Early farmers in the Pacific
As far as the human settlement of the islands of Remote Oceania is concerned, we have essentially three "bouts" of colonizing activity. The first, that described as Lapita by archaeologists, led to the settlement of the islands of central and eastern Melanesia, plus western Polynesia to as far east as Samoa, by makers of red-slipped and stamped pottery (Figure 7.4). This occurred very rapidly between about 1350 and 800 ac. Following 800 BC there was an apparent standstill in the central Pacific (Fiji, Tonga, Samoa). The so-called "Nuclear" Micronesian islands, excluding the Mariana and Palau groups in the west, appear to have been settled about 2,500-2,000 years ago, possibly from Melanesia. The final push involved the archipelagos of eastern Polynesia (including New Zealand), settled by aceramic populations between AD 600 and 1250 (pottery-making was abandoned in western Polynesia soon after 2,000 years ago).
This chronology of colonization with its apparent standstills probably owes little in any direct sense to factors of agricultural causation (Bellwood 2001e). The standstills themselves reflect factors of distance, of sea-level fluctuation - many atolls were submerged by higher sea levels 3,000 years ago - and of maritime technology. Large and efficient canoes were not invented instantly, and sea craft underwent technological improvement as the wave of human expansion spread eastward (Anderson 2000). The movement also reflected desires to exploit naive bird faunas, as well as social factors that encouraged fissioning, and doubtless many other motives, including an interest in finding new sources of exotic exchange items. However, agriculture was a crucial factor in the overall equation. Without it, the Pacific would never have been colonized at all on any long-term basis, at least not the smaller islands in Micronesia and Polynesia. Early colonists faced not only sea gaps of increasing width moving eastward into the Pacific Ocean, but also islands of decreasing size and diminishing native subsistence resources. The latter meant that the agricultural economy as a portable subsistence lifeline came into its own, together with an expectable focus on marine resources. With the development of substantial ocean-going sea craft, the whole Pacific beyond the Solomons was opened for human settlement.'
Thus, we see a vast sweep of agricultural populations moving into new terrain from southern China, through Southeast Asia and into the Pacific Islands, over a time span of about 5,000 years, commencing at about 3500 ac in Taiwan and culminating in the Maori colonization of New Zealand around AD 1250. Within this span of island colonization there are some intriguing instances of longdistance exchange, especially of lithic raw materials (Figure 7.1), that bring home to us the real extent of voyaging ability. Yet, there are two very significant regions that did not form part of this huge voyaging network. One was Australia, a continent of consistent and continuing huntergatherer population until European contact. The other was the interior of the massive island of New Guinea, lying just south of the Equator to the east of Indonesia, but so very different from the major Indonesian islands in terms of agricultural, linguistic, and biological history. New Guinea, and particularly the New Guinea Highlands, forms a unique cultural world with a seemingly independent trajectory into some form of food production.
The New Guinea Agricultural Trajectory and its Role in
Pacific Colonization
Between 1972 and 1977, excavations led by Jack Golson revealed a series of intercutting drainage ditches belonging to six separate phases of activity, all dug into a swamp on the Kuk tea plantation in the Wahgi Valley, Papua New Guinea Highlands." Radiocarbon dating and a series of dated ash showers established that the sequence might have commenced as early as 8000 BC, although the first phase with really substantial ditches, up to 3 meters deep and traceable over a length of at least 500 meters, was dated at that time to about 5000 sc. The six phases were separated by phases of nonusage of the swamp and succeeded each other through prehistory into recent times, the most recent being characterized by a grid of drainage ditches like those used ethnographically in the New Guinea Highlands for growing the introduced American sweet potato. The assumption made was that the main crops grown at this altitude (1,550 meters above sea level) in the early Holocene would have been taro (Colocasia esculenta), pandanus, Australimusa bananas (a native New Guinea section of bananas with vertical fruit stalks), yams, and sugar cane. Today, yams grow in the highlands up to about 1,700-2,000 meters, bananas to about 2,000 meters, and taro to about 2,700 meters (Bayliss-Smith 1988). Presumably, in the last glacial period, these plants would not have grown at all in the broad fertile highland valleys that lie above 1,300 meters, and would have been restricted to lowland areas and to the steeply sloping terrain that surrounds the highlands in most directions. As postglacial temperatures rose, people perhaps moved with the rising upper limits for these plants into the highlands, then as now a region on the "edge of the range" for agricultural activity and thus subject to stress factors that might have stimulated a focus on planting rather than simple collecting.
Since the Kuk findings were published there has been considerable discussion as to just how "agricultural" were the early Holocene Kuk ditches (Spriggs 1996). Some of these questions have now been answered by new research by
Tim Denham and his colleagues (2003). Through an analysis of pollen, phytoliths, and starch grains from the Kuk soil profiles, including the fills of prehistoric ditches, they believe that the Kuk landscape was partially cleared for banana cultivation by 4500 BC, and that some of the bananas at this time were being deliberately grown in mounds close to the edge of the swamp. Slightly uncertain evidence for shifting cultivation extends back as far as 8000 BC, but this team dates the first drainage ditch networks to only 2000 BC, younger than the original date favored by Golson. Starch grains indicate cultivation of taro, and phytoliths indicate cultivation of bananas of the Eumusa section to which most modern commercial bananas belong, rather than bananas of the previously suspected but less significant Australimusa section. If this research is upheld, it will make an important case for origin of many cultivated bananas and some taros in New Guinea, rather than in the islands of Southeast Asia, thus marking an important contribution of Papuan horticulture to Austronesian crop rosters as Austronesian settlers moved into the Melanesian region from Indonesia about 1400 BC.
This research reinforces very strongly the idea that some form of gardening economy with planting of tubers and fruit-bearing small trees, utilizing fertile swamp soils wherever they were available, was present in the New Guinea Highlands in the early Holocene. This qualifies to be considered as true and primary agriculture, albeit not a highly expansive system in the absence of cereals and domesticated animals. No evidence is available to indicate that tropical regions further west in Indonesia witnessed such developments prior to the arrival of Austronesian farmers, so perhaps we can ask why agriculture developed specifically in the New Guinea Highlands, and what were its repercussions in terms of population growth and dispersal.
Firstly, New Guinea is unique in having a continuous highland spine almost 2,000 kilometers long, as opposed to the smaller discontinuous areas of highland characteristic of other large tropical islands such as Borneo and Java. The New Guinea highlands, with their large valleys and dense populations, lie mostly between 1,300 and 2,300 meters above sea level (ground frosts start at 2,600 meters). They thus form a large island of non-tropical climate, at least in terms of temperature, within the vast terrain of equatorial lowland which extends right through Island Southeast Asia and into the western Pacific. Such a special kind of region might, perhaps, be expected to have had a special kind of
prehistory.
Secondly, by 8500 BC the New Guinea Highland late glacial climate had ameliorated to present conditions and the tree-line had risen almost 2,000 meters in a remarkably short period, perhaps only one millennium, to reach its present altitude at ca. 4,000 meters above sea level (Swadling and Hope 1992; Haberle et al. 1991). A warm climatic situation with a relatively non-seasonal rainfall distribution pattern was thus established, suitable for the development of traditional New Guinea agricultural systems focused on tubers and tree products.
Thirdly, technology seems to have changed very little before, during, or after the advent of agriculture in New Guinea. We see no rapid spreads of new art styles, pottery (never manufactured in the main highlands), or new forms of flaked lithics. Neither are there any recognizable harvesting tools in the oldest agricultural contexts. Except for the appearance of ground stone axes at an uncertain date in the early Holocene, the archaeological face of early agriculture shows no real change at all from the hunter-gatherer background assemblages of the Late Pleistocene. This suggests a fundamental continuity of cultural tradition across the transition, even though the tempo of technological change seems to have been much less marked than in regions such as Southwest Asia, China, or Mesoamerica.
Could New Guinea agriculture have developed first in the lowlands and then spread into the highlands? I rather doubt it, as does Paul Gorecki (1986). The altitudinal locations of early sites in New Guinea have been plotted by Simon Haberle (1994), and a virtual absence of sites of all periods between 500 and 1,300 meters above sea level is very apparent. Coastal sites are also few, and show no signs of early agriculture. Finds of plant remains dated to ca. 4000 ac at Dongan in the lowland Sepik basin (candlenut, canarium, coconut, pandanus, possibly sago) are of great interest here, but all could have been exploited from self-propagated rather than planted trees (Swadling et al. 1991). In the New Guinea lowlands there is no hard evidence for actual plant cultivation, as opposed to possible management, prior to the arrival of Austronesian-speaking populations within the past 3,000 years. The highlands also fit best with the "edge-of-the-range" theory for agricultural origins, as it has been applied to Southwest Asia and China (Bellwood 1996b).
Given the rather special environment of the New Guinea Highlands within the Southeast Asian context, it may be suggested that any early Holocene stress factor, such as a long episode of locally unprecedented drought (Brookfield 1989), would have encouraged a switch to swamp-edge planting of wild tubers and fruits at key altitudes in favorable locations. The unstable climatic conditions at the end of the last glaciation could thus have led to fluctuations in food supplies, and in the case of Kuk Swamp the transition to agriculture occurred within the zone where many cultivated plants, such as taro, banana, and sugar cane, were approaching the altitudinal limits of their growth ranges. Once swamp-edge planting commenced, probably in combination with some degree of swiddening on adjacent terrain (Bayliss-Smith 1988; Denham et al. 2003), it is not hard to visualize communities being propelled toward increasing investment in new forms of production, such as the grassland tillage and treefallowing described for the later phases at Kuk by Jack Golson and Don Gardner (1990).
As for agricultural dispersal, it can only be stated that New Guinea does not show the expansive trends so typical of other regions such as the Middle East, Mesoamerica, and China. The archaeological and linguistic records do not indicate any major colonizations from the highlands out into the islands of Melanesia, and the total absence of any agricultural spread into Australia is very striking, despite the fact that it was probably still joined to New Guinea by dry land when the agricultural developments began. Although the Oceanic peoples living beyond New Guinea grew similar crops to the gardeners of the New Guinea Highlands, and might even have acquired some crop varieties from New Guinea sources, the terms they used for them were derived from Austronesian sources in the Philippines and Indonesia rather than from Papuan sources in New Guinea. Perhaps this non-expansive situation reflects in part the isolation of the highlands by inhospitable terrain, and the scourge of malaria afflicting any situations of increasing population density in the surrounding lowlands. However, an eventual spread of farmers from the highlands into the lowlands of New Guinea itself is attested quite well by the linguistic record, to which we return later.
The evidence to hand suggests that the New Guinea transition into some form of food production was perhaps as old a transition as anywhere else in the world, and it was clearly pristine. It might also have had similar causes, if we
can take seriously the many current claims for risk management as a major factor in the beginnings of agriculture. From the viewpoint of overall productivity, in its early days the New Guinea agricultural scene was without any domestic animals, until the pig was introduced from Indonesia after 1000 BC, with dog and chicken perhaps later. The fact remains, however, that even without any major expansion of New Guinea agriculturalists and their languages into regions further away than Timor, Halmahera, and the Solomon Islands, their biological impact on the phenotype of the western Pacific has been immense. Although the languages and agricultural systems of the Austronesian speaking populations of Island Southeast Asia and the Pacific islands for the most part reveal undoubted Southeast Asian, even southern Chinese origins, the same is not true of biological genotypes, at least not in those islands which stretch from New Guinea to Fiji. New Guinea has been a powerhouse in the prehistory of the western Pacific, a circumstance underlined by the fact that its present populations, at least in the Highlands, are with little doubt the direct descendants of populations living on the island during the late Pleistocene. New Guinea, unlike its neighbors, was never seriously colonized by incoming agriculturalists. Neither, of course, was Australia, but that seems to reflect isolation and environmental factors rather than any New Guinealike ability to provide the wherewithal for an independent origin of agriculture.
Chapter 8
Early Agriculture in the Americas
The transitions through time and in space between hunting-gathering and farming are rarely as sharp in the New World as in the Old. One reason for this is that few major meat-producing herd animals were ever domesticated in the Americas, so ancient farmers continued mostly to derive meat from wild resources. The main exception to this generalization, albeit one of fairly restricted regional impact, concerns the domestication of llamas, alpacas, and guinea pigs in the high Andes of Peru and Bolivia. Turkeys were domesticated in Middle America and dogs were also widely eaten, especially in the Maya region, but none of these served as widespread meat staples.
The Americas also lacked the broad base of highly productive cereals available in the Old World, with only maize fulfilling such a role on a large geographical scale, and only after about 2000 BC. The earliest domesticates in the Americas were mainly condiments, fruits, or industrial plants (e.g., chili pepper, gourd, avocado, cotton, and possibly even maize in the first instance) rather than productive staples. In the opinion of Hugh Iltis (2000:37):
As of now, it may well be said that the reason agriculture came to the New World much later than in the Old was a reflection of both the absence of any large-grained Hordeae [the grass tribe that includes wheat, barley and rye] in the Americas, and of the difficulty mankind had in taming teosinte, its only large-seeded annual grass, and even then one with dubious agricultural potential.
The problems of teosinte (the wild relative of maize) are discussed later, but North America north of Mexico was not a source of any domesticated staples equal in productive capacity to Mesoamerican maize, or to the major tropical American tubers such as manioc and sweet potato. Although some native seedbearing plants were domesticated in the Mississippi and Ohio basins, these had
sunk to only a minor resource compared to maize by AD 1500. Very large areas of North America were also beyond the range of agriculture because of their cold and/or dry mountain and prairie environments, with the northern limit of the 120-day frost-free zone running approximately along the US-Canadian border and just to the north of the Great Lakes. At European contact, about half (probably more) of the land area of the Americas was still occupied by hunters and gatherers (Figure 8.1), and many regions potentially suitable for agriculture in western North America, from California northward, simply had not been reached by farming communities.
Figure 8.1 The major early agricultural zones of the Americas - Andes, Mesoamerica, southwestern USA, Eastern Woodlands - together with probable source regions for early domesticated plants. The dates in bold refer to the approximate dispersal chronology for maize.
The American agricultural economies, still essentially Neolithic in technological terms despite a widespread use of copper (but not iron) for
ornaments at European contact, and without draft animals, ploughs, or wheeled transport, were thus not generally as productive as the economies that underpinned the expansive demographic trajectories of the Old World Neolithic and Bronze/Iron Ages. The expansion of agricultural economies in the Americas cannot be expected to be as clear-cut in the archaeological record as in some parts of the Old World, where fully agropastoral food production systems spread extensively through territories of former hunter-gatherers, as for instance in Neolithic Europe, and Iron Age central and southern Africa.
There is another major difference between the Old World and the New, and this is the relative lack of "centricity" in the New World early agricultural record. In the Old World, the Fertile Crescent and central China can be posited as geographically focused regions of early agricultural genesis in terms of their archaeological records and associated botanical and zoological information. In the Americas, it has long been assumed that agriculture evolved first in Mesoamerica and Peru because of their rich archaeological records, albeit with occasional but not widely accepted protestations to the contrary (Lathrap 1977). But it is now becoming apparent that these regions of later high civilization need not have been the only loci for initial agriculture, whatever importance they may ultimately have had in the rise of large-scale agricultural societies.
The focus is instead moving, at least in part, toward the lesser-understood (in an archaeological sense) and geographically diffuse tropical lowlands and midaltitude regions of Middle America and northwestern South America, areas of seasonal forest and broad rivers where the floristic diversity underpinning the central suite of agricultural plants in the Americas (especially maize, beans, and squashes) appears to have been located (Figure 8.1). The picture is made more complicated by the recent verification that the middle Mississippi drainage basin and its tributary valleys contained an independent development of plant domestication. However, as in many regions of the Old World, we need to distinguish conceptually between regions of origin of agriculture as a system of food production, and regions of origin and domestication of individual crop species. The latter were probably far more widespread than the former. While the Americas were quite non-centralized as far as domesticated plant origins are concerned, this need not mean that food production was developed independently in every region where there happened to exist a wild plant species brought into domestication.