The traveling-wave approach to asexual evolution: Muller's ratchet and speed of adaptation
The traveling-wave approach to asexual evolution: Muller's ratchet and speed of adaptation
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DOI：
10.1016/j.tpb.2007.10.004
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发表时间：
2008-02-01
影响因子：
1.4
通讯作者：
Wilke, Claus O.
中科院分区：
文献类型：
--
作者：
Rouzine, Igor M.;Brunet, Eric;Wilke, Claus O.
我们利用行波理论推导出无性种群在Muller棘轮作用下有害突变的累积速度和正选择作用下的适应速度的表达式。行波理论是对进化种群的半确定性描述，其中大部分种群是使用确定性方程建模的，但给予了适当的随机处理，其随时间的演变决定了种群中适应度的丧失或获得。我们推导了改进的方法来为Muller棘轮和自适应进化建立最高适应度类别(随机边)的模型，并计算解析校正项来补偿当将离散适应度类别视为一个连续体时所产生的不准确性。我们发现行波理论很好地预测了Muller棘轮情况下的突变累积率，并在很宽的参数范围内对适应速度做出了很好的预测。我们预测适应率将随着种群规模的对数增长，直到种群规模非常大。(C)2007 Elsevier Inc.保留所有权利。
We use traveling-wave theory to derive expressions for the rate of accumulation of deleterious mutations under Muller's ratchet and the speed of adaptation under positive selection in asexual populations. Traveling-wave theory is a semi-deterministic description of an evolving population, where the bulk of the population is modeled using deterministic equations, but the class of the highest-fitness genotypes, whose evolution over time determines loss or gain of fitness in the population, is given proper stochastic treatment. We derive improved methods to model the highest-fitness class (the stochastic edge) for both Muller's ratchet and adaptive evolution, and calculate analytic correction terms that compensate for inaccuracies which arise when treating discrete fitness classes as a continuum. We show that traveling-wave theory makes excellent predictions for the rate of mutation accumulation in the case of Muller's ratchet, and makes good predictions for the speed of adaptation in a very broad parameter range. We predict the adaptation rate to grow logarithmically in the population size until the population size is extremely large. (C) 2007 Elsevier Inc. All rights reserved.