Phylogeographic concordance, or the sharing of phylogeographic patterns among codistributed species, suggests similar responses to topography or climatic history. While the orientation and timing of breaks between lineages are routinely compared, spatial dynamics within regions occupied by individual lineages provide a second opportunity for comparing responses to past events. In environments with complex topography and glacial history, such as New Zealand's South Island, geographically nested comparisons can identify the processes leading to phylogeographic concordance between and within regional genomic clusters. Here, we used single nucleotide polymorphisms (obtained via ddRADseq) for two codistributed forest beetle species, Agyrtodes labralis (Leiodidae) and Brachynopus scutellaris (Staphylinidae), to evaluate the role of climate change and topography in shaping phylogeographic concordance at two, nested spatial scales: do species diverge over the same geographic barriers, with similar divergence times? And within regions delimited by these breaks, do species share similar spatial dynamics of directional expansion or isolation‐by‐distance? We found greater congruence of phylogeographic breaks between regions divided by the strongest dispersal barriers (i.e., the Southern Alps). However, these shared breaks were not indicative of shared spatial dynamics within the regions they delimit, and the most similar spatial dynamics between species occurred within regions with the strongest gradients in historical climatic stability. Our results indicate that lack of concordance as traditionally detected by lineage turnover does not rule out the possibility of shared histories, and variation in the presence and type of concordance may provide insights into the different processes shaping phylogeographic patterns across geologically dynamic regions.

中文翻译：

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分散的障碍和机遇推动了新西兰南阿尔卑斯山的多种植物学一致性

地理学上的一致性，或共同分布的物种之间的地理学模式的共享，表明对地形或气候历史的类似反应。在常规比较谱系间断裂的方向和时机的同时，单个谱系占据的区域内的空间动力学为比较过去事件的响应提供了第二次机会。在具有复杂地形和冰川历史的环境中，例如新西兰的南岛，地理嵌套的比较可以确定导致区域基因组之间和内部的系统地理一致性的过程。在这里，我们对两个共同分布的森林甲虫物种Agyrtodes labralis（Leiodidae）和Brachynopus scutellaris使用单核苷酸多态性（通过ddRADseq获得）（Staphylinidae），以评估在两个嵌套的空间尺度上气候变化和地形在塑造地理学一致性方面的作用：物种是否在相同的地理障碍上发散，发散时间相似？在这些断裂所界定的区域内，物种是否共享相似的方向扩展或距离隔离空间动态？我们发现，区域之间被最强的扩散障碍（即南阿尔卑斯山）划分的系统地理断裂的一致性更高。但是，这些共享的断裂并不能表示它们所界定的区域内共享的空间动态，物种之间最相似的空间动态发生在历史气候稳定性梯度最大的区域内。