Bernard Kettlewell is best known for his research on industrial melanism, or the effects of industrial pollution on pigmentation in insects, particularly moths and butterflies. He specialized in entomological fieldwork and made a significant contribution to the Lepidoptera collection at the British Museum of Natural History. Kettlewell's work on industrial melanism at Oxford in the 1950s was considered to be the first rigorous scientific study to confirm Charles Darwin 's theory of natural selection.

Henry Bernard Davis Kettlewell was born in Howden, Yorkshire, on February 24, 1907, to Kate (Davis) and Henry Kettlewell, a member of the British Corn Exchange. He attended the prestigious Charterhouse public school from 1920 to 1924, spent a year studying in Paris, then enrolled at Caius College, Cambridge University, in 1926 to study medicine and zoology. He accepted appointments at several hospitals in England, including St. Bartholomew's in London and St. Luke's in Guildford, where he served for...