'Nothing in biology makes sense except in the light of evolution'! So said Theodore Dobzhansky. It is extraordinary how little Darwinism and post-Darwinian evolutionary science has penetrated medicine despite the fact that all biology is built upon its foundations. Randy Nesse, one of the fathers of Darwinian medicine, recently observed that doctors 'know the facts but not the origins'. Clearly, then, in this auspicious year-200 years since Charles Darwin's birth and 150 years since the first edition of the Origin of Species-it is time to reconsider Darwin's legacy to medicine and to invite evolution back into the biomedical fold. Here, we consider the legacy of Darwin and the contribution of the other great evolutionists such as Ernst Mayr to cancer and medicine.