Molecular Phylogeography Of The Godlewski's Bunting(Emberiza Godlewskii)

We used Mitochondrial DNA(partial cytb CO1 and CR)separate sequence and combined sequence data to resolve the molecular phylogeography,genetic diversification,demographic dynamics,origin and expansion of a Godlewski's Bunting(Emberiza godlewskii).Phylogenetic analyses were carried out using cytochrome b from 215 birds,Control Region fragment from 190 birds and three mitochondrial fragments from 190 birds sampled from 26 localities spanning the entire geographical range of the Godlewski's Bunting.We used rax ML and Mrbeyes to estimate the phylogenetic tree and Beast to calculate divergence times.Bayesian skyline plots were used to deduce potential historical changes in population size with Beast.We used Arlequin to assess AMOVA and historical population dynamics,and the origin and dispersal routes were calculated with genetic diversity and haplotype network.The main conclusions are as follows as follows.1.The mitochondrial DNA(mt DNA)gene tree,cytochrome b(cytb)gene tree and CR gene tree showed robustly support for two reciprocally monophyletic groups: a northern clade and a southern clade.The boundary between clade A and B is identical with the zoogeographical barrier between the Palaearctic and Sino-Japanese realms identified by Holt.2.There is no any subclade within clade A or B absolutely in accordance with extant subspecies,so it indicates the certain gene flows existed among geographic subspecies.We assessed the patchy terrain of bushy mountain slopes and montane steppe shaped by thick forest formed the habitats of northern and southern E.godlewskii and it can explain parapatric speciation in E.godlewskii.3.Diversification within Godlewski's Bunting between the northern and southern clade was relatively recent,probably within the last 2.6 million years during the Pliocene/Pleistocene boundary.Bayesian skyline plots and mismatch analysis suggested rapid population expansion in the northern and southern phylogroups in the Pleistocene.4.Nucleotide diversity(Pi)and Haplotype diversity(Hd)indicated that the northern group originated from the regions of DDS/XYH,then the partial ancestral population left from cradle for HJ/UR district northwestward expansion,while partial left from cradle for SX/HB/BJ district eastward expansion.The dispersal pathway to the northwest was from DDS/XYH to HJ/UR and to the east was from DDS/XYH to LAN/LHS/LPS/HLS,then to SX/HB/BJ.Regarding the southern clade,it originated from the regions of DQ/DR/LJ district,then the ancestral population left from cradle for KM/GZ/JZS/MLS district southeastward expansion,while partial left from cradle for BS,LZ,LS/XS district,and partial from cradle for NQ/CD/MK and SP district northwestward and northeastward expansion respectively.The spreading routes southeastward was from DQ/DR/LJ to KM/GZ/JZS/MLS,and the westward was from DQ/DR/LJ to BS,to LZ,to LS/XS,while northwestward and northeastward were from cradle to NQ/CD/MK and SP districts respectively.