The paper ‘In Search of a Unified Theory of Sensory Perception: Possible Links between the Vibrational Mechanism of Olfaction and the Evolution of Language’, published in Biosemiotics, February 2020, introduces and discusses the hypothesis of a unified mechanism of sensory perception, based upon a vibrational mechanism of olfaction. The vibrational theory of olfaction posits that chemoreception in animals is essentially a mechanoreceptor process, which occurs via the quantum phenomenon of electron tunnelling. It is the vibration of bonds within the odour molecules which are detected by chemosensory apparatus, and not the shape of the molecule, as is postulated by the docking theory of olfaction. The paper thus examines the hypothesis that all sensory processes, including colour vision and olfaction, are forms of mechanoreception, and have evolved from a common physiological feature; most likely, olfactory mechanisms. Furthermore, if tested successfully, this hypothesis could reveal a basis for the evolution of complex vocal communication and ultimately, language evolution. The premise for this idea relies on the hypothetical concept of ‘frequency mimicking’. This term describes animals, for example birds, mimicking energy frequencies detected in the environment as olfactory and visual signs, and then reproducing them as an acoustic vocal signal. Significantly, oscines and other groups including the cetaceans, incorporate species which are capable of complex vocal communication, an example of which is birdsong. Indeed, complex animal communications have been found to show characteristics of language such as syntax and rhythm, and moreover, distinct elements of birdsong have been found to have specific meaning. An example of a birdsong element which has an identified semantic meaning is the male nightingale’s broadband trill, which signals territorial aggression. The paper reviews and describes this and further examples from peer reviewed ethological and ecological studies, such as those investigating vocal mimicry in different species, as well as explaining why ‘frequency mimicking’ would be a signalling behaviour which would be advantageous to individuals. For example, frequency mimicking could play an important role in sexual selection and mate choice, as well as aggressive behaviours such as resource defence. Collectively, the examples discussed provide evidence that a unified theory of sensory perception may be possible, and that should supporting evidence be forthcoming, the evolutionary framework for language evolution would potentially be in place.
Amelia Lewis is a zoologist with an interest in ethology, specifically sensory perception and zoosemiotics. Amelia is a member of the Royal Society for Biology, and her main interests lie in theoretical biology. She holds two Master’s degrees in animal behaviour, and has extensive experience working with companion animals, particularly dogs and horses. Amelia has published work on animal social behaviour and human-animal interactions, and is working toward her PhD, with her current affiliation being Queen’s University, Belfast. She is also undertaking her own independent theoretical research on chemosemiosis, sensory perception and language evolution.