Life as we don't know it

Faced with dwindling supplies of human eggs for research, scientists will be told in January whether they have the go-ahead for experiments using animal eggs and human DNA to help create stem cells. But does this leave enough time for an effective ethical debate?

In a proposal that has echoes of the human-animal hybrids of mythology - centaurs, mermaids, satyrs - a combined research team from Newcastle University and King's College, London, have applied to the HFEA - the Human Fertilisation and Embryology Authority - for a licence to fuse animal eggs and human DNA.

The plan involves a technique known as Cell Nuclear Replacement, in which a cell nucleus from an adult human is placed in an animal egg, typically the egg of a goat or cow, that has had its own nucleus removed. The cell is then activated so that it behaves like a fertilised egg after conception, prompting cell division like a normal embryo. The vast majority of the fertilised egg's DNA (about 99.9 per cent) would be of human origin, but a tiny amount of the genetic material (the remaining 0.1 per cent) would be composed of animal mitochondrial DNA, which is the part of the cell that produces energy. Biologists call the resulting entity a "chimera", meaning, in this case, that it is a cross-species genetic mix.

According to the scientists, the advantage of the research programme is that it precludes the use of human eggs, which are difficult to obtain since women are increasingly refusing to donate them for research purposes. That in itself is significant. In a recent survey conducted under the auspices of the HFEA, women gave their reasons. One said: "Having lost two babies I feel that I could not use the beginnings of another baby for research." Another said: "It is the start of a living thing and that makes it a difficult decision."

However, the research team seeking approval for the chimera has suggested that the procedure bypasses the moral dilemma of using human embryos generated in the normal way by sperm and egg. Their argument is that the human DNA component of the chimera comes from the cell of an adult human donor (cloned in other words), while the animal component is a mere receptacle for that genetic material. Hence the chimera is not really a human embryo at all, and there is in any case no intention of implanting the chimera to bring it to term.

Doctor Anne McKlaren, who works on embryonic stem cells at Cambridge University, explains: "Since there are both ethical and practical problems with obtaining human unfertilised eggs, and since it could be very valuable to discover how human body cells can be converted into stem cells that can be used for the repair of damaged tissues, the use of animal eggs to provide information, for research purposes only, of course, not for clinical use, seems a sensible approach."

Last week the HFEA announced that it has yet to develop a policy on the issue, and that its legal remit, as it stands, applies only to human embryonic research and not embryos created from a combination of human and non-human material. The authority expects to clarify the legal position, announce its policy and reach a decision on the licence by January 2007. This allows barely a month (if we exclude the unusually long Christmas and New Year holiday) for the discussion of viewpoints and posing of objections.

Perhaps reflecting public opinion, the media has so far tended to greet the proposal as a joke (witness, typically, the Sun headline: "MOOTANTS"). Meanwhile, among ethicists the response to what appears a major breach of biological, moral and cultural taboos - the crossing of the species barrier in fundamental genetic research - has been unusually muted. As I attempted to canvass opinions from ethicists up and down the country, Christian and non-Christian, I have never had so many requests of "Please don't quote me!" The reluctance, it seems, reveals acknowledgement of the terra incognita that we have entered, where it seems, as Shakespeare put it, "Nothing is but what is not."

However, the Linacre Centre for Healthcare Ethics has been prompt to condemn the initiative. Having reiterated the formal Catholic opposition to "creating new human lives for subsequent destruction", the centre adds that to use cow eggs in cloning experiments "does not solve the moral problem, but in some ways compounds it". There is a risk that human embryos will still be created, states the centre, and that those lives will be treated with even more contempt in view of their animal component. "Human fertility", the statement continues, "is a precious gift: to use human genes to activate an animal ovum violates respect for that gift, even if we are unsure what kind of being will result."

It is of course crucial to be reminded of the formal view of the Church on the inadmissibility of human embryonic experimentation. I have listened, in addition, to a number of additional caveats, ranging from an insistence that the chimera insults the notion of the human embryo as the "imago" of God, to slippery-slope arguments, to "yuk factor" arguments. It is significant, moreover, that countries such as France and Germany have outlawed such experiments, remembering in particular what scientists did in the Nazi era.

At the same time, there is an insistence on the part of ethicists of every persuasion that just because a thing can be done does not mean that it ought to be done. Nor are ethicists easily swayed by purely consequential arguments - particularly of the kind that say: "Let me do this bad or dubious thing so that a good consequence might follow in the form of a new therapy." Whether they oppose or agree with experiments, most commentators insist that we cannot leave such decisions to the scientists alone. "Such decisions", as one theologian told me, "involve a more extensive moral and cultural landscape than the laboratory."

Yet, while honouring the protective ambit established by Church teaching on the mystery of human life at its origins, and taking into account a wide circuit of comments and objections, religious and secular, might there be scope for further consideration, perhaps in favour of such experimentation?

It is an extraordinary tribute to the theologian Karl Rahner SJ that in the mid-1960s he formulated a far-sighted response to just such a scientific possibility in two essays, entitled "The Experiment with Man" and "The Problem of Genetic Manipulation" (Theological Investigations, vol. 9). He sets the groundwork of his thinking by acknowledging that we "no longer merely live in an environment and cultivate it superficially, but actually create it, looking at the given stuff of nature as material for the environment which we intend to produce according to our own design".

Rahner grants "that at the moment of union of the male and female cells a human being comes into existence as an individual person with his own rights". But he then makes this surprising reflection: "It would be conceivable that, given a serious positive doubt about the human quality of the experimental material, the reasons in favour of experiment might carry more weight, considered rationally, than the uncertain rights of a human being whose very existence is in doubt." This, he felt, might yet lead to long-term benefits for the good of mankind.

It seems extraordinarily prophetic of him to have envisaged such experimentation and of course Rahner had no way of knowing, 40 years ago, that such a laboratory chimera, involving "doubt about the human quality of experimental material", would come to pass.

But he was conscious, of course, that "new and practical possibilities are set before us in relatively rapid succession [with] vast and far-reaching effects". Thus he appears to be opening up the possibility of at least entering the debate about the merits of such research, as opposed to condemning it out of hand.

In the final analysis, however, he offers a salutary warning: "In future man must develop a critical attitude towards the fascination exercised by every new possibility."

The problem with the new experimental proposal for human-animal chimera research, and the imminent HFEA decision, is that it leaves scant time and opportunity for the development of critical attitudes towards such a problematic experiment. The HFEA should surely grant more time for discussion and debate. Meanwhile ethicists of every hue should come out of their bunkers, speak plainly, and be prepared to put their names to their opinions.