Department of Biological Science, Florida State University, Tallahassee, Florida 32306-4295, USA.
Ecology. 2010 Mar;91(3):629-36. doi: 10.1890/09-1481.1.
Ecologists have long studied the effect of predators on prey population abundance while evolutionary biologists have measured prey trait evolution in response to predation. Ecological and evolutionary processes were generally thought to occur on different time scales, but recent evidence suggests that evolution may alter the ecological effects of predation over the course of ecological experiments. We used a protozoan and its mosquito-larvae predator, naturally found in the water-filled leaves of pitcher plants, to examine the effect of prey evolution on predator-prey interactions. In experiments conducted over 12 days (approximately 50 prey generations, but less than one predator generation), we measured a decrease in the effect of mosquito larvae predators on protozoa prey populations. In a separate set of experiments, we found that the presence of predators corresponded with evolution of smaller cell size and increased population growth rate. In ecological experiments, two situations commonly occur: strong selection pressure applied by the treatment itself and discrepancies in generation times of associate species. Our results suggest that in either situation, the resulting evolutionary patterns may lead to dramatic and important changes in ecological effect size.
生态学家长期以来一直在研究捕食者对猎物种群数量的影响，而进化生物学家则一直在衡量猎物特征的进化，以应对捕食。生态和进化过程通常被认为发生在不同的时间尺度上，但最近的证据表明，进化可能会在生态实验过程中改变捕食的生态效应。我们使用一种原生动物及其蚊子幼虫捕食者，这些生物自然存在于猪笼草充满水的叶子中，以研究猎物进化对捕食者-猎物相互作用的影响。在为期 12 天的实验中（大约经历了 50 代猎物，但不到一代捕食者），我们发现蚊子幼虫捕食者对原生动物猎物种群的影响减少了。在另一组实验中，我们发现捕食者的存在与细胞尺寸变小和种群增长率增加有关。在生态实验中，两种情况通常会发生：处理本身施加的强烈选择压力和相关物种世代时间的差异。我们的结果表明，在这两种情况下，由此产生的进化模式可能会导致生态效应大小的显著和重要变化。
