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Ecology and Evolutionary Biology

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Theses/Dissertations

2017

Speciation

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The Genetic And Environmental Basis For Chc Biosynthesis In Drosophila, Heather Ke Ward Sep 2017

The Genetic And Environmental Basis For Chc Biosynthesis In Drosophila, Heather Ke Ward

Electronic Thesis and Dissertation Repository

Cuticular hydrocarbons (CHCs) are produced by insects and primarily used to prevent desiccation. In Drosophila, certain compounds have secondary roles as infochemicals that may act during courtship to influence mate choice. Certain CHCs may stimulate courtship with heterospecifics or act to repel conspecifics. The CHC profile produced by an individual is the result of the interaction between its genetic background and the environment, though the genes that underlie species differences in CHC production and how the environment can modulate the abundance of individual compounds within a species is not well known. Here, candidate gene CG5946 was found to be …


Investigating The Role Of Fruitless In Behavioural Isolation Between Drosophila Melanogaster And Drosophila Simulans, Jalina Bielaska Da Silva Aug 2017

Investigating The Role Of Fruitless In Behavioural Isolation Between Drosophila Melanogaster And Drosophila Simulans, Jalina Bielaska Da Silva

Electronic Thesis and Dissertation Repository

Behavioural isolation is a prezygotic mechanism that is usually determined by female preference, such as seen with the rejection behaviour exhibited by Drosophila simulans females to D. melanogaster males. To confirm the role of a previously identified candidate gene fruitless (fru) in behavioural isolation, I proposed to disrupt fru expression in both D. melanogaster and D. simulans to allow for the generation of interspecies hybrids expressing only a species-specific allele of fru. A reciprocal hemizygosity test would then be used to confirm the role of fru in behavioural isolation. Disruptions of fru in both D. melanogaster and …


Ecological Niche Modeling Of The Genus Papio, Amanda J. Fuchs Aug 2017

Ecological Niche Modeling Of The Genus Papio, Amanda J. Fuchs

Theses and Dissertations

Ecological niche modeling investigates how climatic variables have influenced taxonomic diversity in Papio. Models performed well suggesting climatic variables influence the distribution of baboon species. Niche overlap among all possible pairs of taxa determined that species exhibited significantly different niches. The results of these models support a parapatric speciation scenario.


Cellular/Molecular Analysis Of Interspecies Sterile Male Hybrids In Drosophila, Rachelle L. Kanippayoor Jun 2017

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 …


Genetics Of Female Interspecific Mate Rejection In Species Of Drosophila, Ryan Calhoun May 2017

Genetics Of Female Interspecific Mate Rejection In Species Of Drosophila, Ryan Calhoun

Electronic Thesis and Dissertation Repository

Speciation can occur when accumulated differences in mating behavior force diverging species to remain reproductively isolated from one another. A key determinant of behavioural isolation is the evolution of female mating preferences that prevent interspecific males from mating. However, no individual genes involved in species-specific preferences of females have yet been identified. Using various genetic mapping techniques available for studying strains and species of Drosophila, I identify candidate genes involved in D. simulans female discrimination against D. melanogaster males. One candidate gene in particular, Katanin-60, was selected for further characterization. Katanin-60 is a gene encoding a microtubule severing …