The population genetics of adaptation: The distribution of factors fixed during adaptive evolution
The population genetics of adaptation: The distribution of factors fixed during adaptive evolution
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DOI：
10.2307/2411226
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发表时间：
1998-08-01
期刊：
影响因子：
3.3
通讯作者：
Orr, HA
中科院分区：
文献类型：
--
作者：
Orr, HA
我们对适应的遗传基础知之甚少。事实上，我们不能作出任何理论预测，但启发式的，分布的表型效应之间的因素固定在适应过程中，也没有预期的“大小”的最大因素固定。对这个问题的研究需要考虑到种群在适应过程中通过逐步替换有利的突变逐渐接近表型最优。使用Fisher的几何模型的适应，我分析这种方法的最佳，并得出一个近似的解决方案，在适应过程中固定的因素的大小分布。我进一步推广这些结果，允许输入的突变效应的任何分布。在适应过程中固定的因素的分布呈现出一种令人愉快的简单的指数形式。这一结果对适应度函数和突变效应分布的变化非常不敏感。固定的因素之间的指数趋势似乎是一个固定的最佳适应的一般属性。
We know very little about the genetic basis of adaptation. Indeed, we can make no theoretical predictions, however heuristic, about the distribution of phenotypic effects among factors fixed during adaptation nor about the expected "size" of the largest factor fixed. Study of this problem requires taking into account that populations gradually approach a phenotypic optimum during adaptation via the stepwise substitution of favorable mutations. Using Fisher's geometric model of adaptation, I analyze this approach to the optimum, and derive an approximate solution to the size distribution of factors fixed during adaptation. I further generalize these results to allow the input of any distribution of mutational effects. The distribution of factors fixed during adaptation assumes a pleasingly simple, exponential form. This result is remarkably insensitive to changes in the fitness function and in the distribution of mutational effects. An exponential trend among factors fixed appears to be a general property of adaptation toward a fixed optimum.