Adaptation and correlated fitness responses over two time scales in Drosophila suzukii populations evolving in different environments

The process of local adaptation involves differential changes in fitness over time across different environments. While experimental evolution studies have extensively tested for patterns of local adaptation at a single time point, there is relatively little research that examines fitness more than once during the time course of adaptation. We allowed replicate populations of the fruit pest Drosophila suzukii to evolve in one of eight different fruit media. After five generations, populations with the highest initial levels of maladaptation had mostly gone extinct, whereas experimental populations evolving on cherry, strawberry and cranberry media had survived. We measured the fitness of each surviving population in each of the three fruit media after five and after 26 generations of evolution. After five generations, adaptation to each medium was associated with increased fitness in the two other media. This was also true after 26 generations, except when populations that evolved on cr...局部适应（local adaptation）过程指不同环境下适合度（fitness）随时间发生的差异化变化。尽管实验进化（experimental evolution）研究已在单一时间点下广泛验证了局部适应的模式，但目前仅有极少研究在适应的时间进程中多次检测适合度。我们令果蔬害虫斑翅果蝇（Drosophila suzukii）的重复种群在8种不同果实培养基中的一种中进行演化。经过5代演化后，初始不适应程度最高的种群大多已灭绝，而在樱桃、草莓和越橘培养基上培育的实验种群得以存活。我们分别在演化至第5代和第26代时，测定了每个存活种群在三种果实培养基中的适合度。经过5代演化后，对任意一种培养基的适应均伴随着在另外两种培养基中的适合度提升。在第26代时这一规律依然成立，唯有在以……