Data from: Fisher’s geometric model predicts the effects of random mutations when tested in the wild

Fisher's Geometric Model of Adaptation (FGM) has been the conceptual foundation for studies investigating the genetic basis of adaptation since the onset of the neo Darwinian synthesis. FGM describes adaptation as the movement of a genotype toward a fitness optimum due to beneficial mutations. To date, one prediction of FGM, the probability of improvement is related to the distance from the optimum, has only been tested in microorganisms under laboratory conditions. There is reason to believe that results might differ under natural conditions where more mutations likely affect fitness, and where environmental variance may obscure the expected pattern. We chemically induced mutations into a set of 19 Arabidopsis thaliana accessions from across the native range of A. thaliana and planted them alongside the premutated founder lines in two habitats in the mid-Atlantic region of the USA under field conditions. We show that FGM is able to predict the outcome of a set of random induced mutations on fitness in a set of Arabidopsis thaliana accessions grown in the wild: mutations are more likely to be beneficial in relatively less fit genotypes. This finding suggests that FGM is an accurate approximation of the process of adaptation under more realistic ecological conditions.费希尔适应几何模型（Fisher's Geometric Model of Adaptation, FGM）自新达尔文主义综合论诞生以来，一直是探究适应遗传基础的研究的概念基石。该模型将适应描述为基因型因有益突变的积累而向适合度最优值移动的过程。迄今为止，费希尔适应几何模型的一项预测——适应提升概率与距最优值的距离相关——仅在实验室条件下的微生物中得到过验证。有理由认为，在自然条件下实验结果可能存在差异：自然环境中更多突变可能会影响适合度，且环境异质性可能会掩盖预期的模式。我们通过化学诱变的方式，对采自拟南芥（Arabidopsis thaliana）原生分布范围的19个种质系引入突变，并将这些诱变后的株系与未诱变的奠基者株系一同种植于美国大西洋中部地区的两处野外生境中。研究结果表明，费希尔适应几何模型能够预测野外生长的拟南芥种质系中随机诱变突变对适合度的影响结果：在适合度相对较低的基因型中，突变更大概率为有益突变。这一发现表明，在更贴近现实的生态条件下，费希尔适应几何模型能够准确近似适应过程。