Periodic Reporting for period 1 - ENCOUNTER (Demography, Cultural change, and the Diffusion of Rice and Millet during the Jomon-Yayoi transition in prehistoric Japan)
Reporting period: 2019-04-01 to 2020-09-30
Work Package 1 (Demography) has collected several proxy data for population change, namely radiocarbon dates from the entire archipelago (currently over 30,000 dates) and dwelling data from selected case studies (currently over 3,000 units). The collection of radiocarbon dates is scheduled to be completed by the 1st quarter of 2021, while the dwelling data has been completed from one case study (Yamanashi prefecture) and the current target is to complete the remaining 4 case studies by 2021. WP1 has also focused on methodological development, in particular statistical techniques for inferring population dynamics from the density of radiocarbon dates (published in DOI: 10.1017/RDC.2020.95) and handling different forms of chronological uncertainties of artefacts dated via attribution to ceramic-typology based phases (published in DOI: 10.1016/j.jas.2020.105136). The WP has also exploratored, via simulation, potential caveats and challenges for demographic inference based on archaeological data (published in DOI: 10.1098/rstb.2019.0726). These new techniques are currently being applied to the collected data, and preliminary results (see fig1) have already confirmed the demographic impact of the transition, with a rapid population increase in the first few centuries of the 3rd millennium BP.
Work Package 2 (Subsistence and Food Technology) has so far focused on the sampling, extraction, and preparation of an initial set of 300+ potsherds from eight archaeological sites for organic residue analyses. Initial analyses of these and additional samples will commence with the start of the PDRA1 position in January 2021.
Work Package 4 (Environment) focused on the collection of historical (e.g. 19th-century yield records) and environmental data for modelling regional variations in the suitability and the productivity of rice and millet farming at the onset of the Yayoi period. Initial modelling of the thermal niche has already revealed key geographic variation, and a manuscript revealing initial insights in relation to the spatial variation of macro-botanical evidence (see fig.2) is currently under preparation.
Work Package 3 (Material Culture), Work Package 5 (Spread of Rice and Millets), & Work Package 6 (Integration and Synthesis) have primarily focused on preliminary set-up work (data collection, method development) before the appointment of relevant team members.