John Harris in Nature:
In Redesigning Life, molecular pharmacologist John Parrington has produced a veritable compendium of games that scientists like him can play with life itself. He invites us to imagine the potential of life forms “whose very genetic recipe was manufactured in a chemistry lab using new components never seen before on Earth”. What larks! What follows is a thorough and comprehensive account of the methodologies for altering life that have been or are being developed, and the directions that they may take in future. Those methodologies include the insertion or deletion of genes, the engineering of synthetic genes and the design of creatures unprecedented in nature. As Parrington shows, many of the technologies are familiar: for example, designing immunity to disease through vaccination, or animal and plant breeding. He ends with the concept of a “redesigned planet”, replete with new types of people, as well as designer babies, pets, plants and drugs. Invoking the catchphrase of comic-book superhero Spiderman, “with great power comes great responsibility”, he touches on the challenges that such a possibility would entail.
…Why might it be better to aim to increase cognitive powers and perhaps even intelligence by education, diet or exercise than through gene editing or drugs? One would also need to identify elements that would clearly be unethical to design into a person, such as an increased propensity to disease or premature death. Most importantly, one would need to consider why attempts at design are morally worse (if they are) than simply leaving things to the genetic lottery of sexual reproduction. There is a story that in the early twentieth century, the pioneering modern dancer Isadora Duncan suggested to writer George Bernard Shaw that they should have a child, surmising that with her looks and his brains any progeny would have huge advantages. The ever-rational Shaw responded, “But what if it had your brains and my looks?” Was Duncan's proposal unethical or just misconceived? What would or should have made such a proposal ethically problematic? And if it was not ethically problematic, why might more 'techie' attempts become unethical?
More here.