In a special edition of Hardtalk, recorded in front of an audience in the village of Portmeirion in North Wales, Stephen Sackur talks to Sir Mark Walport the Director of the Wellcome Trust. One of the world's most important funding institutions for biomedical research, it distributes close to a billion dollars' worth of grants every year. Much of it goes to cutting edge genetic research which promises to transform human healthcare, but also raises profound ethical questions. Our scientific knowledge is expanding but what about the wisdom with which we use it?