The hyperdiverse shrew genus Crocidura is one of few small mammal genera distributed across Sundaland and all of its boundaries. This represents a rare opportunity to study the geological history of this region through the evolutionary history of these shrews. We generate a phylogeny of all recognized species of Sundaland Crocidura and show that most speciation events took place during the Pleistocene, prior to the inundation of the Sunda Shelf around 400 000 years ago. We find east–west differentiation within two separate lineages on Borneo, and that the current taxonomy of its two endemic species does not reflect evolutionary history, but ecophenotypic variation of plastic traits related to elevation. Sulawesi shrews are monophyletic, with a single notable exception: the black-footed shrew (C. nigripes). We show that the black-footed shrew diverged from its relatives on Borneo recently, suggesting a human-assisted breach of Wallace’s line. Overall, the number of Crocidura species, especially on Borneo, probably remains an underestimate.

中文翻译：

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巽他鼩鼱（Eulipotyphla: Soricidae: Crocidura）的进化史，重点是婆罗洲

超级多样化的鼩鼱属 Crocidura 是分布在巽他兰及其所有边界的少数小型哺乳动物属之一。这代表了一个难得的机会，可以通过这些鼩鼱的进化史来研究该地区的地质历史。我们生成了所有公认的 Sundaland Crocidura 物种的系统发育，并表明大多数物种形成事件发生在更新世期间，在大约 40 万年前 Sunda 大陆架被淹没之前。我们在婆罗洲的两个独立谱系中发现了东西向分化，并且其两个特有物种的当前分类学并未反映进化历史，而是与海拔相关的塑料性状的生态表型变异。苏拉威西鼩鼱是单系的，只有一个值得注意的例外：黑足鼩鼱（C. nigripes）。我们发现黑足鼩鼱最近在婆罗洲与其亲属分道扬镳，这表明有人协助破坏了华莱士的路线。总体而言，Crocidura 物种的数量，尤其是在婆罗洲，可能仍然被低估了。