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

Abstract

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.

Pathways of Rice Diversification across Asia

“…The evolution of largergrained, and higher yielding indica accompanied the growth of population, indicated by more permanent habitation sites and increasing size of larger sites over the course of the Chalcolithic and Iron Age periods throughout the Ganges plains between 1500 and 500 BC, with clear urbanism by the end of this sequence (Conningham 2005). This was also the period when rice became more widespread throughout the Indian subcontinent Silva et al 2015).…”

“…One of the curious aspects of the early history of rice is how long it took to appear south of the Yangtze basin: with the earliest rice in the Pearl River of southern China dating from ca. 2500 BC, and similar ages for the establishment of rice in the Upper Yangtze region in Yunnan or on the coastal plains of the island of Taiwan (Silva et al 2015). It can be suggested that the delay was partly about waiting until less intensive dry rice systems, and upland rice varieties, had evolved from the original wet rices of the Yangtze.…”

“…The evolution of genes connected to productivity under temperate summer conditions may well be related to the subsequent dispersal of rice to other northern regions such as the Korean Peninsula (ca. 1500 BC) and Japan (after 1000 BC) (Silva et al 2015;Fuller et al 2011).…”

“…Over the past decade archaeobotanical research based at the UCL Institute of Archaeology and involving a wide range of collaborators in east, south, and southeast Asia has been seeking new insights into the processes by which rice evolved and rice cultivation systems evolved, and how these relate to cultural change and long-distance cultural relationships across Monsoon Asia. While this research began with critical reflections and debate surrounding the initial cultivation of rice in China (Fuller, Harvey and Qin 2007) and India (Fuller 2006), it has expanded into better documenting the evidence for morphological change during domestication ), the characterisation of variable wet and dry ecologies of early rice cultivation Fuller and Weisskopf 2010;Weisskopf et al 2014), and to tracking the spread of rice through the compilation and analysis of a large database of archaeobotanical evidence (Silva et al 2015). We have completed more than six years of research supported by major NERC (Natural Environment Research Council) grants (Grant NE/G005540/1 "The Identification of Arable Rice Systems in Prehistory" (2009)(2010)(2011)(2012); Grant NE/ K003402/1 "The impact of evolving rice systems from China to Southeast Asia" (2013)(2014)(2015)(2016)), developing and deploying new methods for establishing the past ecology of rice cultivation and its potential impact not just on social change, but also on the global environment through methane emissions produced by methanogenic bacteria that thrive in the warm stagnant water of paddyfields (Fuller et al 2011).…”

“…Based on a database of archaeological evidence for rice from across 400 sites (Silva et al 2015), we can visualize coverage of rice archaeobotany on a heat map (Fig. 1).…”