Final answer:
The hominid Homo erectus is believed to have first used a form of language called protolanguage. Language emergence is closely linked to cognitive and social abilities seen in tool and art creation, with biological evolution of the brain and anatomical speech mechanisms playing fundamental roles.
Step-by-step explanation:
It is estimated that the hominid Homo erectus first used protolanguage, a precursor to modern language. This invention of language likely evolved as part of a complex of material culture, which included the development of stone tools and art, implying sophisticated cognitive and social abilities inherent in language use. The biological evolution of the brain, particularly areas like Broca's area associated with speech, along with the development of mirror neurons are all considered fundamental to the capability for language. Additionally, the production of complex tools necessitated cognitive skills akin to those used in the complex speech production, further indicating an intertwined relationship between tool-making advances and language development. Encephalization, the evolutionary increase in brain size relative to body size, significantly increased in humans compared to other hominids and played a pivotal role in language capacity. Endocasts of ancient hominids' skulls provide evidence of similar brain structure to that of modern humans, suggesting the capacity for language. The invention and use of tools, believed to have emerged around the same time as language, would have been reliant on this evolving communication ability. Language has been a crucial evolutionary advantage, enabling early humans to coordinate activities, communicate abstract ideas, and transmit knowledge across generations.