Data from: Interglacial genetic diversification of Moussonia deppeana (Gesneriaceae), a hummingbird-pollinated, cloud forest shrub in northern Mesoamerica

Recent empirical work on cloud forest-adapted species supports the role of both old divergences across major geographic areas and more recent divergences attributed to Pleistocene climate changes. The shrub Moussonia deppeana is distributed in northern Mesoamerica, with geographically disjunct populations. Based on sampling throughout the species range and employing plastid and nuclear markers, we (i) test whether the fragmented distribution is correlated with main evolutionary lineages, (ii) reconstruct its phylogeographic history to infer the history of cloud forest in northern Mesoamerica, and (iii) evaluate a set of refugia/vicariance scenarios for the region and demographic patterns of the populations whose ranges expanded and tracked cloud forest conditions during the Last Glacial Maximum. We found a deep evolutionary split in M. deppeana about 6–3 Ma, which could be consistent with a Pliocene divergence. Comparison of variation in plastid and nuclear markers revealed several lineages mostly congruent with their isolated geographic distribution, and restricted gene flow among groups. Results of species distribution modelling and coalescent simulations fit a model of multiple refugia diverging during interglacial cycles. The demographic history of M. deppeana is not consistent with an expanding-contracting cloud forest archipelago model during the Last Glacial Maximum. Instead, our data suggest that populations persisted across the geographic range throughout the glacial cycles, and experienced isolation and divergence during interglacial periods.

针对适应云雾林（cloud forest）的物种的近期实证研究表明，大型地理区域间的古老分化与更新世（Pleistocene）气候变化驱动的晚近分化，均在物种演化进程中发挥了关键作用。灌木德氏毛森花（Moussonia deppeana）分布于中美洲北部，其种群呈地理间断分布格局。本研究基于该物种全分布区的采样，并运用质体标记（plastid marker）与核标记（nuclear marker），开展了三项研究内容：(i) 检验其破碎化分布是否与主要演化支系存在关联；(ii) 重建其系统地理学历史，以推演中美洲北部云雾林的演化历程；(iii) 评估该区域的一系列避难所/异域分化情景，以及末次盛冰期（Last Glacial Maximum）期间种群范围扩张并追踪云雾林生境的种群的历史动态模式。研究发现，德氏毛森花存在约600万至300万年前的深层演化分化，这一结果与上新世（Pliocene）分化事件的推测相符。对质体与核标记变异的比较分析显示，其多个演化支系的分布与各自的孤立地理格局基本吻合，且类群间的基因流受限。物种分布模型与溯祖模拟（coalescent simulation）的结果，支持“多个避难所在间冰期旋回中发生分化”的模型。德氏毛森花的种群历史动态模式，并不符合末次盛冰期期间云雾林群岛“扩张-收缩”的模型。与之相反，本研究数据表明，该物种的种群在整个冰期旋回中始终存续于其地理分布范围内，并在间冰期经历了种群隔离与分化。