title: The importance of Anatolian mountains as the cradle of global diversity in Arabis alpina, a key arctic-alpine species.
abstract: OBJECTIVE
  Anatolia is a biologically diverse, but phylogeographically under-explored region. It is described as either a centre of origin and long-term Pleistocene refugium, or as a centre for genetic amalgamation, fed from distinct neighbouring refugia. These contrasting hypotheses are tested through a global phylogeographic analysis of the arctic-alpine herb, Arabis alpina.
  
  
  METHODS
  Herbarium and field collections were used to sample comprehensively the entire global range, with special focus on Anatolia and Levant. Sequence variation in the chloroplast DNA trnL-trnF region was examined in 483 accessions. A haplotype genealogy was constructed and phylogeographic methods, demographic analysis and divergence time estimations were used to identify the centres of diversity and to infer colonization history.
  
  
  RESULTS
  Fifty-seven haplotypes were recovered, belonging to three haplogroups with non-overlapping distributions in (1) North America/Europe/northern Africa, (2) the Caucuses/Iranian Plateau/Arabian Peninsula and (3) Ethiopia-eastern Africa. All haplogroups occur within Anatolia, and all intermediate haplotypes linking the three haplogroups are endemic to central Anatolia and Levant, where haplotypic and nucleotide diversities exceeded all other regions. The local pattern of haplotype distribution strongly resembles the global pattern, and the haplotypes began to diverge approx. 2·7 Mya, coinciding with the climate cooling of the early Middle Pleistocene.
  
  
  CONCLUSIONS
  The phylogeographic structure of Arabis alpina is consistent with Anatolia being the cradle of origin for global genetic diversification. The highly structured landscape in combination with the Pleistocene climate fluctuations has created a network of mountain refugia and the accumulation of spatially arranged genotypes. This local Pleistocene population history has subsequently left a genetic imprint at the global scale, through four range expansions from the Anatolian diversity centre into Europe, the Near East, Arabia and Africa. Hence this study also illustrates the importance of sampling and scaling effects when translating global from local diversity patterns during phylogeographic analyses.
authors.affiliation: Department of Botany, The Natural History Museum, London SW7 5BD, UK. s.ansell@nhm.ac.uk
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Ansell
authors.forename: Hans K
authors.initials: HK
authors.lastname: Stenøien
authors.forename: Michael
authors.initials: M
authors.lastname: Grundmann
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Russell
authors.forename: Marcus A
authors.initials: MA
authors.lastname: Koch
authors.forename: Harald
authors.initials: H
authors.lastname: Schneider
authors.forename: Johannes C
authors.initials: JC
authors.lastname: Vogel
mesh_terms: D031214:Arabis / Q000235:genetics*; D018742:DNA, Chloroplast / Q000235:genetics; D017753:Ecosystem; D005061:Europe, Eastern; D019143:Evolution, Molecular; D014644:Genetic Variation; D005843:Geography; D006239:Haplotypes; D008877:Middle East; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA / Q000379:methods
chemical_list: D018742:DNA, Chloroplast