Natural competence was discovered by Frederick Griffith in 1928, when he showed that a preparation of killed cells of a pathogenic bacterium contained something that could transform related non-pathogenic cells into the pathogenic type.
Since then, natural competence has been studied in a number of different bacteria, particularly Bacillus subtilis, Streptococcus pneumoniae (Griffith's "pneumococcus"), Neisseria gonorrhoeae and Haemophilus influenzae.