Depending on whom you ask, the experiment announced at a Texas medical conference last week was a potential breakthrough for infertile women, a tragic failure or a dangerous step closer to the nightmare scenario of human cloning.
There's truth to all these points of view. Infertility was clearly the motivation when Chinese doctors used a new technique to help one of their countrywomen get pregnant. Unlike some infertile women, the 30-year-old patient produced eggs just fine, and those eggs could be fertilized by sperm. But they never developed properly, largely because of defects in parts of the egg outside the...