Friman Ville-Petri, Hiltunen Teppo, Laakso Jouni, Kaitala Veijo
Department of Biological and Environmental Sciences, University of Helsinki, PO Box 65, 00014 Helsinki, Finland.
Proc Biol Sci. 2008 Jul 22;275(1643):1625-33. doi: 10.1098/rspb.2008.0174.
Productivity is predicted to drive the ecological and evolutionary dynamics of predator-prey interaction through changes in resource allocation between different traits. Here we report results of an evolutionary experiment where prey bacteria Serratia marcescens was exposed to predatory protozoa Tetrahymena thermophila in low- and high-resource environments for approximately 2400 prey generations. Predation generally increased prey allocation to defence and caused prey selection lines to become more diverse. On average, prey became most defensive in the high-resource environment and suffered from reduced resource use ability more in the low-resource environment. As a result, the evolution of stronger prey defence in the high-resource environment led to a strong decrease in predator-to-prey ratio. Predation increased temporal variability of populations and traits of prey. However, this destabilizing effect was less pronounced in the high-resource environment. Our results demonstrate that prey resource availability can shape the trade-off allocation of prey traits, which in turn affects multiple properties of the evolving predator-prey system.
生产力预计将通过不同性状之间资源分配的变化，推动捕食者与猎物相互作用的生态和进化动态。在此，我们报告一项进化实验的结果，在该实验中，猎物细菌粘质沙雷氏菌在低资源和高资源环境中暴露于捕食性原生动物嗜热四膜虫约2400代猎物繁殖周期。捕食通常会增加猎物对防御的资源分配，并导致猎物选择品系变得更加多样化。平均而言，猎物在高资源环境中防御性最强，而在低资源环境中资源利用能力下降得更多。因此，在高资源环境中更强的猎物防御进化导致捕食者与猎物的比例大幅下降。捕食增加了猎物种群和性状的时间变异性。然而，这种不稳定效应在高资源环境中不太明显。我们的结果表明，猎物资源可用性可以塑造猎物性状的权衡分配，进而影响不断进化的捕食者 - 猎物系统的多种特性。
