Data from: Spatially correlated extinctions select for less emigration but larger dispersal distances in the spider mite Tetranychus urticae

Dispersal is a central process to almost all species on earth, as it connects spatially structured populations and thereby increases population persistence. Dispersal is subject to (rapid) evolution and local patch extinctions are an important selective force in this context. In contrast to the randomly distributed local extinctions considered in most theoretical studies, habitat fragmentation or other anthropogenic interventions will lead to spatially correlated extinction patterns. Under such conditions natural selection is thought to lead to more long-distance dispersal, but this theoretical prediction has not yet been verified empirically. We test this hypothesis in experimental spatially structured populations of the spider mite Tetranychus urticae and supplement these empirical results with insights from an individual-based evolutionary model. We demonstrate that the spatial correlation of local extinctions changes the entire distribution of dispersal distances (dispersal kernel) and selects for overall less emigration but more long-distance dispersal.

扩散（Dispersal）是地球上几乎所有物种的核心生命过程，其能够连接空间结构化种群（spatially structured populations），进而提升种群的存续能力。扩散过程会受到（快速）演化的塑造，而局域斑块灭绝在此情境下是一类关键的选择压力。与多数理论研究中所假设的随机分布局域灭绝不同，生境破碎化或其他人为干预会导致灭绝格局呈现空间相关性。在此类条件下，自然选择被认为会促进长距离扩散的演化，但这一理论预测尚未得到实证验证。我们以二斑叶螨（Tetranychus urticae）的实验空间结构化种群为对象验证该假说，并结合基于个体的演化模型（individual-based evolutionary model）的分析结果对实证结论进行补充。本研究表明，局域灭绝的空间相关性改变了扩散距离的整体分布——即扩散核（dispersal kernel），并使得整体迁出率降低但长距离扩散的比例显著升高。