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，可能在演化过程中发挥关键作用，但这类反馈的作用方向与强度仍难以被精准表征。本研究以两个发生次生接触与杂交的演化支系的三棘刺鱼两代群体为研究材料，对这类动态关系展开了探究。通过独立操控实验中型生态系统（mesocosms）中成体的密度与演化支系，我们构建出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。成体对生态系统的改造作用，还会改变针对竞争性杂交与非杂交幼体的选择强度。这种选择强度的差异揭示了两点：(1) 由支系特异性资源消耗与资源依赖驱动的负向生态-演化反馈；(2) 杂交幼体在资源匮乏环境中具备显著的适合度优势。本研究阐明了表型、种群密度与环境之间的互作在塑造选择压力与演化轨迹中的重要性，这一点在发生次生接触与杂交的分布范围扩张情境中尤为突出。