Post by slartibartfast on Apr 9, 2013 7:24:54 GMT 10
Monkey's call tied to origins of human speech
The gurgling call of gelada monkeys — a species closely related to baboons — shares features of the human language and could be similar to the primitive noises our ancestors once made, a new study claims.
Researchers analysed the monkey's unusual call, which they call a "wobble", and published their findings in the journal Current Biology.
The study's lead author, Thore Bergman from the University of Michigan, said: "Geladas make vocalisations that have some speech-like properties — it's the first time that that has been shown in a non-human primates."
Dr Bergman said the research may shed light on the earliest forms of human speech.
Scientists have long been baffled by how speech evolved in human, when our closest evolutionary relatives can seem to manage only the most basic noise.
The only exception is the gelada, which lives in large social groups in Ethiopia's highlands.
A study published last year said that while most primates lack the vocal anatomy required to produce sophisticated sounds, a behaviour known as "lip-smacking" could be related to speech.
This happens when primates rapidly move their jaws, lips and tongues in much the same way that humans do as they speak.
Geladas are reportedly the only known primates to make these facial movements and vocalise complex sounds at the same time.
It is understood the monkeys are using the verbal exchanges to bond with each other, in a similar way to how humans might use small talk.
The researchers also found that the rhythm in the gelada calls are closely matched to patterns heard in human languages.
Dr Bergman said: "In [human] speech, the onset of a syllable is loud and then there are quiet parts in between.
"If you were to look at a waveform where you see how speech gets louder and quieter across time, the time between those peaks happens at a fairly predictable frequency of 3Hz to 8Hz across different languages.
"The same thing happens with the gelada 'wobbles' — the periodicity has the same frequently."
The study suggests that the combination of "lip-smacking" and vocalisations could have been an important step for human speech evolution.
news.ninemsn.com.au/technology/2013/04/09/06/23/monkey-call-tied-to-origins-of-human-speech