C. Melvin Aikens

Takeru Akazawa

The foregoing papers are illustrative of new analytical approaches and orientations that are transforming the study of prehistory in Japan, It is the editors' hope in presenting them here that they will stimulate, by example, further work in the same vein. The integration of scientific, quantitative, ecologically oriented studies into the sturdy framework already created by more traditional typological and distributional analyses is of great potential significance to our understanding of prehistory. This is especially true in such a data-rich country as Japan, but the approach is of course applicable and desirable everywhere.

With regard to this latter point it is also very important that the potential of the unusually favored Japanese situation for yielding insights into prehistoric cultural process and evolutionary change in human populations be made better known to the international scholarly community. The present collection, published in English, is a contribution toward that end as well. A brief and somewhat selective summary of the volume's contents will point up what the editors believe to be some of the main contributions of this book.

The ancient Jomon culture of Japan provides the clearest example known to world prehistory of early hunter-gatherer cultural sedentisrn. Pottery, generally seen around the world to correlate with sedentary or relatively sedentary living, is earlier in Japan than anywhere else. With a date of some 11,000 B.C., it suggests that already in terminal Pleistocene times there existed a significant degree of sedentism there. By early Holocene times, pottery had spread throughout the main Japanese islands, and sturdy, well-defined pithouses had appeared. The paper by Aikens, Ames, and Sanger places the Jomon cultural pattern in broad perspective by comparing it with other well-known examples of rich and sedentary hunter-gatherer lifeways from the western and eastern coasts of North America, and from Baltic Europe.

All of these are north-temperate lands, with heavily indented coastlines characterized by numerous bays, inlets, tidal flats, and estuaries backed by wooded hills. In all four regions, the major elements of the natural resource base were much the same: deer, bear, whale, dolphin, and seal among mammals; salmon, eels, sea bass, and numerous other forms among fishes; waterbirds of many kinds; and shellfish in both abundance and variety, Vegetal food resources were also relied upon. Though species and even genera varied, there were acorns, walnuts, hazel nuts, and berries of one kind or another to be had in all the regions, as well as a variety of roots. The technology people used in exploiting these resources was also much the same in all four regions: fish hooks, leisters, and harpoons; fish nets, as attested by numerous stone or pottery sinkers and occasional floats of wood or pumice; basketry and matting for fetching and carrying; the bow and arrow for hunting; milling stones and/or mortars and pestles for grinding and crushing vegetal foods; and canoes for transportation.

Within this frame of reference it can be seen that Japan is a precocious example of an evolutionary development that was common to temperate coastal settings throughout the northern hemisphere. In these biotically rich and seasonally varied environments, human societies early established home base settlements from which they ranged out in various directions to bring back resources for the community stores. The new logistically organized patterns of collecting established in the early post-Pleistocene differed significantly from the patterns of the preceding glacial age, reflecting the radically changed biotic distributions of Holocene times. With sedentary lifeways came population growth, and an expansion of the managerial demands of maintaining a logistically organized economic system. Thus the ecological circumstances of these regions fostered gradually increasing sociocultural complexity, and brought all four areas, widely separated though they are, into a remarkable evolutionary convergence. Of the four examples, Japan is of particular interest because it has the richest and most extensively researched archaeological record.

In the present volume, ecological and quantitative studies of the kind needed for a detailed understanding of such developments are represented by three analytical papers. All of them focus attention on the subsistence economy and settlement pattern of the Jomon period in ways that explicate the profound influence of ecological relationships in sociocultural development.

From a volumetric and nutritional analysis of the Isarago site near Tokyo Bay, Suzuki was able to calculate the caloric and protein yields represented by the midden accumulation. By taking into account the seasonality of shellfish gathering activities as manifested in the daily growth rings of the shells, and the seasonality of fishing as determined by the analysis of fish scales-along with other evidence-he was able to identify the principal season of occupation of the site. Using figures for number of years of occupation and population size derived from other sources, he was then able to conclude that although per capita caloric yield was low, shellfish gathering alone at the Isarago site could have provided its seasonal occupants as much as 60% of the modern-day level of protein intake. The volumetric analysis also establishes a basis for comparing shell-midden sites of unequal size and dura tion, which is essential to any thoroughgoing analysis of the ecological and social relations of such sites.

The potential of analyses based on the natural sciences to objectify the circumstances under which prehistoric people lived is well-illustrated in Koike's analysis of paleobiomass and hunting pressure during Jomon times in a small subregion east of Tokyo Bay. Her paper demonstrates very well the broad scope of the research required for such an ecological study. It proceeds through accounts of a mapping survey; a population estimate; analyses of molluscan, fish, and mammal remains; estimation of paleotemperature change; reconstruction of the prehistoric shoreline; and reconstruction of prehistoric vegetation in the study area. From there she develops a paleobiomass analysis based on the assessment of shellfish resources in recent and prehistoric tidal flats, and then an account of collecting pressure on the shellfish resource during the period of site occupation. A comparable approach is taken to the analysis of paleobiomass and hunting pressure with regard to the prehistoric deer population of the region. Her research not only provides quantitative estimates of available subsistence resources at the time of site occupation, but also identifies problem areas for future research.

A discriminant function analysis of stone food-processing tools and fishing gear from approximately 200 sites of the later Jomon period, distributed throughout Japan, provides Akazawa with a basis for discussion of regional variation in Jomon procurement systems. The analysis revealed distinctive geographical clusterings. In eastern Japan, specific toolkit clusters correlated with the Pacific littoral of Hokkaido and Tohoku, the coastal lowlands of the Kanto and Tokai districts, and the interior mountains and northern Japan Sea coast. In western Japan a single toolkit was dominant, and there was significant overlap between the western Japan cluster and that for interior/northern Japan.

Based on the typological and distributional analyses, three main ecosystem types, which correspond to exploitation territories, are defined as characteristic of later Jomon huntergatherers. These are: the Combined Forest-Freshwater Ecosystem (western Japan and interior/northeastern Japan), the Combined Forest-Estuary Ecosystem (Kanto and Tokai districts of eastern Japan), and the Combined Forest-Pacific Shelf Littoral Ecosystem (eastern Hokkaido and Tohoku). From this analysis it is clear that terrestrial productivity of edible forest plants was critical to western and eastern interior Jomon populations, while the eastern coastal populations relied heavily on the marine component in developing procurement systems that actually overlapped both forest and waterside zones.

The relative biotic productivity of these various zones provides a basis for ranking the three ecosystem types, or exploitation territories. That of western Japan exhibits the lowest productivity, while that of the Kanto and Tokai districts exhibits the highest. Notably, levels of human population density, as determined from numbers of Late Jomon sites, are correlated with levels of productivity within these exploitation territories.

When the transition to rice agriculture in Japan during the Yayoi period is considered against this background, ecological reasons for regional variation in the rapidity with which cultivation spread become obvious. In western Japan, not only was gross productivity of hunting-gathering lower, but the seasonal procurement round was less stable than it was for the people of eastern Japan, whose procurement systems overlapped two highly productive zones and longer seasons of availability. The Jomon lifeway of western Japan thus offered relatively greater incentive to incorporate new procurement practices (i.e., rice cultivation) than did that of eastern Japan. Moreover, it incorporated a productive technology that was pre-adapted to the requirements of agriculture, and it did not involve the scheduling conflicts that would arise between seasonal planting and fishing activities in. eastern Japan, Traditionally archaeologists have sought to explain the time lag in the eastward spread of rice agriculture with reference to immigration and increasing distance from the continent. Akazawa's analysis strongly implies that cultivation spread differentially within an indigenous population governed by long-established ecological relationships, rather than being simply imported and put down by an immigrant population of outsiders.

In one way or another, all the papers dealing with physical anthropology address the problem of relating the socio-economic transformation of late Jomon-early Yayoi times to physical changes in the Japanese population.

Ossenberg shows clearly, from her analysis of genetically controlled non-metric cranial traits, that there has been significant gene flow from the continent into Japan. She docu- ments a clinal pattern within the country showing greatest similarity to continental populations in the southwest-where Japan and Korea nearly touch-and ever-decreasing similarity northeastward. She concludes that the modern population of Japan is genetically intermediate between continental populations and archaeologically known Jomon skeletal series, though closer to continental groups. The modern Ainu, by contrast, are closer to the Jomon series. Dodo, in a similar analysis based on a different sample, reaches essentially the same conclusions.

On the basis of their craniometric analyses, Dodo and Mizoguchi contribute further to this view, while at the same time suggesting that much in the visible makeup of the modern Japanese population that makes it resemble continental peoples is not due to gene flow. Their data offer support for the transformational theory of H. Suzuki, which holds that the changeover from hunting-gathering to farming after the Jomon period led to nutritional and other differences which caused increasing phenotypic divergence in later Japanese populations. In this process the later, agricultural population of Japan came increasingly to resemble the agricultural populations of the continent.

The paper by Inoue, Ito, and Kamegai, which focuses on dental pathologies in huntergatherer and early farmer skeletal series from Japan, documents non-genetic regional and temporal differences in morphology, caries, and occlusal attrition that relate principally to dietary differences. Cluster analyses suggest that the general size of the facial skeleton was gradually enlarged over time between the Jomon, Yayoi, and Kofun periods, and that dental pathological factors also varied over time. An especially high rate of dental caries was identified in the Yayoi period skeletal series. Considerable regional diversity in morphological factors during the Yayoi and Kofun periods is taken to indicate nutritional differences reflecting variations in regional ecosystems. The analysis of Inoue, Ito, and Kamegai does not suggest major population influx over the period studied, but rather processes of regional diversification related to new dietary factors. In fact, although they acknowledge the likelihood of small immigrant groups having entered Japan from time to time throughout the Jomon, Yayoi, and Kofun periods, they conclude that none of the 18 skeletal series examined by them seems to represent such a group.

The rapidity with which secular change can occur in the skeletal characteristics of a population when it undergoes a change in living conditions is graphically shown in Kouchi's paper. Her study is based on a comparative analysis of three large series of somatometric data collected in the 1910s, 1940s, and 1980s. Previous studies based on the earlier data showed a dine of increasing body size from southwest to northeast, and a concentric distribution of head shape. Brachycephaly was dominant in and around the Kyoto-Nara region, and less brachycephalic head forms appeared in the peripheral regions. This was explained by postulating the migration of people from Korea into the Kyoto-Nara region during Yayoi times.

As Kouchi points out however, the dine in body size turns out to be highly correlated with temperature, body size being greater in the colder areas and smaller in the warmer areas. Moreover, the concentric distribution of head shape was highly correlated with dietary patterns observable in modern data.

Kouchi's restudy based on 1980s data was undertaken to test the hypothesis that the concentric pattern of brachycephaly recognized in the earlier data was due to regional differences in the rate and timing of recent rapid secular change. Her results confirmed in. a rather drarnatic way that secular change was both rapid and regionally varied. They showed that the distribution of brachycephaly actually shifted between the 1940s and 1980s, so that the Kyoto-Nara region was no longer the central focus. Kouchi relates this to rapid secular change in living conditions, with the postulated changes first coming about in the Kyoto-Nara region, and subsequently, with the very recent expansion of mass communication and transportation facilities, spreading more widely throughout Japan. Whatever the reason, the rapidity of change in observable skeletal characters is striking, and makes it clear that the old hypothesis of massive Yayoi period Korean immigration is not supportable on the basis of the somatometric data.

These observations bring us full circle back to the matter of indigenous regional variants in cultural systems, and differential receptivity to rice agriculture, that was brought up by Akazawa's paper. It is evident that the old theory of continental invasion has a factual basis in human genetics, but as usually presented is both too simple and overdrawn. Rather than picturing numerous immigrants pushing their way into Japan from the mainland during the Yayoi period, we must recognize that the process of "continentalization" is one that continued gradually from Jomon tiroes through to the present. This is true in physical anthropology as well as cultural: witness Mizoguchi's conclusion that the Japanese population changed from the Kofun period through the Edo period to modern times, becoming ever more continental.

We believe it is clear that gene flow from the mainland has continued from at least late Jomon times (and probably earlier) onward to the present, gradually making the Japanese population more and more continental in appearance. Thus, the "continentalization" of Japan is a phenomenon of the Yayoi period only in a very limited sense. The establishment then of an agricultural society comparable to that of the continent increased the possibilities and incentives for cultural and genetic flow into Japan, which continued thenceforward as international sociopolitical relations were increasingly expanded by an indigenous Japanese civilization of growing complexity. Over this same period of time, non-genetic secular changes related to the changed nutritional conditions and physical demands of the new way of life were also at work transforming the Japanese physique.

We conclude by reiterating that the kinds of analyses presented in this volume point the way for future prehistoric studies in Japan. They are offered for their inherent interest, and in the hope that, since they deal with problems of kinds that crop up all over the world, they will be of methodological interest to the international scholarly community as well.