![Picture](/uploads/2/7/8/9/27893773/published/4.jpg?250)
Genetic recombination caused by human activity has been occurring since around 12,000 BC, when humans first began to domesticate organisms. Genetic engineering as the direct transfer of DNA from one organism to another was first accomplished by Herbert Boyer and Stanley Cohen in 1972. Resulting in advancements in techniques that allowed the direct modification of the genome. The introduction of genetic engineering in the 1970s and 80s enabled the possibility of moving beyond the conventional sources of random genetic variation, described above, by allowing researchers to introduce a specific single new or altered gene, or to disrupt or enhance an existing gene.