Edited by Ofer Bar-Yosef, Harvard University, Cambridge, MA, and approved December 7, 2006 (received for review September 8, 2006)
Archaeological research in the African rainforest reveals unexpected results in the search for the origins of hominoid technology. The ancient Panin sites from Côte d'Ivoire constitute the only evidence of prehistoric ape behavior known to date anywhere in the world. Recent archaeological work has yielded behaviorally modified stones, dated by chronometric means to 4,300 years of age, lodging starch residue suggestive of prehistoric dietary practices by ancient chimpanzees. The “Chimpanzee Stone Age” pre-dates the advent of settled farming villages in this part of the African rainforest and suggests that percussive material culture could have been inherited from an common human–chimpanzee clade, rather than invented by hominins, or have arisen by imitation, or resulted from independent technological convergence.
Author contributions: J.M. and C.B. designed research; J.M. and C.B. performed research; J.M., H.B., J.G., J.H., S.K., R.T., and C.B. analyzed data; J.M. and C.B. wrote the paper; H.B. and R.T. were part of blind test (starch); J.G. contributed placebo sample for blind test (stone); and J.H. and S.K. were part of blind test (stone).
The authors declare no conflict of interest.
This article is a PNAS direct submission.
This article contains supporting information online at www.pnas.org/cgi/content/full/0607909104/DC1.
