Respuesta :
Modern Genetic engineering differs significantly from the past due to advances in biotechnology that have occurred beginning in the early 1970's. Human's Genetic engineering before this time consisted primarily of selective breeding to obtain desired traits in both plants and animals. Since the early 70's however, biotechnological advances have enabled Genetic engineers to directly manipulate the DNA of both plants and animals, greatly increasing the potential to create new desired characteristics that were not possible before.