The results of these experiments were at first sceptically received by the scientific community . Not until the discovery of other methods of genetic transfer ( conjugation in 1947 and transduction in 1953 ) by Joshua Lederberg were Avery 's experiments accepted . The results of Avery et al . 's experiments were at first sceptically received by the scientific community and it was not until the development of genetic markers and the discovery of other methods of genetic transfer ( conjugation in 1947 and transduction in 1953 ) by Joshua Lederberg that Avery 's experiments were accepted .