A gelada baboon in Simien Mountains National Park, Ethiopia. Photo by A. Davey via Flickr.
Scientists studying the evolution of speech have long puzzled over why there are no good models in primates. While primates share many traits with humans -- they've been known to play, grieve, fight, even laugh -- speech isn't one of them.
With one possible exception. A group of wild monkeys from the Ethiopian highlands called geladas, which are closely related to baboons, make gutteral babbling noises that sound eerily human-like. And they do it while smacking their lips together. The combination of lip smacking and vocal sounds is called a "wobble." A study in this week's issue of the journal Current Biology analyzed the rhythm of the wobble and found that it closely matched that of human speech.