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Chimeras: Beyond Our Moral Depth?

By Jonathan Balcombe, Ph.D.

The chimeras I learned about as a biology student—obscure, strange-looking fishes of the ocean depths—are not the same as the ones now at the center of a debate in medical ethics. These chimeras are made by humans, not by nature. As stem cell technology marches ahead, science now has the means to create creatures that attempt to blur the line between humans and other animals. If experimenters have their way, the specter of a half-chimp/half-man or a mouse with a human brain will no longer be the stuff of science fiction.

If experimenters have their way, the specter of a half-chimp/half-man or mouse with a human brain will no longer be the stuff of science fiction.

The allure, from the biomedical perspective, is the hope that such chimeras will provide a “hugely useful” tool in biomedical research.1 That’s why new guidelines for research issued in April 2005 by the U.S. National Academy of Sciences concluded, in a special section titled “Interspecies Mixing,” that there were valid reasons for creating chimeras.

The moral minefield, as expressed by those closest to the debate, revolves around the potential for more animal suffering, as species are manipulated, bred, and killed.

Irving Weissman at Stanford University (and of StemCells, Inc.) is trying to create a strain of mouse that loses its own brain cells just before birth. By transplanting human neuronal stem cells into the brains of these mice, scientists could create a mouse with a brain made almost entirely of human brain cells.2

Clearly, moral restraint is called for. Yet more often than not, concerns are expressed only with regard to potential human suffering. Science isn’t likely to abide the production of humanized chimeras, but what about the animals who stand to lose so much more in the chimera stakes? Modern studies demonstrate that they, too, have thoughts, feelings, and experiences.

Animals believe, play, plan, anticipate, deceive, remember, and create tools.3 They feel a broad range of emotions ranging from joy and excitement to frustration and despair4 and they’re attracted to the same environmental rewards (e.g., palatable food, social and sexual contact) as are we.5

Today, animals in laboratories routinely endure deplorably confined, impoverished, and stressful conditions6 and are subjected to experiments that are only rarely in their own interests. Until these conditions are improved and the animals given a decent quality of life, chimeras ought to be left where they are—swimming in the ocean depths.

1. Shreeve J. I, chimera. New Scientist. 2005;186:39-43.
2. Ibid.
3. Griffin DR, Speck GB. New evidence of animal consciousness. Anim Cogn. 2004;7:5-18.
4. Panksepp J. 2005. Affective consciousness: core emotional feelings in animals and humans. Conscious Cogn 14:30-80.
5. Balcombe JP. Pleasurable kingdom: animals and the nature of feeling good. London: Macmillan; in press.
6. Balcombe JP, Barnard N, Sandusky C. 2004 Laboratory routines cause animal stress. Contemp Top Anim Sci. 2004;43(6):42-51.


Good Medicine Cover

Autumn 2005
Volume XIV
Number 4

Good Medicine

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