-
No Real Categories, Only Chimeras and Illusions: The Interplay between Morality and Science in Debates over Embryonic Chimeras
- The American Journal of Bioethics
- The MIT Press
- Volume 3, Number 3, Summer 2003
- pp. 31-33
- Article
- Additional Information
The American Journal of Bioethics 3.3 (2003) 31-33
[Access article in PDF]
No Real Categories, Only Chimeras and Illusions:
The Interplay between Morality and Science in Debates over Embryonic Chimeras
Rachel A. Ankeny
University of Sydney
Our moral and visceral reactions to proposals to create human-to-animal embryonic chimeras are complicated indeed, and Jason Scott Robert and Françoise Baylis (2003) begin to excavate some of the conceptual difficulties underlying such reactions. They compellingly argue that everyday understandings of how species are defined do not seem to take account of ongoing debates in evolutionary biology and the philosophy of biology that aim to clarify our understanding of species identity. More empirical data are needed to evaluate such lay understandings (and also those held by biologists within and beyond the field of evolutionary biology) and their impacts on public policy making in the biomedical sciences (as other commentators have noted; e.g., Rollin 2003). But, as I have argued elsewhere (2002) with regard to disease concepts and molecular medicine, the question of species identity also is connected to deeper conceptual issues in the public understanding of science and in particular to issues about the actual and potential outcomes of the Human Genome Project (HGP).
Robert and Baylis hint that we should consider ways in which the boundaries between species have been socially negotiated rather than fixed by "nature," not in the least part because it is unclear what the relationship is between "putatively representative" species-specific genomes and individual members of a given species. Robert and Baylis focus primarily on the variability in the human genome in order to emphasize that there is nothing identifiable at the genomic level that is common to all human beings. But the reader might be led to conclude that this high degree of variability is found in the human genetic sequence merely because our sequencing technologies are still being refined, because we are limited by the actual human research subjects used (who, after all, are not standardized as most laboratory animals are), or because we are overly focused on variability, given our own anthropocentric point [End Page 31] of view and our desire to identify mutations that lead to disease and other undesirable conditions. Functional genomics, it is claimed, will allow us to go beyond the sequence to a deeper understanding of the fundamentals of what make us human. After all, it might be argued that examinations of simpler organisms—for instance, yeast, worms, and mice—have shown that "standard" or "typical" genomic sequences can be determined, providing a sort of kit for finding the fundamentals of life itself, and such fundamentals could be articulated in human beings if we weren't so complicated. But what have the genomes of simpler organisms actually shown?
The model organism projects of the HGP have in fact revealed that establishing typicality and universality of particular traits is difficult, if not impossible, even for the simplest of organisms. Even when research focuses on "normal" organisms that have been inbred and highly standardized as lab animals (already an idealized state of affairs, extremely far removed from the natural state of these organisms), individual phenotypic differences between organisms that are identical in genotype need to be eliminated in order to establish canonical models to be used for future research, as I have shown in my work on the nematode worm Caenorhabditis elegans (Ankeny 2000). Therefore, the genomic sequences, neural wiring diagrams, or charts of the cell division processes that we might think of as representative of a species are actually representations based on an abstract model of a particular species in terms of the "typical," not exhibited by any one specimen alone, but only by a more abstract construct.
What emerges is that our working notion of fixed species boundaries is just that: a working model that allows biologists to get on with their work (Ankeny 2001), oftentimes without explicit consideration or concern by these scientists about species boundaries. To study variation, a norm must be established by a scientific...