This paper outlines a model for the domestication of Panicum miliaceum (broomcorn millet) in Northern China. Data from 43 archaeological sites indicate a continuous increase in average grain size between 6000 and 3300 bc. After this date there is a divergence, with grain size continuing to increase in some populations, while others show no further size increase. The initial increase in grain size is attributed to selection during domestication, while later divergence after 3300 bc is interpreted as resulting from post-domestication selection. Measurements of grains from two archaeological populations of P. ruderale, showed grains were longer in length by 3300 bc than the earliest grains of P. miliaceum. This suggests this sub-species includes many feral, weedy and/or introgressed forms of P. miliaceum and therefore is probably not entirely representative of the true wild ancestor. It is argued that changes from shattering to non-shattering are contemporary with increasing grain size and the commencement of cultivation. The window of P. miliaceum domestication is therefore likely to lie between 7000 and 3300 bc. However, it is probable that a lengthy period of millet harvesting and small-scale management preceded its domestication.
Bibliographical noteFunding Information:
The research undertaken within this paper was supported by a European Research Council grant “Comparative Pathways to Agriculture” (ComPAg, no. 323842) and work in China was facilitated through ICCHA (中国文化遗产保护与考古学研究国际中心; International Centre for Chinese Heritage and Archaeology). The funding for the fieldwork in Liaoning was provided by the Israel Science Foundation (Grants no. 501/11 and 728/17 to G.S), and the National Geographic Society (Grant no. 8 614-09 to G.S.) and a large portion of the samples were floated by Wang Huan from these sites. Material collected in Ying and Luo Valley Survey in Henan was undertaken with the assistance of the Henan Provincial Institute of Cultural Heritage and Archaeology, along with the Luoyang Institute of Cultural Heritage and Archaeology. Some of the measurements on archaeological P. ruderale from Tonglin were taken by Mukund Kajale when he was a visiting scholar at UCL, and we are grateful for the use of these data.
© 2020, The Author(s).
- Grain size
- Origins of agriculture