Sir Ronald Aylmer Fisher FRS (17 February 1890 – 29 July 1962) was an English statistician, evolutionary biologist, eugenicist and geneticist. He was described by Anders Hald as "a genius who almost single-handedly created the foundations for modern statistical science," and Richard Dawkins described him as "the greatest of Darwin's successors". This days we take genetics for granted, but it is R.A. Fisher who went a long way to make it a testable science. Fisher put in place the mathematical tools and conceived of experimental designs to test complex biological hypotheses. This programme tells Fisher's story, the genius of his insight, the arguments and the struggle for acceptance of his ideas.