How and where are the universal features of language specified? We consider language users as situated agents acting as conduits for the cultural transmission of language. Using multi-agent computational models we show that certain hallmarks of language are adaptive in the context of cultural transmission. This observation requires us to reconsider the role of innateness in explaining the characteristic structure of language. The relationship between innate bias and the universal features of language becomes opaque when we consider that significant linguistic evolution can occur as a result of cultural transmission.