LTREB: The Long-Term Evolution Experiment with Escherichia Coli

细菌在人类一生中经历了数千代，因此它们可以迅速进化，产生潜在的重要后果。在这项长期的实验研究中，我们对12个大肠杆菌种群的细菌进化动态进行了监测、测量并保存了数千代，以检查进化变化的动态、结果的可预测性以及表型和遗传变化的耦合。具体目标包括实验种群的日常繁殖、样本的定期存储以及进化株和祖先株之间的竞争。这个系统的一个关键特点是，祖先的细菌可以被冷冻并复活，以供以后研究。由于细菌在自然界中的重要作用，社会必须了解支配它们进化的原则。该项目将提供关于这些原则的基本知识，这些知识可能会为管理传染病和环境实践的政策提供参考。例如，首席调查员已经就这项研究与预测病原体(包括用于生物恐怖主义的病原体)的基因变化率的相关性咨询了联邦机构。该项目还解决了许多公众非常感兴趣的问题，特别是生物体如何适应环境。

Bacteria undergo many thousands of generations during a human lifetime, and thus they can evolve rapidly with potentially important consequences. In this long-term experimental research, the dynamics of bacterial evolution are being monitored, measured, and preserved for thousands of generations in twelve populations of Escherichia coli in order to examine the dynamics of evolutionary change, the predictability of outcomes, and the coupling of phenotypic and genetic changes. Specific objectives include daily propagation of the experimental populations, periodic storage of samples, and competitions between the evolved and ancestral strains. A key feature of this system is that the ancestral bacteria can be frozen and revived for later study. Owing to the important roles of bacteria in nature, it is imperative that society understands the principles that govern their evolution. This project will provide fundamental knowledge about these principles that may inform policies on managing infectious diseases and environmental practices. For example, the principal investigator has consulted with federal agencies about the relevance of this research for predicting the rate of genetic change in pathogens, including those used in bioterrorism. This project also addresses a subject of great interest to many members of the public, specifically how organisms adapt to their environments.