title: Melanesian origin of Polynesian Y chromosomes.
abstract: BACKGROUND
  Two competing hypotheses for the origins of Polynesians are the 'express-train' model, which supposes a recent and rapid expansion of Polynesian ancestors from Asia/Taiwan via coastal and island Melanesia, and the 'entangled-bank' model, which supposes a long history of cultural and genetic interactions among Southeast Asians, Melanesians and Polynesians. Most genetic data, especially analyses of mitochondrial DNA (mtDNA) variation, support the express-train model, as does linguistic and archaeological evidence. Here, we used Y-chromosome polymorphisms to investigate the origins of Polynesians.
  
  
  RESULTS
  We analysed eight single nucleotide polymorphisms (SNPs) and seven short tandem repeat (STR) loci on the Y chromosome in 28 Cook Islanders from Polynesia and 583 males from 17 Melanesian, Asian and Australian populations. We found that all Polynesians belong to just three Y-chromosome haplotypes, as defined by unique event polymorphisms. The major Y haplotype in Polynesians (82% frequency) was restricted to Melanesia and eastern Indonesia and most probably arose in Melanesia. Coalescence analysis of associated Y-STR haplotypes showed evidence of a population expansion in Polynesians, beginning about 2,200 years ago. The other two Polynesian Y haplotypes were widespread in Asia but were also found in Melanesia.
  
  
  CONCLUSIONS
  All Polynesian Y chromosomes can be traced back to Melanesia, although some of these Y-chromosome types originated in Asia. Together with other genetic and cultural evidence, we propose a new model of Polynesian origins that we call the 'slow-boat' model: Polynesian ancestors did originate from Asia/Taiwan but did not move rapidly through Melanesia; rather, they interacted with and mixed extensively with Melanesians, leaving behind their genes and incorporating many Melanesian genes before colonising the Pacific.
authors.affiliation: Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany. kayser@eva.mpg.de
authors.forename: M
authors.initials: M
authors.lastname: Kayser
authors.forename: S
authors.initials: S
authors.lastname: Brauer
authors.forename: G
authors.initials: G
authors.lastname: Weiss
authors.forename: P A
authors.initials: PA
authors.lastname: Underhill
authors.forename: L
authors.initials: L
authors.lastname: Roewer
authors.forename: W
authors.initials: W
authors.lastname: Schiefenhövel
authors.forename: M
authors.initials: M
authors.lastname: Stoneking
mesh_terms: D001208:Asia / Q000208:ethnology; D002874:Chromosome Mapping; D004272:DNA, Mitochondrial / Q000235:genetics*; D005843:Geography; D006239:Haplotypes; D006801:Humans; D007214:Indonesia / Q000208:ethnology; D008297:Male; D008542:Melanesia; D011114:Polynesia / Q000208:ethnology; D044469:Racial Groups / Q000235:genetics*; D013624:Taiwan / Q000208:ethnology; D014998:Y Chromosome
chemical_list: D004272:DNA, Mitochondrial