Integrating phylogenomic and morphological data to assess candidate species-delimitation models in brown and red-bellied snakes (Storeria)

Systematics at the species level is still marked by theoretical and empirical tensions amongst the desires to identify geographical lineages, delimit species, and estimate their relationships. These goals are often confounded because each relies, at least to some extent, on the others being known. However, recently developed methods can simultaneously address all three. Furthermore, next-generation genomic sequencing allows us to generate large-scale molecular data sets to examine variation within species at a fine scale. Finally, a renaissance in morphological species validation allows us to integrate historical species definitions with coalescent models for species delimitation. Here, we investigate the applicability of these methods in an empirical case, in the Nearctic snake genus Storeria. Integrating trait data into species delimitation reduces the number of species delimited from molecular data alone. Whereas molecular data support eight distinct species-level lineages, including...

物种级别的系统分类学（Systematics）仍存在理论与实证层面的张力：学界在识别地理支系、界定物种以及估算物种亲缘关系这三项研究目标之间难以兼顾。这些目标往往彼此掣肘，因为任一目标的达成，都至少在一定程度上依赖于其余目标的相关研究成果已被探明。不过，近年开发的研究方法可同时兼顾这三项任务。此外，下一代基因组测序（next-generation genomic sequencing）技术可助力生成大规模分子数据集，以精细尺度解析物种内部的遗传变异。最后，形态学物种验证领域的复兴，使得我们能够将历史物种界定标准与用于物种界定的溯和模型（coalescent models）相结合。本研究以新北区（Nearctic）食卵蛇属（Storeria）为实证案例，探究上述方法的适用性。将性状数据纳入物种界定流程后，仅基于分子数据所界定的物种数量有所减少。尽管分子数据支持存在8个独立的物种级支系，包括……