1944: Oswald Avery, Colin MacLeod and Maclyn McCarty demonstrate that DNA is the hereditary material 1953: James Watson and Francis Crick describe the double-helical structure of DNA 1972. Stanley Cohen and Herbert Boyer develop recombinant DNA technology 09:5409:54 ◼ 1944: Oswald Avery, Colin MacLeod and Maclyn McCarty demonstrate that DNA is the hereditary material ◼ 1953: James Watson and Francis Crick describe the double-helical structure of DNA. ◼ 1972: Stanley Cohen and Herbert Boyer develop recombinant DNA technology