Dr Rosie Hails MBE is an Ecologist at the NERC Centre for Ecology and Hydrology in Oxford, where she researches pathogen population ecology. She also teaches quantitative methods to undergraduates at Oxford University, and is a Fellow of St Anne's College, Oxford. Professor Alan Grafen is at the Zoology Department and St John's College, Oxford. He has written on inclusive fitness, evolutionarily stable strategies, kin recognition, the statistics of cross-species comparisons, Zahavi's handicap principle, and the natural selection of economic behaviour. His current project is to put modern Darwinism on a secure mathematical foundation.Grafen, Alan is the author of 'Modern Statistics for the Life Scientists', published 2002 under ISBN 9780199252312 and ISBN 0199252319.