
Synthetic Ion Channels: A New Class Of Membrane Disruptor And Efflux Pump Inhibitor For The Recovery Of Antibiotic Potency, Mohit Bharatkumar Patel
Synthetic Ion Channels: A New Class Of Membrane Disruptor And Efflux Pump Inhibitor For The Recovery Of Antibiotic Potency, Mohit Bharatkumar Patel
Dissertations
Antibiotic resistance has become a world-wide health care crisis. In 2013 there were 50,000 deaths in U.S. and EU, associated with hospital acquired bacterial infections. This problem is exacerbated by the lack of new antibiotics in development. Here, we report that synthetic amphiphiles represent a new class of adjuvants that rescue antibiotic potency against multidrug resistant bacteria. Hydraphiles are amphiphiles, designed and synthesized in Gokel lab, that show many of the same properties as protein ion channels. Hydraphiles were previously shown to have antimicrobial activity against Escherichia coli, Bacillus subtilis and Saccharomyces cerevisiae. Here, we report that hydraphiles recover the …
Endogenous Small Interfering Rna: Insights Into Esirna Biogenesis And Their Precursors, Andrew White Harrington
Endogenous Small Interfering Rna: Insights Into Esirna Biogenesis And Their Precursors, Andrew White Harrington
Dissertations
Rarely in research is the path to an answer straightforward. Initial questions lead to more questions, many times doubling back to allow for greater insight into the original question. For example, discovery of interactions between previously unrelated pathways can lead to breakthroughs with regard to understanding of gene regulation. One such novel interaction and the subsequent discoveries this interaction spurred are discussed herein. Transposons, or “Jumping Genes” are mobile genetic elements found throughout all three major domains of life. Transposons comprise 44% of the human genome and possess the ability to move within the genome. This ability makes them an …
Color-Mediated Foraging By Pollinators: A Comparative Study Of Two Passionflower Butterflies At Lantana Camara, Gyanpriya Maharaj
Color-Mediated Foraging By Pollinators: A Comparative Study Of Two Passionflower Butterflies At Lantana Camara, Gyanpriya Maharaj
Dissertations
Colorful floral signaling and resulting insect foraging behaviors have only been extensively examined in hymenopteran pollinators, especially bees, in comparison to flies, beetles, and butterflies regardless of their ecological importance. Therefore, my study provides novel information by focusing on foraging behaviors of adult passionflower butterflies, Heliconius melpomene and Dryas iulia, to the color changing flowers of Lantana camara. My dissertation which is divided into four chapters, aims to explore various aspects of color mediate foraging in passionflower butterflies by combining observations in the wild with controlled field and laboratory experiments. In the first chapter I reviewed flower color development and …
Historical Biogeography, Spatial Distribution, And Within-Host Interactions Of Avian Haemosporidian Parasites (Apicomplexa, Haemosporida), Leticia De Souza Soares
Historical Biogeography, Spatial Distribution, And Within-Host Interactions Of Avian Haemosporidian Parasites (Apicomplexa, Haemosporida), Leticia De Souza Soares
Dissertations
This dissertation addresses several aspects of the biogeography and evolution of avian malarial parasites (Haemosporida: Plasmodium and Haemoproteus), and the interactions of these pathogens with their hosts and other avian blood parasites. In Chapter 1, I investigate change in haemosporidian assemblages on the West Indies over millennial time scales, taking advantage of the historical isolation of islands by postglacial rising sea levels. I found that, the prevalence of parasite lineages is highly dynamic over periods from decades to thousands of years. Turnover of lineages requires more time than variation in lineage prevalence, suggesting that competitive exclusion of parasite lineages, likely …
Investigations Of Storage Root Development In Cassava (Manihot Esculenta Crantz), Yeetoh Chaweewan
Investigations Of Storage Root Development In Cassava (Manihot Esculenta Crantz), Yeetoh Chaweewan
Dissertations
The tropical root crop cassava is cultivated for its large starchy storage roots. Understanding critical processes in root tuberization is essential if improvement programs are to secure future yields for farmers. Studies were undertaken to identify critical components of storage root development at the anatomical and gene expression levels. Two types of roots were identified from greenhouse-grown stem cuttings: basal roots, which develop from the stem cut end and are prolific in nature, and nodal roots, which originate from the region of the buried axillary bud. Only nodal roots develop to produce storage organs. Anatomical sectioning was performed to determine …
Oxidative Stress In Avian Embyros, Toshi Tsunekage
Oxidative Stress In Avian Embyros, Toshi Tsunekage
Dissertations
Oxidative stress has been implicated in mediating trade-offs in the evolution of life histories. Oxidative stress results from an imbalance in the production of free radicals and an organism’s antioxidant defenses. Higher metabolic rates associated with more rapid growth and shorter development periods may increase oxidative stress and accumulated cellular damage in embryonic tissues. In my dissertation I explored oxidative stress and antioxidant defenses in avian embryos. I measured levels of oxidative stress in tissues of different stage embryos of Japanese quail (Coturnix japonica), and tested if patterns of lipid peroxidation could be explained by changes in the developing embryo’s …
Ecological Strategies And Disturbance Response Of Tropical Forest Trees: Insight From Functional Trait Variation, Oyomoare Lolade Osazuwa-Peters
Ecological Strategies And Disturbance Response Of Tropical Forest Trees: Insight From Functional Trait Variation, Oyomoare Lolade Osazuwa-Peters
Dissertations
Tropical forests store 40% of terrestrial carbon, process six times as much carbon as is released through fossil fuel use, and are epicenters of biodiversity. Despite all that we know about tropical forests, there remains much to discover about variation in ecological strategies, differences in the way species acquire limited resources through dissimilarities in construction and allocation patterns. We also know little as to how this variation shapes the resilience of tropical tree communities to disturbance. These forests are increasingly threatened by global change stressors, such as anthropogenic land-use and climate change. Recent advances in ecological literature show that …
Relationships Of Haemosporidian Parasites To Populations Of Their Avian Hosts In Eastern North America, Vincenzo Alexander Ellis
Relationships Of Haemosporidian Parasites To Populations Of Their Avian Hosts In Eastern North America, Vincenzo Alexander Ellis
Dissertations
Avian Haemosporida are common, vector-transmitted blood parasites of birds throughout the world. During my dissertation research, I explored how multiple host species respond immunologically to natural infections in the wild (Chapter 1) and to experimental infections in the laboratory (Chapter 2). Despite their tractability as a model host-parasite system and a burgeoning literature on avian Haemosporida, little is known about how their populations interact across large areas (hereafter “regions”). I present data from parasite surveys of birds across eastern North America suggesting that continental parasite populations track host populations across the region, but also that the host breadth of a …
The Role Of Arabidopsis Aminoalcoholphosphotransferase 1 And 2 In Plant Development And Oil Production And Transcriptional Regulation Of Seed Oil Accumulation By Glabra2, Yu Liu
Dissertations
Vegetable oils are important commodities as human foods, animal feeds, renewable industrial feedstocks, and biofuels. Many biochemical and regulation events are involved in seed oil formation, including phospholipids metabolism and transcriptional regulation. In this work, I investigated 1) the role of aminoalcoholphosphotransferases (AAPTs) in phospholipid synthesis and plant development, 2) the effects of AAPTs on seed storage lipid production in Arabidopsis and the emerging oil crop Camelina, and 3) the interaction of the lipid mediator phosphatidic acid (PA) with GLABRA2 (GL2), a negative regulator in seed oil production. AAPTs are the enzymes that produce phosphatidylcholine (PC) and phosphatidylethanolamine (PE). The …
Climate-Driven Change In Himalayan Rhododendron Phenology, Robert Evan Hart
Climate-Driven Change In Himalayan Rhododendron Phenology, Robert Evan Hart
Dissertations
Phenology – the seasonal timing of life-history events – is a critical dimension of natural history. It is also one of the earliest and most noticeable traits by which organisms respond to climate change. However, these responses are complex, and only beginning to be understood, especially in the montane and alpine environments that are among the ecosystems most vulnerable to climate change. Drawing from diverse data sets and employing multiple methodologies, I examined how climate affects phenology in Himalayan Rhododendron spp. Comprehensively monitoring flowering phenology over gradients of season and elevation on Mt. Yulong, China – home to a diverse …
Spatial Ecology, Genetic Diversity And Population Structure Of Armenian Vipers, Montivipera Raddei, In Two Different Landscapes, Jeffery Alan Ettling
Spatial Ecology, Genetic Diversity And Population Structure Of Armenian Vipers, Montivipera Raddei, In Two Different Landscapes, Jeffery Alan Ettling
Dissertations
In an effort to gain a better understanding of the impact that human-modified landscapes are having on snake populations I studied the spatial ecology, gene diversity and population structure of the Armenian Viper, Montivipera raddei in two different landscapes in Armenia. We first examined the spatial ecology and habitat use of Armenian Vipers in a human-modified landscape with a combination of agricultural fields and overgrazed native steppe habitat. While there were no differences in movement rates for either sex through croplands compared to steppe, we did find that males had larger home ranges during the spring if it included cropland. …
Comparative Phylogeography And Demographic Histories Of West Indian Birds, Maria Wilhelmina Barbosa De Oliveira Pil
Comparative Phylogeography And Demographic Histories Of West Indian Birds, Maria Wilhelmina Barbosa De Oliveira Pil
Dissertations
My dissertation investigates the demographic history of multiple island populations of several Caribbean bird species through an assessment of contemporary genetic diversity, while inferring relationships between the comparative demography of individual island populations and characteristics of the islands and species. The sizes and distributions of populations vary over time, and episodes of expansion and contraction create characteristic patterns of genetic variation within and among populations. Consequently, contemporary patterns of genetic diversity open a window onto demographic and phylogeographic history. The strength of the study lies in the scale and comprehensiveness of the analysis, encompassing most of the West Indian islands …
Galapagos Seabirds' Lice Community: Host Hetero-Specific Interactions And Parasite Evolution, Jose Luis Rivera
Galapagos Seabirds' Lice Community: Host Hetero-Specific Interactions And Parasite Evolution, Jose Luis Rivera
Dissertations
My dissertation focused on understanding the factors behind host-parasite specificity and parasite diversification, using Galapagos seabirds and their ectoparasites as the study system. This system comprised the seabird hosts (magnificent and great frigatebirds, Nazca, blue-footed and red-footed boobies) and nine species of ectoparasitic lice (one Pectinopygus ischnoceran louse species infecting each host, two species of Colpocephalum amblyceran lice, one on each frigatebird species, and two shared amblyceran lice, Eidmanniella albescens found on Nazca and blue-footed boobies and Fregatiella aurifasciata found on the two frigatebirds). Using as focal species Eidmanniella albescens and Fregatiella aurifasciata, which infect multiple hosts, I analyzed how …
Evolution And Ecology Of Two Iconic Australian Clades: The Meliphagidae (Birds) And The Hakeinae (Plants), Eliot Trimarchi Miller
Evolution And Ecology Of Two Iconic Australian Clades: The Meliphagidae (Birds) And The Hakeinae (Plants), Eliot Trimarchi Miller
Dissertations
The first part of this dissertation explores the evolution of two iconic groups of species through Australian climate space: the Meliphagidae, or honeyeaters, which are primarily nectar-feeding birds, and the Hakeinae, a section of the plant family Proteaceae. Both groups are inferred to have had their origins in Gondwanan rainforests that were widespread across Australia 45 million years ago and then diversified into more arid environments as the continent’s climate became more arid. Accordingly, dry environments are inhabited by closely related (phylogenetically clustered) sets of species, although, in contrast to the honeyeaters, Hakeinae communities are characterized by more localized diversification. …
Mechanisms Of Condition-Specific Regulation Of Mrna Stability By Puf Proteins: From Yeast To Humans, Joseph Russo
Mechanisms Of Condition-Specific Regulation Of Mrna Stability By Puf Proteins: From Yeast To Humans, Joseph Russo
Dissertations
RNA binding proteins regulate mRNA decay and translation, two key steps in the control of gene expression in cells. Controlling mRNA metabolism allows cells to respond rapidly to altering conditions by utilizing already available mRNA, bypassing the wait for newly transcribed mRNA. The Puf family of RNA binding proteins bind specific mRNAs through interactions with sequences located in the 3’ untranslated region (UTR). Puf proteins are conserved throughout eukaryotes and have diverse roles including stem cell maintenance, neuronal development, stress response and organelle biogenesis. In Saccharomyces cerevisiae, Puf proteins are conditionally regulated in response to the cells metabolic. Specifically, in …
Elucidation Of The Role Of Auxin-Input Pathways In Auxin Homeostasis., Gretchen Spiess
Elucidation Of The Role Of Auxin-Input Pathways In Auxin Homeostasis., Gretchen Spiess
Dissertations
Auxin is a phytohormone involved in cell elongation and division. Levels of indole-3-acetic acid (IAA), the most abundant auxin, are tightly regulated through biosynthesis, degradation, sequestration, and transport. Sequestration of IAA occurs in reversible processes by adding amino acids, polyol or simple alcohols, or sugars, forming IAA conjugates, or via a two-carbon elongation forming indole-3-butyric acid (IBA). These forms of auxin have decreased activity and are located in multiple organelles. Using a combination of molecular and genetic tools, I examined how these storage forms are working together to contribute to overall IAA levels and IAA response in both the model …
Community Organization Of Avian Malaria Parasites In Lowland Amazonia: Prevalence, Diversity, And Specialization In A Local Assemblage, Linda Maria Elenor Svensson
Community Organization Of Avian Malaria Parasites In Lowland Amazonia: Prevalence, Diversity, And Specialization In A Local Assemblage, Linda Maria Elenor Svensson
Dissertations
I characterized a lowland Amazonian assemblage of haemosporidian (“malaria”) parasites (Haemoproteus and Plasmodium) of understory birds by analyzing variation in prevalence (proportion of infected host individuals) among years and host species, documenting diversity of haemosporidian evolutionary lineages, and quantifying host specialization. Using standard molecular methods to screen for haemosporidia in 2488 individual birds from 104 species in the Tiputini Biodiversity Station, Ecuador, I found 21.7% to be infected. Prevalence ranged significantly among years and host species. Forty-five putative evolutionary lineages of haemosporidia were identified, by sequencing part of the cytochrome b (cyt b) gene. Based on a comparative analysis, among …
Phospholipase D- And Phosphatidic Acid-Mediated Signaling In Plant Response To Abscisic Acid And Reactive Oxygen Species, Liang Guo
Dissertations
The Arabidopsis genome has 12 phospholipase D (PLD) genes that are classified into six types, PLDα, PLDβ, PLDγ, PLDδ, PLDε, and PLDζ, based on sequence similarities, domain structures, and biochemical properties. Phosphatidic acids (PA) produced by PLDs have been identified as important lipid signaling molecules in cell growth, development, and stress responses. This study was undertaken to determine the role of PLD and PA in plant response to abscisic acid (ABA) and reactive oxygen species (ROS). The lipid mediator PA was found to interact with sphingosine kinases (SPHKs) in Arabidopsis. Two unique SPHK cDNAs were cloned and expressed. Both SPHKs …
The Evolution Of Floral Symmetry Across The Plant Order Lamiales, Jinshun Zhong
The Evolution Of Floral Symmetry Across The Plant Order Lamiales, Jinshun Zhong
Dissertations
Bilaterally symmetrical corollas have evolved independently numerous times from radially symmetrical ancestors and are thought to represent adaptation to specific pollinators. However, evolutionary losses of bilateral symmetry have occurred sporadically in different lineages. CYC2-like and RAD-like are genes needed for the normal development of bilateral symmetry in snapdragon corollas. However, exactly how changes in the floral symmetry patterning genes correlate with the origin and loss of floral bilateral remains poorly known. To address this question, a densely sampled phylogeny of CYC2-like genes across the order Lamiales was inferred and calibrated. The expression patterns of these genes in early diverging and …
Elucidating The Factors That Modulate The Distribution Of Avian Haemosporida Parasites Across A Community Of Hosts, Matthew Christopher Ikaika Medeiros
Elucidating The Factors That Modulate The Distribution Of Avian Haemosporida Parasites Across A Community Of Hosts, Matthew Christopher Ikaika Medeiros
Dissertations
Parasites are heterogeneously distributed across host species, host populations, and host individuals within populations. A primary aim of infectious disease ecology seeks to uncover the factors that drive this heterogeneity. At a fundamental level, host infection is determined by exposure and susceptibility to a pathogen. My dissertation explores how evolutionary and ecological forces associated with these fundamental determinates of infection shape variation in parasite host breadth and host infection status. Here, I focus on a community of vector-borne avian Haemosporida parasites among suburban birds of Chicago, IL. These parasites exhibit strong variation in their distribution among available hosts, and provide …