Evolving a bridge from praxis to language

We first address diverse criteria on what a theory of language evolution should explain, focusing on six divides: evolution did/did not yield a Universal Grammar; brain evolution is/is not important; language is to be viewed as speech or multimodal communication; language evolution is/is not best understood solely with reference to tools for communication; we do/do not need a notion of protolanguage as a precursor to language; and protolanguage was/was not in great part holophrastic. We argue against a role for an innate Universal Grammar in language acquisition and language change, and then present a brief case study of the emergence of Nicaraguan Sign Language in a few decades. Finally, we present the mirror system hypothesis on the evolution of the language-ready brain locating it within the 6 divides and charting a path for biological evolution supporting mechanisms for simple and complex imitation, pantomime, protosign and protospeech in turn, claiming that this provided an adequate base for true languages to emerge through cultural evolution.