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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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Populations Included in This Study(A) HGDP-CEPH population locations. The two Pacific groups are boxed.(B) Pacific population locations. Our population samples are blue; the 2 HGDP-CEPH Melanesian “Oceanic” groups are red.
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pgen-0040019-g001: Populations Included in This Study(A) HGDP-CEPH population locations. The two Pacific groups are boxed.(B) Pacific population locations. Our population samples are blue; the 2 HGDP-CEPH Melanesian “Oceanic” groups are red.

Mentions: The populations in New Guinea and the islands immediately to the east (the Bismarck and Solomons archipelagos) are well-known for their great diversity in cultures, languages, and genetics, which by a number of measures is unsurpassed for a region of this size [1]. This area is referred to as Near Oceania, as opposed to the islands farther out in the Pacific, known as Remote Oceania [2] (see Figure 1). For simplicity, we refer only to the peoples of Near Oceania as “Melanesians,” although this term ordinarily encompasses additional groups to the east as far as Fiji, who are not covered in this study. Major parts of Near Oceania were settled from Southeast Asia early in modern human prehistory, between ∼50,000 and ∼30,000 years before present (YBP) [3–5]. Populations were relatively isolated at this edge of the human species range for the following 25,000 years. The early settlers in Near Oceania were very small groups of hunter-gatherers. For example, New Ireland, which is more than 300 km long, is estimated to have had a pre-Neolithic carrying capacity of ∼1,200 people or fewer [6]. There is evidence of sporadic, modest contact between New Guinea and the Bismarcks from 22,000 YBP, and with Bougainville/Buka in the Solomons only from ∼3,300 years ago [3,7].


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)

Populations Included in This Study(A) HGDP-CEPH population locations. The two Pacific groups are boxed.(B) Pacific population locations. Our population samples are blue; the 2 HGDP-CEPH Melanesian “Oceanic” groups are red.
© Copyright Policy
Related In: Results  -  Collection

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

pgen-0040019-g001: Populations Included in This Study(A) HGDP-CEPH population locations. The two Pacific groups are boxed.(B) Pacific population locations. Our population samples are blue; the 2 HGDP-CEPH Melanesian “Oceanic” groups are red.
Mentions: The populations in New Guinea and the islands immediately to the east (the Bismarck and Solomons archipelagos) are well-known for their great diversity in cultures, languages, and genetics, which by a number of measures is unsurpassed for a region of this size [1]. This area is referred to as Near Oceania, as opposed to the islands farther out in the Pacific, known as Remote Oceania [2] (see Figure 1). For simplicity, we refer only to the peoples of Near Oceania as “Melanesians,” although this term ordinarily encompasses additional groups to the east as far as Fiji, who are not covered in this study. Major parts of Near Oceania were settled from Southeast Asia early in modern human prehistory, between ∼50,000 and ∼30,000 years before present (YBP) [3–5]. Populations were relatively isolated at this edge of the human species range for the following 25,000 years. The early settlers in Near Oceania were very small groups of hunter-gatherers. For example, New Ireland, which is more than 300 km long, is estimated to have had a pre-Neolithic carrying capacity of ∼1,200 people or fewer [6]. There is evidence of sporadic, modest contact between New Guinea and the Bismarcks from 22,000 YBP, and with Bougainville/Buka in the Solomons only from ∼3,300 years ago [3,7].

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