In this dissertation we describe the microscopic behavior and emergent phenomena of evolutionary dynamics. We introduce frameworks that explicitly incorporate the effects of beneficial and deleterious mutations, and distributions of mutations. We treat a full distribution of mutations in adapting populations, providing a unified description of interference between established mutations. We compute experimentally observable parameters, including the speed of adaptation and the distribution of fixed mutations, for a general underlying distribution of available beneficial mutations. We identify an equivalence between the adaptive dynamics using a distribution of mutations, and the well known dynamics of mutations with a single fitness effect. Treating beneficial and deleterious mutations simultaneously, a dynamic mutation-selection balance emerges, which we argue is an evolutionarily stable state. The dynamic balance state describes a population in which rare beneficial mutations are sufficient to halt the stochastically driven extinction of subclasses in the population. This introduces a stationary state which we argue lies in an attractive basin, such that any generic adaptive population or fitness degrading population will approach the same equilibrium. The existence of this evolutionary "attractor" and its stability introduce this description as a new null expectation for any evolving population. We suggest that more complicated biological effects, such as changes in mutation rate, may be viewed as effective perturbations away from this state.
|Advisor:||Shraiman, Boris I.|
|Commitee:||Berenstein, David, Campas, Otger|
|School:||University of California, Santa Barbara|
|School Location:||United States -- California|
|Source:||DAI-B 74/06(E), Dissertation Abstracts International|
|Subjects:||Applied Mathematics, Evolution and Development, Biophysics|
|Keywords:||Adaptation, Applied physics, Evolutionary dynamics, Fitness, Muller's ratchet, Mutation, Population genetics, Selection|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be