This article will tackle the ethical arguments against the use of hybrid or "chimera" embryos involving mixing animal and human DNA. It will try to analyse and criticise these arguments with the aim of justifying it mainly from a utilitarian perspective but also to warn of the risks even from this conclusion. In order to focus more clearly on the issue in question this essay will take as a premise that experimentation on human embryos up to the point of a primitive streak developing is permissible for research purposes. According to a Department of Health public consultation (although possibly flawed in its technique) there is a majority feeling against the idea of hybrid embryos (Science and Technology Committee 2006-07). However the reason why is much less clear. I intend to analyse these reasons and show why they may be lacking depth or reason.
The first and possibly most superficial is a sort of fear that if a hybrid embryo were to come to term it may be superior to humans. This argument is usually overlooked as the scientific chance of this occurring is incredibly minimal. However that does not mean it should be completely disregarded as it could still happen in the future. The response is that this is irrelevant as the current law under consideration still limits the life of an embryo, hybrid or otherwise, to fourteen days.
The second issue to challenge the idea of chimera embryos is that of human dignity. The Scottish Council on Human Bioethics suggested that hybrids "could seriously undermine the whole concept of human dignity" (cited by Science and Technology Committee 2006-07). Unfortunately the idea of dignity is a very difficult concept to pin down and consequently very difficult to argue against. Therefore in order to criticise this argument we need to question the humanity aspect. The first and most obvious criticism in this category is that genetically they are not human. Unfortunately this is not a particularly viable argument as it implies anything with slightly different DNA to an average human (assuming there is such a thing) does not count as human and certainly doesn't have the same moral status. This same argument could also rule out certain genetic abnormalities and mutations that happen naturally from humanity. In order to rule out this argument therefore we have to return to the premise that embryo experimentation is ok up to fourteen days as twinning is still a possibility.
Similar logic can be used to dismiss arguments based on human rights as the embryo never truly becomes a human. It also goes some way to tackle the problem that the research treats "another human, or a part-human, as a means to an end rather than as an end in itself" (Johnston and Eliot) however the method becomes weaker in this criticism. On the other hand the argument for dismissing claims from human rights can be further encouraged by pointing to the human rights of those afflicted by diseases that could be solved by the research. This begins to rely on a consequentialist argument and as the arguments in favour of the research have been easily criticised then it begins to become a utilitarian argument.
The initial response from utilitarianism is that the research is justified on the basis of the millions of lives it could save or improve. However this does not take into account all factors. There is the general ill feeling of the majority to consider and the possibility that the research will be fruitless. The impossibility of calculating these probabilities could on its own persuade a utilitarian to oppose the experimentation. In addition to this one must consider the right of the human parent in some possible cases. Certainly the Catholic Church of England and Wales believes that if a mother has a change of heart she should be able to keep the embryo to term (CCEW press release 19/02/2008). This immediately challenges arguments against human rights and dignity as it broaches the possibility of a human with animal DNA. However if held to a decision the utilitarian would still probably fall on the side of allowing the research as these probabilities are so unlikely. Problems begin to arise however when rule utilitarianism is involved. The precedent allowing this research to go ahead could be very damaging. Once passed the case for allowing embryos to come to term in order to observe and test could easily emerge. This would cause concerns over the human rights if an embryo were to come to term from a diseased or damaged strain as well as the possibility of creating a new illness or allowing illnesses to cross species that the human body is not conditioned to even try to fight. Essentially there could be a serious risk not in the act of allowing this research but in what could follow from it.
The case to be made therefore is whether the risk of future problems is worth the possibility of curing numerous diseases. The government proposals at present are clear in the tough regulation on the creation of such embryos and their enforced destruction but that by no means draws a line under the matter and certainly doesn't rule out future legislation altering these guidelines. Taking into account my opening premise I would suggest that the argument for the research hangs essentially on the moral status of the embryos if they were allowed to progress beyond the development of a primitive streak. Unfortunately this is difficult to judge without allowing it to occur as assuming its status is based on how human it is that is a quality than cannot be scientifically measured without offending human dignity by treating human life as a commodity (Resnik 2003).
The conclusion I would therefore make is that it is important to ensure that no precedent is set by the proposals but in themselves they are a good thing in terms of maximising utility. As the moral status of a hybrid embryo carried to term cannot be accurately judged until after it has developed its primitive streak then the risks are to great(if for instance it had the same sentience as an animal and showed no defining human characteristic, was born into a permanently vegetative state, had to live with an incredibly destructive disease built into its DNA or just lived in extreme pain). Added to the risk arguments of developing a new disease and the arguments from human rights and human dignity the conclusion to be made is that no attempt should be made to continue the life of a hybrid chimera embryo beyond the allotted time of fourteen days when the possibility of twinning disappears. Before this point even if based on imperfect knowledge and reasoning it is the least repugnant option and the benefits could be one of the greatest leaps forward in medical history.
House of Commons Science and Technology Committee (2006-2007), "Report on Government proposals for the regulation of hybrid and chimera embryos"
Robert and Baylis (2003) "Crossing Species Boundaries", The American Journal of Bioethics 3.3
Resnik (2003) "Patents on Human-Animal Chimeras and Threats to Human Dignity", The American Journal of Bioethics 3.3
Munthe, C. (2001), "Divisibility and the moral status of embryos", Bioethics 15 (5/6), pp.382-97