Tom Holland and Iszi Lawrence follow history’s lines and linkages to uncover connections and compelling stories. This week, with the imminent arrival of a new Royal baby, Tom and Iszi examine bloodlines - from some of the Queen’s own surprising ancestors, to the vagaries of dog breeding.

Adam Rutherford discusses how DNA testing has informed the study of history and the programme asks if race really is a question of genetics, or a cultural construct. Producer: Alison Vernon-Smith A Pier production for BBC Radio 4