Gerry Davis was an experienced television writer when he came to Doctor Who as Script Editor in 1966. Wanting to explore stories rooted more closely in real science, Davis contacted Dr Kit Pedler. The resulting collaboration resulted in several notable Doctor Who scripts, and in particular the creation of the Cybermen. Gerry Davis returned to Doctor Who in 1975 and novelised several of his and Pedler's Doctor Who stories for Target books. Gerry Davis died in 1991.
Christopher ('Kit') Pedler was a medical researcher, and head of the Electron Microscopy Department at the University of London when he was recommended to Script Editor Gerry Davis as someone who might be useful as an adviser to Doctor Who. Davis presented Pedler with hypothetical, fictional problems and asked to extrapolate what would happen, the answer to which formed the basis of Doctor Who stories. Pedler told Davis that as a doctor his greatest phobia was a time when spare part surgery had reached the stage where it was commonplace. There would come a point where it was impossible to tell how much of the original human being remained... From this fear was created the Cybermen. Kit Pedler died in 1981.