Emeritus Professor Stephen Hillier delivers the fourth lecture in the 2015 Our Changing World series entitled, Fertility Futures in a Changing World. As total population increases fertility (number of children per woman) falls and expectations change, especially in more developed regions of the world. Medical, educational and societal norms encourage people to control how many children they have and when to have them. Options are opened by assisted reproductive technology based on in-vitro fertilisation (IVF). In this lecture, Professor Hillier looks at controversial genome engineering tools. These tools raise the spectre of non-therapeutic ‘gene enhancement’ beyond strictly therapeutic gene repair. Might they prove useful? Would they be acceptable? Recorded on Tuesday 20 October at the University of Edinburgh's George Square Lecture Theatre.