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The genetic structure of Pacific Islanders.

Friedlaender JS, Friedlaender FR, Reed FA, Kidd KK, Kidd JR, Chambers GK, Lea RA, Loo JH, Koki G, Hodgson JA, Merriwether DA, Weber JL - PLoS Genet. (2008)

Bottom Line: As a result, population relationships there have been open to debate.Neither of these provided an unequivocal signal of phylogenetic relations or population intermixture proportions in the Pacific.Our analysis indicates the ancestors of Polynesians moved through Melanesia relatively rapidly and only intermixed to a very modest degree with the indigenous populations there.

View Article: PubMed Central - PubMed

Affiliation: Anthropology Department, Temple University, Philadelphia, Pennsylvania, United States of America. jfriedla@temple.edu

ABSTRACT
Human genetic diversity in the Pacific has not been adequately sampled, particularly in Melanesia. As a result, population relationships there have been open to debate. A genome scan of autosomal markers (687 microsatellites and 203 insertions/deletions) on 952 individuals from 41 Pacific populations now provides the basis for understanding the remarkable nature of Melanesian variation, and for a more accurate comparison of these Pacific populations with previously studied groups from other regions. It also shows how textured human population variation can be in particular circumstances. Genetic diversity within individual Pacific populations is shown to be very low, while differentiation among Melanesian groups is high. Melanesian differentiation varies not only between islands, but also by island size and topographical complexity. The greatest distinctions are among the isolated groups in large island interiors, which are also the most internally homogeneous. The pattern loosely tracks language distinctions. Papuan-speaking groups are the most differentiated, and Austronesian or Oceanic-speaking groups, which tend to live along the coastlines, are more intermixed. A small "Austronesian" genetic signature (always <20%) was detected in less than half the Melanesian groups that speak Austronesian languages, and is entirely lacking in Papuan-speaking groups. Although the Polynesians are also distinctive, they tend to cluster with Micronesians, Taiwan Aborigines, and East Asians, and not Melanesians. These findings contribute to a resolution to the debates over Polynesian origins and their past interactions with Melanesians. With regard to genetics, the earlier studies had heavily relied on the evidence from single locus mitochondrial DNA or Y chromosome variation. Neither of these provided an unequivocal signal of phylogenetic relations or population intermixture proportions in the Pacific. Our analysis indicates the ancestors of Polynesians moved through Melanesia relatively rapidly and only intermixed to a very modest degree with the indigenous populations there.

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Population DiversityValues of θ̂ for the HGDP-CEPH and Pacific datasets, for 687 microsatellites. Populations are ordered by their declining values of θ̂, but systematic regional distinctions are indicated by vertical lines. Conglomerate groups tend to have higher values than nearby populations (Bantu South, Sepik, Highlands, Micronesia, Samoa, and Columbia). Papuan-speaking groups are in bold italics; the Melanesian inland/shore distinction is indicated by the two shades of orange. Abbreviated names are spelled out in Table S1.
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pgen-0040019-g002: Population DiversityValues of θ̂ for the HGDP-CEPH and Pacific datasets, for 687 microsatellites. Populations are ordered by their declining values of θ̂, but systematic regional distinctions are indicated by vertical lines. Conglomerate groups tend to have higher values than nearby populations (Bantu South, Sepik, Highlands, Micronesia, Samoa, and Columbia). Papuan-speaking groups are in bold italics; the Melanesian inland/shore distinction is indicated by the two shades of orange. Abbreviated names are spelled out in Table S1.

Mentions: Figure 2 shows the estimated values of θ (θ̂) calculated from expected heterozygosity (He) arranged from highest to lowest values, combining our Pacific populations and the HGDP-CEPH global set (the values of θ̂, He, and the average number of alleles per locus are given in Table S1). From Ohta and Kimura [25], under a stepwise model, the expected relationship between θ and heterozygosity (H) is


The genetic structure of Pacific Islanders.

Friedlaender JS, Friedlaender FR, Reed FA, Kidd KK, Kidd JR, Chambers GK, Lea RA, Loo JH, Koki G, Hodgson JA, Merriwether DA, Weber JL - PLoS Genet. (2008)

Population DiversityValues of θ̂ for the HGDP-CEPH and Pacific datasets, for 687 microsatellites. Populations are ordered by their declining values of θ̂, but systematic regional distinctions are indicated by vertical lines. Conglomerate groups tend to have higher values than nearby populations (Bantu South, Sepik, Highlands, Micronesia, Samoa, and Columbia). Papuan-speaking groups are in bold italics; the Melanesian inland/shore distinction is indicated by the two shades of orange. Abbreviated names are spelled out in Table S1.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2211537&req=5

pgen-0040019-g002: Population DiversityValues of θ̂ for the HGDP-CEPH and Pacific datasets, for 687 microsatellites. Populations are ordered by their declining values of θ̂, but systematic regional distinctions are indicated by vertical lines. Conglomerate groups tend to have higher values than nearby populations (Bantu South, Sepik, Highlands, Micronesia, Samoa, and Columbia). Papuan-speaking groups are in bold italics; the Melanesian inland/shore distinction is indicated by the two shades of orange. Abbreviated names are spelled out in Table S1.
Mentions: Figure 2 shows the estimated values of θ (θ̂) calculated from expected heterozygosity (He) arranged from highest to lowest values, combining our Pacific populations and the HGDP-CEPH global set (the values of θ̂, He, and the average number of alleles per locus are given in Table S1). From Ohta and Kimura [25], under a stepwise model, the expected relationship between θ and heterozygosity (H) is

Bottom Line: As a result, population relationships there have been open to debate.Neither of these provided an unequivocal signal of phylogenetic relations or population intermixture proportions in the Pacific.Our analysis indicates the ancestors of Polynesians moved through Melanesia relatively rapidly and only intermixed to a very modest degree with the indigenous populations there.

View Article: PubMed Central - PubMed

Affiliation: Anthropology Department, Temple University, Philadelphia, Pennsylvania, United States of America. jfriedla@temple.edu

ABSTRACT
Human genetic diversity in the Pacific has not been adequately sampled, particularly in Melanesia. As a result, population relationships there have been open to debate. A genome scan of autosomal markers (687 microsatellites and 203 insertions/deletions) on 952 individuals from 41 Pacific populations now provides the basis for understanding the remarkable nature of Melanesian variation, and for a more accurate comparison of these Pacific populations with previously studied groups from other regions. It also shows how textured human population variation can be in particular circumstances. Genetic diversity within individual Pacific populations is shown to be very low, while differentiation among Melanesian groups is high. Melanesian differentiation varies not only between islands, but also by island size and topographical complexity. The greatest distinctions are among the isolated groups in large island interiors, which are also the most internally homogeneous. The pattern loosely tracks language distinctions. Papuan-speaking groups are the most differentiated, and Austronesian or Oceanic-speaking groups, which tend to live along the coastlines, are more intermixed. A small "Austronesian" genetic signature (always <20%) was detected in less than half the Melanesian groups that speak Austronesian languages, and is entirely lacking in Papuan-speaking groups. Although the Polynesians are also distinctive, they tend to cluster with Micronesians, Taiwan Aborigines, and East Asians, and not Melanesians. These findings contribute to a resolution to the debates over Polynesian origins and their past interactions with Melanesians. With regard to genetics, the earlier studies had heavily relied on the evidence from single locus mitochondrial DNA or Y chromosome variation. Neither of these provided an unequivocal signal of phylogenetic relations or population intermixture proportions in the Pacific. Our analysis indicates the ancestors of Polynesians moved through Melanesia relatively rapidly and only intermixed to a very modest degree with the indigenous populations there.

Show MeSH
Related in: MedlinePlus