Marske Katharine A, Thomaz Andréa T, Knowles L Lacey
Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, OK, USA.
Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA.
Mol Ecol. 2020 Dec;29(23):4665-4679. doi: 10.1111/mec.15655. Epub 2020 Oct 24.
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.
系统发育地理学一致性，或共分布物种间系统发育地理模式的共享，表明对地形或气候历史有相似的响应。虽然通常会比较谱系间间断的方向和时间，但单个谱系所占据区域内的空间动态为比较对过去事件的响应提供了第二个机会。在地形复杂且有冰川历史的环境中，如新西兰南岛，地理嵌套比较可以识别导致区域基因组簇之间和内部系统发育地理学一致性的过程。在这里，我们使用单核苷酸多态性（通过ddRADseq获得）对两种共分布的森林甲虫物种，即唇拟隐翅虫（拟隐翅虫科）和盾短跗隐翅虫（隐翅虫科）进行研究，以评估气候变化和地形在两个嵌套空间尺度上塑造系统发育地理学一致性的作用：物种是否在相同的地理屏障上分歧，且分歧时间相似？在这些间断所界定的区域内，物种是否共享相似的定向扩张或距离隔离的空间动态？我们发现，被最强扩散屏障（即南阿尔卑斯山）分隔的区域之间，系统发育地理间断的一致性更高。然而，这些共享的间断并不表明它们所界定区域内的空间动态相同，物种间最相似的空间动态出现在历史气候稳定性梯度最强的区域内。我们的结果表明，传统上通过谱系更替检测到的不一致并不排除共享历史的可能性，一致性的存在和类型的变化可能为了解地质动态区域系统发育地理模式形成的不同过程提供见解。
