Reinforcement occurs when natural selection strengthens behavioral discrimination to prevent costly interpopulation matings, such as when matings produce sterile hybrids. This evolutionary process can complete speciation, thereby providing a direct link between Darwins theory of natural selection and the origin of new species. My dissertation presents the first study on the genetics of reinforcement. This study is framed in a conceptual body that explains how genomic architecture, selection and recombination, interact to facilitate divergence in the presence of gene flow. In addition, in my dissertation I produced a dense recombination map for D. pseudoobscura, which together with the genome sequence opens many possibilities for classic population genetic and genomic analyses in this system.
I examine a case of speciation by reinforcement in Drosophila. I present the first high-resolution genetic study of variation within species for female mating discrimination that is enhanced by natural selection. I show that reinforced mating discrimination is inherited as a dominant trait, exhibits variability within species, and may be influenced by a known set of candidate genes involved in olfaction. My results show that the genetics of reinforced mating discrimination is different from the genetics of mating discrimination between species, suggesting that overall mating discrimination might be a composite phenomenon, which in Drosophila could involve both auditory and olfactory cues. Examining the genetics of reinforcement provides a unique opportunity for both understanding the origin of new species in the face of gene flow and identifying the genetic basis of adaptive female species preferences, two major gaps in our understanding of speciation.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-04062005-121156 |
| Date | 13 April 2005 |
| Creators | Ortiz-Barrientos, Daniel |
| Contributors | Daniel G. Satterlee, David D. Pollock, Michael E. Hellberg, Mark A. Batzer, Mohamed A. F. Noor |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-04062005-121156/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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