Asian Herpetological Research 2012, 3(2): 103–113 DOI: 10.3724/SP.J.1245.2012.00103 1. Introduction Quaternary climatic oscillations, punctuated by the Pleistocene glaciations, caused massive changes to the distribution of species in the Palaearctic realm (Hewitt, 2000; Schmitt, 2007). Recent research on Testing Hypotheses of Pleistocene Population History Using Coalescent Simulations: Refugial Isolation and Secondary Contact in Pseudepidalea raddei (Amphibia: Bufonidae) Bingjun DONG 1, 2 , Jing CHE 3 , Li DING 4 , Song HUANG 5 , Robert W. MURPHY 3, 6 , Ermi ZHAO 1, 4﹡ and Yaping ZHANG 3﹡ 1 Key Laboratory for Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu 610064, Sichuan, China 2 College of Chemistry and Life Sciences, Shenyang Normal University, Shenyang 110034, Liaoning, China 3 State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan, China 4 Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610064, Sichuan, China 5 Department of Biology, Huangshan University, Huangshan 245021, Anhui, China 6 Centre for Biodiversity and Conservation Biology, Department of Natural History, Royal Ontario Museum, 100 Queen’s Park, Toronto, ON, M5S 2C6, Canada ﹡ Corresponding authors: Prof. Yaping ZHANG, from Kunming Institute of Zoology, Chinese Academy of Sciences, China, with his research focusing on molecular evolution and genetics; and Prof. Ermi ZHAO, from Chengdu Institute of Biology, Chinese Academy of Sciences, China, with his research focusing on systematics and biogeography of amphibians and reptiles. E-mail: zhangyp1@263.net.cn (Yaping ZHANG); zem006@163.com (Ermi ZHAO) Received: 19 December 2011 Accepted: 28 March 2012 the microevolution of East Asian species has focused largely on the locations of refugia during the Pleistocene glaciations and dispersal routes during the postglacial period (Stöck et al ., 2006; Zhang et al ., 2008; Song et al., 2009; Ding et al., 2011). Much of the research has centered on tropical and subtropical species with geographic distributions that sometimes include the Palaearctic (Ding et al., 2011). Regardless, few detailed analyses of the populations from the Palearctic are available (Bauert et al., 1998). Widely distributed amphibians, being terrestrial poikilotherms with narrow habitat requirements and limited dispersal potentials, are useful model animals for Keywords Mongolian toad, Pleistocene refugia, phylogeography, biogeography Abstract The impact of the Quaternary glaciation on eastern China’s local fauna and lora is a topic of considerable interest. We use mitochondrial DNA (mtDNA) sequences and coalescent simulations to test two general biogeographic hypotheses related to the effect of the Pleistocene climatic luctuations on a widespread, eastern Chinese amphibian, Pseudepidalea raddei. Genealogical reconstructions are made and they detect major western and eastern lineages, which overlap in northwestern China, and possibly indicate the secondary contact of the populations that had entered the region from separate glacial refugia. Coalescent tests rejected alternative hypotheses of fragmentation of either a widespread ancestor or panmixia. The tests instead supported the hypothesis of geographic isolation and a remarkable dispersal pattern in one of the lineages. Though the Pleistocene climatic events are known to have affected the historical distributions and intra-speciic divergence of Chinese squamates, coalescent and non-coalescent demographic analyses indicated that the toad P. raddei was not adversely affected by glacial cycling. Presumably, an increase in the amount of climatically mild habitats in East Asia is due to the development of monsoons since the Mid-late Pleistocene is responsible for the relatively mild effects.