Adaptive walks toward a moving optimum
Adaptive walks toward a moving optimum
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DOI：
10.1534/genetics.107.072926
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发表时间：
2007-06-01
期刊：
影响因子：
3.3
通讯作者：
Acquisti, Claudia
中科院分区：
文献类型：
--
作者：
Collins, Sinead;de Meaux, Juliette;Acquisti, Claudia
我们通过模拟响应固定幅度但可变速度的环境变化的适应性行走，研究自然选择适应的动态和结果如何受到环境稳定性的影响。在这里，我们考虑通过有益突变的连续固定来适应的单态谱系。这是通过选择短 RNA 序列来模拟的，以确保温度升高时的折叠稳定性和二级结构的保存。使用短 RNA 序列使我们能够根据基因型（序列）和表型（二级结构）来描述适应性结果，并跟踪适应度增加的动态。我们发现，较慢的环境变化率通过降低固定有益突变的适应度效应以及增加可能发生最大效应替代的时间范围来影响适应性行走的动态。此外，与适应突然变化的谱系相比，适应较慢的环境变化率会导致更适合的终点，可能的最终表型更少。这表明，当使用突然的环境变化进行实验来预测对逐渐变化的适应性反应时，应该小心。
We investigate how the dynamics and outcomes of adaptation by natural selection are affected by environmental stability by simulating adaptive walks in response to an environmental change of fixed magnitude but variable speed. Here we consider monomorphic lineages that adapt by the sequential fixation of beneficial mutations. This is modeled by selecting short RNA sequences for folding stability and secondary structure conservation at increasing temperatures. Using short RNA sequences allows us to describe adaptive outcomes in terms of genotype (sequence) and phenotype (secondary structure) and to follow the dynamics of fitness increase. We find that slower rates of environmental change affect the dynamics of adaptive walks by reducing the fitness effect of fixed beneficial mutations, as well as by increasing the range of time in which the substitutions of largest effect are likely to occur. In addition, adaptation to slower rates of environmental change results in fitter endpoints with fewer possible end phenotypes relative to lineages that adapt to a sudden change. This suggests that care should be taken when experiments using sudden environmental changes are used to make predictions about adaptive responses to gradual change.