Department of Biosciences, University of Exeter, Penryn, UK; Imperial College London, Ascot, UK.
J Evol Biol. 2014 Feb;27(2):374-80. doi: 10.1111/jeb.12303. Epub 2013 Dec 23.
Although microevolution has been shown to play an important role in pairwise antagonistic species interactions, its importance in more complex communities has received little attention. Here, we used two Pseudomonas fluorescens prey bacterial strains (SBW25 and F113) and Tetrahymena thermophila protist predator to study how rapid evolution affects the structuring of predator-prey communities. Both bacterial strains coexisted in the absence of predation, and F113 was competitively excluded in the presence of both SBW25 and predator during the 24-day experiment, an initially surprising result given that F113 was originally poorer at growing, but more resistant to predation. However, this can be explained by SBW25 evolving greater antipredatory defence with a lower growth cost than F113. These results show that rapid prey evolution can alter the structure of predator-prey communities, having different effects depending on the initial composition of the evolving community. From a more applied perspective, our results suggest that the effectiveness of biocontrol bacteria, such as F113, could be weaker in communities characterized by intense bacterial competition and protist predation.
虽然微观进化在种间对抗性相互作用中起着重要作用，但它在更复杂的群落中的重要性却很少受到关注。在这里，我们使用了两种荧光假单胞菌（SBW25 和 F113）猎物细菌菌株和嗜热四膜虫原生动物捕食者来研究快速进化如何影响捕食者-猎物群落的结构。在没有捕食的情况下，两种细菌菌株共存，并且在 24 天的实验中，当 SBW25 和捕食者同时存在时，F113 被竞争性排斥，这是一个最初令人惊讶的结果，因为 F113 最初的生长能力较差，但对捕食的抵抗力更强。然而，这可以通过 SBW25 比 F113 进化出更高的抗捕食防御能力，同时生长成本更低来解释。这些结果表明，快速的猎物进化可以改变捕食者-猎物群落的结构，其效果取决于进化群落的初始组成。从更实际的角度来看，我们的结果表明，生物防治细菌（如 F113）在细菌竞争和原生动物捕食强烈的群落中的有效性可能较弱。
