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The Ethics of Chimeric Research

microscopic image of human embryos

Recently, various news outlets covered the creation of the first human-monkey chimeras in China. A chimera is an organism whose cells come from two or more species. Researchers managed to develop monkey embryos containing human cells after previous attempts relied on pig and sheep embryos. While this type of research is prohibited in the U.S., the work was legal in China. 

Such projects have been conducted with the hope of developing human organs which can then be transplanted into humans and for conducting research into neurological and psychiatric diseases in humans. Even though such embryos do not progress past one or two weeks of growth, these efforts have been controversial. This is because it is difficult to restrict human cell growth to just one organ. According to Robin Lovell-Badge the concern is that without some way to restrict the contribution of human cells they could contribute to the animal’s central nervous system.

Such scientific endeavors present several ethical issues. These include concerns about animal ethics. For example David Shaw, Wybo Dondorp and Guido de Wert argue that given the limited number of organs for transplant, harvesting organs from human/non-human chimeras is a valid option so long as there is a substantial potential benefit to humans and if there are no reasonable alternatives present. 

Unlike other forms of animal research where the benefits may be less certain, harvesting human organs from a chimera would in most cases save a human life, so there is a large proportional benefit. Also, while there may potentially be other options for saving the life of a human requiring an organ transplant (such as research into artificial organs or changes to public policy requiring that people opt-out of organ donation), those options have not been established. For specific people who will die without an organ transplant there is no established alternative option. Thus, with these two conditions met, Shaw et al. argue that it is permissible to kill chimeras for their organs.  

César Palacios-González has argued that while harvesting organs of a human/pig chimera may be acceptable on such grounds, the case for great-ape/human chimera is more problematic. He argues that from a species-neutral standpoint great apes who possess qualities of self-awareness, complex social structures, and the potential to form rudimentary cultures are “borderline persons.” Because of this, great-ape/human chimeras are deserving of moral protection. 

Killing such animals for their organs would be no more morally justified than killing humans who possess less psychological capacities such as infants, toddlers, and adults with less mental capacities than great apes. Palacios-González suggest that we either accept that it is morally acceptable to kill great apes, great-ape/human chimeras and some human borderline persons for their organs, or we must reject harvesting the organs of any of them. 

While the animal rights argument covers some of the ethical issues involved with human/non-human chimeras, ethicists and philosophers also recognize the distinct ethical concerns presented by chimeric research. One of these concerns is whether it is wrong to cross species boundaries to create part-human beings. Is there some fixed line that distinguishes the human species from other animals, and should this boundary be breached?

According to some, crossing the boundary line of the human species is wrong because it is a challenge to God’s existence, however such arguments will not satisfy those who do not believe in a god. For others, crossing the species boundary is inherently wrong because it is unnatural. There are also those who would argue that is morally wrong because it would create too much moral confusion as we must determine the moral status of human-animal hybrids (for discussion, see Meredith McFadden’s “Moral Standing and Human/Non-human Hybrids”). 

On the other hand, such arguments are difficult to pin down because the concept of species is complicated. For example, according to Jason Robert and Françoise Baylis, “Biologists typically make do with a plurality of species concepts, invoking one or the other depending on the particular explanatory or investigative context.” 

One concept of species holds that species are defined in terms of reproductive isolation. If two populations of creatures do not successfully interbreed, then they belong to two different species. However, this definition only applies to species that reproduce sexually. Another definition considers the lineage of a population of organisms and its continuity over time. Such a definition is more encompassing but also more vague. Operationally it can be very difficult to arrive at a set of traits or qualities that completely distinguishes one species from another.  

The scientific conception of species, therefore, is not fixed. There are many ways to describe species, and it can be very difficult to arrive at a specific and distinctive definition of what makes homo-sapiens a distinct species. Because of this, the notion that it is immoral to cross species boundaries is problematic because it is difficult to define the human species in a fixed way. 

On the other hand, as Robert and Baylis point out, the fact that scientists do not have an account of fixed differences between species does not mean that the ethicist couldn’t employ a fixed account. They explain, “notwithstanding the claim that biologically species are fluid, people believe species identities and boundaries are indeed fixed and in fact make everyday moral decisions on the basis of this belief.” They use the example of race as an analogy; where race is not a biologically useful concept, but it can be a socially useful concept. 

If there are good reasons to adopt fixed notions of species for ethical purposes, then there may be a basis to claim that it is wrong to cross the species boundary, particularly because of the moral confusion it could create. Settling some of these issues will likely require that the public take note of the tension that can exist between a scientific account of something and an ethical account. Should we pursue a more open concept of species and of moral status in line with an experimental approach to these issues, or should we rely on the concept of fixed distinctions when it comes to moral matters. The issue of animal/human chimeras asks us to consider what, ethically, does it mean to be human and what does it mean to be a person?

Our Bodies, Ourselves?  Death, Values, and the Material We Leave Behind

Photograph of a replica of Lincoln's coffin. It is black and draped with white cloth and has a few flowers on top

Death of those we care about is deeply distressing for many reasons, one of which is that the empty space the person once occupied is often soon filled with dangling, unanswered questions. Many of these questions will likely never be answered, but some of the most captivating might be addressed by analysis of the biological material the person left behind. What considerations ought to guide our behavior when it comes to use of a person’s remaining biological material?

A fairly straightforward answer would be to say that there are no constraints that should govern our behavior. The motivating philosophy behind this view might be that when a person is dead, they can no longer be harmed, because that person no longer exists. If we find this argument compelling, we might have to rethink our attitudes about things like respect for a person’s wishes after death and about the moral permissibility of necrophilia. After all, if bodies are just things, we can’t do them any moral harm. Even the most expansive theories about the kinds of things that are deserving of moral consideration maintain that, for an entity to be morally considerable, it must have interests—there must be ways in which things can go better or worse for it. Dead bodies don’t meet this condition.  In this sense, a dead body is more like a stone or a glass of water.

Our social policies suggest that plenty of people disagree with this position.  Necrophilia is a crime, and we have many laws that govern the use of a person’s biological material after death. Many of these policies may be justified, but many may also not be.

One domain in which we seem to feel fairly comfortable treating a dead body as a thing is when we conduct autopsies on the victims of crime. One of the motivating considerations behind performing an autopsy is the idea that the body left behind potentially has many important secrets to reveal. Some of these secrets might turn out to be embarrassing or harmful to the ongoing reputation of the victim or might be painful to the loved ones left behind. Nevertheless, it seems that we have concluded, rightly or wrongly, that there are two related values that are more important in these kinds of cases than harm to the deceased—protection of the community against potential future crimes, and retributive justice.

On some occasions, bodies are exhumed so that genetic relationships can be evaluated. If they are old enough, some cases intuitively fall under the heading of forensic archaeology. When a body dating back to the 15th century was found under a Leicester car park in 2013, genetic tests were done to confirm that it was indeed the body of notorious British monarch Richard III. Officials have continued to take a different position when it comes to King Richard’s two young nephews. The bodies of two young boys were found in a wooden box buried on the grounds of the Tower of London in 1647. They were buried in Westminster Abbey, but their identity has never been confirmed. The concerns protecting the princes seem to be more pragmatic than moral in motivation. What should be done with the remains if the test reveals that they are not the princes? What might the tests tell us about lines of succession? In any event, it is interesting that time seems to make some difference in our perception of the moral landscape of these kinds of cases. Many seem to view disruption of a long dead body as morally neutral, while they view the exhumation of the more recently dead as disrespectful. Perhaps this is simply an irrational bias. On the other hand, it may well be that, at some point, the value of the historical knowledge we obtain from these kinds of cases outweighs the more limited privacy interests of the long dead.

Famous exhumations to test for parentage have been done in more recent cases as well. Famously, in 2017, the body of Salvador Dali was exhumed to determine if he was the father of Spanish astrologer and tarot card reader Pilar Abel. The result? Not the father. Similarly, chess grandmaster Bobby Fischer was exhumed in 2010 to determine whether he was the father of a then nine-year–old girl. The result? Not the father. There is an element of historical value involved in these cases as well—after all, both Dali and Fischer were famous individuals. There may be some value in knowing more of their stories. In addition to these considerations, one might think that children have the right to know who their parents are. For many people, knowledge about their parents is important on an existential level—it tells them something about who they are. One might also think that a person’s child has certain rights to inheritance that, at least at first glance, should be respected. On the other hand, anyone can make a paternity claim. Under what conditions would such a claim justify the exhumation of a body?

Moral dilemmas of this type don’t always involve exhumations. Sometimes they involve more accessible biological material—and sometimes that material is used for perhaps even more controversial purposes. Well-known utilitarian Jeremy Bentham left behind unusual instructions for his body. He wanted it preserved as an “auto-icon” and kept on display at the University College, London.His wishes were honored. Recently, scientists have collected biological samples that they intend to use to determine whether Bentham was autistic. Similarly, sheets on the bedding on which Abraham Lincoln died are being tested to determine whether the beloved president had a genetic condition known as Marfan Syndrome—a condition characterized in part by towering height and long limbs. These cases motivate important moral questions. Is it morally defensible to reveal a person’s personal medical information after they have died? Does revealing such information serve to further stigmatize and sensationalize medical conditions, or should we understand these revelations as normalizing and empowering? Should these decisions be governed by respect for the wishes of the dead, or should they be made in a way that promotes the best interests of the living?