Narrow Domain Distribution Of Six Odontoid Toad High Genetic Variation Phenomenon Analysis

So far most studies on effect of narrow geographical range on genetic diversity use plants as research objects. The known research results from plants showed that geographical range plays an important role in shaping genetic characteristics of plant populations. Some studies showed lower levels of genetic diversity in species with narrow distributional ranges than their widespread sibling species due to genetic drift, bottleneck, isolation, inbreeding, low levels of gene flow, directional selection promoting adaptation to local environments. While other results showed narrow endemic species possess moderate to high levels of genetic variation. However very few animals are used to conduct the similar analysis.Genetic diversity and demographic history of the narrow endemic alpine stream frog Scutiger liupanensis from Liupanshan National Forest Park, central China, were estimated using cytochrome b on64individuals from5local populations. Both haplotype diversity (Hd) and nucleotide diversity (Pi) are very high. Phylogenetic analysis of the47haplotypes revealed four major phylogroups. AMOVA analysis suggested that most of the variation was attributed to within populations. SAMOVA analysis showed no phylogeographic structure. The results of neutral test, mismatch distribution analyses rejected a sudden demographic expansion.Scutiger liupanensis was described by Huang from Liupan Mountains. South Ningxia (Huang1985). It inhabits a very narrow mountain area. It could be found only in few alpine streams located in Jingyuan County of Ningxia at altitude ranged from1900m to2500m above the sea level. These localities include Fresh Water River (another name is Wild Lotus Valley). Cool Palace Gorge, Small South River and Double-Dragon River (Zhang et al.1998). Fortunately, we collected tadpoles of this species on Mount Xuanfengshan. Huating County, Gansu Province besides above localities, expanding the distribution range of this species southward by50km (Fig.1). However, we failed to find them elsewhere during extensive targeted searches along the whole Liupan Mountains, which suggests that the existence of this species resulted from long isolation and speciation rather than the remnant consequences of extensive anthropogenic changes. Scutiger liupanensis (Pelobatidae) is the species that inhabits the northernmost part of distribution region of the genus Scutiger. Assumedly, Scutiger expanded northward after the Quaternary glaciation and evolved S. liupanensis. S. liupanensis has two neighbour conspecies. they are S. boulengeri and S. ningshanensis. The nearest localities of S. boulengeri are Yuzhong County and Jone County. Gansu Province. Yuzhong is150km away from the locality of S. liupanensis, Jone270km away. The nearest locality of S. ningshanensis is Ninghan County, Shaanxi Province,250km away from the distribution region of S. liupanensis.The sympatric anura amphibians in the Liupan Mountain area include the Bufo melanostictus melanostictus Schneider (Bufonidae), Bufo mingshanicus Stejneger, Bufo reddei Strauch, Rana nigromaculata Hallowell, Rana chensinensis David.Based on the mtDNA cyt b, the present study aims to analyze the genetic diversity and demographical history in S. liupanensis, exploring the effect of narrow geographical range on shaping the genetic characteristics and demographical dynamics.