Joshua Lederberg

Joshua Lederberg (1925-2008), American bacterial geneticist and microbiologist who won a Nobel Prize in physiology or medicine in 1958 for his discovery that bacteria can exchange genetic material. He is considered a founder of the field of molecular biology.

Lederberg was born in Montclair, New Jersey. He received a Ph.D. degree from Yale University in 1947 and joined the faculty of the Stanford University School of Medicine in 1959. While engaged in research at Yale, he discovered (1947) that bacteria have an elementary sex life; that is, they reproduce by conjugation, the mutual exchange of genes between sexually undifferentiated one-celled organisms. This discovery considerably expanded the possibilities of genetic research. Considered even more important was Lederberg’s later discovery that some viruses carry hereditary materials from one bacterial cell to another and thereby change the heredity of their hosts. From 1978 until 1990 he was president of Rockefeller University in New York. He also coined the term exobiology and worked with Carl Sagan to study the possible existence of extraterrestrial life in outer space.