Did speech evolve from vocal chords or bodily movements?
Body movement, particularly with the hands, appears to be ingrained in human communication. “All humans gesture. They gesture when they talk on the phone, they gesture even if they know the other person can’t see them,” says primatologist Amy Pollick. She is studying evolutionary precursors to speech in chimpanzees at the Yerkes Living Links Center at Emory.
“Chimp vocalizations can actually be quite complex, but they don’t have as many vocalizations as they do gestures,” she says.
Watch an interview with Pollick in this excerpt from a Swedish documentary. Photo at top shows a scene from the documentary, "On the Road with Homo Sapiens."