Fig. 2.

(A–C) Cucurbita phytoliths from early preceramic sediments directly associated with grinding stones 319d (A and B) and 318 e (C) with sizes and morphological attributes (surface cavities and marks; faint scalloped impressions) characteristic of domesticated plants. (D) A phytolith from a hybrid between the wild species C. argyrosperma ssp. sororia and the domesticated species C. argyrosperma that is heterozygous at the Hr genetic locus and exhibits the same morphological attributes as the archaeological phytoliths, a result of human selection at this genetic locus.