Economic change after the agricultural revolution in Southeast Asia?

King, Charlotte L. ; Bentley, R. Alexander ; Higham, Charles 等

[ILLUSTRATION OMITTED]

Introduction

Variations both over time and between sites in carbon, oxygen and strontium isotope signatures from human teeth recovered from five prehistoric settlements on the Khorat Plateau of north-eastern Thailand have been identified (Bentley et al. 2005, 2009; Cox et al. 2011; King et al. 2013). These sites centre around two valley systems, the Upper Mun River Valley and the Sakon Nakhon Basin (Figure 1).

Extensive sampling from the sites of the Upper Mun River has enabled the construction of a precise chronology for the prehistoric occupation, derived from a Bayesian analysis of 106 radiocarbon determinations (T. Higham 2004; Higham & Higham 2009; C. Higham 2011). This makes it possible to follow changes in the isotopic values over time and among sites. Of the Upper Mun River Valley sites, Ban Non Wat has the longest prehistoric sequence, as well as the largest sample of human burials (Table 1). Ban Lum Khao has three mortuary phases that integrate with the Ban Non Wat sequence, while Noen U-Loke presents four phases covering the entirety of the Iron Age. By examining isotopic patterns and differences within and among these sites, which cluster within 10km of each other, interpretations may be made regarding subsistence change through time and social differences among the sites.

In order to examine subsistence differences on a larger scale, comparison is also made with the Sakon Nakhon Basin, approximately 230km to the north-east of the Upper Mun River Valley. In this area, the sites of Ban Chiang and Ban Na Di have previously been isotopically sampled (Bentley et al. 2005; King 2006). It has been proposed (Bentley et al. 2007; White 2011) that the introduction of agriculture into Southeast Asia was not the 'revolution that is suggested elsewhere, and that instead there was a level of variation in agricultural uptake. In comparing the sites of the Mun River Valley, both to each other and to those of the Sakon Nakhon Basin, we aim to describe regional variation and examine possible reasons for this.

[FIGURE 1 OMITTED]

There is some debate over the dating of sites in the Sakon Nakhon Basin, with some researchers claiming initial occupation as substantially before 2000 BC (White 1982, 2008; White & Hamilton 2009) and more recent analysis as the sixteenth century BC (Higham et al. 2011).The latter harmonises precisely with the Bayesian analyses undertaken on the Upper Mun sites, and we adopt this chronology in this comparative analysis.

Although not universally accepted, most agree that Ban Non Wat and Ban Chiang were initially occupied by Neolithic groups whose ultimate ancestors expanded south from the Yangtze Valley probably from the third millennium BC (Rispoli 2008; Zhang & Hung 2010; White 2011). By that juncture, rice was fully domesticated and early farmers were also familiar with domestic stock including pigs, dogs and cattle. For these two sites, therefore, it is possible through the biological remains to appreciate that food production, while established, by no means ruled out hunting, gathering and fishing as significant contributors to the diet (Kijngam 1979, 2010).

The early Neolithic middens at Ban Non Wat include fragments of rice chaff and hundreds of freshwater fish bones, thousands of shellfish and abundant bones of mammals (Kijngam 2010). Deer predominate, followed by pigs and both domestic and wild cattle. The conjunction of rice and stock with hunting, gathering and fishing continued into the Bronze and Iron Ages, as did the incorporation of pig, chicken, cattle, water buffalo and fish bones in human graves. It was during Iron Ages 3 and 4 that significant and probably interconnected changes took place (Higham forthcoming).

During the Neolithic and Bronze Ages, rice was probably cultivated in low-lying areas near settlements, reliant on rainfall. A handful of Early Iron Age burials from Ban Non Wat contained iron hoes. During the Late Iron Age, smiths forged heavy iron ploughshares and sickles during a period when remote sensing has identified the presence of bounded rice fields around contemporary Iron Age sites in north-western Cambodia (Hawken 2011). The construction of multiple banks around the Upper Mun River Valley settlements formed moats/reservoirs that could have supplied irrigation water (Boyd et al. 1999), and rice was heavily involved in mortuary rituals. These changes took place as the climate deteriorated, with a reduction in monsoon rainfall (White et al. 2004; Wohlfarth et al. 2012).

The two Sakon Nakhon sites confirm a region-wide conjunction of rice farming and maintenance of domestic stock with intensive fishing, shellfish collecting and hunting (Kijngam 1979; Higham 1984). However, while the Upper Mun River Valley is highly strategic in terms of exchange, and has the advantage of major salt deposits (Nitta 1991; El Tabakh etal. 2003), the northern basin is more remote from natural trade routes, and lacks evidence for the construction of moats and reservoirs around Iron Age settlements.

Materials and methods

This study compares carbon isotope results from the sites of the Upper Mun River Valley with those of the Sakon Nakhon Basin to analyse dietary change through time and dietary differences between contemporary settlements. Primary data come from the cemetery sample from Ban Non Wat, and comparative isotopic results are taken from previously published studies at Noen U-Loke (Cox et al. 2011), Ban Lum Khao (Bentley et al. 2009) and Ban Chiang (Bentley et al. 2005). The sample sizes from each of the sites, and their chronology, are given in Table 1. More detailed sample lists are given in Table S1 in the online supplementary material, including references.

It is worth noting that other samples from Ban Chiang and Ban Na Di have also been analysed isotopically by King (2006), but are not used as comparative data here as they were measured from bone apatite, not dental enamel. These different tissues reflect different periods of an individual's life, with dental apatite crystallising during childhood and bone apatite remodelling during adulthood. Previous studies (e.g. Van der Merwe et al. 2000) have reported this resulting in higher [delta][sup.13]C by approximately 1 [per thousand] in dental enamel. Bone apatite is also more sensitive to diagenetic alteration, which may cause further differences in isotopic results.

Studying diet archaeologically

Diet is commonly studied archaeologically through the proxy of carbon and nitrogen isotopes in skeletal material. In this study only carbon isotopes in dental enamel were analysed because collagen, containing organic carbon and nitrogen, is not well preserved at Ban Non Wat (King et al. 2011).

The theory behind carbon isotope analysis as a dietary proxy has been explained in depth elsewhere (Vogel 1993; Hobbie & Werner 2000). Broadly speaking, carbon isotopes reflect the photosynthetic pathway of plants consumed ([C.sub.3] versus [C.sub.4]). It is therefore possible to separate individuals consuming [C.sub.4] crops, such as maize and millet, from those subsisting on more common [C.sub.3] plants, such as rice and wheat (e.g. Schwarcz & Schoeninger 1991; Schoeninger & Moore 1992). Marine resources also have a characteristic carbon isotope signature (Schoeninger & DeNiro 1984), but their use is considered unlikely due to the inland location of the Upper Mun River Valley. Within a predominantly [C.sub.3] diet [delta][sup.13]C variability is small and unlikely to identify specific diets, but does yield broad information on the food groups being consumed by an individual.

Isotopic analysis

Material for isotopic analysis was preferentially taken from the second molar, which gives a dietary signal from childhood--approximately 3-6 years of age (Hillson 1996). If the second molar could not be sampled then other teeth were chosen based on the principles set out in King et al. (2013). Analyses were conducted on a chip of dental enamel weighing between 5 and 10mg according to established procedures (Koch et al. 1997; King et al. 2013) at the Stable Isotope Laboratory, Department of Earth Sciences, Durham University.

Carbon isotope ratios, measured in the carbonate portion of tooth enamel, were normalised to international standards NBS 19 and LSVEC, and standardised to PDB. Repeated measurements of internal standard DCS01 were used to constrain temporal drift in measurement. Powdered samples were run in two periods of analysis, with the standard deviation of [delta][sup.13]C measurements in DCS01 during each being 0.05 [per thousand] and 0.04 [per thousand] (2 s.d.). The precision of [delta][sup.13]C analysis of natural enamel was established via replicate measurements of selected samples (B144 and B263), giving average error of 0.18 [per thousand].

Results

Supplementary Table S1 (online) presents the full isotopic results for samples from BNW analysed in this study. Figure 2 shows change through time in [delta][sup.13]C ([per thousand] PDB) from the Neolithic to the Iron Age using results from Ban Non Wat, Ban Lum Khao and Noen U-Loke.

Figure 2 indicates a shift towards lower [delta][sup.13]C in the Early Bronze Age, with lowest values recorded in Bronze Age 2. Fligher [delta][sup.13]C is then recorded through the rest of the Bronze Age and into the Early Iron Age at Ban Non Wat. Later Iron Age results from Noen U-Loke return to lower typical [delta][sup.13]C. Lower [delta][sup.13]C values indicate increased consumption of [C.sub.3] plants; in Southeast Asia this is most likely to reflect increased importance of rice as a resource.

A one-way ANOVA to test the significance of differences between mortuary phases (p = 0.001) and direct comparison of adjoining mortuary phases was conducted using two-tailed t-tests, the results of which are given in Table 2.

Significant differences were recorded between the Neolithic phases, BA1 and BA2, BA2 and BA3, and the Iron Age phases (excluding IA4).

Statistical analysis also indicates significant differences in mean carbon isotope ratio between contemporaneous phases of the sites within the Upper Mun River Valley (Table 3). Change in [delta][sup.13]C through time in the Sakon Nakhon Basin is presented in Figure 3.

As with the Upper Mun River Valley, the isotopic pattern in the Sakon Nakhon Basin superficially indicates lower [delta][sup.13]C, and therefore more reliance on [C.sub.3] crops such as rice in the Early Bronze Age (according to Fligham et al.'s (2011) chronology). The difference between the Neolithic and Bronze Age values, however, is less pronounced, and not significant (two-tailed t-test, p = 0.297). [delta][sup.13]C values become marginally more positive through the Late Bronze Age, though again this is non-significant (two-tailed t-test, p = 0.558). The return to lower values, and therefore more rice reliance, seen in the Iron Age Upper Mun River Valley does not seem to occur in the Sakon Nakhon Basin sites.

[FIGURE 2 OMITTED]

[FIGURE 3 OMITTED]

Discussion

Change in subsistence through time in the Upper Mun River Valley

The Upper Mun River Valley sequence shows an increase in rice consumption coinciding with the second Bronze Age mortuary phase, followed by a lessening in rice reliance through the rest of the Bronze Age and Early Iron Age (see King et al. 2013 for an in-depth discussion of this pattern). There is a further increase in rice reliance with the later Iron Age at Noen U-Loke.

The lowest [delta][sup.13]C values in the Upper Mun River Valley are recorded in Bronze Age 2, a phase which contains the richest burials at Ban Non Wat and is interpreted by Higham and Kijngam (2012) as involving the rise of an elite group. The control of an agricultural surplus has long been interpreted as essential to the establishment of an elite (e.g. Childe 1950; Harris 1959; Johnson 2000), and it should perhaps be no surprise that we find a surfeit of rice during the period of greatest social inequality.

The low [delta][sup.13]C values found in the later Iron Age at Noen U-Loke also link well with archaeological evidence for an intensification of rice agriculture during this period. The construction of moats around sites in the Iron Age Upper Mun River Valley has been interpreted as a water conservation measure, allowing more efficient cultivation of rice (Boyd 2008), and evidence for Iron Age field systems in the area has also recently been proposed (Higham forthcoming). An increase in frequency of the rice-field-suited shellfish Pila ampullacea in the later layers of Noen U-Loke also supports this interpretation of rice agriculture intensification (Higham & Thosarat 2005). The isotopic evidence for an intensification in rice agriculture links well with the obvious increase in symbolic importance of rice at Noen U-Loke compared to earlier sites. Here, for the first time, graves were filled with rice (Higham & Thosarat 2005; Boyd & Chang 2010), perhaps signifying its ritual importance in Iron Age society.

Intersite differences in the Upper Mun River Valley

Though intersite differences in the Upper Mun River Valley may be partially due to change through time, there is also strong evidence for significant intersite differences between contemporaneous phases (Table 3).

Differences in mean [delta][sup.13]C ([per thousand]) between sites suggest that, overall, the people of Ban Non Wat were less reliant on rice than their contemporaries at both Ban Lum Khao and Noen U-Loke. This may be a function of sample size as both Ban Lum Khao and Noen U-Loke have fewer isotopic samples than Ban Non Wat, reflecting limited excavation areas, but it is also possible that differences reflect culturally mediated subsistence choices.

Complete reliance on agriculture is extremely rare and the human diet is almost always supplemented with broad-spectrum hunting or gathering. This is particularly true in a highly productive sub-tropical environment, where wild resources would have been plentiful (e.g. Gepts 2008). The higher [delta][sup.13]C ([per thousand]) typical of Ban Non Wat may reflect slightly greater levels of dietary supplementation with meat/game/fish, or indeed [C.sub.4] crops such as millet. The possibility of millet use is still under investigation in the region, but there is currently no evidence for [C.sub.4] crops in the Upper Mun River Valley (Castillo 2011). Macrofossil (Weber et al. 2010) and phytolith (Kealhofer & Piperno 1994) analyses conducted in the Khao Wong Prachan valley about 100km to the west, however, indicate the presence of both rice and millet during the first half of the second millennium BC. The possibility of millet in the Upper Mun River Valley cannot, therefore, be discounted.

It is possible that different isotope ratios simply reflect differences in the wild resources available to each settlement due to their locations on the floodplain. It has been ethnographically observed in areas such as the Democratic Republic of the Congo (Turnbull 1965) that clearance around villages for farming leads to a lack of game, making supplementation of the diet with hunting very rare. It is possible that the creation of field systems within the Upper Mun River Valley cut off access to game, with only those sites closer to the edge of the floodplain having access to forest resources.

[FIGURE 4 OMITTED]

Faunal analysis at Ban Non Wat indicates that the diet was supplemented with wild meat from deer and wild bovids. These species, particularly the former, prefer forest margins and clearings where there is better grass growth (Lekagul & McNeely 1977), and while the sites of this study are close together, they do occupy slightly different regions of the valley, with Ban Non Wat and Noen U-Loke closer to the edge of the floodplain, and therefore the forest edge (Figure 4).

Any discussion on differences in diet must also take into consideration the idea that there may be a wealth/prestige component to diet. Complete reliance on a carbohydrate staple crop has associations with poverty. This has been noted in present-day societies (e.g. Ruel et al. 2010), and reported in isotopic studies of archaeological populations (e.g. Ambrose et al. 2003). Meat, conversely, is usually highly valued in subsistence economies as it is by far the most efficient provider of energy (Mead et al. 1986). Game, therefore, ranks high in an optimal forager diet (Layton et al. 1991). The importance of meat means that the consumption of higher proportions or better cuts of meat is often the prerogative of high status individuals, and this has been observed archaeologically in geographically and culturally disparate groups (see van der Veen 2003 for a review). The use of meat as a prestige food has been observed ethnographically in Southeast Asia, particularly in the tribes of highland Myanmar and northern Thailand (Leach 1954; Falvey 1977), and is also common worldwide (Sahlins 1963; Arhem 1989).

In light of this, it is suggested that the significant difference in [delta][sup.13]C ([per thousand]) between Ban Non Wat and Ban Lum Khao may be evidence of greater access to prestige meat at Ban Non Wat. This is supported by differences in material cultural between the two sites evident in the second Bronze Age phase. During this period all individuals excavated at Ban Non Wat had a far greater number of grave offerings than the 'richest' at Ban Lum Khao, hinting that there may have been a marked difference in access to prestige materials and effort expended on mortuary ritual between the sites (Higham & Kijngam 2012). This pattern could, of course, be affected by sampling bias at Ban Lum Khao, where excavation was limited to the edge of the site and may have only incorporated the 'poorer' section.

Comparison of the Upper Mun River Valley with the Sakon Nakhon Basin

The general pattern of increased reliance on rice in the Early Bronze Age, followed by less reliance through the rest of the Bronze Age into the Early Iron Age is present in both the Upper Mun River Valley and the Sakon Nakhon Basin. The return to heavy rice reliance in the later Iron Age, seen in the results from Noen U-Loke, does not seem to be present in contemporary phases of the Sakon Nakhon Basin. This corresponds with the lack of evidence for moat construction and water management at Ban Chiang and Ban Na Di. The differences in dietary isotope results from the two valleys may, therefore, feed into larger-scale hypotheses about variations in the intensification of agriculture between regions. Just as western Thailand seems not to have experienced bronze technology (Glover 1991), and there may have been differential involvement in trade in southern Thailand (White & Hamilton 2009), it appears that agricultural reliance was non-uniform across Thailand. There is potential that the strategic position of the Upper Mun River Valley in terms of trade routes and salt deposits meant that developments in agricultural technology and method were more likely to reach the area, and more effort was expended to make rice agriculture viable despite environmental decline in the Iron Age.

This is not, of course, the only explanation of the data. It is just as plausible that occupants of the Sakon Nakhon Basin responded to environmental stress during the Iron Age by focusing on other resources, rather than intensifying rice agriculture. King (2006) suggested that the increase in [delta][sup.13]C in later levels of Ban Chiang may be the result of greater reliance on domesticated animals as a food source, or supplementation of the diet with [C.sub.4] crops such as millet or Job's tears. It is also possible that greater rice reliance is present in the Iron Age Sakon Nakhon Basin but is not seen in this set of results. The excavations of the two sites in this region were modest compared with Ban Non Wat, and key areas of the cemetery may not have been excavated.

Conclusion

Though rice agriculture was introduced to Thailand by at least 1800 BC (Rispoli 2008; Zhang & Hung 2010), the isotopic results indicate that it was not until the Early Bronze Age (c. 1000BC; Higham & Higham 2009) that reliance on rice reached its peak. The Bronze Age peak in rice consumption coincides, in the Upper Mun River Valley, with the presence of elite 'super-burials', connecting the ability to produce a rice surplus to this period of social aggrandisement. T his peak in rice consumption is also present in the Early Bronze Age of the Sakon Nakhon Basin, but there is no evidence for accompanying elite emergence there. Variation in the level of social inequality and agricultural reliance within and between different valley systems contrasts sharply with the proposal of a complete and universal shift in subsistence strategy which characterises the European Neolithic (e.g. Rowley-Conwy 2011). The persistence of mixed economies beyond the introduction of agriculture is, however, increasingly being proposed in Thailand (White 2011). New techniques involving fine-scale carbon isotope sampling are also revealing similar patterns in some areas in the European Neolithic (Montgomery et al. 2013).

The Iron Age in the Upper Mun River Valley saw a further increase in rice consumption, which links well with the growing archaeological evidence for intensification of rice agriculture. This period is accompanied by moat building as a measure to control water resources (Boyd et al. 1999; Boyd & McGrath 2001), an increase in the symbolic importance of rice (Boyd & Chang 2010) and the implementation of plough agriculture in fixed fields (Higham forthcoming). Though many of these developments are also seen in Iron Age Cambodia (Moore et al. 2007), they seem to be contemporaneously absent in the Sakon Nakhon Basin. Here there is neither archaeological evidence for water control nor the accompanying isotopic shift to lower [delta][sup.13]C values in the Iron Age. There are many potential reasons for this regional difference, but perhaps the most parsimonious of these is that the Sakon Nakhon Basin sites were only distantly integrated with the burgeoning maritime trade network, and therefore remote from the social and technological innovations characteristic of the later Iron Age.

Supplementary material is provided online at http://antiquity.ac.uk/projgall/king339/

References

Ambrose, S.H., J. Buikstra & H.W. Krueger. 2003. Status and gender differences in diet at Mound 72, Cahokia, revealed by isotopic analysis of bone. Journal of Anthropological Archaeology 22: 217-26. http://dx.doi.org/10.1016/S0278-4165(03)000369

Arhem, K. 1989. Maasai food symbolism: the cultural connotations of milk, meat and blood in the pastoral Maasai diet. Anthropos 84: 1-23.

Bentley, R.A., M. Pietrusewsky, M.T. Douglas & T.C. ATKINSON. 2005. Matrilocality during the prehistoric transition to agriculture in Thailand? Antiquity 79: 865-81.

Bentley, R.A., N. Tayles, C.F.W. Higham, C.G. Macpherson & T.C. Atkinson. 2007. Shifting gender relations at Khok Phanom Di, Thailand. Current Anthropology 48: 301-14.

Bentley, R.A., K. Cox, N. Tayles, C.F.W. Higham, C.G. Macpherson, G. Nowell, M. Cooper & T.E.F. Hayes. 2009. Community diversity at Ban Lum Khao, Thailand. Asian Perspectives 48: 79-97. http://dx.doi.Org/10.1353/asi.0.0017

Boyd, W.E. 2008. Social change in late Holocene mainland SE Asia: a response to gradual climate change or a critical climatic event? Quaternary International 184: 11-23. http://dx.doi.Org/10.1016/j.quaint.2007.09.017

Boyd, W.E. & N. Chang. 2010. Integrating social and environmental change in prehistory: a discussion of the role of landscape as a heuristic in defining prehistoric possibilities in NE Thailand, in S. Haberle, J. Stevenson & M. Prebble (ed.) Altered ecologies--fire, climate and human influence on terrestrial landscapes: 273-97. Canberra: ANU E-Press.

Boyd, W.E. & R.J. McGrath. 2001. The geoarchaeology of the prehistoric ditched sites of the Upper Mae Nam Mun Valley, NE Thailand, III: Late Holocene vegetation history. Palaeogeograpky, Palaeoclimatology, Palaeoecology 171: 307-28. http://dx.doi.org/10.1016/S00310182(01)00251-6

Boyd, W.E., R.J. McGrath & C.EW. Higham. 1999. The geoarchaeology of the prehistoric ditched sites of the Upper Mae Nam Mun Valley, Thailand, II: stratigraphy and morphological sections of the encircling earthworks. Indo-Pacific Prehistory Association Bulletin 18: 169-79.

Castillo, C. 2011. Rice in Thailand: the archaeobotanical contribution. Rice A: 114-20. http://dx.doi.org/10.1007/s12284-011-9070-2

Childe, V.G. 1950. The urban revolution. Town Planning Review 21(1): 3.

Cox, K.J., R.A. Bentley, N. Tayles, H.R. Buckley, C.G. Macpherson & M.J. Cooper. 2011. Intrinsic or extrinsic population growth in Iron Age northeast Thailand? Journal of Archaeological Science 38: 665-71. http://dx.doi.org/10.1016/j.jas.2010.10.018

El Tabakh, M., C. Utha-Aroon, J.K. Warren & B.C. SCHREIBER. 2003. Origin of dolomites in the Cretaceous Maha Sarakham evaporites of the Khorat Plateau, northeast Thailand. Sedimentary Geology 157(3): 235-52. http://dx.doi.org/10.1016/S0037-0738(02)00235-X

Falvey, L. 1977. Ruminants in the highlands of northern Thailand. Thai-Australian Highland Agronomy Project. Chiang Mai: Chiang Mai University Press.

Gepts, P. 2008. Tropical environments, biodiversity, and the origin of crops, in P. Moore & R. Ming (ed.) Genomics of tropical crop plants: 1-20. New York: Springer.

Glover, I.C. 1991. The late prehistoric period in western Thailand. Bulletin of the Indo-Pacific Prehistory Association 10: 349-56.

Harris, M. 1959. The economy has no surplus? American Anthropologist 61: 185-99.

Hawken, S. 2011. Metropolis of ricefields: a topographic classification of a dispersed urban complex. Unpublished PhD dissertation, University of Sydney.

Higham, C.F.W. 1984. The biological remains from Ban Na Di, in C.F.W. Higham & A. Kijngam (ed.) Prehistoric investigations in northeast Thailand (British Archaeological Reports international series 231): 353-90. Oxford: British Archaeological Reports.

--2011. The Iron Age of the Mun Valley, Thailand. The Antiquaries Journal 91: 1-44. http://dx.doi.org/10.1017/S0003581511000114

--Forthcoming. From the Iron Age to Angkor: new light on the origins of a state. Antiquity.

Higham, T.F.G. 2004. Dating the occupation of Ban Lum Khao, in C.F.W. Higham & R. Thosarat (ed.) The origins of the civilization of Angkor. Volume 1: the excavation of Ban Lum Khao: 5-7. Bangkok: Fine Arts Department of Thailand.

Higham, C.F.W. & T.F.G. Higham. 2009. A new chronological framework for prehistoric Southeast Asia, based on a Bayesian model from Ban Non Wat. Antiquity 83:125-44.

Higham, C.F.W. & A. Kijngam. 2012. The origins of the civilization of Angkor. Volume 5: the excavation of Ban Non Wat, the Bronze Age. Bangkok: Fine Arts Department of Thailand.

Higham, C.F.W. & R. Thosarat (ed.). 2005. The origins of the civilization of Angkor. Volume 1: the excavation of Ban Lum Khao. Bangkok: Fine Arts Department of Thailand.

Higham, C., T.F.G. Higham & A. Kijngam. 2011. Cutting a Gordian knot: the Bronze Age of Southeast Asia: origins, timing and impact. Antiquity 85: 583-98.

Hillson, S. 1996. Dental anthropology. Cambridge: Cambridge University Press.

Hobbie, E.A. & R.A. Werner. 2000. Intramolecular, compound-specific, and bulk carbon isotope patterns in [C.sub.3] and [C.sub.4] plants: a review and synthesis. New Phytologist 161: 371-85. http://dx.doi.org/10.1111/j.14698137.2004.00970.x

Johnson, A.W. 2000. The evolution of human societies: from foraging group to agrarian state. Redwood City (CA): Stanford University Press.

Kealhofer, L. & D. Piperno. 1994. Early agriculture in Southeast Asia: phytolith evidence from the Bang Pakong Valley, Thailand. Antiquity 68: 564-72.

Kijngam, A. 1979. The faunal remains from Ban Chiang and its implications for Thai culture history. Unpublished MA dissertation, University of Otago.

--2010. The mammalian fauna, in C.F.W. Higham & A. Kijngam (ed.) The origins of the civilization of Angkor. Volume 4: the excavation of Ban Non Wat. Part 2: the Neolithic occupation: 189-97. Bangkok: Fine Arts Department of Thailand.

King, C.A. 2006. Paleodietary change among pre-state Metal Age societies in northeast Thailand: a stable isotope approach. Unpublished PhD dissertation, University of Hawaii.

King, C.L., N. Tayles & K.C. Gordon. 2011. Re-examining the chemical evaluation of diagenesis in human bone apatite. Journal of Archaeological Science 38: 2222-30. http://dx.doi.Org/10.1016/j.jas.2011.03.023

King, C.L., R.A. Bentley, N. Tayles, U. Strand Vidarsdottir, G. Nowell & C.G. Macpherson. 2013. Moving peoples, changing diets: isotopic differences highlight migration and subsistence changes in the Upper Mun River Valley, Thailand. Journal of Archaeological Science 40: 1681-88. http://dx.doi.Org/10.1016/j.jas.2012.11.013

Koch, P.L., N. Tuross & M.L. Fogel. 1997. The effects of sample treatment and diagenesis on the isotopic integrity of carbonate in biogenic hydroxylapatite. Journal of Archaeological Science 24: 17-29. http://dx.doi.org/10.1006/jasc. 1996.0126

Layton, R. R. Foley, E. Williams, C. Chang, T. Ingold, D.I. Olszewski, M. Rosenberg, M.S. Shackley, E.A. Smith & M. Zvelebil. 1991. The transition between hunting and gathering and the specialized husbandry of resources: a socio-ecological approach. Current Anthropology 32: 255-74.

Leach, E.R. 1954. Political systems of Highland Burma: a study of Kachin social structure. Boston (MA): Beacon.

Lekagul, B. & J.A. McNeely. 1977. Mammals of Thailand. Bangkok: Kuruspha Ladprao.

Mead, J.F., R.B. Alfin-Slater, D.R. Howton & G. Popjak. 1986. Lipids: chemistry, biochemistry and nutrition. New York: Plenum.

Montgomery, J., J. Beaumont, M. Jay, K. Keefe, A.R. Gledhill, G.T. Cook, S.J. Dockrill & N.D. Melton. 2013. Strategic and sporadic marine consumption at the onset of the Neolithic: increasing temporal resolution in the isotope evidence. Antiquity 87: 1060-72.

Moore, E., T. Freeman & S. Hensley. 2007. Spaceborne and airborne radar at Angkor: introducing new technology to the ancient site, in J. Wiseman & F. El-Baz (ed.) Remote sensing in archaeology: 185-216. Springer: New York.

Nitta, E. 1991. Archaeological study on the ancient iron-smelting and salt-making industries in the northeast of Thailand. Preliminary report on the excavations of Non Yang and Ban Don Phlong. Journal of Southeast Asian Archaeology 11: 1-46.

Rispoli, F. 2008. The incised and impressed pottery style of mainland Southeast Asia: following the paths of neolithization. East and West 57: 235-304.

Rowley-Conwy, P. 2011. Westward Ho! Current Anthropology 52(S4): S431-51.

Ruel, M.T., J.L. Garrett, C. Hawkes & M.J. Cohen. 2010. The food, fuel, and financial crises affect the urban and rural poor disproportionately: a review of the evidence. The Journal of Nutrition 140: 1705-65. http://dx.doi.org/10.3945/jn.109.110791

Sahlins, M.D. 1963. Poor man, rich man, big-man, chief: political types in Melanesia and Polynesia. Comparative Studies in Society and History 5: 285-303.

Schoeninger, MJ. & M.J. DeNiro. 1984. Nitrogen and carbon isotopic composition of bone collagen from marine and terrestrial animals. Geochimica et Cosmochimica Acta 48: 625-39.

Schoeninger, M.J. & K. Moore. 1992. Bone stable isotope studies in archaeology. Journal of World Prehistory 6: 247-96. http://dx.doi.org/10.1007/BF00975551

Schwarcz, H.P. & M.J. Schoeninger. 1991. Stable isotope analyses in human nutritional ecology. American Journal of Physical Anthropology 34: 283-321. http://dx.d0i.0rg/l 0.1002/ajpa. 1330340613

Turnbull, C.M. 1965. Wayward servants: the two worlds of the African pygmies. Westport (CT): Greenwood.

Van der Merwe, N.J., R.H. Tykot, N. Hammond & K. Oakberg. 2000. Diet and animal husbandry of the Preclassic Maya at Cuello, Belize: isotopic and zooarchaeological evidence, in S. Ambrose & M.A. Katzenberg (ed.) Biogeochemical approaches to paleodietary analysis: 23-38. New York: Kluwer Academic.

van der Veen, M. 2003. When is food a luxury? World Archaeology 34(3): 405-27. http://dx.doi.org/10.1080/0043824021000026422

Vogel, J.C. 1993. Variability of carbon isotope fractionation during photosynthesis, in J.R. Ehleringer, A.E. Hall & G.D. Farquhar (ed.) Stable isotopes and plant carbon-water relations: 29-46. New York: Academic Press.

Weber, S., H. Lehman, T. Barela, S. Hawks & D. Harriman. 2010. Rice or millets: early farming strategies in prehistoric central Thailand. Archaeological and Anthropological Science 2: 79-88. http://dx.doi.org/10.1007/sl 2520-010-0030-3

White, J.C. 1982. Ban Chiang: discovery of a lost Bronze Age. Philadelphia: University Museum, University of Pennsylvania & Smithsonian Institution Traveling Exhibition Service.

--2008. Dating early bronze at Ban Chiang, Thailand, in J.-P. Pautreau, A.-S. Coupey, Z. Zeitoun & E. Rambault (ed.) Archaeology in Southeast Asia: from Homo erectus to the living traditions. Choice of Papers from the 11th EurASEAA Conference, Bougon: 91-104. Chiang Mai: European Association of Southeast Asian Archaeologists.

--2011. Emergence of cultural diversity in mainland Southeast Asia: a view from prehistory, in N. Enfield (ed.) Dynamics of human diversity: 9-46. Canberra: Pacific Linguistics.

White, J.C. & E.G. Hamilton. 2009. The transmission of early bronze technology to Thailand: new perspectives. Journal of World Prehistory 22: 357-97. http://dx.doi.org/10.1007/s10963-009-9029-z

White, J.C., D. Penny, L. Kealhofer & B. Maloney. 2004. Vegetation changes from the Late Pleistocene through the Holocene from three areas of archaeological significance in Thailand. Quaternary International 113: 111-32.

Wohlfarth, B., W. Klubseang, S. Inthongkaew, S.C. Fritz, M. Blaauw, P.J. Reimer, A. Chabangborn, L. Lowemark & S. Chawchai. 2012. Holocene environmental changes in northeast Thailand as reconstructed from a tropical wetland. Global and Planetary Change 92-93: 148-61. http://dx.doi.Org/10.1016/j.gloplacha.2012.05.008

ZHANG, C. & H-C. Hung. 2010. The emergence of agriculture in southern China. Antiquity 84: 11-25.

Received: 27 September 2012; Accepted: 6 December 2012; Revised: 2 April 2013

Charlotte L. King (1), R. Alexander Bentley (2), Charles Higham (3), Nancy Tayles (4), Una Strand Vidarsdottir (1), Robert Layton (1), Colin G. Macpherson (3) & Geoff Nowell (6)

(1) Department of Anthropology, Durham University, South Road, Durham DH1 3LE, UK

(2) Department of Archaeology and Anthropology, University of Bristol, 43 Woodland Road, Bristol BS8 1UU, UK

(3) Department of Anthropology and Archaeology, University of Otago, Castle Street, Dunedin 9054, New Zealand

(4) Department of Anatomy, University of Otago, PO Box 913, Dunedin 9054, New Zealand

(5) Stable Isotope Laboratory, Department of Earth Sciences, Durham University, Elvet Hill, Durham DH1 3 TH, UK

(6) Department of Earth Sciences, Science Labs, Durham University, South Road, Durham DH1 3LE, UK

Table 1. The isotopic samples used in this study, ordered
by burial phase. For convenience, the mortuary phase names
used are those of the primary sample at Ban Non Wat, with
comparative sites fitted into this chronology. We use the
most recently produced dates from Higham et al.
(2011) for the Sakon Nakhon Basin (BC = Ban Chiang; EP,
MP and LP refer to Early, Middle and Late Phases).

           Upper Mun River Vallley

Phase       Date        BNW   BLK   NUL

Neo 1   1650-1250 BC    8
Neo 2   1250-1050 BC    11    4
BAI     1050-1000 BC    2
BA2      1000-900 BC    14    19
BA3A      90-850 BC     13
BA3B     850-800 BC     5
BA4      800-700 BC     35
BA5      700-420 BC     6
IA1      420-100 BC     15          4
IA2     200 BC-AD 200   4           10
IA3      AD 200-400                 11
IA4      AD 400-600                 9

           Sakon Nakhon Basin

Phase          Date           BC

Neo 1   1550-1250 BC (EPI)
Neo 2   1250-1050 BC (EPII)   9
BAI     1050-900 BC (EPIII)   5
BA2     900-420 BC (EPIV-V)   7
BA3A                          13
BA3B
BA4
BA5
IA1            MP VI          1
IA2           MPVIII          5
IA3            LPIX
IA4             LPX           1

Table 2. Results of statistical testing for differences
in mean carbon isotope values between phases in the
Upper Mun River Valley. Figures in # are
statistically significant.

                    Mean [delta]        p (two-tailed
                   [sup.13]C ([per      t-test) with
Mortuary phase      thousand] PDB)     following phase

Neolithic 1            -11.4               0.008#
Neolithic 2            -13.1               0.230
BA1                    -12.4               0.001#
BA2                    -13.8               0.001#
BA3a                   -13.3               0.874
BA3b                   -13.3               0.207
BA4                    -13.2               0.051
BA5                    -12.9               0.719
LAI                    -12.7               0.039#
IA2                    -13.4               0.034#
IA3                    -13.8               0.448
IA4                    -13.9                N/A

Table 3. Intersite comparison of mean [delta][sup.13]C (%c PDB) for
contemporaneous burials with significance tested using two-tailed
independent f-testing.

                Mean [delta][sup.13]C     Mean [delta][sup.13]C
                ([per thousand] PDB)       ([per thousand] PDB)
Phase              at Ban Non Wat            at Ban Lum Khao

Neolithic 2             -12.8                     -14.0
Bronze Age 2            -13.4                     -14.1
Iron Age 1              -12.6                      N/A

                Mean [delta][sup.13]C
                ([per thousand] PDB)
Phase              at Noen U-Loke        Significance

Neolithic 2              N/A              p = 0.001
Bronze Age 2             N/A              p = 0.001
Iron Age 1              -14.0             p = 0.001