Jones Adam G, Bürger Reinhard, Arnold Stevan J
Department of Biology, Texas A&M University, 3258 TAMU, College Station, Texas 77843, USA.
Institut für Mathematik, Universität Wien, Wien 1090, Austria.
Nat Commun. 2014 May 14;5:3709. doi: 10.1038/ncomms4709.
The evolutionary trajectories of complex traits are constrained by levels of genetic variation as well as genetic correlations among traits. As the ultimate source of all genetic variation is mutation, the distribution of mutations entering populations profoundly affects standing variation and genetic correlations. Here we use an individual-based simulation model to investigate how natural selection and gene interactions (that is, epistasis) shape the evolution of mutational processes affecting complex traits. We find that the presence of epistasis allows natural selection to mould the distribution of mutations, such that mutational effects align with the selection surface. Consequently, novel mutations tend to be more compatible with the current forces of selection acting on the population. These results suggest that in many cases mutational effects should be seen as an outcome of natural selection rather than as an unbiased source of genetic variation that is independent of other evolutionary processes.
复杂性状的进化轨迹受到遗传变异水平以及性状间遗传相关性的限制。由于所有遗传变异的最终来源是突变，进入种群的突变分布深刻影响着现有变异和遗传相关性。在此，我们使用基于个体的模拟模型来研究自然选择和基因相互作用（即上位性）如何塑造影响复杂性状的突变过程的进化。我们发现上位性的存在使自然选择能够塑造突变分布，从而使突变效应与选择表面相匹配。因此，新突变往往更能与当前作用于种群的选择力相兼容。这些结果表明，在许多情况下，突变效应应被视为自然选择的结果，而非独立于其他进化过程的无偏遗传变异来源。
