title: Molecular evidence for Pleistocene refugia at the eastern edge of the Tibetan Plateau.
abstract: The role of the Quaternary ice ages in forming the contemporary genetic structure of populations has been well studied in a number of global regions. However, due to the different nature of glaciations and complex topography, their role in shaping eastern Eurasian genetic diversity, particular in areas surrounding the Tibetan Plateau have remained largely unstudied. We aimed to address this question by examining the genetic structure of an alpine forest-associated taxon, the blood pheasant (Ithaginis cruentus) to infer its phylogeographic history. We detected three phylogenetic lineages and four current population groups. By comparing molecular and palaeovegetation data, we found that major glaciations during the Pleistocene have had a major impact upon the current genetic diversity of this species. Coalescent simulations indicate that the populations retreated to different refugia during some glacial periods in the Pleistocene, but persisted through the last glacial maximum (LGM). The most significant recent population expansion was found to have occurred before the LGM, during which palaeoclimatic data indicate that the climate was both warmer and wetter than today. In contrast, during the LGM populations may have adopted an altitudinal shift strategy in order to track changes in alpine glaciers, exemplifying a general response for montane species in the region where alpine glaciations were not large enough to cause qualitative changes in vegetation. Although analysis based on a plumage related gene showed that divergent selection may have contributed to current patterns of intra-specific diversity, demographic isolation is inferred to have played a more dominant role.
authors.affiliation: Key Lab of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 1-5 Beichenxi Road, Chaoyang, Beijing 100101, China.
authors.forename: Xiangjiang
authors.initials: X
authors.lastname: Zhan
authors.forename: Yifang
authors.initials: Y
authors.lastname: Zheng
authors.forename: Fuwen
authors.initials: F
authors.lastname: Wei
authors.forename: Michael W
authors.initials: MW
authors.lastname: Bruford
authors.forename: Chenxi
authors.initials: C
authors.lastname: Jia
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000235:genetics; D002681:China; D002980:Climate; D004272:DNA, Mitochondrial / Q000235:genetics; D019143:Evolution, Molecular; D046094:Galliformes / Q000235:genetics*; D006239:Haplotypes; D046448:Ice Cover; D010802:Phylogeny; D058974:Phylogeography; D011157:Population Dynamics; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial