Predator macroevolution drives trophic cascades and ecosystem functioning

Biologists now recognize that ecology can drive evolution, and that evolution in turn produces ecological patterns. I extend this thinking to include longer time-scales, suggesting that macroevolutionary transitions can create phenotypic differences among species, which then have predictable impacts on species interactions, community assembly, and ecosystem functioning. Repeated speciation can exacerbate these patterns by creating communities with similar phenotypes and hence ecological impacts. Here, I use several experiments to test these ideas in dragonfly larvae that occupy ponds with fish, ponds without fish, or both. I show that macroevolutionary transitions between habitats cause fishless pond species to be more active relative to fish pond specialists, reducing prey abundance, shifting prey community composition, and creating stronger trophic cascades. These effects scale-up to the community level with predictable consequences for ecosystem multi-functioning. I suggest that macr...

当代生物学家已认识到，生态学可驱动演化，而演化反过来亦会塑造生态格局。我将这一认知拓展至更长时间尺度，提出宏演化（macroevolution）转变可造就物种间的表型（phenotypic）差异，而此类差异会对物种相互作用（species interactions）、群落构建（community assembly）以及生态系统功能（ecosystem functioning）产生可预测的影响。反复发生的物种形成（speciation）事件会加剧这类格局：当群落内物种具有相似表型时，其生态影响也会趋于同质化。本研究以栖息于三类池塘——有鱼池塘、无鱼池塘以及兼具两类生境的池塘——中的蜻蜓幼虫为研究对象，通过多组实验验证上述假说。研究结果表明：不同生境间的宏演化转变，使得无鱼池塘专性物种的活动水平高于鱼类池塘专性物种；这一差异会降低猎物丰度、改变猎物群落组成，并催生更强的营养级联（trophic cascades）效应。此类效应可延伸至群落尺度，对生态系统多功能性（ecosystem multi-functioning）产生可预测的影响。我提出，宏演化……