Data from: Complex longitudinal diversification across South China and Vietnam in Stejneger's pit viper, Viridovipera stejnegeri (Schmidt, 1925) (Reptilia: Serpentes: Viperidae)

Viridovipera stejnegeri is one of the most common pit vipers 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 analysed 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 and 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）是亚洲最为常见的颊窝毒蛇（pit viper）之一，在中国南方及越南分布广泛。本研究对其历史种群动态展开调查，并探讨了环境与气候因子如何塑造了这一有毒蛇类的遗传多样性与演化历史。研究共采集了来自47个采样点的171份样本，对两段线粒体基因片段与三段核基因进行了测序与分析。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——中国西南支系与中国东南支系，且该物种内部包含7个特征显著、支持度强劲且具有明确地理结构的亚支系。分化时间与祖先分布区估算结果表明，杰氏原矛头蝮起源于中新世晚期的云贵高原，距今约600万年。台湾与海南岛屿种群的起源及分化时间，与这两座岛屿的地质形成时间高度吻合。线粒体基因树分析揭示，杰氏原矛头蝮种群存在东西向的分化格局。复杂的造山运动、异质化生境，以及冰期循环等气候介导的生境分化事件，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，该亚种大概率属于无效分类单元。