Why do pacific islanders look black
Our sampling strategy concentrated on Papuan-speaking populations and their immediate Oceanic-speaking neighbors from the islands immediately to the east of New Guinea, in what is called Northern Island Melanesia, consisting of the Bismarck and Solomon Archipelagos see Figure 1 B.
The three largest islands of the region were most intensively sampled—New Britain, New Ireland, and Bougainville—along with two nearby smaller islands New Hanover and Mussau. The details of the sample locations and language family affiliations are given in Table S1 and in the Methods section. Abbreviated names are spelled out in Table S1. In contrast, H asymptotically approaches a value of 1 as the effective population size increases.
The pattern of variation in Figure 2 is consistent with a series of successive founder effects that modern humans underwent in their expansions out of Africa also shown by [ 26 ]. The three non-Pacific groups in the range between 4. Columbia and other conglomerate groups made up of individuals from different populations e.
This combining of groups has caused inflated levels of diversity and effective population size estimates i. Ramachandran et al. We analyzed this correlation by major region, adding our expanded Pacific dataset. The results, shown in Figure 3 , show the extremely heterogeneous nature of the linear correlations and distributions from region to region. The sampled Melanesian populations were distributed across a comparatively small geographic area, but their range of pairwise F ST values was extremely large.
Only the Native American groups had an equivalent range of F ST values, but these were unreliable since there were only five American populations distributed across very large distances. Regional correlations between F ST and geographic distance for population pairs. In the current analysis based on microsatellites, the Americas had the highest among-population variation component, followed in order by Melanesia, Africa, Asia, and Europe.
As shown in Table 2 , the microsatellite variation in Melanesia New Guinea, New Britain, New Ireland, and Bougainville was apportioned first by language group and then by island. The variation among the three New Guinea samples in our series was lower, most likely because of their less rigorous population definitions see the Methods section for sampling details.
Apportioning the molecular variance by language group between Oceanic speaking and Papuan speaking populations only accounted for 0.
Since the two language categories are scattered across the islands, geography and intermixture will confound possible language effects. While the microsatellite variation among the Oceanic-speaking populations was significant, it was much greater among the Papuan-speaking populations many of which are located in the mountainous interiors of the larger islands.
This program identifies groups of individuals who have similar allele frequency profiles. The great advantage of this clustering approach is that it avoids a priori population classifications, and instead estimates the shared population ancestry of individuals based solely on their genotypes under an assumption of Hardy-Weinberg equilibrium and linkage equilibrium in ancestral populations.
It infers individual proportions of ancestry from K clusters, where K is specified in advance and corresponds to the number of posited ancestral populations; K can be varied across independent runs. Individuals can be assigned admixture estimates from multiple ancestral populations, with the admixture estimates summing to 1 across these population clusters. Each increase in K split a cluster that had been defined in an earlier run, and individuals from the same populations had very similar membership coefficients in the inferred clusters.
Each vertical line represents an individual. The colors represent the proportion of inferred ancestry from K ancestral populations. The longest branches belonged to the Native American and separate Melanesian groups. The Mamusi, who are Oceanic-speaking neighbors of the Ata, are the exception.
There is reason to suspect the Mamusi were originally a Papuan-speaking group perhaps Ata speakers who adopted an Oceanic language [ 34 ]. Papuan-speaking group names are in bold italics. Asterisks denote inland groups. Populations are arranged geographically, approximately from west to east.
Oceanic-speaking regions are stippled; the different Papuan-speaking regions have stripes or grid marks. Inland group locations are dark orange dots; shore group locations are light orange dots. Baining Mali and Baining Kaket are two dialects; elsewhere, the two Kaket-speaking locales are identified Rangulit and Malasait , as is Marabu Mali-speakers.
The Micronesians had low levels of inferred ancestry shared with populations in New Guinea, which is not far from Belau, where most of the Micronesian samples are from.
This relationship is echoed in mtDNA results as well [ 35 ]. The typical ancestral proportions by population for a majority rule run are given in Table S6. Neighboring groups tended to share similar profiles. Bougainville groups had two common cluster assignments, while there was only one common cluster in New Ireland. Figure 9 shows the unrooted neighbor-joining tree for the East Asia—Pacific populations from a pairwise F ST coancestry distance matrix for microsatellites the pairwise F ST values are in Table S7.
Bootstrap values for the branches, generated with the PHYLIP program from population allele frequencies for different trees, are indicated by branch thicknesses.
As shown, most of the trunk elements had high bootstrap values, as did a number of branches within Northern Island Melanesian groups. By contrast, the mainland East Asian group relationships were considerably more ambiguous, their branches were shorter, and only the Taiwan Aborigines had a strong internal branch.
These populations tend to be Papuan-speaking groups in island interiors. Neighbor-joining F ST -based tree for microsatellites from the Pacific, East Asia, and French populations, with the range of bootstrap values indicated by branch thicknesses. New Britain populations are circled. Papuan-speaking groups are in bold italics; inland groups in Melanesia have asterisks.
With our enlarged dataset and microsatellite coverage, we also compared patterns of private alleles and allele sharing between regions Table 3. We recovered Melanesian-specific alleles, which in raw numbers actually exceeded those for Africa.
Correcting for sample sizes, the rate of Melanesian-specific alleles was at the high end of the range for the major regions except for Africa. The number of alleles missing from only one continent, also given in Table 3 , shows the dramatic effect of genetic drift on the American populations.
The number of shared alleles between pairs of regions is shown in Table 4 , with the correction for sample sizes in Table 5. All non-African regions including Melanesia shared the most alleles with Africa, indicating they were primarily subsets of African diversity. Melanesia shared more alleles with East Asia than with any other non-African region, but they cannot simply be viewed as an extension or subset of East Asian diversity.
When Papuan and Oceanic speaking groups in Melanesia were analyzed separately, the Papuan-speaking groups showed greater isolation, as they shared fewer alleles with all other regions than did Oceanic speaking groups unpublished data.
Our study suggests that in the Pacific, and specifically in Near Oceania, there is only a modest association between language and genetic affiliation. The result suggests that Oceanic languages were adopted by many formerly Papuan-speaking groups, while at the same time there was little genetic influence or marital exchange.
At least in Near Oceania, rates of language borrowing and language adoption have been faster and more pervasive than rates of genetic admixture. The size of the differences among the populations would appear to equal or surpass those among populations across East Asia, Europe, or even Africa. However, the large Melanesian population distinctions are a direct consequence of their very low levels of internal variation or heterozygosity.
These low levels will directly inflate both the proportion of among group variation in AMOVA and also pairwise F ST genetic distances for a full discussion of this point, see especially [ 27 ] and also [ 26 , 37 ]. As population heterozygosities decrease, pairwise F ST s should increase because of this intrinsic mathematical relationship.
The genetic distances used were the set of pairwise F ST s involving Bantu South the population with the highest heterozygosity , highlighted in Table S4. Our Structure and tree analyses of the combined microsatellite datasets indicate that Melanesians are quite far removed from Africans, in spite of their superficial similarities in hair form and skin pigmentation [ 38 ].
There, they split from Eurasia before Asians and Native Americans [ 39 ]. This also differed from the result of a genome-wide SNP study [ 40 ] on a very small world-wide dataset. The extreme positioning of Melanesians in our tree was not due to our over sampling. Rather, our extensive coverage of Melanesian variation has enabled a clearer resolution of their relationships with populations outside the region.
The pattern of Near Oceanic diversity has been made clear. The AMOVA analysis of the microsatellites showed that the larger and more rugged the island, the greater the differentiation among populations. Genetic variation from one large Near Oceanic island to the next was also significant. While our coverage of microsatellite variation elsewhere in the Pacific was admittedly spotty, our data as well as other smaller scale microsatellite analyses [ 21 , 41 ] suggest that, excluding the large islands of Near Oceania, there is a gradual decline in variation as one moves from Asia eastward, and variation among populations in the Pacific otherwise is not nearly as great as that in the large islands of Near Oceania.
Our sample coverage and definition was less rigorous there, and we expect equivalent coverage in New Guinea would equal or surpass the divergence of our New Britain series. The biogeographic pattern of population divergences in Near Oceania is most likely attributable to the restricted marital migration distances that have been documented most clearly for inland Bougainville groups [ 42 ], as well as for some New Guinea highlands populations [ 43 ].
Few people in small inland communities traditionally married and established households more than 1—2 kilometers from their birthplaces, while marital migration distances tended to be longer among shoreline communities. Nettle has argued that in ecologically rich tropical regions such as Near Oceania, small populations easily became self-sufficient, which in turn encouraged isolation and discouraged exchange [ 44 , 45 ], causing the development of extreme diversity among populations in both language and genetics.
We suggest this was the underlying cause of the short marital migration distances among inland groups in Near Oceania, which in turn was responsible for the low population heterozygosities and resulting large genetic distinctions among groups [ 42 ]. Because they arrived first and came to occupy large island interiors, the Papuan-speaking groups are considerably more diverse than Oceanic-speaking groups, which tend, in large islands, to be arranged along the shorelines.
The prehistoric record suggests there was a gradual reduction after initial settlement in the size of foraging zones of formerly mobile groups, associated with the filling up of the landscape [3, p. In many ways, these patterns and dynamics parallel the biogeography of birds and ants in the same region, where dispersal abilities of different species have dictated their patterns of diversity, and dispersal tendencies have, in many cases, contracted in island interiors over time [ 46 , 47 ].
The Tolai of East New Britain, with an assignment profile similar to New Ireland groups, are known to have migrated from southern New Ireland over 1, years ago [ 42 ]. Although the two Baining groups of east New Britain formed a cluster of their own, it has been suggested from the mtDNA, Y, and X chromosome analyses that they have been separated by thousands of years [ 48 ] see their long branch lengths in Figure 9.
Also, the clustering of the Polynesians, Taiwan Aboriginals, and East Asians reflects ties older than 3, years. In the Pacific, the change in genetic clustering apparently has evolved over thousands of years, and in many cases tens of thousands. There were indications from the mtDNA, NRY, and certain autosomal microsatellites that in Remote Oceania, where islands are generally smaller in size, genetic variation among human groups is comparatively reduced, which is a contrast to Near Oceania [ 17 , 19 — 21 , 49 ].
At some point, prehistoric Oceanic mariners apparently became so accomplished that the inter-island water crossings in the central Pacific were often no more of an impediment to travel than the already occupied rugged terrain of the larger island interiors in the western Pacific.
In many areas, the ocean was transformed from a formidable barrier into a highway [ 50 , 51 ]. However, exactly where the relatively homogeneous Polynesians came from has remained controversial, and the number of proposed explanatory models for their origin form a continuum [ 49 , 52 ]. It suggests that, although there certainly must have been a series of introductions and influences from Asia into the Pacific over the millennia, no decipherable signal has survived that can be identified as specifically ancestral to Polynesians, because of the complexities of human interactions from the outset [ 54 ].
Proponents argue that tree-like representations of population or linguistic relationships cannot be expected to develop regularly and are likely to be entirely inappropriate representations of population relationships in many, if not all, instances, since they so often ignore interactions between neighboring groups.
Models at the other end of the continuum assume contemporary genetic as well as cultural similarities can carry a clear signal of past population relationships. It proposes a rapid movement of the ancestors of the Polynesians from the vicinity of Taiwan to the Central Pacific, without extensive contact with indigenous Near Oceanic populations along the way. At present, the state of the evidence for this association is as follows: a the precursor haplotype to B4a1a1 has been identified in Taiwan aboriginal populations [ 56 ]; b the final development of B4a1a1 with the key mutation at nucleotide site seems to have occurred in eastern Indonesia or Near Oceania [ 17 ]; c its frequency varies widely over Near and Remote Oceania before becoming ubiquitous in Central and Eastern Polynesian populations; d in Near Oceania, it is common along many Oceanic-speaking coastal groups, as well as a number of Papuan-speaking groups, especially in New Ireland and Bougainville [ 17 ]; and e its expansion dates are relatively recent, although old enough to suggest to some observers that it cannot be easily tied to the Polynesian expansion [ 17 , 56 ].
Because of their comprehensive nature, we believe the results of our autosomal microsatellite survey present a resolution to this issue with regard to human genetic relationships. The fact that the STRUCTURE cluster containing Micronesians, Samoans, and Maoris has a detectable signature only in Oceanic-speaking Melanesians and Taiwan Aborigines supports the position that an expansion of peoples from the general vicinity of Taiwan is primarily responsible for the ancestry of Remote Oceania, and that these people left a small but still identifiable signature in some Oceanic-speaking populations of Near Oceania.
Scenarios for different male and female dispersals have been proposed to reconcile the divergent mtDNA and NRY patterns in Oceania [ 35 , 59 ], but the autosomal microsatellite results should now serve as the primary reference. Although the Polynesians in our analysis were similar to Taiwan Aborigines and East Asians, they might be even closer to other populations not covered in our study, from Indonesia, the Philippines, or Southeast Asia.
While there is a substantial body of evidence that indicates Taiwan is the primary point of Austronesian dispersal [ 60 , 61 ], there are now also suggestions of the importance of Island Southeast Asia as well [ 62 , 63 ]. The ties of particular Near Oceanic populations to those regions also remain poorly understood, but should be resolved with additional sampling from these regions and similar analyses.
To revisit the questions posed at the beginning, we can provide answers as follows. Outside the Pacific, East Asian populations are apparently the closest but still very distant relatives of Melanesians.
Africans and Europeans are the most distant. The within-group diversity in Melanesian populations is consistently very low, which acts to exaggerate the considerable among-group distinctions there. This great diversity in such a small region makes comparisons of human population structure from continent to continent problematic. The diversity among groups is primarily organized by island size and topographic complexity, with the inland Papuan-speaking groups the most isolated and differentiated.
Shore-dwelling Oceanic-speaking groups are more intermixed dispersal along the shorelines was easier. The sailing capabilities of the ancestors of the Polynesians transformed the nature of their Diaspora and kept them relatively homogeneous. Our Asia—Pacific sample set came from a variety of sources.
The objective was to include between 15 and 25 unrelated individuals minimally excluding reported first-degree relatives from locales where individuals and their parents had all lived. These criteria were achieved in most instances. Details are given below. Samples from Northern Island Melanesia were collected in three field seasons , , and in collaboration with the Institute for Medical Research of Papua New Guinea.
Besides a 10 ml blood sample, a simple genealogy and residency questionnaire was taken, including in most instances parent and grandparent names, residences, and native languages.
Among over 1, samples collected, were chosen for submission to the Marshfield Clinic for microsatellite and indel analysis. We included multiple locales in larger language groups where feasible; and picked samples from individuals whose family's residence histories suggested close identification with the sampling locale. People of mixed parentage especially with one grandparent from a different language group or island could not always be excluded if the minimum required sample size was to be achieved.
DNA was extracted as previously described [ 17 ]. All individuals gave their informed consent for participation. DNA was extracted from blood using Qiagen kits. Taiwan Aboriginal samples comprise the Northeastern Taroko tribe from Hsiulin, part of the Atayal language group, and the Amis tribe living on the east coast of Taiwan and speaking Amis. All individuals were unrelated and had both parents belonging to the same tribe.
Each individual gave informed consent to participation in population genetics studies and the project was approved by the Ethics Committee of the Hospital and the Department of Health of Taiwan.
Blood samples were collected in acid citrate dextrose tubes. The microsatellites were drawn from Marshfield Screening Sets 16 and 54, and the indel markers were drawn from Marshfield Screening Set Where the primer changed, allele sizes from one of the two data sets were adjusted Table S9. The expected heterozygosity and average number of alleles per locus were computed on the microsatellites with the GDA software [ 65 ], using the sample-size corrected estimator, as in [ 66 ].
F ST was estimated on the microsatellites as in Equation 5. Cluster analysis of genotypes utilized the Structure versions 2. Results using Structure 2. When multiple runs at the same values of K produced discrepant results, we relied on majority rule i.
Details are provided in the Tables S3 and S5. Individual similarity coefficients for pairs of runs were calculated as in [ 24 ] and Methods. Great circle geographic distances were calculated with the Haversine method as described in [ 26 ].
After Blust [ 10 , 71 , 72 ] and Pawley personal communication. We are greatly indebted to the people from the different parts of Oceania who collaborated so willingly with us in this project. We hope this paper will help to illuminate their population histories and relationships, as we promised them at the outset. We thank Jeff Long and two anonymous reviewers for their suggestions, which have considerably strengthened the paper.
We thank Andrew Pawley, Glenn Summerhayes, and Peter Bellwood for suggestions on the historical linguistics and prehistory. Sarah Tishkoff suggested the genotyping of these samples at the Marshfield Clinic and was involved in a number of helpful subsequent discussions. Author contributions. JLW supervised genotyping at the Marshfield Clinic.
Competing interests. The authors have declared that no competing interests exist. National Center for Biotechnology Information , U. PLoS Genet. Published online Jan Andrew Merriwether , 8 and James L Weber 9.
Andrew Merriwether. Jonathan K Pritchard, Editor. Author information Article notes Copyright and License information Disclaimer. E-mail: ude. Received Jun 12; Accepted Dec This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. This article has been corrected. See PLoS Genet. This article has been cited by other articles in PMC.
Abstract Human genetic diversity in the Pacific has not been adequately sampled, particularly in Melanesia. Author Summary The origins and current genetic relationships of Pacific Islanders have been the subjects of interest and controversy for many decades.
Introduction 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 ]. Open in a separate window. Figure 1. The two Pacific groups are boxed. Results Our sampling strategy concentrated on Papuan-speaking populations and their immediate Oceanic-speaking neighbors from the islands immediately to the east of New Guinea, in what is called Northern Island Melanesia, consisting of the Bismarck and Solomon Archipelagos see Figure 1 B.
Figure 2. Figure 3. Figure 4. Figure 5. When Pacific Islanders identified as Black, furthermore, they found friends among many people of African descent. As Swan writes, in , Mildred Sope, a leading woman in the national liberation struggle of New Hebrides, was invited to attend the Tanzania Sixth Pan-African Congress on behalf of her independence struggle.
As far as the Pan-African Congress was concerned, she was a Black sister and they had one struggle. From a purely genetic perspective, the peoples of the Pacific islands in question were as distant to Africans as white Europeans.
They were as African, in other words, as any human being. Black signified the inferiority of the Aboriginal Australian as it did to the African. Over time, the concept of being Black was assimilated by the natives. The Black Power movement spread across the whole region. In , many of the very same activists who found it more strategic to appeal to an aboriginal identity for land rights were, in fact, members of the Black Panther Party. Privacy Policy Contact Us You may unsubscribe at any time by clicking on the provided link on any marketing message.
Generations later, in Guyana, Britain, Australia, New Zealand, and the Pacific Islands, many young indigenous people, and many young people of Indian descent, are growing up oblivious to the fact that some of their grandparents used to call themselves Black.
Is the question more controversial now than it was back then? Do these indigenous activists get to be incorporated into the canon of the Black radical tradition? Join our new membership program on Patreon today. JSTOR is a digital library for scholars, researchers, and students. Black Radicals. How the meaning of Blackness, and the social construction of race, varies across era and region. A protest during the Australian bicentenary, By: Mohammed Elnaiem. August 20, August 19, Share Tweet Email Print.
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