Data from: Mutation accumulation and the formation of range limits

The dynamics of range formation are important for understanding and predicting species distributions. Here, we focus on a process that has thus far been overlooked in the context of range formation; the accumulation of mutation load. We find that mutation accumulation severely reduces the extent of a range across an environmental gradient, especially when dispersal is limited, growth rate is low and mutations are of intermediate deleterious effect. Our results illustrate the important role deleterious mutations can play in range formation. We highlight this as a necessary focus for further work, noting particularly the potentially conflicting effects dispersal may have in reducing mutation load and simultaneously increasing migration load in marginal populations.物种分布范围形成的动态机制，对理解与预测物种分布格局具有重要意义。本研究聚焦于迄今为止在分布范围形成相关研究中被忽视的一类过程：突变负荷（mutation load）的积累。研究发现，突变积累会显著压缩物种沿环境梯度的分布范围，尤其在扩散受限、种群增长率较低，且突变具有中等有害效应的情况下，该现象更为显著。本研究结果揭示了有害突变在物种分布范围形成过程中可发挥的关键作用。我们强调，这一过程应作为后续研究的必要重点，尤其需关注扩散可能存在的双重效应：一方面可降低突变负荷，另一方面又会同时增加边缘种群的迁移负荷（migration load）。