Might this be a hint of how human speech came to be? Researchers at the University of Michigan say wild monkeys of Ethiopia known as geladas smack their lips together and make gutteral noises to produce a sound like our speech, reports PBS. The pattern of these "wobbles" follows the same rhythm as human speech, say the scientists in Current Biology. The male geladas, cousins of the baboon, appear to use the noises to communicate in friendly interactions, reports GlobalPost.
"Our finding provides support for the lip-smacking origins of speech because it shows that this evolutionary pathway is at least plausible," says the lead researcher. "It demonstrates that nonhuman primates can vocalize while lip-smacking to produce speech-like sounds." A Princeton prof not involved with the study called it "incredible," though not proof of a direct link to human speech. (Read more speech stories.)