New species boundaries and the diversification history of marsh rat taxa clarify historical connections among ecologically and geographically distinct wetlands of South America

Taxa with broad geographic ranges that occur in different biomes and exhibit plastic morphological traits and/or adaptations to particular habitats make inferences about species boundaries especially challenging. However, technological and conceptual advances in the generation and analysis of genomic data have advanced the description of biodiversity. Here we address the outstanding questions about the delimitation of species in the genus Holochilus, a rodent with morphological specializations to wetland habitats, distributed through almost all the South America continent using genome‐wide SNP and morphometric data. Specifically, we apply a Bayesian model‐based species delimitation that revealed significant re-arrangements of species boundaries based on consideration of both morphometric and genomic data alone, or in combination. With these shifts in species boundaries, our results provide an insightful framework for inferring the group's biogeographic history and considering possible c...

地理分布范围广泛、栖息于不同生物群系，且表现出可塑性形态特征或对特定生境具有适应性的类群，会使得物种界限的推断工作极具挑战性。不过，基因组数据的产生与分析技术及概念层面的进步，推动了生物多样性研究的深化。本研究以几乎遍布整个南美洲大陆、具有特化适应湿地生境形态特征的啮齿类类群——原鼠属（Holochilus）为研究对象，针对其物种界定领域的悬而未决的问题展开探讨，研究整合了全基因组单核苷酸多态性（SNP）与形态测量数据。具体而言，本研究采用基于贝叶斯模型的物种界定方法，结果显示：仅单独使用形态测量数据、仅单独使用基因组数据，或是将二者结合分析时，均揭示出物种界限发生了显著重构。基于上述物种界限的重构结果，本研究为推断该类群的生物地理历史以及探讨潜在的……