The primate precursors of human consonants and vowels

Informations projet

THE VERBAL APE

N° de convention de subvention: 702137

DOI

10.3030/702137

Projet clôturé

Date de signature de la CE 11 Mars 2016

Date de début 1 Avril 2017

Date de fin 31 Mars 2019

Financé au titre de

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Coût total

€ 195 454,80

Contribution de l’UE

€ 195 454,80

Coordonné par

THE UNIVERSITY COURT OF THE UNIVERSITY OF ST ANDREWS
United Kingdom

Periodic Reporting for period 1 - THE VERBAL APE (The primate precursors of human consonants and vowels)

Période du rapport: 2017-04-01 au 2019-03-31

Résumé du contexte et des objectifs généraux du projet

Speech is a human diagnosing feature but its evolution is problematic. Critically, while speech is essentially learned anew each generation, great apes – our closest relatives – are presumed incapable of learning to produce new calls. Recurring to large data analyses of great ape vocal recordings, playback field experiments in great ape territory and experimental test with great ape captivities, this project sought to resolve the seeming disparity between great ape and human vocal capacities, and by extension, the seeming lack of evolutionary continuity between a putative ancestral ape-like vocal system and human language. This project unveiled that great ape consonant-vowel–like call combinations behave, vary and evolve as human syllables, indicating that both combinatorial system are structurally homologous and therefore giving support to the view that early forms of proto-language and proto-linguistics could have emerged within the human clade, from which fully fledge language as used today may have stemmed. This project determined that the communication channel (between two communicating great apes) as a source of ecological noise does not drive the combinatorial marriage between consonant-like with vowel-like calls, and by extension, most likely did not do so either between the first-linguistic human ancestors. Moreover, the project demonstrated that, contra orthodox ideas, great apes exert motor control over their voice (i.e. vocal fold oscillation action), their supralaryngeal articulators (i.e. lips, tongue and jaw) and their breathing musculatures (i.e. diaphragm, abdominal and intercostal muscles) sufficient to allow them to both invented and learn new calls, and consequently, increase their vocal repertoire, something that our own direct hominid ancestors were therefore likely also capable of. Altogether, the project shows that humans’ first linguistic ancestors owned a constellation of structural and motor traits upon which language evolution could have piggybacked. Doing so, this project demonstrates that great apes still have much to say about the origin and evolution of human language.

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

This project conducted three major work packages: (1) large data analyses of great ape vocal recordings to investigate potential acoustic dependencies between great ape consonant- and vowel-like calls used in combination with one another within and across populations, (2) playback field experiments in great ape territory and experimental test with great ape captivities to investigate the acoustic propagation properties over distance of consonant- vs. vowel-like great ape calls, and (3) “do-as-I-do” imitation games and experimental in captivity other tests at the Indianapolis Zoo and the Leipzig Zoo to investigate in detail the motor control exercised by great ape over the major anatomical deployed during vocal production, whether these structures could be dynamically and in real time be engage to expand individuals’ own vocal repertoire, namely, via vocal invention and vocal (production) learning. These activities have resulted, thus far, in three major peer-reviewed publications and 8 other papers at final stages of completion/publication. The three release publications are:

Lameira, A.R. (2017) Bidding evidence for primate vocal learning and the cultural substrates for speech evolution. Neuroscience and Biobehavioural Reviews, 83, 429-439.

Nater A, Mattle-Greminger M.P. Nurcahyo A., Nowak M.G. de Manuel M., Desai T., Groves C., Pybus M., Sonay T.B. Roos C, Lameira A.R. Wich S.A. Askew J., Davila-Ross M., Fredriksson G., de Valles G., Casals F., Prado-Martinez J., Goossens B., Verschoor E.J Warren K.S. Singleton I., Marques D.A. Pamungkas J., Perwitasari-Farajallah D., Rianti P., Tuuga A., Gut I.G. Gut M., Orozco-ter Wengel P., van Schaik C.P. Bertranpetit J., Anisimova M., Scally A., Marques-Bonet T., Meijaard E., Krützen M. (2017) Morphometric, behavioral, and genomic evidence for a new orangutan species. Current Biology, 27, 3487-3498.

Lameira, A.R. J. Call (2018) Time-space–displaced responses in the orangutan vocal system. Science Advances, 4, eaau3401.

Dissemination of this work has been achieved via media coverage and/or interviews by major news outlets worldwide, including and not limited to Science Magazine, Forbes and BBC, as well via several popular science publications and social media.

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

Altogether, the findings produced by the project challenge traditional assumptions about what great ape can and (mostly) cannot do vocally. Great apes can do much more than what has hitherto been assumed. Critically, old believes have taken root in the field without explicit testing or examination or otherwise based on historical projects that embarked in the study great ape cognitive and communicative capacities some half-century ago in “home-labs”. This project carried out a reassessment of great ape cognitive and communicative capacities for the production of speech-like sounds and linguistic-like combinations using state-of-the-art analyses as well as following modern ethical guidelines for the study of captive and wild great apes. Doing so, it reinstated how and why great apes represent in fact highly desirable study models for the study of language evolution. They represent our closest living relatives among all extant animals, but most importantly, their vocal system exhibits unparalleled affinities with human spoken language. Great ape vocal behaviour, namely, their consonant- and vowel-like calls and their combinations of these two elements together, offer an empirical window back on our last pre-linguistic ancestors and can be empirically approached as living proxies of the original building blocks of language.

Figure 1 of paper in Science Advances demonstrating that orangutans communicate about past events