Michael Rosen hears the fascinating story of the origin of all Indo-European languages from Laura Spinney, the author of Proto: How One Ancient Language Went Global. Today, nearly half of humanity speaks an Indo-European language and Laura has been investigating how that came to be. Produced for BBC Audio Bristol by Beth O'Dea, in partnership with the Open University. Subscribe to the Word of Mouth podcast and never miss an episode: https://www.bbc.co.uk/sounds/brand/b006qtnz