Sir Peter Brian Medawar OM CBE FRS (28 February 1915 – 2 October 1987) was a British biologist born in Brazil, whose work on graft rejection and the discovery of acquired immune tolerance was fundamental to the practice of tissue and organ transplants. He was awarded the 1960 Nobel Prize in Physiology or Medicine with Sir Frank Macfarlane Burnet. For his works he is regarded as the "father of transplantation". He is remembered for his wit in real life and popular writings. Famous zoologists such as Richard Dawkins, referred to him as "the wittiest of all scientific writers", and Stephen Jay Gould, as "the cleverest man I have ever known".Medawar was an only child of Lebanese father and a British mother, and was naturalised British citizen. He studied at Marlborough College and Magdalen College, Oxford. He was professor of zoology at University of Birmingham and University College London. Until he was partially disabled by a cerebral infarction, he was Director of the National Institute for Medical Research at Mill Hill.