Data from: Evolution of camouflage drives rapid ecological change in an insect community

Evolutionary change in individual species has been hypothesized to have far-reaching consequences for entire ecological communities, and such coupling of ecological and evolutionary dynamics (“eco-evolutionary dynamics”) has been demonstrated for a variety systems. However, the relative importance of evolutionary dynamics for ecological dynamics remains unclear. Here, we investigate how spatial patterns of local adaptation in the stick insect Timema cristinae, driven by natural selection, gene flow and founder effects, structure metapopulations, communities, and multitrophic interactions.

Observations of a wild T. cristinae metapopulation show that locally imperfect camouflage reduces population size, and that the effect of such maladaptation is comparable to the effects of more traditional ecological factors, including habitat patch size and host-plant species identity. Field manipulations of local adaptation and bird predation support the hypothesis that maladaptation reduces population size through an increase in bird predation. Furthermore, these field experiments show that maladaptation in T. cristinae and consequent increase in bird predation reduce the pooled abundance and species richness of the co-occurring arthropod community, and ultimately cascade to decrease herbivory on host plants. An eco-evolutionary model of the observational data demonstrates that the demographic cost of maladaptation decreases habitat patch occupancy by T. cristinae but enhances metapopulation-level adaptation.

The results demonstrate a pervasive effect of ongoing evolution in a spatial context on population and community dynamics. The eco-evolutionary model generates testable predictions about the influence of the spatial structure of the patch network on the abundance and adaptive camouflage evolution.

单一物种的演化改变曾被假说认为会对整个生态群落产生深远影响，而生态动力学与演化动力学的这种耦合（即“生态-演化动力学（eco-evolutionary dynamics）”）已在多种系统中得到证实。然而，演化动力学对于生态动力学的相对重要性仍不明确。本研究针对由自然选择、基因流与奠基者效应驱动的克里斯娜竹节虫（Timema cristinae）的局域适应空间格局，探讨其如何调控集合种群、群落以及多营养级互作的结构。

对野生克里斯娜竹节虫集合种群的野外观测显示，局域不完全的伪装会降低种群规模，且这种适应不良的影响程度可与栖息地斑块面积、寄主植物物种身份等经典生态因子的效应相匹敌。针对局域适应与鸟类捕食的野外操控实验，验证了“适应不良通过提升鸟类捕食压力降低种群规模”这一假说。此外，这些野外实验还表明，克里斯娜竹节虫的适应不良及其伴随的鸟类捕食压力上升，会降低共现节肢动物群落的总丰度与物种丰富度，并最终产生级联效应，削弱寄主植物上的植食作用。

基于观测数据构建的生态-演化模型表明，适应不良带来的种群统计代价，会降低克里斯娜竹节虫对栖息地斑块的占据率，但却能提升集合种群层面的适应能力。本研究结果证实，空间背景下持续进行的演化过程，会对种群与群落动力学产生广泛且深远的影响。该生态-演化模型针对斑块网络的空间结构对共现节肢动物群落丰度以及适应性伪装演化的影响，生成了可验证的预测。