Self-domesticated ape theory
When compared with other primates, whose communication system is restricted to a highly stereotypic repertoire of hoots and calls, humans have very few prespecified vocalizations, extant examples being laughter and sobbing. Moreover, these remaining innate vocalizations are generated by restricted pathways, whereas language is generated by a highly distributed system involving numerous regions of the human brain.
A salient feature of language is that while language competency is inherited, the languages themselves are transmitted via culture. Also transmitted via culture are understandings, such as technological ways of doing things that are framed as language-based explanations. Hence one would expect a robust co-evolutionary trajectory between language competency and culture: proto-humans capable of the first, and presumably rudimentary, versions of protolanguage would have better access to cultural understandings, and cultural understandings, conveyed in protolanguages that children's brains could readily learn, were more likely to be transmitted, thereby conferring the benefits accrued.
Hence proto-humans in'dubitably (бесспорно) engaged in, and continue to engage in, what is called niche construction, creating cultural niches that provide understandings key to survival, and undergoing evolutionary changes that optimize their ability to flourish in such niches.