Evolutionary ecology of spoken language: co-evolutionary hypotheses are testable.

Evolutionary ecological frameworks can give us new insights into the emergence of human adaptations such as language and cultural learning. There now exist several well-speciŽed models of the social and ecological conditions in which the human capacity for language came under strong positive selection pressure. We critically review them, and ask how we can test them using archaeological evidence. We identify a series of critical archaeological and palaeontological parameters whose values we must know if we are to discriminate among competing hypotheses of the evolutionary ecology of language.