Our hominid ancestors are fascinating -- our shared ancestry always drawing us in. While it is incredible how much we have been able to discern about their skeletal and muscular structures, their diets and habits, and their behavior and evolution, little is known about the physiology of our early ancestors. How were their brains organized? Did they play music? Considering most of what is left of the early hominids consists only of a handful of bone fragments, we can’t exactly run a CT scan while we play Homo heidelbergensis some Brahms. What we can do, however, is try to understand the disparity between when the first anatomically modern humans appeared compared to the first archaeological evidence of musical instruments. Exploring this 80,000-year gap, Dr Iain Morley of Cambridge University compiled studies on the physiology and neurology of our ancestors, but I want to focus specifically on how the larynx could have informed speech and vocal music.
The first area to investigate with regard to vocal music production is the soft tissue near the supralaryngeal and oral cavities. Obviously, direct evidence of these do not survive in the fossil record, but their connection and wear on the bones still provide some clues as to their ability to control and variate sound. The position of the human larynx is lower in the pharynx than in any other primate, resulting in greater reverberation that is not inhibited by the epiglottis and soft palette. Analysis of human and orangutan morphology has shown a strong correlation between the curvature of the basicranial flexion (bottom curvature of skull) and the position of the larynx and hyoid bones associated with speech ability.
Measurements of fossil hominids from as far back as the pleistocene show that Homo ergaster probably could have formulated basic ‘o’ and ‘e’ vowel sounds, along with numerous consonants, around 1.75 mya and Homo heidelbergensis would have been able to formulate the full range of human speech sounds around 400,000 ya. Further connection between laryngeal position and speech can be found when examining cases of Down’s syndrome, where the larynx is abnormally high in the pharyngeal cavity and is likely related to reduced pronunciation ability of more resounding sounds. Similarly, the larynx of infants is positioned higher, as it is in most other animals, and migrates lower with age. Could this be why children take time to develop full speech ability and pronunciation?
'Turkana Boy' Homo ergaster
Homo hiedelbergensis
References
Moraes, C. (2013, March 4). Homo heidelbergensis - forensic facial reconstruction. Retrieved October 15, 2017, from https://upload.wikimedia.org/wikipedia/commons/7/79/Homo_heidelbergensis_-_forensic_facial_reconstruction.png
Morley, I. (2002). Evolution of the Physiological and Neurological Capacities for Music. Cambridge Archaeological Journal, 12(2), 195-216. doi:10.1017/s0959774302000100
Turkana Boy. (2014). Retrieved October 16, 2017, from http://www.crystalinks.com/turkanaboy.html
Hi Josie, great post! I found an article on the development of the larynx which suggested that the organ is found between C1 and C4, between the epiglottis and the soft palette in order to help with both suckling and breathing. This led me to the theory that as the need for suckling decreases, the height of the larynx falls as well, which could be one of the reasons that support the idea that children take longer to develop speech and pronunciation abilities. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4439709/)
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