Chapter 7
Physical anthropology
and genetics
According to the standard view from archaeology, there is "continuity – genetically, culturally and linguistically" between the Lapita pottery makers and Polynesians (Kirch (1997:69). This raises the serious difficulty that if Lapita potters were the ancestors of Polynesians as affirmed, and these ancestors were Melanesian like the present-day occupants of Fiji and the other putatively ancestral areas, then there is a problem of phenotype. Since Kirch wrote the above statement there has been a highly significant Lapita find in Vanuatu which calls it to question:
In 2004, archaeologists excavated a site at Teouma near Port Vila, where they uncovered a large number of headless skeletons in association with intact Lapita pots, offering opportunity for DNA analysis of the skeletal remains (Bedford et al. 2006). Up to the time of writing, official results of the DNA analysis are still awaited but preliminary findings released to the media indicated absence of a nine-base-pair deletion which is characteristic of 94% of present-day Polynesians, suggesting that these particular potters may have been ancestors not of Polynesians but of Melanesians like those still living in Vanuatu.
The problem of phenotype
Even without the most recent research, the matter of phenotype was long ago comprehensively evaluated by the physical anthropologist William Howells in his book The Pacific Islanders, published in 1973 at a time when Lapita studies had already begun. In this book, Howells compared Melanesians and Polynesians, using a variety of evidence available at this time, ranging through outer differences such as colour, size and shape, to inner ones including serum proteins, enzymes, and even ear wax. Having done so and reviewed the linguistic and archaeological evidence, Howells was so convinced of the essential differences between the two groups as to suggest that Polynesians could not have reached the limits of Western Polynesia through Melanesia but must have done so through Micronesia. A Micronesian path for Polynesians has gone into limbo as a result of the currently accepted Lapita hypothesis, but not so Howells's findings from physical anthropology, which have received strong support from recent research in this subject.
Having reviewed craniametric, dental, and other evidence from all of the areas relevant to Lapita, as well as examining the implications of Green's 1991 paper about disestablishing Melanesia, the physical anthropologist Michael Pietrusewsky reports as follows:
Samples from Melanesian Remote Oceania, including Fiji, Vanuatu, Loyalty, and New Caledonia, connect with those from Melanesian Near Oceania and are separate and distinct from Polynesia. Although Micronesian cranial series sometimes cluster with Melanesians, they, along with Polynesians, Indonesians, Southeast Asian and East Asian populations, group together to the exclusion of Australia and Melanesian populations of both Near and Remote Oceania. Melanesia thus appears to retain a cohesiveness that implies it is a useful concept for understanding the biological history of Pacific populations (Pietrusewsky 1996:351).
Pietrusewsky goes on to affirm connection between Polynesia and Indonesia but not Melanesia, in contradiction to Green's claim, and a clear indication that Melanesians cannot be the immediate ancestors of Polynesians. It will be noticed also that the Melanesian peoples cited as biologically distinct from Polynesians are all of those within Island Melanesia who are en route between Near and Remote Oceania and include the Melanesian members of the Central Eastern Oceanic linguistic subgroup which puts them in the same linguistic category as Polynesians. As well, while dissociating Polynesians from Melanesians, Pietrusewsky's analysis of the physical anthropology agrees with the musical evidence by proving their closest affinities to be with Micronesians. Again, as will be seen in the next section, the same has emerged from genetic evidence.
Genetics
Pietrusewsky's reaffirmation of Melanesia as a unit has been amply confirmed in a 2008 survey by Cox. Although there is no population group that can be termed average Melanesian, modern research is shown to have isolated numerous genetic markers, including eight blood protein alleles that Melanesians possess in greater proportion than peoples outside the area. These are seen to occur in a series of clines transcending the sea gaps that have been deemed so important for the Lapita expansion (Cox 2008:47-9).
Historically, there have been two approaches to the problem of determining the genetic origin of Lapita potters. The first and obvious one is DNA analysis of human remains found in Lapita sites, and the other is indirect evidence of past population movements from analysis of DNA samples from living populations.
Encouraged by positive finds of the nine-base-pair deletion in prehistoric non-Lapita human remains in Eastern Polynesia, Hagelberg and Clegg (1993) attempted analysis of remains found in Lapita sites from Watom Island, in the Bismarck Archipelago, as well as Fiji, Tonga, and Samoa from sites dated 2700–1600 BP. No trace was found of the deletion, leading to a conclusion that the Central Pacific was not settled by putative Polynesian ancestors but more likely from neighbouring Melanesia. This conclusion has been challenged on evidently valid grounds that the samples concerned were too late in date to be representative of early Lapita, and too fragmented and possibly contaminated to be reliable (Merriwether 1999:250; Pietrusewsky in Terrell et al. 2001). In the absence of definitive results from human remains, indirect genetic evidence of the second kind must therefore suffice.
Most genetics literature of the indirect kind is occupied with testing one or more of the three main theories of Polynesian origins known respectively as Fast Train, Slow Boat, and Entangled Bank.
Two main complexes of genetic "markers" have proved useful for the above work. The first is the nine-base-pair deletion and a related marker known as the Polynesian Motif, both found in mitochondrial DNA which is transmitted by females and therefore useful for determining descent through mothers. The other, more recent, approach is through Y chromosome markers which are transmitted by males and therefore of complementary use for tracking family relationships through fathers.
An extremely useful paper which incorporates earlier findings from mitochondrial DNA is Merriwether et al. (1999). This includes a table, with sources, of results from a range of studies, showing percentages of the nine-base-pair and Polynesian Motif throughout Polynesia, Micronesia, and some of Melanesia. As might be expected, Polynesia scores highest with rankings of 100% in some areas, but the next highest rankings are in Eastern Micronesia and the central Carolines; even Vanuatu has a respectable rating of 39.3% according to one survey, though only 12% according to another; and a surprise to many will be an amalgamated result of 24.4% in the Madang area on the north coast of Papua New Guinea, which has no obvious affinities with Polynesia. At the bottom of the table, the very low score of 7.5% for Tolai in the Lapita homeland area of New Britain may also raise eyebrows. The Madang result may be explicable in terms of later Slow Boat findings reported below but, if Lapita potters were ancestral to Polynesians the result for Tolai should have been much higher.
A number of early papers focussing on the Polynesian Motif or nine-base-pair deletion were supportive of the Fast Train hypothesis of Lapita origin – also known as "Express Train" and "Out of Taiwan" – and mostly also demonstrated Polynesian affinities with Indonesia and/or the Philippines, as well as uniformly on this account rejecting Terrell's "Entangled Bank" or exclusive to Melanesia model. Papers supporting the Fast Train model include Melton et al. 1995, Redd et al. 1995, Sykes et al. 1995, and Trejaut et al. 2005.
The next phase of research began with identification of Y chromosome male-specific markers, giving rise to the Slow Boat hypothesis of origin proposed by Kayser et al. (2000). Whereas mitochondrial DNA had tended to minimise links with Melanesia, the Y chromosome data turned up a large number of Melanesian markers in Polynesian DNA, all much further back in the chain of descent than had been expected, implying a slow rather than fast movement of Polynesian ancestors out of Taiwan with substantial Melanesian admixture on the way. This pattern of maternally transmitted mtDNA of Asian origin and paternally transmitted Y chromosome DNA of Melanesian origin has been interpreted by Hage and Marck (2003) as evidence of matrilineal and matrilocal descent in pre-Polynesian populations.
Finally, a very few genetics papers have dealt specifically with Micronesia. Besides the Merriwether paper already referred to, the other studies include Lum and Cann 1998, O'Shaughnessy et al. 1990, and Lum and Cann 2000. Because of the ubiquitous presence of the Polynesian Motif throughout both Polynesia and Micronesia as well as Indonesia and even Madagascar, coupled with its absence in non-Austronesian-speaking populations, Lum and Cann (2000:160) offer the suggestion that it could perhaps better be called the "Austronesian Motif". But this is far from all. In the several papers, taking account of a variety of genetic markers, relationships are also demonstrated with the north coast of New Guinea, and a complex picture emerges of lineages, some shared, and some unique to particular areas. Lum and Cann refrain from drawing firm conclusions beyond suggesting that Western Micronesia was independently settled from SE Asia, and " Central-Eastern Micronesians and Polynesians most likely shared a common origin in Island Southeast Asia, and a common route into the Pacific along the north coast of New Guinea" (Lum and Cann 2000:166). O'Shaughnessy et al. seemingly depart from the standard settlement scenario as follows:
Our study has not revealed any markers that differentiate between "mongoloid" components of Micronesians and "mongoloid" components of Polynesians: at the relatively low resolving power of these analyses they are indistinguishable. The globin gene data are not inconsistent with a Polynesia colonisation scenario that includes routes through both Melanesia and Micronesia, perhaps meeting in the melting pot of Fiji-Samoa-Tonga from which the final later migrations to the far reaches of the eastern Pacific took place (O'Shaughnessy et al. 1990:153).
As the sample used for this study includes Guam and Palau in Western Micronesia which, as Lum and Cann affirm, are believed to have been settled direct from SE Asia, the authors have probably assumed that the "Mongoloid" component both in Polynesia and the rest of Micronesia came from there. Though running into linguistic difficulties, this is a possibility that will be taken up in a later chapter.
In summary, evidence from both physical anthropology and genetics is supportive of a Micronesian rather than Melanesian route for Polynesian ancestors, with Taiwan, the Philippines and Indonesia, and the north coast of New Guinea all involved with population movements ancestral to both Polynesians and Melanesians.
The most recent genetic data for Oceania is reported in a massive study by Friedlaender et al (2008). Its author summary begins with a seemingly unequivocal statement that "Polynesians and Micronesians have almost no genetic relation to Melanesians, but instead are strongly related to East Asians, and particularly Taiwan Aborigines." But true as this may be, the results are skewed by the nature of the sampling, and it is unfortunate that opportunity was missed to test possibilities that emerge out of the earlier studies.
The area referred to as Melanesian in the above statement is limited to the Near Oceania region of the Bismarck Archipelago and the northern Solomons, where the sampling is extensive, but with no attention at all to the highly crucial remaining areas of Island Melanesia southwards through Vanuatu, New Caledonia, the Loyalties, and Fiji.
Mainland New Guinea is represented only by sampling from the Sepik lowlands, and just two areas from the Eastern Highlands (Gimi, and Goroka township). The New Guinea area most in need of sampling, however, is the entire northern coast, which on linguistic as well as genetic grounds could have been the path taken by the earliest speakers of Oceanic on their way to the Bismarck Archipelago (see Chapter 15).
Most disappointing of all is the inadequacy of sampling for Micronesia and Polynesia, which preccludes comparison of these two areas with each other. The association found between Micronesia and Taiwan is to be expected as a result of the limitation of the Micronesian sample to Belau which, along with the rest of Western Micronesia is widely accepted to have been settled direct from Indonesia or the Philippines. If associations with Polynesia are to be sought, however, they will be found not in Belau but most readily in Eastern Micronesia, especially the Carolines and islands closest to Tuvalu which probably played a key role in Polynesian pre-history but again is not part of the Friedlaender sample. Instead, Samoa is the sole representative for Western Polynesia, and NZ Maori for Eastern Polynesia. It is to be hoped that having made an excellent start with the Bismarck Archipelago as a basis for enquiry, these authors will now extend their search to the other areas where answers to the vexing problem of Polynesian origins may yet be uncovered.
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