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

Abstract

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.

Multilocus phylogeography of the brown-spotted pitviper Protobothrops mucrosquamatus (Reptilia: Serpentes: Viperidae) sheds a new light on the diversification pattern in Asia

“…Samples were obtained through fieldwork, or through tissue loans from colleagues or museums. Based on previous molecular studies on Asian pitvipers (Liu et al, 2012;Guo et al, 2016), several representatives of its closely related congeners P. maolanensis, P. tokarensis, and P. flavoviridis were also included, and P. flavoviridis was chosen as the outgroup.…”

“…jerdonii (Guo et al, 2011), T. albolabris (Zhu et al, 2016), and V. stejnegeri (Guo et al, 2016), but have not been detected in other widespread and generally co-distributed species in southern China such as D. acutus (Huang et al, 2007), G. brevicaudus (Ding et al, 2013), and N. atra (Lin et al, 2014). They are all presumably subject to the same or similar climatic oscillations and biogeographic scenarios; however, they display different population structure and genetic diversity.…”

“…Himalayan, Indo-Burman, and the Mountains of Southwest China (CEPF, 2017). This region, which exhibits extremely complex topography and varied climate, harbors rich biodiversity, and is an ideal setting for investigating species diversification and biogeographic pattern of organisms (Che et al, 2010;Zhou et al, 2013;Guo et al, 2011Guo et al, , 2016Zhu et al, 2016). Due to their limited dispersal ability and sensitivity to climatic fluctuations (being heterothermic), snakes are an ideal model to examine the influence of climate oscillations and geological events on population structure, genetic diversity, and evolutionary history (Guiher and Burbrink, 2008;Ursenbacher et al, 2008;Pyron and Burbrink, 2009;Fijarczyk et al, 2011;Zhu et al, 2016).…”

“…Due to their limited dispersal ability and sensitivity to climatic fluctuations (being heterothermic), snakes are an ideal model to examine the influence of climate oscillations and geological events on population structure, genetic diversity, and evolutionary history (Guiher and Burbrink, 2008;Ursenbacher et al, 2008;Pyron and Burbrink, 2009;Fijarczyk et al, 2011;Zhu et al, 2016). An increasing, but still limited, number of studies on snakes inhabiting this (or neighbouring) region have attempted to track species evolutionary history (Huang et al, 2007;Ding et al, 2011;Lin et al, 2014;Guo et al, 2011Guo et al, , 2016Zhu et al, 2016), and include Deinagkistrodon acutus, Gloydius brevicaudus, Protobothrops jerdonii, Naja atra, Viridovipera stejnegeri, and Trimeresurus albolabris (Huang et al, 2007;Ding et al, 2011;Lin et al, 2014;Guo et al, 2011Guo et al, , 2016Zhu et al, 2016). All studies have indicated that these snakes experienced population expansion in some or all mtDNA lineages defined, and the five pitvipers consistently showed an east-west division, or longitudinal divergence, while latitudinal divergence was also detected in T. albolabris and V. stejnegeri.…”

“…mucrosquamatus is a monotypic species and no significantly morphological differences have been detected among populations (Zhong et al, 2017). However, whether P. mucrosquamatus displays distinct genetic structure similar to co-distributed pitvipers (e.g., P. jerdonii and V. stejnegeri) (Guo et al, 2011(Guo et al, , 2016, or not as in the case of N.…”