Structure and evolutionary dynamics in fitness landscapes
Evolution can be conceptualized as an optimization algorithm that allows populations to search through genotypes for those that produce high fitness solutions. This search process is commonly depicted as exploring a “fitness landscape”, which combines similarity relationships among genotypes with the concept of a genotype-fitness map. As populations adapt to their fitness landscape, they accumulate information about the fitness landscape in which they live. A greater understanding of evolution on fitness landscapes will help elucidate fundamental evolutionary processes. I examine methods of estimating information acquisition in evolving populations and find that these techniques have largely ignored the effects of common descent. Since information is estimated by measuring conserved genomic regions across a population, common descent can create a severe bias by increasing similarities among unselected regions. I introduce a correction method to compensate for the effects of common descent on genomic information and empirically demonstrate its efficacy.Next, I explore three instantiations of NK, Avida, and RNA fitness landscapes to better understand structural properties such as the distribution of peaks and the size of basins of attraction. I find that the fitness of peaks is correlated with the fitness of peaks within their neighborhood, and that the size of peaks' basins of attraction tends to be proportional to the heights of the peaks. Finally, I visualize local dynamics and perform a detailed comparison between the space of what evolutionary trajectories are technically possible from a single starting point and the results of actual evolving populations.
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- In Collections
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Electronic Theses & Dissertations
- Copyright Status
- In Copyright
- Material Type
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Theses
- Authors
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Pakanati, Anuraag R.
- Thesis Advisors
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Ofria, Charles A.
Adami, Christoph
- Committee Members
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Pennock, Robert T.
Goodman, Erik D.
- Date Published
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2015
- Subjects
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Evolution (Biology)--Mathematical models
Natural selection--Mathematical models
Population genetics--Mathematical models
Biological fitness
Mathematical models
- Program of Study
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Computer Science - Doctor of Philosophy
- Degree Level
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Doctoral
- Language
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English
- Pages
- xxi, 203 pages
- ISBN
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9781321733570
1321733577
- Permalink
- https://doi.org/doi:10.25335/ama6-rh18