Making scientific history is hard enough. It's tougher still when a lot of people wish you hadn't. That was the problem facing Woo Suk Hwang and Dr. Shin Yong Moon of Seoul National University when they announced in February that they had cloned human embryos for the first time. With that development, a medical and ethical door that had remained mostly closed was kicked wide open.
The researchers' method was familiar to anyone who has been following the cloning parade from sheep to mice to other animals over the past several years. After harvesting 242 eggs from 16 female volunteers, Hwang and Moon removed the eggs' genetic material and replaced it with DNA extracted from adult cells donated by the same women. They then used tiny bursts of electricity to fuse together the donor material and egg. Nourished in dishes, 30 of the hybrid eggs developed into blastocysts-balls of hundreds of cells that represent one of the earliest stages of fetal development. When couples undergo in-vitro fertilization, a blastocyst successfully implanted in the womb has a very good chance of becoming a baby.
That's what spooks cloning foes, since in this case, the resulting babies would have been not random mixes of two parents but perfect copies of the women who donated the DNA. That, however, is not what Hwang and Moon wanted. "We will never try to produce cloned human beings," Hwang said. What they do want to produce and, in fact, did is embryonic stem cells, the biological blank slates that develop into all the body's tissues. Thanks to stem-cell technology, people could become their own tissue donors with pristine, unrejectable cells at the ready to repair damage done by, say, Alzheimer's disease or spinal-cord injury. Stem-cell research in the U.S. has been hamstrung since the Bush Administration's 2001 decision restricting federal funding for the work to existing cell lines. In South Korea, which forbids human cloning only for reproductive purposes, the game is much more open.
Nobody pretends that Hwang and Moon's findings are ready for clinical application or that they don't raise some disturbing possibilities. But few people deny that they raise some thrilling ones too precisely what science is supposed to do.
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