Cristina Castillo

The contribution of rice agriculture and livestock pastoralism to prehistoric methane levels An archaeological assessment

We review the origins and dispersal of rice in Asia based on a data base of 443 archaeobotanical reports. Evidence is considered in terms of quality, and especially whether there are data indicating the mode of cultivation, in flooded (‘paddy’ or ‘wet’) or non-flooded (‘dry’) fields. At present it appears that early rice cultivation in the Yangtze region and southern China was based on wet, paddy-field systems from early on, before 4000 bc, whereas early rice in northern India and Thailand was predominantly dry rice at 2000 bc, with a transition to flooded rice documented for India at c. 1000 bc. On the basis of these data we have developed a GIS spatial model of the spread of rice and the growth of land area under paddy rice. This is then compared with a review of the spread of ungulate livestock (cattle, water buffalo, sheep, goat) throughout the Old World. After the initial dispersal through Europe and around the Mediterranean (7000–4000 bc), the major period of livestock expansion is after 3000 bc, into the Sub-Saharan savannas, through monsoonal India and into central China. Further expansion, to southern Africa and Southeast Asia dates mostly after 1000 bc. Based on these two data sets we provide a quantitative model of the land area under irrigated rice, and its likely methane output, through the mid to late Holocene, for comparison to a more preliminary estimate of the expansion of methane-producing livestock. Both data sets are congruent with an anthropogenic source of later Holocene methane after 3000 bc, although it may be that increase in methane input from livestock was most significant in the 3000–1000 bc period, whereas rice paddies become an increasingly significant source especially after 2000 bc.

Modelling the Geographical Origin of Rice Cultivation in Asia Using the Rice Archaeological Database

We have compiled an extensive database of archaeological evidence for rice across Asia, including 400 sites from mainland East Asia, Southeast Asia and South Asia. This dataset is used to compare several models for the geographical origins of rice cultivation and infer the most likely region(s) for its origins and subsequent outward diffusion. The approach is based on regression modelling wherein goodness of fit is obtained from power law quantile regressions of the archaeologically inferred age versus a least-cost distance from the putative origin(s). The Fast Marching method is used to estimate the least-cost distances based on simple geographical features. The origin region that best fits the archaeobotanical data is also compared to other hypothetical geographical origins derived from the literature, including from genetics, archaeology and historical linguistics. The model that best fits all available archaeological evidence is a dual origin model with two centres for the cultivation and dispersal of rice focused on the Middle Yangtze and the Lower Yangtze valleys.

Rice in Thailand: The Archaeobotanical Contribution

There are few archaeological projects incorporating archaeobotanical sampling and even fewer published archaeobotanical studies in Thailand. Available data show that rice was the ubiquitous cereal in prehistory and particularly during the Metal/Iron Age. This either signifies the importance of rice as a crop or signals a preservation bias; both topics are considered in this paper. The site Khao Sam Kaeo in Peninsular Thailand (ca. 400–100 BCE) is strategically located between the Indian Ocean and the South China Sea providing evidence of Indian, Han Chinese and locally produced cultural material. The archaeobotanical assemblage attests to South Asian and East Asian influence as well: the mungbean and horsegram of Indian origin and the northern Chinese cereal foxtail millet. But the site has also yielded the greatest amount of rice from Thai archaeology and provides information on the domestication of rice and the cultivation practices during this Late Prehistoric period.

Sembiran and Pacung on the north coast of Bali: a strategic crossroads for early trans-Asiatic exchange

Abstract Studies of trade routes across Southeast Asia in prehistory have hitherto focused largely on archaeological evidence from Mainland Southeast Asia, particularly the Thai Peninsula and Vietnam. The role of Indonesia and Island Southeast Asia in these networks has been poorly understood, owing to the paucity of evidence from this region. Recent research has begun to fill this void. New excavations at Sembiran and Pacung on the northern coast of Bali have produced new, direct AMS dates from burials, and analytical data from cultural materials including pottery, glass, bronze, gold andsemi-precious stone, as well as evidence of local bronze-casting. This suggests strong links with the Indian subcontinent and Mainland Southeast Asia from the late first millennium BC, some 200 years earlier than previously thought.

Emergence and Diversification of the Neolithic in Southern Vietnam: Insights From Coastal Rach Nui

ABSTRACT We examine the southern Vietnamese site of Rach Nui, dated to between 3390 and 3850 cal BP, in the context of three major aspects of the Neolithic in Mainland Southeast Asia: mound formation and chronology, construction techniques, and subsistence economy. Results indicate that this ca. 75 m in diameter, 5 m high mound, comprising over a dozen phases of earthen platforms, upon which were raised sophisticated wooden structures, was built in <200 years. While consuming domesticated millet, rice, and occasionally dogs and pigs, the main subsistence orientation included managed tubers and fruits and a range of mangrove ecosystem taxa: catfishes, turtles, crocodiles, monitor lizards, macaques and langurs, to name a few. This combined vegeculture-foraging lifeway in a mangrove forested environment, likely in the context of a tradable goods extractive industry, adds to a growing picture of significant diversity, and sophisticated construction skills in the Southeast Asian Neolithic.

Rice, Beans and Trade Crops on the Early Maritime Silk Route in Southeast Asia

Abstract Plant macrofossils from the sites of Khao Sam Kaeo and Phu Khao Thong on the Thai-Malay Peninsula show evidence of cross-cultural interactions, particularly between India to the west and Southeast Asia to the east. Archaeobotanical analysis of various cereals, beans and other crops from these assemblages sheds light on the spread and adoption of these species for local agriculture. There is also early evidence for the trade of key commodities such as cotton. The plant remains illustrate a variety of influences and networks of contact across South and Southeast Asia during the late first millennium BC.

Multi-layered population structure in Island Southeast Asians

The history of human settlement in Southeast Asia has been complex and involved several distinct dispersal events. Here, we report the analyses of 1825 individuals from Southeast Asia including new genome-wide genotype data for 146 individuals from three Mainland Southeast Asian (Burmese, Malay and Vietnamese) and four Island Southeast Asian (Dusun, Filipino, Kankanaey and Murut) populations. While confirming the presence of previously recognised major ancestry components in the Southeast Asian population structure, we highlight the Kankanaey Igorots from the highlands of the Philippine Mountain Province as likely the closest living representatives of the source population that may have given rise to the Austronesian expansion. This conclusion rests on independent evidence from various analyses of autosomal data and uniparental markers. Given the extensive presence of trade goods, cultural and linguistic evidence of Indian influence in Southeast Asia starting from 2.5 kya, we also detect traces of a South Asian signature in different populations in the region dating to the last couple of thousand years.

Intensive Archaeological Survey in Southeast Asia: Methodological and Metallurgical Insights from Khao Sai On, Central Thailand

Intensive surface surveys are a well-established method in the landscape archaeology of many parts of the world, but have remained relatively rare in Southeast Asian research. This article summarizes the contribution of existing surveys in the latter region and offers results from a short but informative survey of a metal-producing landscape in central Thailand. We argue that there is much to be gained from a fuller integration of systematic landscape reconnaissance into wider Southeast Asian research agendas and consider some of the strengths and weaknesses of such an approach in this cultural and physical environment.

Between foraging and farming: strategic responses to the Holocene Thermal Maximum in Southeast Asia

Large, ‘complex’ pre-Neolithic hunter-gatherer communities thrived in southern China and northern Vietnam, contemporaneous with the expansion of farming. Research at Con Co Ngua in Vietnam suggests that such hunter-gatherer populations shared characteristics with early farming communities: high disease loads, pottery, complex mortuary practices and access to stable sources of carbohydrates and protein. The substantive difference was in the use of domesticated plants and animals—effectively representing alternative responses to optimal climatic conditions. The work here suggests that the supposed correlation between farming and a decline in health may need to be reassessed.

A tale of two rice varieties: Modelling the prehistoric dispersals of japonica and proto-indica rices:

We model the prehistoric dispersals of two rice varieties, japonica and proto-indica, across Asia using empirical evidence drawn from an archaeobotanical dataset of 400 sites from mainland East, Southeast and South Asia. The approach is based on regression modelling wherein goodness of fit is obtained from log–log quantile regressions of the archaeologically inferred age versus a least-cost distance from the origin(s) of dispersal. The Fast Marching method is used to estimate the least-cost distances based on simple geographical features. We explicitly test three hypotheses for the arrival of japonica rice to India where, it has been proposed, it hybridized with the indigenous proto-indica, subsequently spreading again throughout India. Model selection, based on information criteria, highlights the role of the Inner Asia Mountain Corridor in introducing japonica rice into northeast India, followed closely by a ‘mixed-route’ model, where japonica was also almost simultaneously introduced via Assam, Bangladesh and Myanmar. Finally, we estimate the impact of future archaeological work on model selection, further strengthening the importance of the Inner Asia Mountain Corridor.