title: Postglacial colonization of the Tibetan plateau inferred from the matrilineal genetic structure of the endemic red-necked snow finch, Pyrgilauda ruficollis.
abstract: Most phylogeographical studies of postglacial colonization focus on high latitude locations in the Northern Hemisphere. Here, we studied the phylogeographical structure of the red-necked snow finch Pyrgilauda ruficollis, an endemic species of the Tibetan plateau. We analysed 879 base pairs (bp) of the mitochondrial cytochrome b gene and 529 bp of the control region in 41 birds from four regional groups separated by mountain ranges. We detected 34 haplotypes, 31 of which occurred in a single individual and only three of which were shared among sampling sites within regional groups or among regional groups. Haplotype diversity was high (h = 0.94); nucleotide diversity was low (eth = 0.00415) and genetic differentiation was virtually non-existent. Analyses of mismatch distributions and geographically nested clades yielded results consistent with contiguous range expansion, and the expansion times were estimated as 0.07-0.19 million years ago (Ma). Our results suggest that P. ruficollis colonized the Tibetan plateau after the extensive glacial period (0.5-0.175 Ma), expanding from the eastern margin towards the inner plateau. Thus, in contrast to many of the post-glacial phylogeographical structures known at high latitudes, this colonization occurred without matrilineal population structuring. This might be due to the short glacial cycles typical of the Tibetan plateau, adaptation of P. ruficollis to cold conditions, or refugia and colonized habitat being semicontinuous and thus promoting population mixing.
authors.affiliation: Institute of Zoology, Chinese Academy of Sciences, 25 Beisihuanxi Road, Haidian District, Beijing 100080, People's Republic of China. quyh@panda.ioz.ac.cn
authors.forename: Yan Hua
authors.initials: YH
authors.lastname: Qu
authors.forename: Per G P
authors.initials: PG
authors.lastname: Ericson
authors.forename: Fu Min
authors.initials: FM
authors.lastname: Lei
authors.forename: Shou Hsien
authors.initials: SH
authors.lastname: Li
mesh_terms: D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics; D003710:Demography; D019143:Evolution, Molecular; D046369:Finches / Q000235:genetics* / Q000502:physiology; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D006239:Haplotypes / Q000235:genetics; D016013:Likelihood Functions; D008390:Markov Chains; D008969:Molecular Sequence Data; D009010:Monte Carlo Method; D010802:Phylogeny; D011157:Population Dynamics; D017422:Sequence Analysis, DNA; D018609:Tibet
chemical_list: D017931:DNA Primers; D004272:DNA, Mitochondrial