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 geographical 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 phylogeographical 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 geographical 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 geographical range throughout the glacial cycles, and experienced isolation and divergence during interglacial periods.

针对适应云雾林（cloud forest）物种的近期实证研究表明，主要地理区域间的古老分化与更新世（Pleistocene）气候变化引发的较新分化均发挥了重要作用。灌木芒森苣苔（Moussonia deppeana）分布于中美洲北部，其种群呈现地理间断分布格局。本研究基于该物种全分布范围的采样，并采用质体（plastid）标记与核（nuclear）标记，开展了三项研究：（i）检验其破碎化分布是否与主要演化支系相关联；（ii）重建其系统地理学（phylogeographical）历史，以推断中美洲北部云雾林的演化历史；（iii）评估该区域的一系列避难所/异域分化（vicariance）情景，以及在末次冰盛期（Last Glacial Maximum）期间种群范围扩张并追踪云雾林生境的种群动态模式。本研究发现芒森苣苔（Moussonia deppeana）在约600万至300万年前存在深度演化分化，这与上新世（Pliocene）的分化事件相符。对质体标记与核标记变异的比较分析显示，存在多个演化支系，其分布大多与各自孤立的地理范围相匹配，且类群间的基因流受限。物种分布模型与溯祖（coalescent）模拟的结果，与冰间期多重避难所发生分化的模型相符。芒森苣苔的种群动态历史并不符合末次冰盛期期间云雾林群岛“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循环中始终存续于其地理分布范围内，并在冰间期发生了隔离与分化。