By Margaret Somerville
November 24, 2010 - Being an incurable optimist, I do not believe the human race will end, but, if it were to, I think it would most likely come about through human intervention in human life with avant-garde technoscience. Such interventions could either intentionally wipe out the species, as in the case of the transhumanists, or unintentionally, as could happen with xenotransplantation.
Transhumanism is a movement supporting the belief that humans, and the human experience as we know and treasure it, should become obsolete. Transhumanists are working towards a future in which humans are redesigned through technology, especially robotics and artificial intelligence, to become cyborgs - human machines. Transhumanists say the physical, mental, emotional, and even moral capacities of cyborgs will far outstrip those of “unmodified humans”. In this techno-utopian vision - one I, and others, see as dystopian - of a post-human future, people like us - “unmodified humans” - are obsolete models.
In a nutshell, transhumanists describe a “human, transhuman, post-human” continuum. They believe that the technological revolutions now underway - in infotech, biotech, nanotech, robotics, and artificial intelligence - will converge to alter the fundamental nature of being human, and with that, our concepts of what it means to be human. We - and all our most important values and beliefs - will be transformed beyond recognition. Eventually, we will reach the nirvana of a post-human future: we won’t be human at all, transhumanists say. For them, “human” is not the end of evolution; it is the beginning.
Transhumanists want only to do good - but this is dangerous. When we have an overwhelming desire to do good, it is much more difficult to see the risks involved. In their own words, transhumanists “seek to expand technological opportunities for humans to live longer and healthier lives and to enhance their intellectual, physical, psychological and emotional capacities.” Taking them at face value, most of us would endorse those goals. But the ultimate goal of transhumanism is that superior beings will be created by redesigning Homo sapiens with technoscience to become Techno sapiens.
The benefits promised by the new technologies, as described by the transhumanists, are deeply seductive. It is no accident that the issues of life-prolongation and age-retardation are front and center on their pro-technology agenda. They believe - probably rightly - that these issues will appeal to many people and in doing so will generate support for transhumanism and post-humanism.
Life-prolongation involves using technology to extend our “natural” life spans by repairing or replacing our “parts” as they wear out. The implications of age retardation are far more radical. The technology involves reprogramming, at the embryonic stage, the genes that control aging. so that we would reach puberty around 40 years of age, early middle age at 80, and old age much later, if ever. Transhumanists speak of ultimately achieving immortality.
Xenotransplantation is another technoscience that creates a very remote, but real, possibility of wiping out the human race. It involves transplanting organs between different species - for instance, taking organs from pigs and putting them in a human. At first glance, this idea seems very attractive, because it could mean an unlimited supply of organs. But what does it involve?
When a human organ is transplanted from one person to another, the recipient’s body will, to some extent, reject that organ because the donor’s genetic makeup (genome) does not exactly match the recipient’s (unless they are identical twins). But when we transplant an organ from an animal to a human, an additional, very powerful rejection reaction - a hyper-acute rejection reaction - occurs within minutes to hours after the transplant. To overcome this problem, scientists modify the genome of the pigs.
One approach is to insert human complement inhibitor genes in the genomes of pig embryos, which, when they reach adulthood, will be used as the source of transgenic organs. These genes trick the organ recipient’s immune system and overcome the hyper-acute reaction - that is, the recipient’s immune system reacts more as though the organ comes from a member of the human rather than a non-human species.
This poses a risk, not only to transplant recipients, their sexual partners, and their families, but also, possibly, to the public as a whole. An animal virus or other infective agent could be transferred to humans, with potentially tragic results - not just for the person who received the organ but for other people, who could subsequently become infected. Furthermore, there might be a very remote possibility that it could wipe out the human race.
Such concerns about xenotransplantation have been raised by some eminent scientists. For example, an article in Nature Medicine, written by one of the world’s leading immunologists - Professor Fritz Bach of Harvard University - and his colleagues, surprised many people with the strength of its suggestion: that given the risks xenotransplantation poses to the public, there should be a moratorium on it until the public has been better informed and consulted. However, the authors stressed that this suggestion was not intended to be anti-xenotransplantation or anti-science in any way.
As an example of the dangers of tampering with nature, those who oppose xenotransplantation often cite mad cow disease - new variant Creutzfeldt-Jakob disease, or nvCJD, which came from giving cattle, which are herbivores, feed made from sheep carcasses infected with a mutated prion, which is a protein molecule. Other concerns about xenotransplantation include pig retroviruses being introduced into the human population, and such novel possibilities as sequences of viral DNA in the pig genome (which are harmless to the pig) combining with sequences of viral DNA in the human genome (which are harmless to the human) to form a totally new and as yet unknown virus. (These viral sequences come from the pigs’ ancestors and our ancestors, respectively, who survived their exposure to the viruses, of which remnants remain.)
Research has also indicated that as few as 300 genes may form a new living organism. Could inactive viral sequences from the pig and from the human combine to form such an organism? Or could infectious agents in pig organs combine with innocuous human retroviruses to form chimeric agents? (Such a combination is believed to have caused human influenza epidemics.) We cannot know in advance what effect such new infectious agents would have in humans in terms of illness and death.
Humans could also develop serious illnesses from an infective agent to which pigs are immune, or that causes them little trouble. This is the case with the human immunodeficiency virus (HIV) in some primates. Moreover, research on HIV indicates that it may be a virus that crossed from animals (green monkeys) into humans, with disastrous results.
Are we ethically justified in creating risks - some of which we cannot foresee - with xenotransplantation or any other technology? To answer this question, the allocation of the burden and standard of proof will be crucial. I suggest that those who wish to undertake xenotransplantation have the burden to show that, at least on the balance of probabilities, and possibly to the standard of clear and convincing evidence, it is both reasonably safe and ethical. It will also be crucial to consult the public if they are placed at risk, especially if there is any possibility of ending the human race.
Margaret Somerville is Director of the Center for Medicine, Ethics, and Law, McGill University, Montreal, Quebec, Canada.
