Universität zu Köln

Nowak, Stefan (2015). Properties of Random Fitness Landscapes and Their Influence on Evolutionary Dynamics. A Journey through the Hypercube. PhD thesis, Universität zu Köln.

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Abstract

A fitness landscape is a theoretical concept in population genetics where a fitness value, which measures the reproductive success of an organism and is represented by a real number, is assigned to each genotype. Content of this thesis is the analytical and numerical study of stochastic models for fitness landscapes. The focus is on the landscape ruggedness and its influence on evolutionary dynamics. One proxy for the ruggedness is the number of local maxima, i.e., genotypes from which every mutation leads to lowered fitness. Another way to quantify ruggedness is the study of accessible paths, i.e., successions of mutations that increase the fitness monotonically. The question whether accessible paths exist can be interpreted as a kind of percolation problem. One model for evolutionary dynamics that will be used is the adaptive walk. In this model type, populations are treated as single entities that move through the space of genotypes according to certain probabilistic rules. They are closely related to both ruggedness measures as they follow accessible paths and terminate at local maxima. Furthermore, the individual-based Wright-Fisher model is used to study recombination of genotypes, interactions between individuals and the influence of the underlying fitness landscape on these mechanisms.

Item Type:	Thesis (PhD thesis)
Creators:	Creators Email ORCID ORCID Put Code Nowak, Stefan sn@thp.uni-koeln.de UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-65665
Date:	1 October 2015
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Physics > Institute for Theoretical Physics
Subjects:	Physics
Uncontrolled Keywords:	Keywords Language statistical physics, evolutionary biology, fitness landscapes, adaptive walks, percolation, spin glasses English
Date of oral exam:	23 November 2015
Referee:	Name Academic Title Krug, Joachim Prof. Dr. Bovier, Anton Prof. Dr.
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/6566