Jean-Jacques Weigle (9 July 1901 – 28 December 1968) was a Swiss molecular biologist at Caltech and formerly a physicist at the University of Geneva from 1931 to 1948.
After suffering his first heart attack in 1946 he emigrated to the US in 1948, resigned from the faculty of the University of Geneva and went to Caltech in Pasadena, California.
There he turned to biology and worked in the Phage group of Max Delbrück, Seymour Benzer, Elie Wollman, and Gunther Stent.
He is most noted for his demonstration, with Matthew Meselson, of Caltech and Grete Kellenberger of Geneva, that genetic recombination involves actual breakage and reunion of DNA molecules.
[12] "The interest of physical scientists such Max Delbrück and Jean Weigle in the 20th Century had a revolutionizing effect on biology".