I was about to take off for the holidays when some news came along. One of the main arguments in favor of the gesture-first theory of language evolution took a blow this past week when scientists reported that an orangutan has learned to whistle on cue. (To view video of whistling ape click here.)
Although whistling is not a normal feature of language, many investigators have argued that speech depends on the ability to make learned sounds voluntarily, but great apes cannot voluntarily repeat sounds. Michael Tomasello is perhaps the most prominent researcher to conclude from those points that our ancestors must have gestured first. After all, apes can make ad hoc gestures. Thus, recorded proof that an ape can spontaneously learn to whistle by listening to a human whistler weakens the argument.
An article ("A case of spontaneous acquisition of a human sound by an orangutan") in the journal Primates by Serge Wich and his large team reports that "Bonnie," a 30-year-old orangutan in the Washington DC Zoo. began whistling after hearing one of the zoo keepers whistling. (Press release here)
Wich says of the observation:
We need to be a little careful with this story because it could be a joke. The learning occurred without scientific observation, so we do not really know what led to the whistling. But it suggests that the gesture-only theory is not built on a solid foundation. This blog has bent toward the idea that gesture and vocalization evolved together as a means of organizing joint attention, and I feel a little more sure-footed with the idea today.