Agricultural origins in North China pushed back to the Pleistocene–Holocene boundary

Abstract

Two grains, common (proso or broomcorn) millet (Panicum miliaceum) (Fig. 1) and foxtail millet (Setaria italica), were fundamental to the development of agricultural societies that eventually evolved into the first urban societies of China between 4500 and 3800 calibrated years (cal.) B.P. (1). Today, these grains are important mainly in parts of Russia, South Asia, and East Asia. How, when, and in what settings these millets initially evolved is not well known (2). One hypothesis holds that common millet was domesticated rapidly in the central Wei river basin shortly after ca. 8000 cal. B.P. (3). Another hypothesis proposes that common millet was domesticated in the Northeast China Liao river basin around the same time (4). In reality, archaeological data have simply not been adequate to resolve the issues surrounding the domestication of millet and the development of the first agricultural communities in North China. Complicating the problem, common millet is also present in Europe ca. 8000–7500 cal. B.P. (2), so this timing opens the possibility that the crop was domesticated more than once. Otherwise, its origins must predate 8000 cal. B.P. The Early Holocene Cishan site in North China is one of several sites considered key to understanding millet domestication and the origin of dry-land agriculture in China, yet the dating and identity of the crops recovered there have never been adequately documented. The study published in this issue of PNAS (5) revisits Cishan, located on a terrace on the western edge of the North China Plain ≈9 km from where the Nanming river emerges from the Taihang mountains. Two outstanding issues regarding the early archaeological record of millet at Cishan first reported nearly 30 years ago (6, 7), their dating and identification, are resolved in the new study.