The genetic modification, or ‘humanization’, of pigs could provide an opportunity for animal viruses to fool the human immune system and ‘hide’ inside the human body. German virologist Joachim Denner and others point out that retroviral infections from pigs may recombine with human endogenous retroviruses, leading to recombinant ‘superviruses’ with unknown, and possibly more virulent properties. These could become preadapted for human infection and subsequent human-to-human transmission…. In this vein, some scientists are concerned that xenotransplants could alter the human gene pool, by favoring the evolution of porcine-human chimeras (beings containing the genes of both pigs and humans)(CFRT, 1999).
M. Bucheler and A Haisch also maintain that ‘Like any other retrovirus, PERV can also introduce genes into the host genotype and thus damage the human organism in a hitherto unknown manner’ (2003:550)
The fear of zoonosis has been expressed by those in the biomedical community namely, Murphy (1996), Parry & Horton (2000), Takeuchi & Weiss (2000) Daar (2000), Takeuchi (2000) and Michie (2001). Indeed according to T.L. Platt: ‘… a zoonotic agent might undergo genetic change, through recombination or mutation, generating a ‘new’ organism that might allow it to pose a greater danger to humans’. Zoonosis has more recently been exacerbated by ‘mad cow disease’, ‘bird flu’ (HN51 virus) Human/Swine Flu (H1N1), which has crossed the animal, human, species boundary. Mary Murray, citing Somerville, states:
If it is eventually decided that it is ethically acceptable to go ahead with human trials of xenotransplantation, Somerville suggests that as well as the legal and ethical requirements that govern medical research involving human subjects, because of infective risks, additional ethical and legal requirements might need to be put in place. These might include lifetime surveillance and monitoring; an autopsy at death; and informed consent from recipients, their sexual partners, and their families all of whom might be required to regularly give blood and other body fluids for testing.
Murray further maintains, ‘…anthropological and sociological research suggests that human-to human organ transplantation has the potential to affect the organ recipient’s subjective sense of who they are’ (2006). Consequently, the transplantation of animal organs into the human would change the individual’s concept of themselves. This is partly due to the fact that we place symbolic significance on organs such as the heart and lungs - the most likely organs to be transplanted from animals into humans. Murray argues that animal to human organ transplantation may continue discourses that suggest personality types are linked to certain diseases and recipients of animal organs may be perceived as monstrous. Society, Religion and Technology Project also caution on this point:
If human life and animal life become intermingled, it might be argued that there is a danger of the distinctive moral claims ascribed to human life being undermined. It has been observed by some that the closer one moves animals, in concept, towards humans (so increasing one’s duty of care to animals), the more ready is the danger of treating some humans merely "like animals" (1996)
Julie Clarke 2009.
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A couple of quick comments:
ReplyDeleteWe are the result of 'natural' genetic crossovers between species and are in fact a symbiotic collection of various fauna and not strictly independent entities. So you could argue that these recent scientific event are only an acceleration of natural processes and a part of the evolutionary system.
And secondly - the pragmatic. If first world governments legislate to stop or over-regulate this work then it will simply move to less regulated countries. For example I think there is good reason to believe that many of the super-rich have clones on ice somewhere to be used for spare-part or life extension purposes.
And thirdly (!) - the positive. Maybe a successful (in the evolutionary fitness stakes) chimera would be an interesting successor to the human. Anyone read Cordwainer Smith's wonderful sci-fi which is packed with chimeras who are integrated with humanity?
What is a species?
ReplyDeleteConventionally, species are defined as those organisms that can breed with each other, whilst other definitions may focus on similarity of DNA or morphology.
Since our notions of identity have become gene obsessed owing to the phenomenal rise of DNA related technologies and the dominance of Neo-Darwinst discourses in scientific narratives, these questions related to DNA based taxonomies play havoc with our definition of what a 'species' is.
So what aspects of a 'species' is at risk when thinking about these kinds of cellular technological manipulations?
Could we really define what 'human' is on the basis of DNA sequencing alone given that many people have genetic anomalies that may go undetected and that people with chromosomal variations such as Trisomy 21 (Down's Syndrome) are members of the human race?
In terms of linear sequencing codes, which is what gene technology seeks to manipulate we are already aware of the huge similarity of DNA codes for morophologically distinct organisms, rather than differences between them. Interestingly in his book 'Engines of Creation' Martin Amos notes that if DNA sequencing is thought of in 3D terms, then small differences in linear sequences can have profound spatial effects ... but this is not the way that we think about gene sequencing.
When the human genome was finally published in 2003 and after the initial excitement about 'decoding the Book of Life' had quelled, researchers began to decipher the meaning of some of the surprises the human genome had in store for them, notably that there were only about 30,000 genes, which was far fewer than the 100,000 anticipated. It also appeared that proteins were more complex than previously imagined and that there were large amounts of non-coding or 'Junk' DNA throughout the entire human genome whose origin and role within the cell continues to remain speculative.
The full significance of these and other findings from the sequencing of the human genome is still being considered but it has rapidly become accepted that the regulation and expression of genes is an almost unfathomably complex system and the relatively few genes needed to build a human, which is only one third more needed than the 17,000 that were required to build C. Elegans, gave scientists the first clues to the degree of sophistication of gene regulatory networks. It is becoming clear that as more work is carried out on deciphering the human genome, certain impasses are emerging that can’t be fully ‘explained’ by Darwinistic mechanisms. Feminist perspectives, such as those postulated by the Harvard scientist Evelyn Fox Keller, offer the potential to open new possibilities for interpreting the principles of life that shed new light on the nature of the organism.
Keller sought to rebel against the growing notion around the time of the sequencing of the human genome that genes allegedly controlled all aspects of development. Her focus of attack was on the central dogma of the gene and argued that this notion of a discreet unit of biological ‘code’ did not even exist in the way it was described. Keller emphasized the observation that DNA is unable to copy itself on its own, requiring the cooperation of other molecules that were under alternative, more complex modes of instruction. Ultimately then, Keller proposed that complex networks made the decisions about what parts of the genetic code were actually expressed, not the ‘genes’.
“Which protein should a gene make, and under what circumstance? And how does it choose? In fact, it doesn’t. Responsibility for this decision lies elsewhere, in the complex regulatory dynamics of the cell as a whole. It is from these regulatory dynamics, and not from the gene itself, that the signal (or signals) determining the specific pattern in which the final transcript is to be formed actually comes.” The Century of the Gene, By Evelyn Fox Keller, Harvard University Press, 2000 P63
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ReplyDeleteYet gene theory in these kinds of discussions dominates notions of 'identity' when in fact, there is only an arbitrary relationship between genetics and identity which completely negates environmental and social influences on the development of organisms.
And just in case this seems a particularly 'human' concern, bacteria are similarly difficult to define according to their genetics alone.
Shapiro & Dworkin in their 2003 book 'Bacteria as Multicellular Organisms' investigate the possibility of the superorganism like qualities of bacteria that transcend our current notions of species with sophisticated intracellular signalling mechanisms and liberal exchanges of genetic material, even between bacteria that are not genetically from the same species at all.
The sociobiology of bacteria, largely unappreciated and ignored by the microbiology research community two decades ago is now a major research area, catalyzed to a significant degree by studies of communication and cooperative behavior among the myxobacteria and in quorum sensing (QS) and biofilm formation by pseudomonads and other microbes. Recently, the topic of multicellular cooperative behaviors among bacteria has been increasingly considered in the context of evolutionary biology.
Until a decade ago, scientists categorized microorganisms almost exclusively by their physical characteristics: how they looked, what they ate, and the by-products they produced but the gene is making a definite play for the supremacy of identity and the reason, is manufacturing. J. Craig Venter's work implies that perhaps a better method for classifying species than the traditional morphological appraoch may be through the genomic sequence rather than the phenotype owing to the considerable amount of manipulation that can be achieved at the genetic level of an organism. Venter’s group is in the process of compiling a database of bacterial genetic codes anticipating the time when they can freely mix and match sequences to produce designer organisms.
“We're coming up with new modified life forms, and we should be able to go from the digital world right to the analog world in the computer, and … crank out synthetic chromosomes.” J. Craig Venter from 'Life What a Concept', an Edge publication.
These developments termed ‘combinatorial genetics’ and their implications are currently being hotly debated in the scientific community for if Venter's perspective is adopted it will have implications not just for bacteria, but for how all species are viewed, including humans.
So, what are the scientific alternatives to genetics as the 'regulators' if not the controllers of identity?
Whilst Venter explores gene-centred models of organismal identity, other research groups have taken a different approach and are trying to find ways to build an entire organism from scratch that may not even need genes to instruct them.
These new model systems raise questions about what exactly constitutes a living system, since it is possible that ‘life’ may not actually be a discreet property of matter but a scalar concept and whilst a working definition of what may or may not be alive is useful to researchers, so that they know when they have observed something interesting or not. Steen Rasmussen and colleagues currently at the Southern University of Denmark, have proposed that a ‘minimal cell’ needs a compartment, program and metabolism providing a model by which a synthetic cell can be made from scratch and setting a new benchmark for the creation of artificial organisms.
(to be continued) ...
Continued ....
ReplyDeleteScientist Andrew Ellington from the University of Texas, at Austin, argues that since there is no adequate definition of ‘life’ it is better to look at fundamental material systems that are capable of ‘interesting’ behaviour from a bottom up perspective rather than use top down approaches in the creation of synthetic organisms. Ellington argues that ‘nanotechnology’ is not just a challenging hardware problem to address but also an insurmountable software issue, a conundrum that was famously addressed by Tom Knight from MIT who observed that ‘Biology is the nanotechnology that works.'
Ellington’s group are working on chemical systems that give the appearance of ‘life’. Using oil in water emulsion the research group is trying to equip these systems with the ability to make simple decisions, in other words, they are striving to create chemical systems, without programming them with instructions embedded in a biological ‘code’ such as, DNA that will be capable of computation. Ellington’s research demonstrates that although organic molecules may be necessary in attempting to design a bottom up model of an organism, genes may not actually be essential, since the ‘decision making’ potential of a living system is embedded in the entire organism.
So, the notions and definitions of 'species', 'human' and even 'life' itself are consensus concepts ... we need to be clear about what anxieties technological interventions are precipitating about the future and be clear about our own prejudices and reasons are behind our concerns and aspirations.
And my final thought rests somewhat historically with Hans Vaihinger's reflections in his 1911 Philosophie des Als Ob (Philosophy of As If), where he argued that human beings can never really know the underlying reality of the world, and that as a result we construct systems of thought and then assume that these match reality: we behave "as if" the world matches our models.
THE END
Paul, I think that there is a real concern in our community that hybridization of the 'human' with animals & machines would undermine the integrity & purity of the species, even though as you suggest, that purity is something of a misnoma. I am wondering if your statement in relation to the super-rich having clones 'on-ice' is serious, given that the rich can pay a meager amount of money to purchase a kidney (& other spare parts) from poverty stricken individuals in underdeveloped countries, or rent out the womb (hire a surrogate mother)of a woman living in poverty!
ReplyDeleteRachel, you raise interesting points about 'life' and the way that it is currently defined in the biological sciences. Definitions of species & life is an important aspect, as is who determines and enacts policies after those definitions. In that context I've put up another post that may provoke further discussion.
The kidney from the underdeveloped world donor will mean the recipient has to take anti-rejection drugs (and be close to a supply of) for the rest of their life. They might also harbour undetected retroviruses. The close will be a perfect fit!
ReplyDeleteAnd, from my point of view (as a sort-of buddhist) the whole idea of 'integrity & purity of the species' is just another ego illusion. Samsara, all the way down.... We are just machines built by a blind evolutionary process. We have no purpose apart, perhaps from the urge to reproduce and introduce some variety into the process itself. Purity is certainly not what it's about.
Whilst humanism champions the unity of the human species through its DNA code, the creation of a hybrid species pollutes the purity of the very species that it intends to protect and advance through these self-same technologies. In fact, those who favour biotechnological advances that might improve the quality of human life and those who oppose them, based on the fact that biotechnology challenges nature, fall back on ideas that stem from the humanist tradition that puts faith in foundational assumptions about what it means to be human (Hubbard, 1986, Rose 1997, Gordon 1999). This emphasis on what is human or what may be counted as human is made problematic in contemporary biomedical experiments in which human cells are fused with animal eggs, producing transgenic entities that are embryos of ‘mostly’ human stem cells. In debates that follow such experiments, the primary question is whether the embryo is human. All this emphasis on the meaning of the word ‘human’ exposes humanist concerns about the crucial importance of preserving the purity of the species, the natural order and the idea of the unique and autonomous human being as distinct from the non-human. Paradoxically the humanist pursuit of advancing humanity through transgenics and hybridity points to the fact that nature has no intrinsic boundaries. In a future in which human embryos may be enhanced by the recombination of animal or therapeutic viral DNA, those individuals who are more-or-less than human will stand at the periphery of what we currently perceive as human. Might genetic engineering be a way of circumventing the blind evolutionary process, so that human beings have more control (albeit illusionary) over their destiny?
ReplyDelete