Data from: Rapid divergence and convergence of life-history in experimentally evolved Drosophila melanogaster

Laboratory selection experiments are alluring in their simplicity, power, and ability to inform us about how evolution works. A longstanding challenge facing evolution experiments with metazoans is that significant generational turnover takes a long time. In this work, we present data from a unique system of experimentally evolved laboratory populations of Drosophila melanogaster that have experienced three distinct life-history selection regimes. The goal of our study was to determine how quickly populations of a certain selection regime diverge phenotypically from their ancestors, and how quickly they converge with independently derived populations that share a selection regime. Our results indicate that phenotypic divergence from an ancestral population occurs rapidly, within dozens of generations, regardless of that population's evolutionary history. Similarly, populations sharing a selection treatment converge on common phenotypes in this same time frame, regardless of selection pressures those populations may have experienced in the past. These patterns of convergence and divergence emerged much faster than expected, suggesting that intermediate evolutionary history has transient effects in this system. The results we draw from this system are applicable to other experimental evolution projects, and suggest that many relevant questions can be sufficiently tested on shorter timescales than previously thought.

实验室选择实验以其简洁性、高效性以及阐明演化运作机制的能力而极具吸引力。后生动物演化实验长期面临的一大挑战在于，显著的世代更替需要耗费漫长的时间。本研究呈现了一套独特的实验演化体系数据，该体系包含经实验演化培育的黑腹果蝇（Drosophila melanogaster）实验室种群，且这些种群历经三种截然不同的生活史选择策略。本研究的核心目标为：明确特定选择策略下的种群，其表型与祖先种群产生分化的速度，以及共享同一选择方案的独立起源种群之间趋同的速度。研究结果表明，无论种群自身的演化历史如何，与祖先种群的表型分化均可在数十个世代内快速发生。同样，无论种群过往经历过何种选择压力，共享同一选择方案的种群均可在相同的时间范围内趋同至统一的表型。这类趋同与分化的模式出现速度远超预期，表明在该体系中，中期演化历史仅会产生短暂的影响。本体系所得出的研究结果可推广至其他实验演化研究，同时也意味着诸多相关问题可在比此前预想更短的时间尺度内得到充分验证。