Credits

Researchers
Amy Pollick, Frans de Waal, and Bill Hopkins, Living Links, Yerkes National Primate Research Center, Emory University, Atlanta, GA

Paper
Pollick, A. S., and F. B. M. de Waal. Ape Gestures and Language Evolution. PNAS. 104: 19, 8184–8189 (2007).

Data and Images
Chimpanzee brain MRI reconstruction (Bill Hopkins, Emory University)
Chimpanzee and bonobo gestures (Amy Pollick, Emory University)