Characteristic time in quasispecies evolution

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• 作者：Arturo Marí ; n^a ; Hé ; ctor Tejero^a ; Juan Carlos Nu&ntilde ; o^b ; Francisco Montero^a ; ^{framonte@quim.ucm.es}
• 关键词：Optimal mutation rate ; Evolution time ; Error threshold ; Exploration&ndash ; fixation trade-off
• 刊名：Journal of Theoretical Biology
• 出版年：2012
• 期刊代码：79_00225193
• 类别：mt
• 出版时间：21 June, 2012
• 卷：303
• 期：Complete
• 页码：25-32
• 文件大小：470 K

摘要

The time a phenotype takes to achieve a stationary state from an initial condition depends on multiple factors. In particular, it is a function of both its fitness and its mutation rate. We evaluate the average time, referred to as the characteristic time, T_c, that the system takes to reach a final steady state of simple models of populations formed by self-replicative sequences. The dependence of T_c on the mutation rate and on the fitness landscape is also studied. For simple fitness landscapes, e.g. single peak, the characteristic time can be analytically obtained as a function of the system parameters. In this case, T_c for obtaining the quasispecies distribution presents a maximum at a Q-value that depends on the initial conditions and decreases monotonously as the mutation rate tends to zero. For most of the complex landscapes handled in this paper, the characteristic time to achieve the quasispecies distribution picked around the fittest phenotype attains a local minimum for a given mutation rate between 0 and the Q-value at which T_c reaches its local maximum. Thus, in these cases, an optimum value for the mutation rate exists that corresponds to the lowest value of the characteristic time for quasispecies evolution.