DNA is the very core of human existence. The thought of humans manipulating the DNA base sequence of a living thing can be unsettling, disturbing, and sometimes intensely controversial. What are some of the techniques and what are some of the purposes? And what are the concerns? Chapter 10 considers the most controversial use of DNA technology: genetic engineering. It also explores twenty-first century technologies recently developed beyond the “old-fashioned” genetic engineering methods of the 1970s and ’80s. These newer technologies, with curious names, will soon be responsible for putting new products on the market. Synthetic DNA and gene drive are recent additions raising both exciting new possibilities and, simultaneously, old fears. New genome editing technologies, with cool names such as CRISP-Cas9, RNAi, Zinc Finger, and Talens, alter the native DNA in the genome—hence genome editing—and thus forego the need to add DNA from other species or to synthesize entirely. This strategy, say proponents, should quiet the concerns raised from those worried about introducing “foreign” genes from different species. Are you ready?