Paper Info
Title
Distribution of the fittest individuals and the rate of Muller's ratchet in a model with overlapping generations.
Abstract
Muller's ratchet is a paradigmatic model for the accumulation of deleterious mutations in a population of finite size. A click of the ratchet occurs when all individuals with the least number of deleterious mutations are lost irreversibly due to a stochastic fluctuation. In spite of the simplicity of the model, a quantitative understanding of the process remains an open challenge. In contrast to previous works, we here study a Moran model of the ratchet with overlapping generations. Employing an approximation which describes the fittest individuals as one class and the rest as a second class, we obtain closed analytical expressions of the ratchet rate in the rare clicking regime. As a click in this regime is caused by a rare, large fluctuation from a metastable state, we do not resort to a diffusion approximation but apply an approximation scheme which is especially well suited to describe extinction events from metastable states. This method also allows for a derivation of expressions for the quasi-stationary distribution of the fittest class. Additionally, we confirm numerically that the formulation with overlapping generations leads to the same results as the diffusion approximation and the corresponding Wright-Fisher model with non-overlapping generations.
Year
DOI
Venue
2013
10.1371/journal.pcbi.1003303
PLOS COMPUTATIONAL BIOLOGY
Keywords
DocType
Volume
computational biology,mutation
Journal
9
Issue
ISSN
Citations 
11
1553-734X
1
PageRank 
References 
Authors
0.38
2
2
Name
Order
Citations
PageRank
Jakob J Metzger110.38
Stephan Eule211.06