Data from: Complex longitudinal diversification across south China and Vietnam in Stejneger’s pitviper, Viridovipera stejnegeri (Schmidt, 1925) (Reptilia: Serpentes: Viperidae)

Viridovipera stejnegeri is one of the most common pitvipers in Asia, with a wide distribution in southern China and Vietnam. We investigated historical demography and explored how the environment and climatic factors have shaped genetic diversity and the evolutionary history of this venomous snake. A total of 171 samples from 47 localities were sequenced and analyzed for two mitochondrial gene fragments and three nuclear genes. Gene trees reveal the existence of two well-supported clades (Southwest China and Southeast China) with seven distinct and strongly supported, geographically structured subclades within V. stejnegeri. Estimation of divergence time and ancestral area suggests that V. stejnegeri originated at ~6.0 Ma in the late Miocene on the Yunnan-Guizhou Plateau. The estimated date of origin and divergence of the island populations of Taiwan and Hainan closely matches the geological origin of the both islands. The mtDNA gene tree reveals the presence of west-east diversification in V. stejnegeri populations. Complex orogenesis, heterogeneous habitats, as well as climate-mediated habitat differentiation including glacial cycles, all have influenced population structure and the distribution of this taxon. The validity of V. stejnegeri chenbihuii is questionable, and this subspecies most probably represents an invalid taxon.

杰氏原矛头蝮（Viridovipera stejnegeri）是亚洲分布最广的蝮亚科蛇类（pitvipers）之一，广泛栖息于中国南方及越南地区。本研究对其历史种群动态进行了系统调查，并解析了环境与气候因子如何塑造该有毒蛇类的遗传多样性与进化历史。研究共获取了来自47个采样点位的171份样本，对2个线粒体基因片段与3个核基因开展了测序与分析。基因树分析结果显示，杰氏原矛头蝮存在两个支持度极高的支系（分别对应中国西南与中国东南区域），其下还包含7个特征鲜明、支持度优异且具有清晰地理结构的亚支系。分化时间与祖先分布区重建结果表明，杰氏原矛头蝮起源于中新世晚期约6.0百万年前的云贵高原。台湾与海南岛屿种群的起源及分化时间估算值，与这两座岛屿的地质形成时间高度契合。线粒体基因树分析揭示，杰氏原矛头蝮种群存在显著的东西向分化格局。复杂的造山运动、异质性生境，以及气候介导的生境分化（包括冰期旋回），均对该物种种群结构与分布范围产生了重要影响。此外，杰氏原矛头蝮陈氏亚种（V. stejnegeri chenbihuii）的分类有效性存疑，该亚种大概率为无效分类单元。