Data from: Plasticity for desiccation tolerance across Drosophila species is affected by phylogeny and climate in complex ways

Comparative analyses of ectotherm susceptibility to climate change often focus on thermal extremes, yet responses to aridity may be equally important. Here we focus on plasticity in desiccation resistance, a key trait shaping distributions of Drosophila species and other small ectotherms. We examined the extent to which 32 Drosophila species, varying in their distribution, could increase their desiccation resistance via phenotypic plasticity involving hardening, linking these responses to environment, phylogeny and basal resistance. We found no evidence to support the seasonality hypothesis; species with higher hardening plasticity did not occupy environments with higher and more seasonal precipitation. As basal resistance increased, the capacity of species to respond via phenotypic plasticity decreased, suggesting plastic responses involving hardening may be constrained by basal resistance. Trade-offs between basal desiccation resistance and plasticity were not universal across the phylogeny and tended to occur within specific clades. Phylogeny, environment and trade-offs all helped to explain variation in plasticity for desiccation resistance but in complex ways. These findings suggest some species have the ability to counter dry periods through plastic responses, whereas others do not; and this ability will depend to some extent on a species’ placement within a phylogeny, along with its basal level of resistance.针对变温动物（ectotherm）对气候变化敏感性的比较分析，往往聚焦于极端热环境，然而物种对干旱化的响应或许同样至关重要。本研究聚焦于抗干燥性（desiccation resistance）的表型可塑性（phenotypic plasticity）——这是塑造果蝇属（Drosophila）物种及其他小型变温动物分布格局的关键性状。我们针对32个分布范围各异的果蝇物种展开研究，考察其通过涉及硬化（hardening）的表型可塑性提升抗干燥性的能力，并将这些响应与物种所处环境、系统发育（phylogeny）及基础抗性（basal resistance）建立关联。我们未发现支持季节性假说（seasonality hypothesis）的证据：硬化可塑性更强的物种，并未栖息于降水更高且降水季节波动更显著的环境中。随着基础抗性水平提升，物种通过表型可塑性产生响应的能力随之下降，这表明涉及硬化的塑性响应或受基础抗性的约束。基础抗干燥性与可塑性之间的进化权衡（trade-offs）并非在所有系统发育类群中普遍存在，而是仅集中于特定演化支（clades）内部。系统发育、环境条件以及权衡效应，均有助于解释抗干燥性表型可塑性的变异，但二者的关联方式较为复杂。这些研究结果表明，部分物种可通过塑性响应应对干旱期，而另一部分物种则不具备该能力；且这种能力在一定程度上取决于物种在系统发育中的位置，以及其基础抗性水平。