Crossing the Rubicon

The news in recent weeks that South Korean scientists have succeeded in cloning 30 human embryos and developing them to the 100-cell stage filled me with a mixture of awe and apprehension, and I am sure I am not alone in this.

In my grandparents' day, it was widely believed that 'nature knows best', and congenital conditions, birth defects, infertility and terminal diseases were accepted with resignation, if not equanimity, as being your lot in life.

As scientists have pushed back the boundaries of knowledge, it has become clear that in some instances nature gets it badly wrong. But the question remains: to what extent should we interfere? Just because we can do something, should we?

Who, if it was in their power, would not prevent children being born with spina bifida or cerebral palsy? Who would not prevent muscular dystrophy, or Huntingdon's disease or rare forms of cancer being passed down to successive generations?

But creating an embryonic life with no intention of allowing it to develop into a human being; to see it as nothing more than a source of stem cells to be used to repair defects - that cannot be morally acceptable, can it?

And yet, it is not so long ago that the public - and some scientists - were questioning the morality of organ transplants and IVF treatment.

Since the decoding of the human genome, the line between what we think we know instinctively to be right or wrong is becoming increasingly blurred with every new development. The idea that we could engineer the genetic make-up of a foetus to create a child whose bone marrow could save the life of a sibling was anathema to many people, but if it is that child's only chance of life, is it not better than leaving things to chance? Left to its own devices, nature could not only fail to create a suitable donor but may even repeat its original mistake.

As things stand, the creation of a human being in the perfect image of another is not only beyond our capabilities but also well outside our ethical tolerance. But there are those who will persist in trying.

The cloning of animals has been carried out with limited success: the resulting offspring have failed to reach their normal lifespan and have suffered from a range of defects.

This may be no more than yet another obstacle to be surmounted. Or perhaps it is nature's way of calling a halt to progress in this direction.

One thing is for sure: every advance in cloning technology will pose more questions than it answers.