"Why Language Evolved Only Once"
It is easy, almost trivial, to claim the superiority of a combinatorial linguistic system over a finite repository of fixed expressions. The traditional problem has always been to explain how the finite-to-infinity transition might have taken place. For a gradualist approach to the origin of language, a common answer points to the recapitulation of phylogeny in ontology. The developmental stages in child language acquisition are said to trace similar steps in language evolution as both processes are envisioned to move from formulaic expressions to increasingly abstract grammatical processes.
We present evidence suggests that a formulaic stage in child language does not exist. Rather, language use is detectably compositional as it employs abstract categories and rules from the earliest stage of language acquisition. A gradualist account of language evolution thus loses its starting position never mind the transitional steps toward the terminal point. And we are left with the saltationist alternative, that the key component of Language (compositionally aka “merge”) evolved only once. Along the way, we discuss the implications of child language for the comparative cognition and linguistic theories in the age of big data.