What can the classification of languages tell us about human origins and human prehistory? This book presents a popular account of the origin of language. It is intended for an audience with no prior knowledge of comparative linguistics, genetics or archaeology. The present volume is a reprint of the 2009 second edition of the book, and includes the text of the first edition (1994) with minor modifications, as well as the scientific evidence for monogenesis, and a Postscript recounting developments in the field since the original publication of the book.