Joshua Lederberg’s legacy to bacterial genetics

Joshua Lederberg (1925–2008) was an extraordinarily gifted person. Starting his professional career at the age of 17 as a dish washer in Francis Ryan’s laboratory in Columbia University, he rose to be the President and later University Professor Emeritus at Rockefeller University, occupying chairs of Genetics at Wisconsin and Stanford Universities. He was only thirty three when he received the Nobel Prize, along with George W Beadle and Edward L Tatum in 1958. He also received the Presidential Medal of Freedom and the National Medal of Science. His scientific work encompassed not only bacterial genetics but also astrobiology (exobiology, as he called it) and artificial intelligence. He was part of the Stanford team which developed the artificial intelligence software program DENDRAL. With his passing away in February 2008, the last of the founding fathers of bacterial genetics is gone. It is an honour for me to write this small article in his memory. In this article, I will focus on just two of his outstanding contributions to bacterial genetics, namely, the spontaneous, selection-independent origin of bacterial mutations and the discovery of genetic recombination and sexuality in Escherichia coli.