The ENCOUNTER project (fig.1) was organised into five core work packages (WP), each focusing on different aspects of the transition to rice and millet agriculture in the Japanese archipelago during the 1st millennium BCE. While we generated some new data (e.g. organic residue analyses of Jomon and Yayoi ceramics for WP2), most analyses were carried out on legacy data that were collated, digitised, and curated to facilitate core computational and statistical analyses.
WP1 gathered and examined more than 35,000 radiocarbon dates and developed novel statistical methods to infer population changes from such data. The methodology we developed was made available to the larger academic community as open-source software packages and enabled us to identify regional differences in the demographic response to the arrival of farming (fig.2) revealing major differences in the consequences of the new subsistence economy that can only be in part explained by the differences in the suitability of farming modelled in WP4.
WP2 investigated changes in the culinary practices within the Japanese islands during the adoption and diffusion of rice and millet agriculture by carrying out biomolecular analyses of food crust remains recovered from ceramics (fig.3). New collaborations offered the opportunity to examine a larger sample of previously collected data, enabling the WP to identify continuity in culinary practices within Japan and notable differences to what we observe in the Korean peninsula. These findings suggest that the transmission of the new subsistence economy did not entail a faithful transmission of culinary practises, which instead retained many of its pre-existing elements.
WP3 reconstructed spatial and temporal variation in the material culture (fig.4) and developed a simulation model to understand better how different cultural elements are transmitted together or separately. The analyses of the material culture identified distinct cultural clines for both functional traits and cultural traits, providing insights into how farming dispersal led to the emergence of new regional patterns of cultural interaction. The simulation model provided a theoretical framework for determining the circumstances under which selectively ‘neutral’ were transmitted along with beneficial innovation through a ‘cultural hitchhiking’ process.
WP4 modelled the ecological niche of rice (fig.5) to determine how variations observed in material culture, culinary traditions, demographic growth, and dispersal rate can be explained by differences in the suitability of farming. The analyses entailed a combination of paleoclimate and statistical modelling, field experiment data, and a range of archaeological proxies linked to rice cultivations (paddy field sites, macrofossil remains, and dedicated tools for harvesting) to examine both where and when rice could have been cultivated and where it was grown.
WP5 examined in detail the archaeobotanical evidence, tracking the dispersal and the diffusion rate of rice agriculture (fig.6) the relative contribution of the new crops in relation to pre-existing wild plant resources, and morphological variations in the rice grain during its diffusion in the Japanese islands. Some of the analyses required the development of new statistical methods to identify more accurately and precisely where and when we can identify episodes of slowdowns and accelerations in the diffusion of farming.
The picture emerging from these different lines of enquiries provides a new insight into the tempo, mode, and consequences of the introduction of rice and millet farming in the Japanese archipelago. These results have been presented in 25 conference papers, 11 journal articles, and a major international symposium, advancing our understanding of this pivotal moment in Japanese prehistory, generating new hypotheses, and offering a suite of new methods for pursuing similar research in other regions.
