Human speech is a challenging subject, one approached from many academic angles. Recent studies of orangutans may shed light on why human speech developed in the first place.
According to Popular Science the answer may lie in part with differences in communication. Orangutans and ground dwelling chimpanzees and bonobos communicate differently. Orangutans are the most arboreal of the great apes and use far more consonant like sounds than their ground dwelling cousins. All human languages are consonant driven, so researchers would expect the primates most closely related to us to use more consonant sounds.
Phys.org says that reserchers at the University of Warwick believe that our ancestors may have been more arboreal than previously believed.
“Arboreal versus terrestrial lifestyles appear to have driven great apes to develop different vocal repertoires, with large and varied inventories of consonant-like calls arising from tree-dwelling apes like orangutans, rather than the ground-dwelling apes. The study suggests that our own evolutionary ancestors might have lived a more tree-dwelling lifestyle than previously thought.
Dr. Adriano Lameira, Associate Professor of Psychology at The University of Warwick, investigated the origins of human spoken language, which is universally composed of vowels that take the form of voiced sounds, whereas voiceless sounds take the form of consonants.”
Note: The professor’s link says he is an assistant professor, not an associate professor.
According to Popular Science there are about 7,000 languages on Earth.
“All spoken languages are composed of both vowels and consonants. Vowels are almost always voiced produced by the larynx. Consonants are typically more voiceless and produced by moving the supra-laryngeal articulators, such as, the lips, tongue, and mandible.”
This speech research mirrors a recent study that argues human ancestors transitioned to two-footed movement as a way to better forage for food among tree branches. These new findings could revise a long-standing theory of how human bipedalism evolved. (links in original)”
The difference in use of consonant like sounds and vowel like sounds is striking. Our closest primate relatives, gorillas, chimpanzees and bonobos, use very few.
“According to Lameira, orangutans have a diverse array of smacking, clicks, kiss-sounds, splutters, and raspberries within their vocal repertoire. Some of the aspects of an arboreal lifestyle and feeding habits could help explain the sophistication and complexity of their consonant-like calls.” Popular Science quoted Lameira as saying.
The research was published in Trends in Cognitive Science.
Recently, chimps have been seen practicing medicine on each other.
On a sadder note, leprosy has been spotted among wild chimpanzees for the first time