High Quality Content by WIKIPEDIA articles! Human directed genetic modification has been occurring since we first domesticated organisms in 12 000 BC. Genetic engineering as the direct transfer of DNA from one organism to another was first accomplished by Herbert Boyer and Stanley Cohen in 1973. Advances have allowed scientists to manipulate and add genes to a variety of different organism and to induce a range of different effects. Since 1976 the technology has been commercialised, with companies producing and selling genetically modified food and medicine.