There has been much handwringing about the news that scientists injected human stem cells into pig embryos, creating a mostly-pig-but-a-little-bit-human chimera. Some have expressed fears that these experiments constitute a first step toward a hybrid species with human intellectual capacities, like that in H. G. Wells’s horrific Island of Doctor Moreau.
Given our neurological complexity, it is highly unlikely that reputable scientists will ever want—or be able—to manufacture such grotesque creatures. Doing so would be unbelievably cruel to the resulting whatever-you-would-call-it, and would offer no significant human or animal benefit. Sure, there is always mad-scientist potential, but the cost and time required to produce such a twisted result would be daunting.
Advancing the Dr. Moreau scenario was certainly not the point of this particular study. The purpose of the experiment was to determine the feasibility of using pigs to grow human organs suitable for transplantation. Here’s the idea: Let’s say I needed a kidney transplant. Scientists would use my skin cells to create induced pluripotent stem cells capable of becoming any tissue type. They would then change the stem cells into kidney cells and, at the right time, introduce my now-transformed cells into a pig embryo. In theory—which is what we are discussing here—the animal would grow a human kidney genetically compatible with me for use in transplantation.
Yes, the animal would technically be a chimera, since it would contain human tissue. But—and this is important morally—the rest of the animal would remain pig. Even if the hybrid pig mated, only pig genes would be passed down through the generations, because the essential genetic nature of the animal would not have been altered.
(This isn’t the first such experiment. Dolly the sheep was cloned as an initial step toward creating a herd of cloned “transgenic” ewes that would contain certain human genes enabling their milk to create substances suitable for use in human medicines—a technique given the moniker “pharming.”)
Think of the human benefit to be derived by learning how to raise pigs as human organ donors! Lives could be saved and health restored to countless people with all sorts of ailments, from diabetes, to kidney failure, to heart disease. But human benefit isn’t the only issue we need to consider. Here are some other questions that must be debated about this emerging technology while it remains in the gestational stage:
- Safety: Transplanting organs that were grown in pigs could be very risky. For example, it is possible that porcine viruses against which we have no immune defense could break the species barrier via the transplanted organ, creating the potential for a terrible plague. And here’s another problem: How do scientists conduct experiments to determine the extent of that risk and how to surmount it? One suggestion published in the Journal of Medical Ethics was to remove the kidneys from persistently unconscious patients and replace them with pig organs to test whether porcine viruses would infect the subjects. But that would be a moral atrocity. Unless this and other potential safety issues can be solved without compromising basic human decency, I don’t see how the field advances.
- Animal Rights: Animal rights ideology—not to be confused with animal welfare—holds that it is “speciesist” to treat the lives of animals as having lesser value than those of human beings. Thus, should scientists succeed in creating pig human organ donors, expect angry protests from the PETAs of the world claiming that the process is akin to Auschwitz. In the end, however, I don’t think the objections of animal rights activists would amount to an insurmountable hurdle. If we can eat bacon, we can surely use pigs to save lives.
- Experiments on the Brain: If we can create pigs with human kidneys or livers, why not also create pig brains containing human neural cells? This is where firm lines need to be drawn. Using pigs to grow vital organs does not change the essential nature of the pig. Tinkering with their brains does have that potential. Some would applaud such experiments as a way of learning about the human brain. But it would also subvert human exceptionalism, which is precisely why such studies must not be permitted.
There is much more that needs to be discussed about the utilitarian value and moral propriety of creating animal/human hybrids. What does it mean to be human? What are the boundaries of genetic tinkering beyond which we should not stray? Is it proper to create such radical alterations in nature, even if they are carefully controlled?
These and other essential ethical questions need to be debated, at length and in depth, by regulatory agencies, within scientific organizations, at university symposia, and in the democratic deliberation of governance and electoral politics. Alas, rather than engaging in fruitful discussions, we mostly hear the sound of corn growing.