Cyril Clarke

Sir Cyril Astley Clarke (1907–2000) was an English physician, geneticist, and lepidopterist whose work on the genetics of butterfly mimicry led directly to the prevention of haemolytic disease of the newborn caused by Rhesus blood-group incompatibility. He was born in Leicester, the son of a solicitor, and educated at Oundle School, Caius College, Cambridge, and Guy's Hospital in London, qualifying in medicine in 1932.

He served as a medical officer in the Royal Naval Volunteer Reserve during the Second World War, then settled in Liverpool and joined the staff of the Royal Liverpool Hospital. From the 1950s he combined hospital medicine with genetic research at the University of Liverpool, where he was appointed professor of medicine in 1965.

His amateur passion for breeding swallowtail butterflies of the genus Papilio led him to work out how mimicry of poisonous models was inherited as a single supergene. Recognizing that human Rh incompatibility was a similar problem of antigen mismatch between mother and child, Clarke and his colleagues Ronald Finn, Philip Sheppard, and others showed in the early 1960s that injecting anti-D immunoglobulin into Rh-negative mothers shortly after the birth of an Rh-positive child prevented sensitization. The treatment, introduced into general practice in the late 1960s, has saved very large numbers of newborn lives.

He was knighted in 1974 and served as president of the Royal College of Physicians from 1972 to 1977. He died in West Kirby, Wirral, in 2000.

Cyril is an English masculine given name from the Greek Kyrillos, derived from kyrios meaning lord; he carried the masculine form.