Evaluating the impact of population bottlenecks in experimental evolution.
Evaluating the impact of population bottlenecks in experimental evolution.
复制标题
评估实验进化中种群瓶颈的影响。
作者：
L. Wahl;P. Gerrish;I. Saika
实验进化涉及在连续转移期间接种新鲜培养基时，种群大小的严重周期性减少。这些瓶颈影响了进化的动力，降低了有益突变达到固定的可能性。我们量化了这些瓶颈对进化动态的影响，对于那些在转移之间呈指数增长的种群，以及那些增长受到资源有限环境限制的种群。我们发现，在这两种情况下，在单位时间内，在生长阶段的任何时候，在瓶颈中存活下来的突变发生的可能性都是一样的。我们估计了在实验进化方案中由于瓶颈而丢失的有益突变的总比例，并推导出“最佳”稀释比，即使幸存的有益突变数量最大化的比例。虽然在文献中经常使用更严格的稀释比例，但我们发现0.1-0.2的比例可以最大限度地减少罕见的有益突变丢失的机会。最后，我们提供了一些有用的近似结果，并说明了我们的方法与实验进化协议在文献中的应用。
Experimental evolution involves severe, periodic reductions in population size when fresh media are inoculated during serial transfer. These bottlenecks affect the dynamics of evolution, reducing the probability that a beneficial mutation will reach fixation. We quantify the impact of these bottlenecks on the evolutionary dynamics, for populations that grow exponentially between transfers and for populations in which growth is curbed by a resource-limited environment. We find that in both cases, mutations that survive bottlenecks are equally likely to occur, per unit time, at all times during the growth phase. We estimate the total fraction of beneficial mutations that are lost due to bottlenecks during experimental evolution protocols and derive the "optimal" dilution ratio, the ratio that maximizes the number of surviving beneficial mutations. Although more severe dilution ratios are often used in the literature, we find that a ratio of 0.1-0.2 minimizes the chances that rare beneficial mutations are lost. Finally, we provide a number of useful approximate results and illustrate our approach with applications to experimental evolution protocols in the literature.
细菌的补偿性突变、抗生素耐药性和适应性进化的群体遗传学。
影响因子：
3.3
作者：
Levin,BR;Perrot,V;Walker,N
通讯作者：
Walker,N
简单非结构化环境中的微生物进化：大肠杆菌的遗传分化。
影响因子：
3.3
作者：
Rosenzweig,RF;Sharp,RR;Treves,DS;Adams,J
通讯作者：
Adams,J