Scientists seem intent on producing the first human clone, but why would someone want a clone, asks Dick Ahlstrom, Science Editor
An Italian fertility doctor, Severino Antinori, claimed this week that the world's first human clone would be born next January. While most of the scientific world doesn't believe the claim, the issue still raises questions about why someone might want a clone. What possible reasons are there for pursuing such an unnatural goal?
For the sake of simplicity, before looking at possible answers, it is first worth sidelining the moral and ethical issues, the issues that in reality are impossible to ignore. The notion of a cloned human causes deep-seated disquiet in most people. It runs counter to all mainstream religions and the experimental work necessary to produce a clone is banned in many countries.
Human cloning raises the most profound issues about the nature of life and the steps that might or should be taken to create it. Are any means justifiable if the end is the birth of a baby? There are no simple answers when cloning enters the frame.
Let's assume then, for the sake of argument, that we have overcome these problems. The only question remaining is would we want a clone and if so why? What reasons are there for pursuing this technology?
It provides a way for childless couples to have children
Human cloning would follow the methodology developed at the Roslin Institute near Edinburgh, the centre that in 1996 produced Dolly, the cloned sheep. It involves acquiring a human egg cell, taking out its nucleus and replacing this with the nucleus from a donor cell. An electric shock stimulates this construct to divide and the developing embryo would then be implanted in a surrogate mother.
The nucleus contains DNA, the genetic blueprint that includes all the instructions for making a person. A person's DNA is unique to the individual, so the donor nucleus would produce a cloned copy of the donor. A couple unable to have children using existing fertility techniques could potentially clone either the man or woman and produce a child.
There are huge dangers however. It took Dolly's creator, Dr Ian Wilmut, 277 attempts before a lamb was delivered. All the others aborted spontaneously or resulted in malformed animals. What if the human clone survived but was malformed? It couldn't be put down like an animal, so the donor would have to take what arrived whatever the outcome.
Dolly has also developed early arthritis. Her DNA came from an adult sheep and has retained the characteristics of an older animal, not an animal just six years old. So is Dolly six years old or is she actually 12?
Researchers don't know what effect this will have on her life expectancy. Would a human clone live to a ripe old age or experience premature ageing? No one knows.
Cloning would allow dead children or relatives to be brought back to life
The traumatic loss of a child has encouraged one family in the US to attempt to bring the child "back to life" through cloning. A tiny preserved blood or tissue sample would provide enough DNA to produce a clone using the technique above. But would the child be the same? Certainly not.
A fertilised egg undergoes a staggeringly complex process before a child results. It depends on DNA elements known as genes working interactively to grow limbs, eyes and brain. This interaction is confounded, however, by external influences such as the mother's diet, radiation from space, chemical substances in food and water and hundreds of other things, any one of which could modify the process ever so slightly.
Clearly the clone would be a dead ringer for its donor, but there is the possibility of differences. There is no way to exactly reproduce the outside events that took place during the original child's gestation.
That new child would undergo a different childhood. The parents would be the same but older and the child would have different life experiences, moulding in turn a different personality. The child might look much the same but it would be a different person. Identical twins that have identical DNA have different personalities, despite growing up in the same home. Would the parents accept the reconstituted child even if it had a much different personality?
You could use a clone to grow replacement body parts and transplant organs
This is one of the most ridiculous presumptions about cloning humans. It results from our shared perception that a clone must somehow be a lesser human, an automaton without mind or will.
Despite the nature of its conception, a clone would still be a distinct human being. It would expect - and have - a right to its own life and would not willingly give up its heart or liver, in effect its life, to save its donor. It also remains unclear, given the external influences described above, whether the donor's perfect DNA match would be perfect enough to allow direct transplantation without implications. It has never been tested.
You could clone yourself repeatedly and live forever
Another daft notion. While you could presumably clone a clone ad infinitum, the connection from one clone generation to the next would be little different than from child to parent to grandparent. The notion holds that somehow the donor's brain could just be transplanted from one clone to the next. This would be a challenging surgical procedure, however, given we can't yet even repair the simplest spinal cord damage. There is no way to transplant the donor's mind and personality into the new being. Equally, the clone might have something to say about giving up its own sense of self to provide an empty vessel for the donor.