Lip-Smacking Primate Hints at Speech Evolution
Most primates make rudimentary calls that consist of one or two syllables. But the gelada—native only to the grasslands of the Ethiopian plateau—displays “rapid fluctuations in pitch and volume” akin to human speech.
The similarity has researchers’ tongues wagging.
“Our finding provides support for the lip-smacking origins of [human] speech, because it shows that this evolutionary pathway is at least plausible,” study leader Thore Bergman, of the University of Michigan in Ann Arbor, said in a statement.
Lip-smacking is unlike other primate calls in that the rhythm corresponds to the opening and closing of parts of the mouth—which in turn, well, smacks of human speech, according to the study authors.