title: Demographic history of Oceania inferred from genome-wide data.
abstract: BACKGROUND
  The human history of Oceania comprises two extremes: the initial colonizations of Near Oceania, one of the oldest out-of-Africa migrations, and of Remote Oceania, the most recent expansion into unoccupied territories. Genetic studies, mostly using uniparentally inherited DNA, have shed some light on human origins in Oceania, particularly indicating that Polynesians are of mixed East Asian and Near Oceanian ancestry. Here, we use ∼1 million single nucleotide polymorphisms (SNPs) to investigate the demographic history of Oceania in a more detailed manner.
  
  
  RESULTS
  We developed a new approach to account for SNP ascertainment bias, used approximate Bayesian computation simulations to choose the best-fitting model of population history, and estimated demographic parameters. We find that the ancestors of Near Oceanians diverged from ancestral Eurasians ∼27 thousand years ago (kya), suggesting separate initial occupations of both territories. The genetic admixture in Polynesian history between East Asians (∼87%) and Near Oceanians (∼13%) occurred ∼3 kya, prior to the colonization of Polynesia. Fijians are of Polynesian (∼65%) and additional Near Oceanian (∼35%) ancestry not found in Polynesians, with this admixture occurring considerably after the initial settlement of Remote Oceania. Our data support a greater contribution of East Asian women than men in the admixture history of Remote Oceania and highlight population substructure in Polynesia and New Guinea.
  
  
  CONCLUSIONS
  Despite the inherent ascertainment bias, genome-wide SNP data provide new insights into the genetic history of Oceana. Our approach to correct for ascertainment bias and obtain reliable inferences concerning demographic history should prove useful in other such studies.
authors.affiliation: Cologne Center for Genomics, University of Cologne, D-50931 Cologne, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Wollstein
authors.forename: Oscar
authors.initials: O
authors.lastname: Lao
authors.forename: Christian
authors.initials: C
authors.lastname: Becker
authors.forename: Silke
authors.initials: S
authors.lastname: Brauer
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Trent
authors.forename: Peter
authors.initials: P
authors.lastname: Nürnberg
authors.forename: Mark
authors.initials: M
authors.lastname: Stoneking
authors.forename: Manfred
authors.initials: M
authors.lastname: Kayser
mesh_terms: D001499:Bayes Theorem; D002877:Chromosomes, Human / Q000737:chemistry; D004641:Emigration and Immigration; D015894:Genome, Human; D006579:Heterozygote; D006801:Humans; D015810:Linkage Disequilibrium; D020641:Polymorphism, Single Nucleotide; D011114:Polynesia; D011157:Population Dynamics; D025341:Principal Component Analysis