In H.G. Wells' "The Island of Doctor Moreau," a key distinction between humans and monkeys lies in the structure of the larynx. This anatomical difference symbolizes humans' ability to produce a wide range of sounds, enabling them to communicate complex ideas and sustain intricate thoughts through language.
This highlights the significance of vocal capability in fostering advanced communication and thought processes, suggesting that the evolution of language is what elevates humans above other species, particularly in their cognitive abilities and social interactions.