| In the foreseeable future, human/nonhuman chimeras will be applied to study human cell lineages within developing animal hosts. This study concerns the applications of such experiments to study human retinal cell lineages within the eye and brain of nonhuman mammals. Chimeras study the basic biology of human cell development, and may one day function as applied models in the study of human diseases. The scientific validity and value of these experiments is first established. Ethical and social ramifications are then considered with an emphasis on principled moral concerns as they apply to chimeras. The most convincing arguments are not necessarily derived from the unnaturalness or wrongness of interspecies hybridization, but rather due to a visible and tangible metaphor between human appearance and moral value. It is the coupling of appearance, function and the recognition of value that informs persons of another being's moral status. The recognizable alteration of a research animal's neural characteristics and capacities is the primary moral grounds for the wrongness of such experimentation. An analysis of prenatal cell and tissue transplants is then carried out with such concerns in mind. |
