Life Sciences Commons^™

Adaptation Reshapes The Distribution Of Fitness Effects, Diego Tenoch Morales Lopez

Electronic Thesis and Dissertation Repository

The process of adaptation has been of interest since the XIX century, when Darwin first proposed the idea of natural selection. Since then, there has been a myriad of theoretical and empirical works that have expanded the field. From the many evolutionary insights these works have produced, a foundational idea is that spontaneous mutations in the genome of organisms can produce changes to their reproductive success that might confer an advantage for the mutant organisms with respect to their peers. Therefore, mutations drive adaptive evolution by virtue of their heritable effects on fitness. Empirical measures of the distribution of these …

Investigating The Soil Mycobiome Of American Ginseng, Rachel Amelia Rajsp

Electronic Thesis and Dissertation Repository

American ginseng (Panax quinquefolius L.) is a perennial herbaceous plant cultivated for its medicinal properties. Growers report that when ginseng is replanted in a field previously used to cultivate ginseng, it soon succumbs to disease, known as ginseng replant disease. I examined changes in composition in the ginseng mycobiome throughout cultivation in a newly planted garden and beyond (i.e., 3–14 years post-harvest) with a third-generation metabarcoding approach (Pacific Biosciences, single-molecule real-time sequencing). Amplicons of about 600 nucleotides from the nuclear ribosomal internal transcribed spacer (ITS) region and translation elongation factor 1-α gene were chosen to help discriminate between closely …

Freezing Tolerance Of Herbaceous Legumes Within Southwestern Ontario: Evidence Of Disproportionate Freezing Sensitivity, Samuel L. Rycroft

Electronic Thesis and Dissertation Repository

Legumes (Fabaceae) represent a diverse and ecologically significant plant taxon; most described legumes form mutualisms with diazotrophic rhizobia, potentially fixing substantial quantities of nitrogen within habitats where they are well-established. Stressors causing lethal or sub-lethal impacts in legumes or rhizobial symbionts may therefore impact the nitrogen dynamics of such habitats. In recent decades, variability of winter temperatures, precipitation, and soil freeze-thaw cycling has increased in temperate regions. Without adequate snow cover to insulate roots and shoot bases, herbaceous plants will likely be exposed to more frequent or severe freezing. In southwestern Ontario, a pattern of disproportionate freezing sensitivity relative to …

The Introduction Of Nursery Seedlings And Their Fungi To A Spruce-Fir Forest In Newfoundland, Alicia G. Banwell

Electronic Thesis and Dissertation Repository

A few species of boreal trees form symbiotic relationships with many ectomycorrhizal (ECM) fungi that allow trees to thrive on nutrient poor soils in Canada. A small number of ECM species grow on tree seedlings raised in nurseries for reforestation of clearcut sites. The native ECM fungal community composition of a mixed spruce-fir forest in Newfoundland was determined through next generation sequencing. With the introduction of nursery seedlings, the transfer of native ECM fungi to seedlings and nursery-established ECM fungi to roots was investigated over 20 months. ECM community composition was found to be similar to that of other boreal …

Short-Term Versus Long-Term Effects Of Nitrogen Addition And Warming On Ecosystem N Dynamics In A Grass-Dominated Temperate Old Field, Benjamin F. A. Souriol

Electronic Thesis and Dissertation Repository

Increased atmospheric nitrogen (N) deposition and climate warming are both anticipated to influence the ecosystem N dynamics of northern temperate ecosystems substantially over the next century. Nevertheless, in field experiments with N addition and warming treatments, temporal scale can play an important role in determining the extent of treatment effects on N dynamics, and it is unclear to what extent the results of short-term studies can be extrapolated to responses over longer time scales. I compared the short-term versus long-term effects of N addition and warming on net N mineralization, N leaching, and N retention in a grass-dominated old field. …

The Detectability Of Atlantic Salmon (Salmo Salar) Microsatellite And Mitochondrial Environmental Dna, Simone N. Miklosi

Electronic Thesis and Dissertation Repository

Little is known about what information can be gathered from microsatellite eDNA. It is important to gain a deeper understanding of the detectability and analysis of microsatellite eDNA because it could provide information about population size that mitochondrial eDNA cannot. Water samples were collected from tank and river experiments, and rivers known to contain Atlantic salmon (Salmo salar) and analyzed for Atlantic salmon mitochondrial and microsatellite eDNA. Mitochondrial eDNA was detected from all the tank experiments and 10 out of 15 rivers known to contain Atlantic salmon. Microsatellite eDNA was detected from all the tank experiments and none …

Evolution Of Overlapping Reading Frames In Virus Genomes, Laura Muñoz Baena

Electronic Thesis and Dissertation Repository

Viruses are formidable pathogens that represent the majority of biological entities in our planet, and their genomes are a source of interesting enigmas. One feature in which virus genomes are usually rich, is the presence of overlapping reading frames (OvRFs) — portions of the genome where the same nucleotide sequence encodes more than one protein. OvRFs are hypothesized to be used by viruses to encode proteins more compactly and to regulate transcription. In addition, OvRFs might be a source of gene novelty, facilitating the creation of new open reading frames (ORF) within the transcriptional context of existing ones.

To characterize …

The Effect Of Dietary Thiaminase On Cardiac Function And Morphology In Lake Trout (Salvelinus Namaycush), Peter Baker

Electronic Thesis and Dissertation Repository

Thiamine deficiency from the consumption of invasive, high-thiaminase prey fishes is considered to be a major barrier for lake trout restoration in the Great Lakes. In fishes, an understudied aspect of thiamine deficiency is its effect on cardiac function. I examined the effects of dietary thiaminase on cardiac function and morphology in lake trout, specifically as they relate to thermal tolerance. Two hatchery strains of lake trout (Seneca and Slate) were raised on a control or thiaminase diet for nine months. The thiaminase diet was associated with significant ventricle enlargement, impaired cardiac function, and reduced thermal tolerance; these effects were …

Addressing The Impact Of Time-Dependent Social Groupings On Animal Survival And Recapture Rates In Mark-Recapture Studies, Alexandru M. Draghici

Electronic Thesis and Dissertation Repository

Mark-recapture (MR) models typically assume that individuals under study have independent survival and recapture outcomes. One such model of interest is known as the Cormack-Jolly-Seber (CJS) model. In this dissertation, we conduct three major research projects focused on studying the impact of violating the independence assumption in MR models along with presenting extensions which relax the independence assumption. In the first project, we conduct a simulation study to address the impact of failing to account for pair-bonded animals having correlated recapture and survival fates on the CJS model. We examined the impact of correlation on the likelihood ratio test (LRT), …

Effects Of 11-Kt And Prolactin On Gene Expression, Parental Care Behaviour And Immune Response In Male Bluegill Sunfish., Adriano A P Da Cunha

Electronic Thesis and Dissertation Repository

Parental care is very critical for reproduction in species that provide it. Hormones such as prolactin and androgens play a crucial role in parenting and reproductive behaviours. In mammals and birds, prolactin’s role in parental care is well-established; it stimulates milk production and stimulates attachment to newborns by its release in the preoptic area of the hypothalamus (POA), among other functions. Androgens, on the other hand, are commonly associated with male secondary sex characteristics, territoriality, and aggressiveness in mammals and birds. There are similar reports of prolactin and androgen effects in fish, but there are fewer studies. I investigated if …

Age And Sex Differences In Stopover Behaviours And Flight Performance In Black-Throated Blue Warblers, Patricia Rokitnicki

Electronic Thesis and Dissertation Repository

Differential migration by sex and age is commonly observed in passerines. Previous studies have found differences in wing morphology between sex and age classes which could affect their movement ecology. In this thesis, I examine whether migratory stopover duration and nocturnal flight speeds differed between age and sex classes in 89 Black-throated Blue Warblers (Setophaga caerulescens) using movement data obtained by Motus Wildlife Tracking System and meteorological data from the NCEP/NCAR Reanalysis II project. Second year birds (hatched during the previous breeding season) had longer stopovers but similar post-departure movements to after second year birds (hatched before the last breeding …

Pillars Of Biology: 'The Genetical Evolution Of Social Behaviour, I And Ii'., Geoff Wild

Applied Mathematics Publications

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From Micro To Macro: Examining Potential Microbiome Mediated Influences On Human Growth And Health Outcomes Through Breastfeeding And Antibiotic Exposures, Nicole K. Phillips

Electronic Thesis and Dissertation Repository

Human microbiome research has rapidly developed over the past two decades yet absent from most research is the composition and dynamics of microbiomes within human populations. Given the limitations in longitudinal studies which requires decades of repeated microbe taxonomic testing of a population sample, an alternative option is to examine microbiomes and their influences via proxies using pre-existing health datasets. This research demonstrates preliminary associations between presumed disrupted and supportive microbiomes dynamics proxied by antibiotic and breastmilk exposure respectively. Using health record data across the life span from approximately 500,000 U.K. participants, this research demonstrates variable altered growth and health …