WHAT should we make of the news from South Korea on cloning human embryos? Some have rapturously welcomed the study as the breakthrough that will finally unlock the awesome medical potential of embryonic stem cells. Others are outraged, arguing that it will encourage reproductive cloning and lead to a world in which human embryos are routinely destroyed to supply 鈥渟pare part鈥� tissues. In reality, neither side provides an adequate lens through which to judge an advance that is richer in shades of grey than black and white.
Will the study help would-be reproductive cloners? Certainly the experimental details will save time in other labs. And it would be naive to claim that ground-breaking research which establishes that there is no fundamental biological barrier to creating cloned human embryos will not help the mavericks鈥� cause.
Yet there is also plenty in this study to discourage scientists from trying to clone a baby (see 鈥淐loned cells today. Where tomorrow?鈥�). The team used 242 scarce eggs to create 30 embryos, only one of which yielded stem cells. Were the embryos genetically normal? Would they have implanted? Nobody knows. What鈥檚 more, the Korean method only worked when both egg and adult DNA came from the same woman. Clearly, human cloning is neither going to be easy or routine.
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Nor does it follow from these experiments that doctors will soon be using embryos routinely for medical treatment. Indeed, they may never do so. Though scientists still justify the research by talking of tissues that are tailor-made for patients from individually cloned embryos, many stem-cell researchers have moved beyond this early model, believing it will be impractical or even unnecessary.
Instead, they envisage creating banks of generic stem cells to supply tissues that, though not an exact match, would be close enough for most patients. Another route would be to do a limited amount of research with human embryos to find the chemicals that enable eggs to return DNA to its embryonic state. Success here would men personalised tissues could be created without egg or embryo, as would happen if research into adult stem cells fulfils its promise.
Whichever approach prevails, practical treatments are years or decades away. So how should governments police it today? A few nations, the UK and South Korea among them, have already drawn a distinction between cloning for medical research (permitted) and reproductive cloning (forbidden). But the global picture is hopelessly confused, with the US lacking any federal legislation, Australia banning reproductive cloning but waiting to decide on its medical value, and the UN deadlocked between two camps, one pressing for a total ban, the other content to stop at reproductive cloning. This hotchpotch is the worst of all worlds, creating loopholes for maverick reproductive cloners and uncertainty for scientists doing legitimate research. If nothing else, let鈥檚 hope the Korean advance pushes governments into action.
None of these factors addresses the blanket moral objection some people have to all research on human embryos. But they ought to make those on both sides of the debate pause before issuing simplistic statements. Will cloning stem cells lead to routine cannibalisation of embryos? Almost certainly not. Will tailor-made, cloned stem cells be needed for treating Parkinson鈥檚? Almost certainly not: of all the body鈥檚 organs, the brain is the least likely to reject imperfectly matched tissues. It is time to move beyond talk of the awesome benefits, or horrors, of embryonic cloning. The truth is neither black nor white.