Life as Chimera: When Life Combines with Itself
George Tsourdinis
Class of 2021
What a chimera then is man! What a novelty! What a monster, what a chaos, what a contradiction, what a prodigy!
—Blaise Pascal, Pensées 1
Lamassu, sphinx, Ganesha, qilin, centaurs, and griffins: Amalgams of human-animal species have been mythologized, depicted, and
deified throughout the history of human civilization. These hybrid species, known collectively today as chimeras from the eponymous Ancient
Greek myth of a lion-goat hybrid, arose from the wellspring of human imagination and creativity. With modern advancements in biotechnol-
ogy, however, chimeras are much less a myth and more of a reality. I am referring, of course, to the chimeras resulting from genetically-engi-
neered human pluripotent stem cells (hPSCs) implanted into an evolutionarily-related, nonhuman animal embryo; having been an object of
folklore in humanity’s cultural history, the concept of chimeras has transcended myth and is now emerging as a tangible, biological spectacle
that has been touted to solve the organ transplant shortage and bridge the gap between in vivo animal testing and human clinical research
models. Such powerful research does not come without objections, though, with many arguments against developing chimeras spanning the
gamut of moral ideologies. What I hope to show in this brief reflection is the following: In order for us future physicians to grapple with thorny
bioethical dilemmas surrounding concepts like chimera research, we need not only understand their biochemical and clinical mechanisms,
but must also delve into the philosophy and art surrounding these issues. Here, I am not arguing in favor of any sides of the chimera debate
but am aiming to show how the humanities in medicine can aid us in comprehending the full context of said debate before forging our own
opinions. As biotechnology progresses rapidly, we as future physicians will have to trod the murky path of new bioethical dilemmas with both
the humanities of medicine and medicine, itself, as are our guiding lights.
Chimeras have much potential in enhancing human health, and they are already becoming a possibility in the early stages of re-
search—the first human-pig chimeras were created successfully early in 2017. 2 One group has even successfully grown healthy mouse-derived
pancreases in rats, which were then harvested, transplanted into diabetic mice, secreted insulin, and thereby reversed the diabetes of the mice. 3
Chimera technology has seen a dramatic rise in popularity—and dissent. In 2015, the National Institutes of Health (NIH) issued a funding
moratorium on chimera research until the bioethics were better resolved. In August of 2016, the NIH lifted this same moratorium from chi-
mera research under the stipulation that an ethics oversight committee would monitor the research. 4 Legislation is continually being drafted to
prevent such research and the opposition present in the literature is even more deafening.
What forms the basis of this formerly-banned and now-restricted research? We can look along diverse philosophical veins to see
where the discomfort in chimera research originates. One such vein is the “Unnaturalness Argument,” which was supported by a prominent
20th-century philosopher of biology, Hans Jonas. Deeming chimeras as “unnatural” and thus wrong, Jonas claims an inherent disgust at the
concept of chimeras, evoked by their moral intuition that “produce[s] an involuntary shudder” and advises his readers of its wrongness—collo-
quially dubbed the ‘yuck factor.’ The underlying thesis of the Unnaturalness Argument is that chimeras transgress some divide between humans
and nonhumans, and that issues them with a moral prohibition. To Jonas, the very “interchange of genetic material between animals and man”
would summon “ancient, forgotten terms as ‘sacrilege’ and ‘abomination.’” 5
Still, the aversive reflexes evoked from the concept of the “admixture” of an animal and human could be considered an over-inflated
concern by some. In discussing gene therapy technologies that share similar ethical qualms raised by chimeras, another famous philosopher
and biophysicist of our time, Henri Atlan, reviews a report that quips a critique of the “Unnaturalness” camp’s concerns, stating that they harbor
“irrational fears which derive from misunderstandings in biology, and are compounded by the effects of popular creations of fiction, such as
Frankenstein’s monster.” In that same report, Atlan reiterates that, perhaps that it is not simply unjustified fear or “merely a fear of the unknown
that engenders caution, but also a recognition that the ability to modify the genetic endowment of human beings…in touching the gene, there-
fore is touching the essence of life.” Atlan even conceives of the implicit “playing god” phobia—or “master of the hereditary model,” as Jonas
refers to it—the “essence of life” being a “wooly” or vague notion, one that biomedical ethics must eschew from and adopt a more “pragmatic”
analysis of each instance of bioethical debate by “analyz[ing] the specific potentially dangerous or undesirable effects.” 6
One example of such a “pragmatic” analysis lies in the most-feared scenario of chimeric organisms—the situation in which hPSCs
tread off the genetic lineage intended by researchers and into a neural fate. Still today, despite significant progress in (epi)genetic knowledge,
the issue with chimeras is that scientists have still not elucidated how hPSCs precisely migrate in utero. Therefore, it has postulated that hPSCs
could diverge from their original coaxing to instead take hold in the areas that are destined to become embryonic neural tissue. Assuming this
(e.g. human-pig) chimera was brought to full term, what would hypothetically result is a pig with a genetically-human central nervous system.
Questions pour forth: Does the chimeric animal achieve a sort of moral status? Does the chimera have the same rights that a human would?
Can the animal cognize as a human would, and would experimentation/organ harvesting on the animal thus be considered unethical due to its
sense-qualia and suffering it would undergo? The existence of borderline human-nonhuman chimeras could generate moral and ontological
confusion. Consider how the modern surgical procedure of xenotransplanting a pig heart valve to replace a defective human one is not mor-
ally-agitating to anyone. Perhaps, it is the possession of a specifically human central nervous system by a nonhuman animal that truly enlivens
the ‘grotesque’ reaction to chimeras, in some.
When discussing chimeras in scientific research, it is rare that we consider our very selves to be chimeras, too, just shaped by the differ-
ent mechanism of natural selection. À la endosymbiotic theory, our own mitochondria derive from an oxidative prokaryote that was engulfed
by a larger prokaryotic host cell, essentially forming a symbiotic chimera of sorts, evolving to power complex, multicellular organisms like
Homo sapiens. 7 As ‘natural’ chimeras ourselves, we are responsible for directing the course of synthetic chimera research and potential use in
the future of biomedicine, along with other bioethical issues in medicine. The incomprehensibility about what ‘life’ constitutes and what factors
make humans human is grounds for some to hold an instinctive aversion to promoting chimera research. But the utilitarian benefits that could
spring from chimera biomedical research must not be ignored, either. Just as Pascal invokes the clashing qualities of humankind’s essence as
Link to Bibliography: http://healthhumanities.red.uic.edu/student-organizations/body-electric/