Data from: Adaptation to an invasive host is driving the loss of a native ecotype

Locally adapted populations are often used as model systems for the early stages of ecological speciation, but most of these young divergent populations will never become complete species. The maintenance of local adaptation relies on the strength of natural selection overwhelming the homogenizing effects of gene flow; however, this balance may be readily upset in changing environments. Here I show that soapberry bugs (Jadera haematoloma) have lost adaptations to their native host plant (Cardiospermum corindum) and are regionally specializing on an invasive host (Koelreuteria elegans), collapsing a classic and well-documented example of local adaptation. All populations that were adapted to the native host-including those still found on that host today-are now better adapted to the invasive host in multiple phenotypes. Weak differentiation remains in two traits, suggesting that homogenization across the region is incomplete. This study highlights the potential for adaptation to invasive species to disrupt native communities by swamping adaptation to native conditions through maladaptive gene flow.本地适应种群（locally adapted populations）常被用作生态物种形成（ecological speciation）早期阶段的模式系统，但这类年轻的分化种群大多永远无法演化成为完全的物种。本地适应的维持依赖于自然选择（natural selection）的强度足以抵消基因流（gene flow）的均质化效应；然而，在环境变化的背景下，这一平衡极易被打破。 本研究显示，实蝽（soapberry bugs, *Jadera haematoloma*）已丧失对本土寄主植物（*Cardiospermum corindum*）的适应性，并在区域尺度上特化于入侵寄主（*Koelreuteria elegans*），致使一个经典且已被充分记录的本地适应案例出现瓦解。所有原本适应本土寄主的种群——包括现今仍栖息于该本土寄主上的种群——如今在多个表型（phenotypes）性状上均更适配入侵寄主。目前仅两个性状仍存在微弱分化，表明区域内的均质化过程尚未完成。本研究揭示了适应入侵物种的过程可能通过适应不良基因流（maladaptive gene flow）淹没本土环境下的适应性，进而破坏本土群落的潜在可能性。