Alexandria Digital Research Library

Keeping the Red Queen in Check: Dynamic Mutation-Selection Balance in Evolving Populations

Author:
Balick, Daniel J.
Degree Grantor:
University of California, Santa Barbara. Physics
Degree Supervisor:
Boris I. Shraiman
Place of Publication:
[Santa Barbara, Calif.]
Publisher:
University of California, Santa Barbara
Creation Date:
2012
Issued Date:
2012
Topics:
Biology, Evolution and Development, Applied Mathematics, and Biophysics, General
Keywords:
Fitness
Evolutionary dynamics
Applied physics
Adaptation
Muller's ratchet
Population genetics
Genres:
Dissertations, Academic and Online resources
Dissertation:
Ph.D.--University of California, Santa Barbara, 2012
Description:

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.

Physical Description:
1 online resource (264 pages)
Format:
Text
Collection(s):
UCSB electronic theses and dissertations
ARK:
ark:/48907/f3xg9p31
ISBN:
9781267933591
Catalog System Number:
990039502810203776
Rights:
Inc.icon only.dark In Copyright
Copyright Holder:
Daniel Balick
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