Department of Zoology, University of Oxford, Oxford OX1 3PS, UK.
Science. 2011 Apr 1;332(6025):106-9. doi: 10.1126/science.1198767.
Bacteria and their viruses (phages) undergo rapid coevolution in test tubes, but the relevance to natural environments is unclear. By using a "mark-recapture" approach, we showed rapid coevolution of bacteria and phages in a soil community. Unlike coevolution in vitro, which is characterized by increases in infectivity and resistance through time (arms race dynamics), coevolution in soil resulted in hosts more resistant to their contemporary than past and future parasites (fluctuating selection dynamics). Fluctuating selection dynamics, which can potentially continue indefinitely, can be explained by fitness costs constraining the evolution of high levels of resistance in soil. These results suggest that rapid coevolution between bacteria and phage is likely to play a key role in structuring natural microbial communities.
细菌及其病毒（噬菌体）在试管中经历快速的共同进化，但与自然环境的相关性尚不清楚。通过使用“标记-重捕”方法，我们展示了土壤群落中细菌和噬菌体的快速共同进化。与体外共同进化不同，体外共同进化的特征是随着时间的推移，感染性和抗性增加（军备竞赛动态），而土壤中的共同进化导致宿主对当代寄生虫的抗性高于过去和未来寄生虫（波动选择动态）。波动选择动态可能会无限期地持续下去，其可以通过限制土壤中高水平抗性进化的适应性成本来解释。这些结果表明，细菌和噬菌体之间的快速共同进化可能在构建自然微生物群落中发挥关键作用。
