East Asian origins of European holly oaks (Quercus section Ilex Loudon) via the Tibet-Himalaya
East Asian origins of European holly oaks (Quercus section Ilex Loudon) via the Tibet-Himalaya
复制标题
欧洲冬青橡树（栎科 Ilex Loudon）的东亚起源，途经西藏 — 喜马拉雅山
DOI：
10.1111/jbi.13654
复制
发表时间：
2019-07-10
影响因子：
3.9
通讯作者：
Yan, Meng-Xiao
中科院分区：
文献类型：
--
作者：
Jiang, Xiao-Long;Hipp, Andrew L.;Yan, Meng-Xiao
目标 许多亚热带生物表现出东亚-特提斯分离，即东亚和地中海之间的分布分裂。迄今为止，其根本机制和时间仍不清楚。对栎属 Ilex Loudon 的进化史进行了研究，以了解这种分离的关键驱动因素，该树种是东亚-特提斯分离谱系的代表，具有丰富而广泛的化石记录。地点欧亚大陆。方法利用RAD-seq重建栎科冬青属的系统发育。分歧时间是根据三个化石校准来估计的。在校准树上重建祖先范围和生态位，以推断地理分布和生态位转变的时间。通过拟合替代的多机制奥恩斯坦-乌伦贝克模型来估计生态空间的收敛性。使用几何形态测量方法评估了冬青科现存和化石类群之间的叶形状亲和力。结果冬青科中6个进化枝得到很好的解析。祖先范围重建和分歧时间测定表明，沿东特提斯海道广泛分布，最初分歧于始新世中期，所有六个分支都起源于中新世之前。该部分在始新世-渐新世边界处从东亚分散到地中海。在中新世中期或晚期，喜马拉雅分支出现了向更高海拔的转变。中新世早期的欧洲化石谱系在叶子形态上与后来的谱系不同，我们推断这是适应性分化或物种更替的结果。主要结论 栎属冬青树从始新世中期开始沿东特提斯海道广泛分布。欧洲冬青树起源于东亚祖先谱系，在渐新世通过西藏-喜马拉雅走廊传播到欧洲。喜马拉雅山边缘的低地和渐新世西藏山谷是这些物种的扩散路线。气候变化导致了中新世的灭绝和欧洲血统的局部适应。
Aim Many subtropical organisms exhibit an East Asian-Tethyan disjunction, a distribution split between East Asia and the Mediterranean. The underlying mechanisms and timing have remained unclear to date. The evolutionary history of Quercus section Ilex Loudon, a representative East Asian-Tethyan disjunct lineage with a rich and widespread fossil record, was investigated to understand the key drivers of this disjunction. Location Eurasia. Methods The phylogeny of Quercus section Ilex was reconstructed using RAD-seq. Divergence times were estimated based on three fossil calibrations. Ancestral range and niche were reconstructed on the calibrated tree to infer the timing of transitions in geographic distributions and niche. Convergence in ecological space was estimated by fitting alternative multiple-regime Ornstein-Uhlenbeck models. Leaf shape affinities among extant and fossil taxa of section Ilex were assessed using geometric morphometric approaches. Results Six clades were well resolved in section Ilex. Ancestral range reconstruction and divergence time dating suggest a wide distribution along the East Tethys seaway, with initial divergence at the mid-Eocene, and all six clades originating before the Miocene. The section dispersed from East Asia to the Mediterranean at the Eocene-Oligocene boundary. A shift toward higher elevations was detected in the Himalayan clade during the middle or late Miocene. European fossil lineages during the early Miocene differ in leaf morphology from later lineages, which we infer to be a consequence of adaptive differentiation or species turnover. Main conclusions Quercus section Ilex was widespread along the East Tethys seaway from the middle Eocene onward. The European holly oaks originated from an East Asian ancestral lineage that dispersed to Europe via the Tibet-Himalaya corridor in the Oligocene. Lowlands along the margins of the Himalayas and through an Oligocene Tibetan valley served as the dispersal route(s) for these species. Changing climates drove Miocene extinction and local adaptation of European lineages.