Biodiversity Commons^™

Characterizing Mekk1: Candidate Behavioural Isolation Gene, Caryn Dooner

Electronic Thesis and Dissertation Repository

Behavioural isolation can occur due to divergence in aspects of courtship and mating, and can contribute to reproductive isolation. The purpose of this study is to determine how a gene, Mekk1, contributes to female rejection behaviour between D. melanogaster and D. simulans. Unique polymorphisms were identified within D. simulans Mekk1 that could contribute to behaviour, most of which are non-coding. Both transcripts of Mekk1 appear to be expressed at similar levels in D. simulans and D. melanogaster. These data also indicate that Mekk1 may be expressed in a specific region of the brain called the mushroom body, …

Cellular/Molecular Analysis Of Interspecies Sterile Male Hybrids In Drosophila, Rachelle L. Kanippayoor

Electronic Thesis and Dissertation Repository

Over time, genetic differences can accumulate between populations that are geographically separated. This genetic divergence can lead to the evolution of reproductive isolating mechanisms that reduce gene flow between the populations and, upon secondary contact, result in distinct species. The process of speciation is, thus, what accounts for the multitude of species that contribute to the rich biodiversity on Earth. Interspecies hybrid sterility is a postzygotic isolating mechanism that affects the development of hybrids, rendering them sterile. A notable trend, known as Haldane's Rule, describes that heterogametic individual (e.g. males in Drosophila) are more susceptible to sterility than homogametic …

Evolutionary Genetic Aspects Of Host Association In Generalist Ectoparasites, Benoit Talbot

Electronic Thesis and Dissertation Repository

Despite the use of the host for dispersal by most parasite species, the extremely loose relationship typical between highly mobile hosts and generalist ectoparasites may lead to very different gene flow patterns between the two, leading in turn to different spatial genetic structure, and potentially different demographic history. I examined how similar gene flow patterns are between Cimex adjunctus, a generalist ectoparasite of bats present throughout North America, and two of its key bat hosts. I first analyzed the continent-scale genetic structure and demographic history of C. adjunctus and compared it to that of two of its hosts, the …

Rate Of Vegetation Recovery In Restored Prairie Wetlands, Saloni Salaria

Electronic Thesis and Dissertation Repository

Wetlands are restored to compensate for wetland loss and degradation. To determine the potential rate and success of vegetation recovery in restored wetlands, prairie wetlands of different restoration ages (3 to 23 years since restoration), including drained and natural (embedded within both agricultural and protected landscape), were sampled for vegetation in Alberta, Canada. Vegetation was assessed based on species richness, percentage and cover of hydrophytes, natives and non-natives, and community composition. Analysis of covariance with wetland area as a covariate and non-metric multidimensional scaling results indicated that restored wetlands resembled low-integrity natural wetlands that occurred on agricultural landscapes within 3-5 …

The Influence Of Adjacent Forest And Agriculture On Restored Grassland Diversity And Composition, Rachel A. Chambers

Electronic Thesis and Dissertation Repository

Little native grassland remains in North America due to land-use changes. Conversion to agriculture is a common means of loss. This fragmentation creates edges in the landscape and associated edge effects. Grassland plant communities are susceptible to edge effects, directly via dispersal and indirectly through environment. This study took place in Norfolk County, Ontario, Canada, in a landscape of agriculture, forest, rural development, and patches of grassland restored by Nature Conservancy Canada. I examined restored grassland edges bordering forest and crops. An intensive study at a single site identified spatial and soil environmental influences on plant diversity and composition. I …

P08. Unravelling Organelle Genome Evolution Architecture Using Rna-Sequencing Data, Matheus Sanita Lima, David Roy Smith

Western Research Forum

Background: Mitochondria genomes vary from 11 Mb to 6 kb, while plastids can vary from 1 Mb to 30 kb. Non-coding DNA accounts for most of this size variation, but the mechanistic and evolutionary reasons for that are still unknown. Next generation sequencing has generated unprecedented amounts of genomic and transcriptomic data that can be used for organelle genome evolution studies. However, most of these data is used only for the study of cell nucleus. Therefore, I decided to use these untapped data source to investigate the transcription of organelle genomes in plastid-bearing protists.

Methods: I mapped the transcriptomes over …

Fungi Associated With Common Buckthorn (Rhamnus Cathartica) In Southern Ontario, Nimalka M. Weerasuriya

Electronic Thesis and Dissertation Repository

Common buckthorn (Rhamnus cathartica) is a competitive Eurasian woody shrub currently invading North America. Buckthorn thickets reduce native diversity and may reduce mycorrhizal diversity through the release of allelochemicals. Two aspects of buckthorn’s invasional biology are explored: 1) identifying fungi associating with buckthorn, and 2) determining buckthorn’s allelochemical impacts on arbuscular mycorrhizae in forest soils and an open-greenhouse experiment.

Twenty-three fungi were found growing on buckthorn, including Armillaria mellea s.l., Hypoxylon fuscum, H. perforatum, Nectria cinnabarina, and Cylindrobasidium evolvens. Data from invaded and uninvaded sugar maple (Acer saccharum) soils revealed that arbuscular …

Microbial Repopulation Following In Situ Star Remediation, Gavin Overbeeke

Electronic Thesis and Dissertation Repository

In situ STAR (Self-sustaining Treatment for Active Remediation) is an emerging remediation technology which uses smouldering combustion to destroy nonaqueous phase liquid (NAPL) contamination in the subsurface. Since STAR smouldering travels through contaminated soils slowly (~0.5 to 5 m/day) and subjects them to high temperatures (400–1000°C), it is expected that this technology will thoroughly dry and sterilize the zones which it treats. Further, soils surrounding the treatment zone which are not smouldered will be heated, although not smouldered, by virtue of their proximity to STAR, impacting microbial communities within them. Therefore, the objectives of this work are to quantify the …