Department of Biology, Lund University, SE-223 62 Lund, Sweden.
Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norrbyvägen 18D, SE-752 36 Uppsala, Sweden.
Trends Ecol Evol. 2019 May;34(5):422-434. doi: 10.1016/j.tree.2019.01.015.
Mutational input is the ultimate source of genetic variation, but mutations are not thought to affect the direction of adaptive evolution. Recently, critics of standard evolutionary theory have questioned the random and non-directional nature of mutations, claiming that the mutational process can be adaptive in its own right. We discuss here mutation bias in adaptive evolution. We find little support for mutation bias as an independent force in adaptive evolution, although it can interact with selection under conditions of small population size and when standing genetic variation is limited, entirely consistent with standard evolutionary theory. We further emphasize that natural selection can shape the phenotypic effects of mutations, giving the false impression that directed mutations are driving adaptive evolution.
突变输入是遗传变异的最终来源，但突变被认为不会影响适应性进化的方向。最近，标准进化理论的批评者质疑突变的随机性和非定向性，声称突变过程本身就具有适应性。我们在这里讨论适应性进化中的突变偏向。尽管在种群规模较小和遗传变异有限的情况下，突变偏向可以与选择相互作用，但我们几乎没有发现支持突变偏向作为适应性进化中独立力量的证据，这与标准进化理论完全一致。我们进一步强调，自然选择可以塑造突变的表型效应，给人一种定向突变正在推动适应性进化的错觉。
