Abstract
The modern biological definition of a chimera is a single organism composed of cells with multiple distinct genotypes. Chimeras combining human and nonhuman cells are invaluable for various kinds of research, providing a platform for the study of human cell development while avoiding the ethical issues involved in conducting this research on human subjects. There is also the possibility that human/nonhuman chimeras could one day be used to produce human organs for transplant. Yet human/nonhuman chimeras raise a number of unique ethical challenges as well. Critics worry that they are ‘unnatural’, or will cause a kind of ‘moral confusion’, or pose a threat to human dignity. There are also concerns about the kinds of treatment we might owe to human/nonhuman chimeras. For example, introducing human pluripotent stem cells into a gorilla blastocyst could result in the animal developing a ‘humanlike’ brain, or developing human behaviours or characteristics. Would we need to treat such a being as we do our fellow humans? This chapter examines various arguments concerning research involving human/nonhuman chimeras, and the implications of these arguments for research policy. I conclude that research involving human/nonhuman chimeras is not intrinsically morally wrong, though it may be morally impermissible in some cases. However, I criticize the standard approach to evaluating the treatment of nonhumans in research, arguing that the moral treatment of nonhuman animals, including human/nonhuman chimeras, depends on contextual factors, rather than their moral status.
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Notes
- 1.
Mules, created by breeding a female horse and a male donkey, are ‘hybrids’ rather than chimeras. A hybrid results from inter-species breeding, with each cell containing genetic material from both parent species.
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This definition also implies that there could be animals that do possess human dignity. Karpowicz and colleagues state “the family of capacities associated with human dignity seem to belong uniquely to human beings.” If we take this to mean that only humans have any of the capacities associated with dignity, this claim is false; many kinds of non-human animals exhibit rationality, emotional complexity, or social relations. Or, if we take it to mean that only humans have a certain kind of combination of these capacities, this claim might be true, but implies that some humans lack dignity. Thus, if capacities determine human dignity, it cannot be the case that all and only human beings have dignity.
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This is not to say that moral practices must remain unchanging, or cannot be criticized. Without the ability to criticize practice, we risk perpetuating morally illegitimate practices. But appealing to theory or principles is not the only way to criticize practice; most people are able to distinguish certain actions as morally right or wrong without appealing to a moral theory. Various accounts of our pre-theoretical moral practices have been given by Ross (2003), Hare (1981), and Dewey (2008).
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Graham, M. (2023). Of Mice-Rats and Pig-Men: Ethical Issues in the Development of Human/Nonhuman Chimeras. In: Valdés, E., Lecaros, J.A. (eds) Handbook of Bioethical Decisions. Volume I. Collaborative Bioethics, vol 2. Springer, Cham. https://doi.org/10.1007/978-3-031-29451-8_28
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