Mutation supply can influence evolutionary and thereby ecological dynamics in important ways which have received little attention. Mutation supply influences features of population genetics, such as the pool of adaptive mutations, evolutionary pathways and importance of processes, such as clonal interference. The resultant trait evolutionary dynamics, in turn, can alter population size and species interactions. However, controlled experiments testing for the importance of mutation supply on rapid adaptation and thereby population and community dynamics have primarily been restricted to the first of these aspects. To close this knowledge gap, we performed a serial passage experiment with wild-type Pseudomonas fluorescens and a mutant with reduced mutation rate. Bacteria were grown at two resource levels in combination with the presence of a ciliate predator. A higher mutation supply enabled faster adaptation to the low-resource environment and anti-predatory defence. This was associated with higher population size at the ecological level and better access to high-recurrence mutational targets at the genomic level with higher mutation supply. In contrast, mutation rate did not affect growth under high-resource level. Our results demonstrate that intrinsic mutation rate influences population dynamics and trait evolution particularly when population size is constrained by extrinsic conditions.

中文翻译：

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突变供应对实验微生物群落种群动态和性状进化的影响

突变供应可以以很少受到关注的重要方式影响进化，从而影响生态动态。突变供应影响群体遗传学的特征，例如适应性突变池、进化途径和过程的重要性，例如克隆干扰。反过来，由此产生的性状进化动力学可以改变种群规模和物种相互作用。然而，测试突变供应对快速适应以及种群和群落动态的重要性的对照实验主要限于这些方面中的第一个。为了缩小这一知识差距，我们对野生型荧光假单胞菌进行了连续传代实验和一个突变率降低的突变体。结合纤毛虫捕食者的存在，细菌在两个资源水平上生长。更高的突变供应能够更快地适应资源匮乏的环境和反掠夺性防御。这与生态水平上更高的种群规模以及在基因组水平上更好地获得具有更高突变供应的高复发突变靶标有关。相反，突变率不影响高资源水平下的生长。我们的研究结果表明，内在突变率会影响种群动态和性状进化，特别是当种群规模受外在条件限制时。