ABSTRACT
Modern biotechnologies can modify early mammalian embryos, including those of humans. One motivation for doing this would be improving the biological traits of the next generation, e.g., implementing the classic program of eugenics. Espousing eugenics is currently unpopular, but some scientists, bioethicists and science writers assert that it is inevitable. Most informed commentators on these issues refrain from promoting enhancement eugenics, but advocate embryo engineering short of full term at first, to generate therapeutic tissues, and later all the way to birth, to prevent diseases in prospective offspring. This chapter has several objectives: I argue that making inheritable genetic or cellular modifications of embryos intended for full-term development constitutes uncontrolled human experimentation and that the attendant uncertainties are side-stepped or obscured by most observers. This often takes the form of statements in conflict with accepted biological fact. Since manipulations of human embryos can have strong scientific, medical, and commercial benefits, however imperfect the outcomes, there are incentives to pursue them experimentally up to and including full-term development. I conclude that the only way to protect our species from eventual dissolution is to ban embryo manipulation in its entirety.
