Data from: Genetic divergence is decoupled from ecological diversification in the Hawaiian Nesosydne planthoppers

Adaptive radiation involves ecological shifts coupled with isolation of gene pools. However, we know little about what drives the initial stages of divergence. We study a system in which ecological diversification is found within a chronologically well-defined geological matrix to provide insight into this enigmatic phase of radiation. We tested the hypothesis that a period of geographic isolation precedes ecological specialization in an adaptive radiation of host-specialized Hawaiian planthoppers. We examined population structure and history using mitochondrial and multiple independent microsatellite loci in a species whose geographic distribution on the island of Hawaii enabled us to observe the chronology of divergence in its very earliest stages. We found that genetic divergence is associated with geographic features but not different plant hosts and that divergence times are very recent and on the same timescales as the dynamic geology of the island. Our results suggest an important role for geography in the dynamics of the early stages of divergence.

适应辐射（adaptive radiation）指伴随基因库隔离的生态位分化过程。然而，目前学界对驱动物种分化初始阶段的核心机制仍知之甚少。本研究选取一套在年代界定清晰的地质背景下发生生态分化的研究体系，以期为解析这一尚不明晰的辐射演化阶段提供科学洞见。我们以寄主专化的夏威夷蜡蝉类群的适应辐射为研究对象，检验“地理隔离先于生态特化”这一研究假说。针对该类群中在夏威夷岛分布特征明确的物种，我们利用线粒体基因与多个独立微卫星位点分析其种群结构与演化历史，得以直接观测其分化初始阶段的时间进程。研究结果显示，遗传分化与地理特征显著相关，但与寄主植物种类差异并无关联；分化时间极为新近，且与该岛动态活跃的地质作用处于同一时间尺度。本研究结果表明，地理因素在物种分化早期的动态过程中发挥了重要作用。