An evaluation of competing hypotheses for the early adoption of wheat in East Asia

Recent emphasis on the recovery of plant remains from archaeological sites in East Asia permits an analysis of prehistoric cultural contact between East and West. Here we evaluate three prominent hypotheses for the introduction of wheat, a Near Eastern domesticate, to East Asia, specifically northern China. Existing evidence points to a nearly synchronous appearance of the plant, from the Inner Asian Mountains to the Yellow Sea, c. 4600-4200 years ago. Archaeological data, including the spatial distribution of directly dated wheat grains, argue against a wave of wheat-farming colonists, but point to the gradual in situ adoption of novel exotics by a diverse array of pre-existing agricultural peoples. Logic borrowed from the diffusion of innovations literature accounts for the near synchronous appearance of wheat over an enormous area, and allows for the occasional observation of anomalously older evidence without having to imagine such evidence as the origin of the diffusion.