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[abstracts will be added as they become available]
Dorian Q Fuller (UCL)-- Overview: A decade of progress on Early Rice
The past decade or so has seen major progress in research on the archaeobotany or rice. This presentation will consider this advances, including issues of (1) the recognition of domestication, not just cultivation, (2) the genetics and geographic of multiple origins, (3) the importance of hybridization and the proto-indica hypothesis, and (4) the recognition of ecological diversity among rice cultivation systems of the past. This will take the form of some personal reflections, on both Indian and Chinese archaeology. For example, about a decade ago I argued strongly for an independent domestication of rice in the Ganges (J. of World Prehistory 2006), which I would now temper with the more complex proto-indica hypothesis. About a decade ago (2006), I started research at Tianluoshan and began a deconstruction of of the notion of intensive rice agriculture in the Hemudu culture. Some aspects of that critique hold up (e.g. late domestication and transition to agricultural dependence), while others need to be tempered, i.e. the beginnings of cultivation may be much earlier, and patterns may have been different in different parts of China. This presentation will conclude with some of the research themes and methods that the Early Rice Project has tried to develop since it had its first NERC funding in 2009.
Session 1: Arable ecology and subsistence systems: analytical methods
Marco Madella (Universitat Pompeu Fabra)-- Agricultural subsistence systems and non-food products. How phytoliths can help identifying the forgotten production of arable crops.
Rice, and in general cereal, arable systems main produce were the grains. However, these fields also produced abundant biomass in the form of chaff and straw. Sometime this biomass was directly re-incorporated (albeit with a loss of potential carbon feedstock) into the field systems by burning after the harvest, as it also happens today. However, straw and chaff most often entered the economy of early agriculturalists groups in a great variety of ways: from temper for pottery to fuel and livestock food. Phytoliths can help identifying these by-products and understand their economic importance in agricultural subsistence systems. Furthermore, through a better understanding of the use of these by-products, we might be able to improve the assessment of the greenhouse gas emissions of the early Anthropocene.
Alison Weisskopf (UCL)-- A path between the fields: identifying changing rice arable systems in Asia using silica bodies
Different rice agricultural systems require varying degrees of human organisation and water management, indicating possible social and cultural changes. One of the larger aims of our project has been to isolate and identify these developments in arable farming. I use silica bodies, to pinpoint changes in cultivation system. The range of systems produce different sets of weed communities and in turn these produce diverse phytolith assemblages. The first method I used was to create ecological groups of phytoliths from a range of modern traditionally farmed fields and archaeological samples and apply multivariate analysis to these groups. Next I applied Madella's fixed versus sensitive model, which uses plant cells that are predisposed to take up silica (fixed) in contrast to those which are formed when there is increased water flow through the plant (sensitive), to infer wet versus dry farmed rice systems. Here I demonstrate how these methods can be applied through case studies from the region while also considering their limitations.
Huw Barton (University of Leicester)--
Amy Bogaard (University of Oxford)-- Combining functional weed ecology and crop stable isotope values: case studies from the AGRICURB project
Functional weed ecology and crop stable isotope values offer complementary insights into crop growing conditions, present and past. As a multi-stranded method, this combined approach also has the potential to 'triangulate onto' farming regimes for which no close analogue exists. I illustrate these techniques using case studies from western Eurasia under investigation in 'The Agricultural Origins of Urban Civilization' project at Oxford
Session 2: Indian archaeology and rice (1)
Charlene Murphy (UCL)-- Exploring Eastern Patterns, New Archaeobotanical and Radiocarbon Evidence from Kirindia and Kandarodai, Sri Lanka and Harirajpur, Odisha
This paper will present the new radiocarbon dating and environmental data, specifically the archaeobotanical results recovered from flotation, from the historic coastal sites of Kirindia (400-850 AD), in the southern province, and Kandarodai (300-50 BC), located in the Jaffna peninsula in the north of Sri Lanka as well as the Chalcolithic site of Harirajpur (1370-1100 BC) in Odisha, India. This presentation will explore the links between east India and Sri Lanka in terms of the archaeobotanical assemblages. The archaeobotanical assemblages from all three sites are dominated by rice but have key differences which suggest differences in crop processing, agricultural conditions and preferences and local ecological conditions at the time of occupation.
Pramod Joglekar (Deccan College)
Monica L. Smith (UCLA)-- Food, Flood, and Famine: Urban Perspectives on Rice Production and Consumption in the Early Historic Period of the Indian Subcontinent (3rd century BC-4th century AD)
By the late first millennium BC, there were nearly 100 sites in the Indian subcontinent that can be characterized as "urban" on the basis of areal extent and population size. These cities were all dependent on hinterlands for provisioning, in which rice production would have figured prominently. Production would have encompassed two fluctuating inputs: rural labor, which may have become scarce when villagers left farmlands to become city-dwellers; and water, which can fluctuate dramatically in the subcontinent on both a seasonal basis through the monsoon and through the occasional impact of tropical cyclones. Using the concept of "virtual water," the paper will consider the eastern Indian subcontinent and the way in which an abundance of water (even with its risks of overabundance) encompassed challenges but also permitted high productivity within short distance of urban centers. These high levels of productivity per land area enabled cities to engage in short-distance economies for food production, while maintaining regional contacts through durable-goods trade to mitigate occasional episodes of crop failure and famine in times of major flooding.
Session 3: Archaeology from South China to Southeast Asia
Barry Rolett (University of Hawaii)-- Phytolith evidence for Neolithic rice cultivation in Fujian, southeast China by Barry Rolett, Ting Ma, Zhuo Zheng, and Gongwu Lin
Neolithic cultures of the coast of southeast China opposite Taiwan are significant for understanding the spread of rice agriculture and origins of the Austronesian seafarers. Neolithic economies of this area were maritime-oriented. Until now, a lack of direct evidence for agriculture has made it difficult to know if they relied on the exploitation of wild plants such as nuts and sago palm, or a combination of farming and foraging. Here we report the discovery of rice phytoliths found in archaeological deposits of the Zhuangbianshan (ZBS) archaeological site (Fuzhou Basin, Fujian). This is the first robust evidence for Neolithic rice farming in Fujian. Rice was part of a broad-spectrum Neolithic subsistence economy centered on fishing and hunting. Chronologies based on AMS dates and artifact typology place the earliest rice during the Tanshishan Period (5000 - 4300 cal BP) followed by a shift to economic dependency on rice in the Huangguashan Period (4300 - 3500 cal BP). The ZBS phytolith assemblage contains high frequencies of rice husk (glume epidermal cells) phytoliths, with far fewer leaf and stem types. This indicates late stage processing activities such as dehusking, implying a focus on consumption rather than rice production.
Katie Miller (UCL)-- Rice agriculture at Ban Non Wat: Identifying change in the upper Mun Valley from plant macro-remains.
Ban Non Wat is a prehistoric moated site on the Khorat Plateau of the upper Mun Valley. The Environment Change and Society before Angkor: Ban Non Wat and the Upper Mun River Catchment in Prehistory project aims to examine environmental change and acquire 'a more comprehensive view of prehistoric life across the entirety of the site'. It has attempted to achieve this with a series of smaller excavations, mostly in more peripheral areas which complement the large central Origins of Angkor project area. My masters dissertation was based on examination of the archaeobotanical remains from N96, a small trench at the northernmost edge of the site, and aimed to reconstruct aspects of past environments, agricultural practices and diet. A sharp contrast between the weed flora of the Bronze and Iron Ages indicates a change in the form of rice agriculture at the site from upland and dryland to wetland systems probably caused by a combination of environmental and socio-political factors.
Charles Higham (University of Otago) Social changes and rice agriculture in Northeast Thailand: from the Neolithic to the Iron Age
This paper will first outline the chronological sequence in Northeast Thailand from initial Neolithic settlement to the end of the Iron Age. It will then review the evidence for the presence of rice from key sites before concentrating on a major change in cultivation that took place during the later Iron Age. This involved the construction of moat/reservoirs, the application of animal traction through ploughing, and probably, the construction of permanent fields. The social changes seen in mortuary and residential behaviour that integrated with these changes will be summarized and evaluated.
Session 4: Indian archaeology and rice (2), from the Northeast to the South
[UNFORTUNATELY NOT ABLE TO ATTEND] Veena Manikantannair Padmakumari (Anna University, Chennai)-- Holocene vegetation and climate inferences from phytoliths and pollen from catchment area basins of South India. By Veena M.P. and Hema Achyuthan (Department of Geology, Anna University, Chennai 600 025.)
This paper reports the potential of phytoliths and pollen study as a useful tool in evaluating and reconstruction of past climate and human impact in reducing catchment area basins from South India. Natural fresh water lakes in Kerala, South India, are affected by human activity. Anthropogenic activities including increase in population leading to increased demand for agricultural land and water that result in the lowering of water levels. Vellayani Lake and Pookode lake are the two major freshwater lakes in Kerala, which receive both SW and NE monsoon. Detailed study from a 145 cm sediment core from low lying Vellayani lake represents deposition since 3000 years BP, but at least half of the sediment has been deposited since 1650 AD. Low frequency of overall Phytoliths morpho types indicate a reduction in vegetation cover and a significant increase in grassland since 2300 yrs BP due to climate warming, weakened south west monsoon, deforestation reclamation of the lake margins for intensive agricultural practices. These observations are supported by the occurrence of diatoms and sponge spicules that indicate shallowing of the lake since 2300 yrs BP onwards. Integration of all the results show that the Vellayani Lake has contracted because of a weakened Indian southwest monsoon since 3000 yrs BP as well as intense human impact in the form of deforestation, irrigation and agricultural practices. Similarly, a sediment core 125 cm long was investigated for sediment texture, dating and geochemical composition from Pookode Lake, Kerala. Geochemical data of the sediment cores were corroborated with phytolith and pollen studies. Although phytoliths occur in the entire sediment core, pollen assemblages start occurring only since 1500 14C BP (AD 650 cal.). The sediments older than 150014C BP were not suitable for the preservation of the pollen assemblages. There is a major change in the lake hydrology, indicating lacustrine conditions subsequent to 1500 BP. Occurrence of diatoms and variation in sediment detritus in the upper sediment layers of the sediment core indicate shallowing of the lake. Presence of Careya in the Pookode lake sediment core suggests a decline in forest cover in the hinterland of the lake. The best explanation of its appearance may be the clearing of forest for agriculture since 565BP.
Ellie Kingwell-Banham (UCL)-- Identifying rice cultivation systems in South Asia
Phytolith and macrobotanical samples from five sites across India and one from Sri Lanka have been analysed in order to identify the types of rice cultivation systems used at each site. These sites range from the Neolithic-Chalcolithic (Tokwa, Golbai Sasan and Gopalpur) to the Early Historic-Historic periods (Kodumanal, Perur and Mantai). In this way an initial picture of the broader changes that rice agriculture in South Asia went through has been established. The results have implications both for the use of phytolith and macrobotanical samples in this type of study, but also for our understanding of the link between the development of irrigation systems and the development of urbanism in Early Historic South Asia.
Tilok Thakuria (Northeastern Hill University, Meghalaya, India)
Session 5: Southeast Asian archaeology & rice
Janice Stargardt (University of Cambridge)
Rasmi Shoocongdej (Silpakorn University)
Peter Bellwood (ANU) ON THE MERITS OF BIG PICTURES: THE HOLOCENE IN SOUTHEAST ASIA
In my presentation I will discuss first the Mesolithic era in SE Asia, defined as commencing from the Holocene inception at 11.5 kya and lasting until the regional commencement of the Neolithic era. The Mesolithic has Palaeolithic era (Pleistocene epoch) antecedents for pottery and edge-ground axes, but deserves recognition as an era of considerable and unprecedented cultural variegation, contemporary with the Neolithic era in China.Secondly, I discuss Neolithic demography in China, and illustrate some Neolithic high points in SE Asia. The discussion will be peppered with references to genetics (mostly comparative modern genetics, SNP-based), craniometric analysis of skulls, and Austronesian comparative linguistics. I also discuss the Austronesian-region chronological cline in material culture moving south from China and Taiwan, and refer to food production and rice discoveries in Island and Mainland SE Asia. One very good reason why rice cultivation never spread into Oceania or even into New Guinea is presented.I find that most of us nowadays are coming to similar conclusions from different perspectives. The past is partly about admixture/borrowing in genes, languages, economies, and ways of making things, but there is more to it than that, and in my view population migration was from time to time a very real factor. Total replacement of one population by another is a different matter altogether, and we have no reason to suspect that this ever happened in SE Asian prehistory
Session 6: Indian archaeology and rice (3), the Northwest
Jennifer Bates (University of Cambridge)-- Rice Domestication, Cultivation and Agriculture: the role of the Indus Civilisation? By Jennifer Bates, Cameron A. Petrie and Ravindra N. Singh
The nature and timing of rice domestication and the development of rice cultivation is a hotly debated topic in South Asian archaeology. Across northern South Asia there is a significant gap (c.4200 years) between evidence for the first exploitation of wild rice and for the agriculture of fully domesticated rice. This paper presents new data collected from three Indus Civilisation sites in north-west India. The analysis suggests that between 3000-1500BC there was an increase in the proportion of domesticated type spikelet bases and a decrease in wild types present at the sites. This fits with models of the slow development of rice exploitation from wild foraging to full cultivation or agriculture. The weeds however showed no increased proportions of wetland species as has been previously hypothesised. Instead a mix of wetland and dryland species was identified in all samples. Although this data is preliminary, it suggests that the development of an independent rice tradition may have been intertwined with the furthest reaches of the Indus Civilisation and that when fully domesticated Oryza japonica arrived c.1900BC it arrived in an area already familiar with domesticated rice cultivation and a range of cultivation techniques.
Penny Jones (University of Cambridge)-- Stable isotope analysis: a new window into early rice? By Penny Jones, Martin Jones, Tamsin O'Connell and Cameron Petrie
Stable isotope analysis of archaeobotanical remains is a rapidly growing field, with studies on topics from early Holocene water management to manuring in the European Neolithic. However, so far rice has been virtually absent from the archaeobotanical isotope literature, with just one publication to date. In this paper, I will first discuss the potential for isotope analysis to contribute towards understandings of early rice cultivation systems and land management practices. This will include a discussion of some of the limitations of isotopic interpretation, as well as proposals for future methodological studies. The paper will conclude with a presentation of the first archaeobotanical rice isotope data from South Asia. These come from the Indus Civilisation site of Masudpur I. Overall, the data are consistent with a dryland rice cultivation system, and demonstrate the potential for isotope analysis to provide a new line of evidence which can be combined with weed ecology, phytolith and other analyses to build a more holistic understanding of early rice cultivation.
Dorian Q Fuller (UCL)-- The Proto-indica hypothesis and place of rice in the agriculture of Chalcolithic western India and Pakistan
This presentation will outline the proto-indica hypothesis, which proposes that early rice exploitation in northern India followed a non-domestication trajectory, i.e. management without selection for significant features of the domestication syndrome, and was then hybridized to domesticated japonica that was introduced with a full domestication syndrome. The resulting hybrid, once backcrossed with the indigenous proto-indica parent, resulted in subspecies indica as we understand it today-with a distance genomic background but shared domestication alleles. This also implies that throughout history India had a mixture if japonica and indica cultivars. There are two plausible routes by which japonica rice reached the subcontinent, either via central Asia into Pakistan or from the northeast (Yunnan to Assam), but the archaeological and archaeobotanical evidence supports the central Asian route into Northwest India. The evidence for a "Chinese horizon" in northern Pakistan and Kashmir is reviewed. In addition we will consider the place of rice in subsistence in northwest India and Pakistan before and after the likely japonica introduction and hybridization event. While this had little impact on the subsistence systems of the greater Indus region it had a major effect down the line the middle Ganges, essentially and Neolithic Demographic transition in the late Neolithic of Gangetic plains.
Vasant Shinde (Deccan College)
Session 7: Chinese archaeology and rice
Chris Stevens (UCL)
Min Rui (Yunnan Institute of Archaeology)
He will introduce his recent excavations on the Neolithic site of Baiyancun in Yunnan. (Translation into English by Yijie Zhuang).
Yijie Zhuang (UCL)-- Evolution of paddy fields in China
Paddy fields appeared very early in South China and have been a prominent feature in the long-term development of rice-farming dominant subsistence in prehistoric and historic times. The evolution of paddy fields is accompanied with a continuous biological intervention and ecological modification of rice plants by humans, increasing management of water situations, and gradual development of social complexity. By setting the broad scene of the climatic and geomorphological backgrounds of prehistoric paddy fields in South China, this paper examines the physical conditions, ecological modification, and water management of prehistoric rice farming. It will then explore the changing relationship between human societies and rice farming.
Session 8: Rice in the West: the Middle East and Africa
Nicole Boivin (Oxford)-- Introduction of Asian rice to Africa and Madagascar. By Nicole Boivin, Alison Crowther, Leilani Lucas, Dorian Fuller and the Sealinks Team.
Louis Champion (UCL)-- Oryza glaberrima steud. (African rice): history and new evidence from North Benin by Louis Champion, Anne Haour (Univ. of East Anglia) & Dorian Fuller
Currently, the domestication of African rice (Oryza glaberrima Steud.) remains problematic, as little evidence is available (see Porteres1976, Agnoun 2012 Murray 2004). As put by Murray (2004: Page 53): "Archaeological data on the place and timing of African rice domestication remain virtually non-existent". Archaeological excavations in the area of Lake Chad and the Niger Valley provide evidence of African rice around 1000 BP. The oldest evidence of wild rice comes from ceramic impressions in Kursakata (ca.1000BC ) and Gajiganna (1800-800BC) (Klee et al. 2004). Evidence of domesticated rice is more recent, coming from the Inland Niger delta in Jenné-Jeno, Dia and Sorotomo in Mali (Fuller 2013; Murray 2004; McIntosh 1995) and Birni Lafia, Pekinga, Madekali and Tintin in Benin ( this research). Since 500 BC, African rice was probably cultivated along the Niger River bend (Fuller 2013; Murray 2004; Sweeney 2007; Zhi-ming 2011; Agnoun 2012). At Dia, a large quantity of rice grains was studied and AMS dates indicated rice was present from about 2500 years ago; at Jenné-Jeno rice is likewise present from the earliest occupation (250 BC) (Murray 2004)
The present research looks at flotation samples of three sites in northern Benin being investigated as part of Anne Haour's ERC-funded Crossroad of Empire project, investigating the early urban centre of Birni Lafiya and other broadly contemporary sites.
Sureshkumar Muthukumaran (UCL History)-- The origins of rice cultivation in the Middle East and the Mediterranean
Rice (Oryza sativa L.) is at present a common article of food across the Middle East but the origins of rice cultivation in the Middle East remains nebulous. Rice already appears as a staple crop in many regions of the Middle East and Eastern Mediterranean by Late Antiquity (c. 250-600 AD), growing especially in Mesopotamia, Susiana, the lowlands south of the Caspian sea, in the well-watered districts of Palestine and the adjacent Nile Delta and in the low-lying plains of Anatolia like those of the Seyhan river delta in Cilicia. The earliest history of rice in the Middle East and the Mediterranean has, however, elicited scant scholarly attention and its appearance in antiquity has largely been discussed with the aid of Greco-Roman or Hebraic texts. The materials for the study of rice cultivation in the ancient Middle East are, however, already to be found in Akkadian and Elamite, the written languages of Mesopotamia and southwestern Iran. Owing to substantial philological impediments, these texts have rarely been utilised in any discussion of rice cultivation in the ancient Middle East and the Mediterranean. I will attempt in this paper to integrate the diverse strands of archaeological and textual data in order to understand the spatial and chronological distribution of rice consumption and cultivation as well as to postulate potential trade pathways through which rice was introduced into the Middle East and the Mediterranean.
Mark Nesbitt (Kew)-- discussant
Session 9: Southeast Asian subsistence regimes: Hunter-gatherers to the Metal Age
Marc Oxenham (ANU)-- The Mainland Southeast Asian Neolithic: Foragers or Farmers? By MF Oxenham & A Willis
The Neolithic in Mainland Southeast Asia (MSEA) emerges relatively suddenly c. 4000 BP, for the most part in a landscape inhabited by low density and dispersed forager populations more or less directly descended from the original colonists some 50 000 years ago. The term "Neolithic" is a short hand for new technologies, increased fertility and farming, furthermore in MSEA it may be characterised by the variable presence of "uni-bevelled stone adzes with angular cross-sections and frequent hafting reduction, nephrite (in northern Southeast Asia at least), pottery spindle whorls, shell or bone fishhooks, shaped (rather than simply perforated) body ornaments, and evidence of deliberate settlement construction" (Oxenham and Buckley in press). The key question this paper asks is what was the extent and influence of farming in MSEA Neolithic communities? To this end the evidence for subsistence in a range of well documented MSEA Neolithic assemblages is assessed. Moreover, the question of mobility, population growth and sedentism is also explored in the context of known pre-Neolithic forager communities in the region.
Philip Piper (ANU)-- The Origins and Routes of Translocation of the Earliest Domestic Animals in Southeast Asia
Over the past two decades or so, and following similar paths of enquiry as palaeobotanists, there has been a concerted effort by geneticists and archaeologists to address outstanding questions of how, when and why the first domestic animal populations either emerged in, or were introduced to Southeast Asia. In this presentation I will focus on the three earliest domesticated animals to appear in the region, the pig, dog and chicken, and discuss how far animal domestication research has come. The outcomes of this research provide useful complementary information with regards to proposed routes of plant translocation south from China, and potentially west from South Asia.
Cristina Castillo (UCL)-- Archaeobotany in Southeast Asia: What have we learnt so far...
Archaeobotany as a specialisation in Southeast Asia began in the late 1960s. Archaeobotanical methods (e.g. flotation, phytolith and pollen sampling) are still not routinely used in archaeological fieldwork in SEA, although in the past ten years, archaeobotany has gained momentum. For example, several sites in Thailand (Ban Non Wat, Khao Sam Kaeo, Khao Sek, Non Ban Jak, Phu Khao Thong), Vietnam (Lo Gach, Loch Giang, Rach Nui) and Cambodia (Angkor Wat, Ta Phrom) have included archaeobotanical analyses as part of the excavation agenda. This paper will present some of the latest research derived from macroremains analysis from sites in mainland SEA, with an emphasis on rice and the subsistence regimes. Settled peoples have exploited their surroundings and adopted suitable crops for cultivation, but have also found limiting factors that constrained agriculture and cultivation practices. Discussions revolve around the crops and weeds found in the archaeobotanical assemblages, which help define diets, farming systems and habitats.
Session 10: Modelling the impact of early land use
Jed Kaplan (ARVE, Lausanne)
Liviu Giosan (Woods Hole Oceanographic)-- Fluvial Dynamics and Past Civilizations By Liviu Giosan (Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA)
Development of past human civilizations was intimately linked to water availability. Changes in climate were thus more directly perceived through changes in rainfall patterns, river discharge, floods, and droughts rather than changes in temperature. Reconstructing the dynamics of large rivers as integrators of regional hydroclimate may provide a missing link between the evolution of human cultures and changes in climate. Using recent studies and work in progress, I review several cases of large scale feedback between climate and humans via large rivers in Europe and South Asia. I conclude that without understanding the antiquity of anthropogenic signals and the potential feedback loops between humans and climate our Holocene paleoclimate reconstructions may remain significantly imprecise.
Fabio Silva (UCL) Modelling Rice Dispersals: from geographical origins to methane emissions
Dispersals of major technological innovations have been a cornerstone of archaeology since its inception. The advent of radiometric dating has opened this subject up to quantification, the use of statistics and explicit modelling. This paper will look at past, present and future modelling work related to UCL's Early Rice Project. Using an extensive database of archaeobotanical and radiometric evidence for rice across Asia, including 400 sites from mainland East Asia, Southeast Asia and South Asia, the geographical origins of rice farming, its subsequent spread through Asia and its contribution to atmospheric methane will be analysed.
Session 11: Genetics & aDNA
Ryo Ishikawa (Kobe University)-- Evaluation of the domestication-related traits in rice. By Ryo Ishikawa, Yumi Oka, Ryo Nishioka, Mai Ikemoto, Than Myint Htun, Chizuru Inoue, Koji, Numaguchi, and Takashige Ishii (Graduate School of Agricultural Science, Kobe University, Kobe, Japan)
Asian cultivated rice, Oryza sativa, was known to be domesticated from its wild form, O. rufipogon, around 10.000 years ago. Loss of seed shattering, loss of awn formation and closed panicle are very important traits selected for during rice domestication, as they directly affect seed harvest and yield. We are trying to understand how these traits were selected for especially in the early part of rice domestication. To evaluate these traits more precisely, we produced wild rice lines having domesticated alleles from cultivated rice (O. sativa cv. Nipponbare) in the genetic background of wild rice (O. rufipogon W630) by crossing. We will introduce our recent works on these traits and would like to discuss about the possible roles of these genetic changes on rice domestication.
Robin Allaby (Warwick)
Terry Brown (University of Manchestor) -- Independent domestications of the indica, japonica and aus groups of Asian rice
From archaeological and genetic evidence various contradictory scenarios for the origin of different varieties of cultivated rice have been proposed, the most recent based on a single domestication. By examining 'domestication sweeps' - regions of depleted variation in the cultivated rice genomes relative to wild populations, assumed to result from selection during domestication - we show that there were three independent domestications in different parts of Asia. We identify wild populations in southern China and the Yangtze valley as the source of the japonica gene-pool, and populations in Indochina and the Brahmaputra valley as the source of the indica gene-pool. We reveal a hitherto unrecognized origin for the aus variety in central India or Bangladesh. We also conclude that aromatic rice is a result of a hybridization between japonica and aus, and that the tropical and temperate versions of japonica are later adaptations of one crop. Our conclusions are in accord with archaeological evidence that suggests widespread origins of rice cultivation.