Rapid within-species evolution can alter community structure, yet the mechanisms underpinning this effect remain unknown. Populations that rapidly evolve large amounts of phenotypic diversity are likely to interact with more species and have the largest impact on community structure. However, the evolution of phenotypic diversity is, in turn, influenced by the presence of other species. Here, we investigate how microbial community structure changes as a consequence of rapidly evolved within-species diversity using Pseudomonas fluorescens as a focal species. Evolved P. fluorescens populations showed substantial phenotypic diversification in resource-use (and correlated genomic change) irrespective of whether they were pre-adapted in isolation or in a community context. Manipulating diversity revealed that more diverse P. fluorescens populations had the greatest impact on community structure, by suppressing some bacterial taxa, but facilitating others. These findings suggest that conditions that promote the evolution of high within-population diversity should result in a larger impact on community structure.

快速的物种内进化可以改变群落结构，但支持这种效应的机制仍然未知。迅速进化出大量表型多样性的种群可能与更多的物种相互作用，并对群落结构产生最大的影响。然而，表型多样性的演变反过来又受到其他物种存在的影响。在这里，我们使用荧光假单胞菌作为焦点物种，研究微生物群落结构如何随着物种内多样性的快速进化而变化。进化的荧光假单胞菌种群在资源使用（和相关的基因组变化）方面表现出显着的表型多样化，无论他们是在孤立的环境中还是在社区环境中预先适应。操纵多样性表明，更多样化的P. fluorescens种群对群落结构的影响最大，通过抑制一些细菌分类群，但促进其他细菌分类群。这些发现表明，促进高种群内多样性进化的条件应该会对群落结构产生更大的影响。