Under this scenario, parents could choose a variety of options for their unborn children, including everything from cosmetic traits, such as hair or eye color, to endowing their offspring with greater intellectual or athletic ability.Some transhumanists see a huge upside to making changes at the embryonic level.“This may be the area where serious enhancement first becomes possible, because it’s easier to do many things at the embryonic stage than in adults using traditional drugs or machine implants,” says Nick Bostrom, director of the Future of Humanity Institute, a think tank at Oxford University that focuses on “big picture questions about humanity and its prospects.”

But in the minds of many philosophers, theologians and others, the idea of “designer children” veers too close to eugenics – the 19th- and early 20th-century philosophical movement to breed better people.Eugenics ultimately inspired forced sterilization laws in a number of countries (including the U.S.) and then, most notoriously, helped provide some of the intellectual framework for Nazi Germany’s murder of millions in the name of promoting racial purity.