Obituary: Joshua Lederberg, Nobel prize-winning scientist

The American scientist Joshua Lederberg, who has died aged 82, won the 1958 Nobel prize in physiology or medicine for showing that bacteria can conjugate and exchange small strips of genetic material. Among the consequences of this was the realisation that antibiotic resistance can be passed around between bacteria, rather than emerging from selective breeding of resistant strains. This opened new paths in genetic research. He went on to a distinguished career in science policy, advising government committees and presidents, heading Rockefeller University and writing a Washington Post column on science and society. Lederberg's father was an orthodox rabbi - the family had come to New York from Palestine - who wanted Joshua to follow in his footsteps.