https://groups.io/g/AAT/message/73002

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Op zaterdag 27 november 2021 om 22:30:49 UTC+1 schreef DD'eDeN aka note/nickname/alas_my_loves:

https://groups.io/g/AAT/message/73002

Human laryngeal descent has 2 components:
- descent of larynx vs hyoid,
- descent of hyoid vs palate.
Google
"Vaneechoutte seafood diving song speech"

Seafood, Diving, Song and Speech
Mario Vaneechoutte cs 2011
doi 10.2174/978160805244811101010181
... comparative data suggest the various elements of human speech
- evolved at different times,
- originally had different functions.
Nishimura [1-6] shows:
what is commonly known as the laryngeal descent actually evolved in a mosaic way, in minimally 2 steps:
(a) a descent of the thyroid cartilage (Adam's apple) vs the hyoid (tongue bone), a descent which is also seen in non-human hominoids,
(b) a descent of the hyoid bone vs the palate, less obvious in non-human hominoids, and accentuated by the absence of prognathism in the short & flat human face.
Comparisons with other animals suggest:
(a) the 1st descent might be ass.x loud and/or varied sound production,
(b) the 2nd might be part of an adaptation to eating sea-foods, e.g. shell-fish can be sucked into the mouth, and swallowed without chewing, even under water.
We argue:
the origin of human speech is based on different pre-adaptations that were present in human ancestors:
(a) sound production adaptations, related to the descent of the thyroid cartilage ass.x the territorial calls of apes,
(b) transformation of the oral & dentitional anatomy incl. the descent of the hyoid, ass.x reduced biting & chewing,
(c) diving adaptations, leading to voluntary control of the airway entrances & voluntary breath control.
Chimpanzee ancestors became frugivores in tropical forests after they split from human ancestors c 5 Ma,
but human ancestors became littoral omnivores: this helps explain
- why chimps did not evolve speech,
- why human speech is a rel.recent phenomenon,
- why speeh is so strongly dependent upon the availability of voluntary breath control (not seen in other hominoids, but present in diving mammals).

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On Monday, December 6, 2021 at 10:19:00 AM UTC-5, littor...@gmail.com wrote:

Op zaterdag 27 november 2021 om 22:30:49 UTC+1 schreef DD'eDeN aka note/nickname/alas_my_loves:

https://groups.io/g/AAT/message/73002

Human laryngeal descent has 2 components:
- descent of larynx vs hyoid,
- descent of hyoid vs palate.
Google
"Vaneechoutte seafood diving song speech"

Seafood, Diving, Song and Speech
Mario Vaneechoutte cs 2011
doi 10.2174/978160805244811101010181
... comparative data suggest the various elements of human speech
- evolved at different times,
- originally had different functions.
Nishimura [1-6] shows:
what is commonly known as the laryngeal descent actually evolved in a mosaic way, in minimally 2 steps:
(a) a descent of the thyroid cartilage (Adam's apple) vs the hyoid (tongue bone), a descent which is also seen in non-human hominoids,
(b) a descent of the hyoid bone vs the palate, less obvious in non-human hominoids, and accentuated by the absence of prognathism in the short & flat human face.
Comparisons with other animals suggest:
(a) the 1st descent might be ass.x loud and/or varied sound production,
(b) the 2nd might be part of an adaptation to eating sea-foods, e.g. shell-fish can be sucked into the mouth, and swallowed without chewing, even under water.
We argue:
the origin of human speech is based on different pre-adaptations that were present in human ancestors:
(a) sound production adaptations, related to the descent of the thyroid cartilage ass.x the territorial calls of apes,
(b) transformation of the oral & dentitional anatomy incl. the descent of the hyoid, ass.x reduced biting & chewing,
(c) diving adaptations, leading to voluntary control of the airway entrances & voluntary breath control.
Chimpanzee ancestors became frugivores in tropical forests after they split from human ancestors c 5 Ma,
but human ancestors became littoral omnivores: this helps explain
- why chimps did not evolve speech,
- why human speech is a rel.recent phenomenon,
- why speeh is so strongly dependent upon the availability of voluntary breath control (not seen in other hominoids, but present in diving mammals).

Like parrots?

-

suppl.8A:103094
doi 10.1016/j.jhevol.2021.103094

The hyoid apparatus in mammals plays an integral role in swallowing, respiration & vocalization.
Most Placentalia have a rod-shaped basi-hyal, connected to the basi-cranium via both soft tissues & a mobile bony chain (the anterior cornu),
but Anthropoidea have broad, shield- or even cup-shaped basi-hyals, suspended from the basi-cranium by soft tissues only.
How did the unique anthropoid hyoid evolve?
Hyoid morphology of non-anthropoid primates is poorly documented.

Here we use phylogenetic comparative methods & linear morphometrics,
we address knowledge gaps in hyoid evolution among primates & their euarchontan outgroups.
We find:
Dermoptera have variable reduction of cornu elements.
Cynocephalus volans are sexually dimorphic in hyoid morphology.
Tupaia & all lemuroids except Daubentonia have a fully ossified anterior cornu, connecting a rod-shaped basi-hyal to the basi-cranium:
this is the ancestral mammalian pattern, also characteristic of the primate LCA.

Haplorhini exhibit a reduced anterior cornu,
Anthropoidea underwent further increase in basi-hyal aspect ratio values & in relative basi-hyal volume.
Convergent with Haplorhini, lorisoid Strepsirrhini independently evolved a broad basi-hyal & reduced anterior cornua.
A reduced anterior cornu is hypothesized to facilitate vocal tract lengthening & lower formant frequencies in some mammals,
but our results suggest vocalization adaptations alone are unlikely to drive the iterative reduction of anterior cornua within Primates.

Our new data on euarchontan hyoid evolution provide an anatomical basis for further exploring the form/function relationships of the hyoid in vocalization, chewing & swallowing

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