The authors summarise the latest evidence for the introduction of rice cultivation into northern China, and show that it most probably began there in the early seventh millennium BC as a result of influence or migration from the Yangtze Valley
I am too busy on other work to provide a full blog on this now, but I will in due course. Unfortunately this paper is highly mis-leading, and once again Jiahu is the centre of rather selective communication that claims to resolves the origins of rice agriculture but relies on a certain amount slight of hand that obscures the actual data. First the paper slectively picks data from the ealiest levels from the Peking University excavations at Baligang together with the ragtag data from a couple of excavation campaings at Jiahu (in a different river valley). First, as to the photo seen here, these are storage pits and houses of the Third Millennium BC, Qiujialing/Shijiahe/Longshan period, which is the focus of that site. So the authors have selected misleading photo that has nothing to do with the few lower contexts from which the rice and acorn remains discussed in the paper come. The rice data, itself is unpbulished, but in this paper it relies on an student dissertation (a very good) which focused on the Qiujialing/Shijiahe/Longshan and Yangshao period, which in a footnote mentioned some preliminary data on sikelet bases from the 7th millennium BC lower levels. That is actually a personal communication from me and Dr. Qin Ling, on the bais of a preliminary sort of one early sample after it came out of the ground in 2008. The very precise precentages given are prone to revisions once the full analysis of the lower levels are finished. In terms of using the data from Jiahu, there are three sets of archaeobotanical data which are mixed in this paper in selective way. First there is the 1999 monograph on earlier excavations, from which comments on rice and the presence of wild foods in quoted. Later informed comments and discussions of this material (such as Fuller et al 2007 in Antiquity, are carefully avoided, as they suggest this maerial is entirely consistent with wild rice gathering from a range of wild rice species or populations). In absence of spikelet bases from Jiahu we simply do not know how much of this rice might have been cultivated and how gathered wild: the grain morpholoigal diversity tends to point towards wild gathering at least some of this. Second, there are the only systematic samples, collected by wet-sieving by Zhao Zhijun. These rightly provided some quantified data on the present of rice versus other foods and some possible weeds. It should be noted that none of the weeds is exclusively diagnostic of either cultivation nor wet rice. (e.g. Digitaria is typically a dry millet weed, but does occur in early rice cultivation as well). Indeed this site shows rice as a co-staple with acorns and Trapa, much as we see in amongst early cultivators in the Yangtze. Zhao's grain metrics, largely overlap the small grains from the 1999 excavation report, but these too are left out. Third there are grain metrics from the later (2004) excavations.that came not through flotation but from hand collecting and coarse screening, which were published by Liu et al in The Holocene 2007 as a critique of the 1999 measurement. (Collection methods could bias these otwards large sizes.) This measurements are quoted here, but mis-quotes, as they actually show size reduction over time-- a trend more inline with wild rice adapting to changing climate than a domestication process. The problem is all these set of measurements are real and should be taken together. They indicate no clear trend in size change but instead a huge spread of metrical diversity. Unfortunately, apart from those readers who have been through the Chinese monogrpahs and dissertations and know the unpublished material from Baligang, this paper may well mislead as well as inform on the earliest rice farmers!