Data from: Transgenerational selection driven by divergent ecological impacts of hybridizing lineages

Dynamic interactions between ecological conditions and the phenotypic composition of populations likely play an important role in evolution, but the direction and strength of these feedbacks remain difficult to characterize. We investigated these dynamics across two generations of threespine sticklebacks from two evolutionary lineages undergoing secondary contact and hybridization. Independently manipulating the density and lineage of adults in experimental mesocosms led to contrasting ecosystem conditions with strong effects on total survival in a subsequent generation of juveniles. Ecosystem modifications by adults also varied the strength of selection on competing hybrid and non-hybrid juveniles. This variation in selection indicated (1) a negative eco-evolutionary feedback driven by lineage-specific resource depletion and dependence and (2) a large performance advantage of hybrid juveniles in depleted environments. This work illustrates the importance of interactions between phenotype, population density and the environment in shaping selection and evolutionary trajectories, especially in the context of range expansion with secondary contact and hybridization.生态条件与种群表型组成之间的动态互作，大概率在演化进程中发挥着关键作用，但这类反馈的作用方向与强度仍难以精准刻画。我们以两个正经历次生接触（secondary contact）与杂交（hybridization）的演化支（evolutionary lineages）的三刺鱼（threespine sticklebacks）为研究对象，对其两代个体间的这类动态展开了探究。通过在实验中型生态系统（experimental mesocosms）中独立操控成体的密度与演化支，我们构建了差异化的生态系统条件，这些条件对后续世代幼体的总存活率产生了显著影响。成体介导的生态系统改造，同样会改变竞争中的杂交与非杂交幼体所承受的选择强度。此类选择强度的变化揭示了两项核心结论：（1）由演化支特异性的资源消耗与资源依赖所驱动的负向生态-演化反馈（eco-evolutionary feedback）；（2）杂交幼体在资源匮乏的环境中具备显著的生存性能优势。本研究阐明了表型、种群密度与环境之间的互作效应，在塑造选择压力与演化轨迹过程中的重要性，尤其是在伴随次生接触与杂交的物种范围扩张背景下。