Environmental fluctuations restrict eco-evolutionary dynamics in predator-prey system

Environmental fluctuations, species interactions and rapid evolution are all predicted to affect community structure and their temporal dynamics. Although the effects of the abiotic environment and prey evolution on ecological community dynamics have been studied separately, these factors can also have interactive effects. Here we used bacteria–ciliate microcosm experiments to test for eco-evolutionary dynamics in fluctuating environments. Specifically, we followed population dynamics and a prey defence trait over time when populations were exposed to regular changes of bottom-up or top-down stressors, or combinations of these. We found that the rate of evolution of a defence trait was significantly lower in fluctuating compared with stable environments, and that the defence trait evolved to lower levels when two environmental stressors changed recurrently. The latter suggests that top-down and bottom-up changes can have additive effects constraining evolutionary response within populat...

环境波动、物种间相互作用及快速进化均被预测会影响群落结构及其时间动态。尽管非生物环境与猎物进化对生态群落动态的影响已被分别研究，但这些因素亦可能存在交互效应。本研究采用细菌-纤毛虫微宇宙实验，旨在探究波动环境中的生态进化动态。具体而言，当种群暴露于自下而上或自上而下压力源的规律性变化，或两者组合时，我们追踪了种群动态及猎物防御性状随时间的变化。我们发现，与稳定环境相比，波动环境中防御性状的进化速率显著降低；且当两种环境压力源反复变化时，防御性状进化至更低水平。后者表明，自上而下与自下而上的变化可能产生叠加效应，限制种群内的进化响应……