<論説>ラピタ人の起源とオーストロネシア語族の拡散 (特集 : 民族) (特集 : 民族)

Abstract

「民族」を科学的に定義しようとする試みにおいて近代以降に考古学が果たしてきた役割は大きい。しかし近年では言語学・考古学・形質人類学などの連携による学際的な研究が重要になっている。本論ではそうした研究の一例として、オセアニアへの人類の移動におけるラピタ人とオーストロネシア語族に関する研究を概観し、批判的検討を加えた。その結果、東南アジア島嶼部におけるオーストロネシア語族の拡散と新石器文化の成立が関連するという従来のシナリオは成立せず、オーストロネシア語族の拡散は人間集団の実際の移動にともなうよりもむしろ、地域間の交易を通じて拡散した可能性が示された。さらにオセアニアの初期居住民であるラピタ人は遺伝的に多様な起源をもつ個体により構成された集団である可能性が示された。つまりラピタなる現象は、単一の民族の移動としてではなく、むしろ「民族」や「文化」を横断するムーブメントとしてとらえられるだろう。

In the modern era archaeology has played a major role in efforts to define "ethnos" in a scientific manner. However, the study of Indo-Europeans and "Aryans" promoted by Gustav Kossina was exploited in the context of National Socialism and racial persecution. Recently multidisciplinary approaches including linguistics, archaeology and biological anthropology have become vitally important in understanding human history. In this paper, I critically review and explore the issue of the Lapita peoples and the dispersal of Austronesian peoples in the Pacific, which is one of the most pressing research topics in the studies of human history. First, I review the study of the peopling of Oceania, especially the issue of the origin of the Polynesians. There have been several theories about Polynesian origins, such as the theory of South American origin proposed by Thor Heyerdahl in the mid-twentieth century. Since the discovery of "Lapita pottery" in the late twentieth century (which was recovered from the regions between the Bismarck Archipelago, Papua New Guinea, and the western Polynesia including Tonga and Samoa), the majority of scholars have supported the theory of the "Lapita peoples." It has been thought that the Lapita peoples were a part of the Austronesian-language-speaking group, and that they were the common ancestors of Polynesian, Micronesians, and Austronesian-speaking Island Melanesians. The theory of "Express Train to Polynesia" proposed by Peter Bellwood and Jared Diamond assumes that the Lapita peoples originated in Taiwan on the basis of the study of comparative linguistics of Austronesian languages, and that they migrated to Oceania via insular Southeast Asia, Some scholars have believed that the Lapita peoples were derived from Australoid groups in the Bismarck Archipelago, that is the "Melanesian-origin" theory. However, the archaeological evidence from the Bismarck Archipelago indicates no direct link between the indigenous aceramic culture of the Australoid peoples and the newly established Neolithic culture of the Lapita peoples. Therefore, the theory of "Express Train to Polynesia" has widely been accepted in the prehistory of Oceania. However, there are still many unsolved questions about the origin of the Lapita peoples. In particular, no hard archaeological evidence has yet been recovered demonstrating a direct link between Taiwan, Southeast Asia and Oceania. Thus I have explored Neolithic cultures of insular Southeast Asia in the millenniums prior to the Common Era as well as recent studies of linguistics and physical anthropology in order to discover the origin of the Lapita peoples and the Austronesians. Linguistic studies of Austronesian languages support the theory of Taiwan origin. An archaeological review of Neolithic cultures in insular Southeast Asia demonstrates that the culture of red-slipped pottery was established indigenously in several regions of Island Southeast Asia around 2500 BC. Analyses of skeletal remains from Lapita sites show a variety of physical characteristics including not only Polynesian elements but also Melanesian and East Asian elements, which implies multiple genetic origins of the Lapita peoples. Recent genetic studies such as those of mtDNA and Y-chrome DNA indicate that the Oceanic peoples derived mainly from Southeast Asia and also suggest possible gene mixture from Australoid peoples in New Guinea. I synthesize this evidence from archaeology, linguistics and physical anthropology to present a comprehensive scenario about the peopling of the Pacific. The scenario I propose in this paper rejects the previous scenario that the emergence of Neolithic cultures in insular Southeast Asia was associated with the dispersal of Austronesian peoples and demonstrates that the dispersal of languages was accomplished by activities of inter-regional exchange between Neolithic cultures in insular Southeast Asia, rather than human migrations from Taiwan. The research also indicates the possibility that the Lapita peoples were composed of individuals genetically derived from various origins, mainly from the population of insular Southeast Asia but also from Taiwan and Australoid populations in New Guinea. Therefore, the phenomenon of the Lapita cannot be defined as a migration of a single ethnic group, but should be seen as a trans-ethnic and trans-cultural movement of these peoples.