On the Fixation Process of a Beneficial Mutation in a Variable Environment
On the Fixation Process of a Beneficial Mutation in a Variable Environment
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DOI：
10.1534/genetics.110.124297
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发表时间：
2011-08-01
期刊：
影响因子：
3.3
通讯作者：
Hermisson, Joachim
中科院分区：
文献类型：
--
作者：
Uecker, Hildegard;Hermisson, Joachim
适应逐渐环境变化的种群通常会经历其种群规模和选择压力的时间变化。基于不均匀分支过程的数学理论，我们提出了一个框架来描述在这些条件下单个有益等位基因的固定过程。该方法允许选择系数 s(t) 和种群规模 N(t) 的任意时间依赖性，这可能是由基础生态模型产生的。我们得出了固定概率和有益等位基因达到给定中频的通过时间分布的紧凑分析近似值。我们将形式主义应用于几种生物学相关的场景，例如选择系数的线性或循环变化以及逻辑种群增长。与计算机模拟的比较表明，只要选择不是很弱，分析结果对于很大的参数范围都是准确的。
A population that adapts to gradual environmental change will typically experience temporal variation in its population size and the selection pressure. On the basis of the mathematical theory of inhomogeneous branching processes, we present a framework to describe the fixation process of a single beneficial allele under these conditions. The approach allows for arbitrary time-dependence of the selection coefficient s(t) and the population size N(t), as may result from an underlying ecological model. We derive compact analytical approximations for the fixation probability and the distribution of passage times for the beneficial allele to reach a given intermediate frequency. We apply the formalism to several biologically relevant scenarios, such as linear or cyclic changes in the selection coefficient, and logistic population growth. Comparison with computer simulations shows that the analytical results are accurate for a large parameter range, as long as selection is not very weak.