Rapid Independent Trait Evolution despite a Strong Pleiotropic Genetic Correlation
Rapid Independent Trait Evolution despite a Strong Pleiotropic Genetic Correlation
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DOI：
10.1086/661907
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发表时间：
2011-10-01
影响因子：
2.9
通讯作者：
Shaw, Frank H.
中科院分区：
文献类型：
--
作者：
Conner, Jeffrey K.;Karoly, Keith;Shaw, Frank H.
在对适应性进化的所有潜在限制中，遗传相关性是最常被研究的。我们提出了一个由遗传相关性造成的约束的全面测试，将经验结果与理论预测进行了比较。野生萝卜花丝和花冠管之间的加性遗传相关很高，估计精度很高(0.85+/-0.06)，是由多效性引起的。因此，这两个性状的相对长度的进化变化应该受到限制。尽管如此，人工选择还是产生了这些性状在相反方向上的快速进化，因此在相对于对照的一次重复中，它们之间的差异在短短九个世代内增加了六个标准差。这将在先前对该种群自然选择的估计的基础上，导致相对适合度增加54%，并将在不到100代的时间内产生十字花科最极端物种的表型。这些反应在理论预期之内，而且比遗传相关性为零的情况慢得多；因此，有证据表明存在限制。这些结果，再加上其他物种的可比结果，表明尽管受到遗传相关性的限制，进化仍然可以很快。
Genetic correlations are the most commonly studied of all potential constraints on adaptive evolution. We present a comprehensive test of constraints caused by genetic correlation, comparing empirical results to predictions from theory. The additive genetic correlation between the filament and the corolla tube in wild radish flowers is very high in magnitude, is estimated with good precision (0.85 +/- 0.06), and is caused by pleiotropy. Thus, evolutionary changes in the relative lengths of these two traits should be constrained. Still, artificial selection produced rapid evolution of these traits in opposite directions, so that in one replicate relative to controls, the difference between them increased by six standard deviations in only nine generations. This would result in a 54% increase in relative fitness on the basis of a previous estimate of natural selection in this population, and it would produce the phenotypes found in the most extreme species in the family Brassicaceae in less than 100 generations. These responses were within theoretical expectations and were much slower than if the genetic correlation was zero; thus, there was evidence for constraint. These results, coupled with comparable results from other species, show that evolution can be rapid despite the constraints caused by genetic correlations.