"Grooming, Gossip and the Evolution of Language"@en . . . . . . "978-0-674-36334-2" . . "The origin of language in the human species has been the topic of scholarly discussions for several centuries. In spite of this, there is no consensus on the ultimate origin or age of human language. One problem makes the topic difficult to study: the lack of direct evidence."@en . "230"^^ . .