Book: A Clone of your Own?
Author: Arlene Judith Klotzko
Price: Oxford University Press, ?12.99
Arlene Klotzko, a bioethicist, wants us to stop worrying and learn to love the clone. In her beginner's guide to cloning, she argues that this new technology has become a scapegoat for all we fear about uncontrollable, unnecessary and unethical science.
Human cloning is a focus both for the worries about genetic determinism raised by the human genome project, and for long-standing fears about "man-made" people. Nor is its credibility enhanced by its practitioners, full of big talk and little proof - scientific showmen such as Panos Zavos, an American fertility expert, or the Raelians, a UFO-loving cult which claims to have achieved six births through cloning, with more to come.
The reality, Klotzko argues, is that human cloning is no more unnatural than many other now-accepted technologies, and the prospective ethical dilemmas it poses are not much different to those found in more familiar situations. Identical genes do not mean identical lives: just look at twins. There are profound technical barriers to producing healthy human clones, but Klotzko is fairly confident that these will be overcome: "Human reproductive cloning is not a matter of if; it's a matter of when."
Indeed, human cloning of a sort has already occurred. In February, a team of scientists from universities in South Korea announced the first step towards human therapeutic cloning. "Somatic cell nuclear transfer," as it is called, creates embryos without the meeting of egg and sperm. In reproductive cloning, these embryos settle into the womb until birth. In therapeutic cloning, however, they stay in the laboratory, coaxed into becoming multi-cell structures known as blastocysts from which stem cells can be derived.
Unlike most of the body's cells, say in the skin or lungs, which are locked into a single role for a limited lifetime, embryonic stem cells are able to reproduce themselves repeatedly, and when given the right biological signals, can mature into a wide range of different cell types. This makes them a potentially useful source of new cells to repair damaged tissue in, for example, diabetes or Parkinson's disease. Human embryonic stem cells are usually derived from early embryos discarded during in vitro fertilisation. But many scientists think that there is greater potential in human embryonic stem cells derived from nuclear transfer because they could be made from a patient's own genetic material, thereby avoiding problems of graft rejection.
Some scientists have speculated that human cloning might be impossible because structures inside our cells make them more fragile than those in other cloned species such as cattle or mice. The South Koreans have proved this is not the case, thanks to some deft laboratory work. But technical hurdles mean that their clone-derived stem cells, like those from conventional embryos, are still years away from human testing.
Just as well, since governments need time to catch up. The UN has struggled over the past three years to draft an international convention which would ban human cloning. Member states are sharply divided between those, such as America, which want to prohibit all forms of human cloning, and those, such as Britain, which want to permit therapeutic cloning.
Those opposed to therapeutic cloning object to the creation - and destruction - of human life for such utilitarian ends and fear the exploitation of women, particularly in poor countries, for their eggs. But many others want to give therapeutic cloning a chance. Simply banning the procedure because it might lead to reproductive cloning is like outlawing sex because it might lead to unwanted pregnancy. Strong regulation of therapeutic cloning, and strict rules on egg donation and surrogacy, can deal with the concerns.
It is too early to tell if therapeutic cloning will transform medicine. But it already offers a valuable addition to the scientific toolkit for understanding the process of "reprogramming" an adult cell. If researchers knew enough to reproduce this effect with drugs, then they might be able to skip over embryonic stem cells altogether.
As Klotzko rightly argues, the most compelling reason to steer clear of human reproductive cloning, for the moment at any rate, is scientific. Eight years after the birth of Dolly the cloned sheep, reproductive cloning remains a dangerous proposition for both mother and offspring. Cloned animals still perish in high numbers at all stages of development (including Dolly, who expired suddenly last year), for reasons that scientists are only starting to understand. The risks of reproductive cloning do not, as yet, outweigh the potential benefits for overcoming certain forms of infertility.
