Full metadata
Title
The effects of natural selection and random genetic drift in structured populations
Description
Building mathematical models and examining the compatibility of their theoretical predictions with empirical data are important for our understanding of evolution. The rapidly increasing amounts of genomic data on polymorphisms greatly motivate evolutionary biologists to find targets of positive selection. Although intensive mathematical and statistical studies for characterizing signatures of positive selection have been conducted to identify targets of positive selection, relatively little is known about the effects of other evolutionary forces on signatures of positive selection. In this dissertation, I investigate the effects of various evolutionary factors, including purifying selection and population demography, on signatures of positive selection. Specifically, the effects on two highly used methods for detecting positive selection, one by Wright's Fst and its analogues and the other by footprints of genetic hitchhiking, are investigated. In Chapters 2 and 3, the effect of purifying selection on Fst is studied. The results show that purifying selection intensity greatly affects Fst by modulating allele frequencies across populations. The footprints of genetic hitchhiking in a geographically structured population are studied in Chapter 4. The results demonstrate that footprints of genetic hitchhiking are significantly influenced by geographic structure, which may help scientists to infer the origin and spread of the beneficial allele. In Chapter 5, the stochastic dynamics of a hitchhiking allele are studied using the diffusion process of genetic hitchhiking conditioned on the fixation of the beneficial allele. Explicit formulae for the conditioned two-locus diffusion process of genetic hitchhiking are derived and stochastic aspects of genetic hitchhiking are investigated. The results in this dissertation show that it is essential to model the interaction of neutral and selective forces for correct identification of the targets of positive selection.
Date Created
2011
Contributors
- Maruki, Takahiro (Author)
- Kim, Yuseob (Thesis advisor)
- Taylor, Jesse E (Thesis advisor)
- Greenwood, Priscilla E (Committee member)
- Hedrick, Philip W (Committee member)
- Rosenberg, Michael S. (Committee member)
- Arizona State University (Publisher)
Topical Subject
Resource Type
Extent
x, 109 p. : ill. (some col.)
Language
eng
Copyright Statement
In Copyright
Primary Member of
Peer-reviewed
No
Open Access
No
Handle
https://hdl.handle.net/2286/R.I.14295
Statement of Responsibility
by Takahiro Maruki
Description Source
Retrieved on Oct. 24, 2012
Level of coding
full
Note
thesis
Partial requirement for: Ph.D., Arizona State University, 2011
bibliography
Includes bibliographical references (p. 100-109)
Field of study: Biology
System Created
- 2012-08-24 06:07:54
System Modified
- 2021-08-30 01:50:18
- 3 years 2 months ago
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