Data from: Spatial selection and local adaptation jointly shape life-history evolution during range expansion

In the context of climate change and species invasions, range shifts increasingly gain attention because the rates at which they occur in the Anthropocene induce rapid changes in biological assemblages. During range shifts, species experience multiple selection pressures. For poleward expansions in particular, it is difficult to interpret observed evolutionary dynamics because of the joint action of evolutionary processes related to spatial selection and to adaptation toward local climatic conditions. To disentangle the effects of these two processes, we integrated stochastic modeling and data from a common garden experiment, using the spider mite Tetranychus urticae as a model species. By linking the empirical data with those derived form a highly parameterized individual-based model, we infer that both spatial selection and local adaptation contributed to the observed latitudinal life-history divergence. Spatial selection best described variation in dispersal behavior, while variation in development was best explained by adaptation to the local climate. Divergence in life-history traits in species shifting poleward could consequently be jointly determined by contemporary evolutionary dynamics resulting from adaptation to the environmental gradient and from spatial selection. The integration of modeling with common garden experiments provides a powerful tool to study the contribution of these evolutionary processes on life-history evolution during range expansion.

在气候变化与物种入侵的研究背景下，物种分布范围转移（range shifts）日益受到关注——这是因为人类世（Anthropocene）中该过程的发生速率正快速改变着生物群落（biological assemblages）的组成结构。在物种分布范围转移过程中，物种会面临多重选择压力。尤其是向极扩张过程中，由于空间选择（spatial selection）与局地气候适应两类进化过程的共同作用，我们难以解读观测到的进化动态。为厘清这两类过程的作用效应，本研究以二斑叶螨（Tetranychus urticae）为模式物种，整合了随机建模（stochastic modeling）与同质园实验（common garden experiment）的数据。通过将实测数据与高参数化基于个体的模型（individual-based model）所生成的数据相耦合，我们推断空间选择与局地适应共同促成了观测到的纬度梯度生活史分化。空间选择可最佳解释扩散行为的变异，而发育速率的变异则可通过局地气候适应得到最优解释。因此，向极扩张物种的生活史性状（life-history traits）分化，可能由适应环境梯度与空间选择共同驱动的当代进化动态共同决定。将建模与同质园实验相结合，可为研究分布范围扩张过程中上述进化过程对生活史进化的贡献提供强有力的研究工具。