In response to Koplin and Wilkinson, I argue, first, that the uncertain clinical prospects of human-pig chimera based transplantation makes the reason to spend resources for clarifying whether such practice might imply serious ethical breach due to enhanced cognitive capacities of the chimeras rather weak. T he benefits of further pursuing this avenue of research is so uncertain, so that taking even very unclear risks of serious ethical breach is not worth the price in terms of spent resources, (...) and therefore only limited resources should be spent to clarify such risk before the project is abandoned due to unacceptable risks. Second, I argue that as there are some reason to pursue this avenue further, the analogy to the notion of halting all farming of larger animals for food does not hold up. The reason is that we do not need to probe any further any comparable risk to know that such farming practices should be halted. A fundamental underlying issue to the question discussed by Koplin and Wilkinson1 in this paper is formulated when they write: > We should therefore be confident that human-pig chimeras would lack morally relevant cognitive capacities before setting out to use them as a source of transplantable human organs. This leaves open the question of how confident …. (shrink)

Scientists will soon be able to grow human-transplantable organs in pigs. This paper focuses on the question of whether it is morally permissible to eat genetically altered pigs after harvesting their organs. Despite a lack of scholarly discussion of this question, the impetus for it is straightforward. There is no reason to think that peoples’ taste for pig will subside when scientists reach the point of being able to growing mature human organs inside them. In this paper, I (...) argue that there is a good reason why we should eat genetically altered pigs and currently no compelling reasons to the contrary. (shrink)

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. (shrink)

Our recent article begins by describing a new technique for creating human–animal chimeras. This technique—known as interspecies blastocyst complementation—may enable us to generate human organs inside of human–pig chimeras. One central concern about farming human–pig chimeras for their organs is that their moral status would be uncertain and potentially significant. Our article is partly, but not only, about such concerns. At the heart of our paper are two broader questions. First, how should we (...) treat beings of uncertain moral status? And second, do our reasons for thinking that human–pig chimeras have uncertain moral status also provide reason to think regular, non-chimeric pigs have uncertain moral status? We thank Mike King, Christian Munthe, David Resnik, Per Sandin and Rob Streiffer for their commentaries on our paper, each of which serves to clarify the ethical issues at play. In this response, we want to respond to one criticism, acknowledge the force of several others, and point towards some philosophical work that remains to be done. First, the criticism. Resnik questions the parallel we draw between human–pig chimeras and regular pigs. In the case of regular pigs, there is currently a social consensus that it is morally acceptable to farm pigs for food. For Resnik, this consensus imposes a special burden on those who wish to argue against it; ‘one needs substantial evidence that the majority view is wrong’.1 Since an equivalent consensus does not exist in relation to human–pig chimeras, one might think that moral uncertainty concerns have less force in the context of meat production than human–animal chimera research. We do not think the social consensus in favour …. (shrink)

It may soon be possible to generate human organs inside of human-pig chimeras via a process called interspecies blastocyst complementation. This paper discusses what arguably the central ethical concern is raised by this potential source of transplantable organs: that farming human-pig chimeras for their organs risks perpetrating a serious moral wrong because the moral status of human-pig chimeras is uncertain, and potentially significant. Those who raise this concern usually take it to be unique (...) to the creation of chimeric animals with ‘humanised’ brains. In this paper, we show how that the same style of argument can be used to critique current uses of non-chimeric pigs in agriculture. This reveals an important tension between two common moral views: that farming human-pig chimeras for their organs is ethically concerning, and that farming non-chimeric pigs for food or research is ethically benign. At least one of these views stands in need of revision. (shrink)

Xenotransplantation is often deemed morally objectionable because of the costs it imposes on the organ donor and the risks it imposes on the recipient. For some, involving human–pig chimeras as donors makes the practice more objectionable or even abhorrent from the start. For others, by contrast, using such chimeras weakens recipient-based objections because it reduces the risk of organ rejection and malfunctioning, and cancels donor-based objections because the practice does not harm chimeras but instead gives them (...) valuable lives they would not otherwise have. The paper examines and eventually rejects the latter defense. It also discusses the additional risks of chimeric xenotourism in countries with less demanding procedural guidelines and reflects on two very different futures for humanity that may emerge from supporting or rejecting chimeric xenotransplantation. (shrink)

The use of pig derivatives in medicine is forbidden in Islamic law texts, despite the fact that certain applications offer medical advantages. Pigs can be one of the best human organ hosts; therefore, using human–pig chimeras may generate beneficial impact in organ transplantation, particularly in xenotransplantation. In Islam, medical emergencies may allow some pig-based treatments and medical procedures to be employed therapeutically. However, depending on the sort of medical use, emergency situation might differ. Using Islamic legal maxim (...) as bioethical framework, the purpose of this study is to examine the use of pigs for the purpose of human–pig chimeric transplant from the perspective of Islamic bioethics. According to the findings, chimeric organ transplantation using pigs should only be done in emergency situations. (shrink)

Researchers have increasingly been creating chimeras – combinations of cells from two species – raising profound ethical, social and scientific controversies. Such research could lead to the creation of animals such as pigs that contain human organs for transplantation, yet public fears have emerged. Scientists have thus called for enhanced public education and discussion, but these efforts require comprehension of the nature of public concerns. While arguments have viewed chimeras as either “good” or “bad,” artists have long (...) depicted chimeras in ways that can inform these discussions. Chimeras have a long history – the term itself is from Greek mythology – and have generated complex and ambivalent responses, reflecting deep questions regarding who we are as humans. Images across disparate cultures suggest how humans have long seen species boundaries as fluid but in differing ways. These images suggest that emotional, not just rational, utilitarian perspectives need to be addressed and that challenges may arise in altering views of all individuals. Nonetheless, public messages could draw on historic examples of positive such combinations. Thus, artistic representations can aid scientists, policymakers, educators and members of the public-at-large recognize and better comprehend and address the discomforts chimeras can foster. (shrink)

What Ivan Illich regarded in his Medical Nemesis as the ‘expropriation of health’ takes place on the surfaces and in the spaces of the screens all around us, including our cell phones but also the patient monitors and (increasingly) the iPads that intervene between nurse and patient. To explore what Illich called the ‘age of the show’, this essay uses film examples, like Creed and the controversial documentary Vaxxed, and the television series Nurse Jackie. Rocky’s cancer in his last film (...) (submitting to chemo to ‘fight’ cancer) highlights what Illich along with Petr Skrabanek called the ‘expropriation of death’. In contrast to what Illich denotes as ‘Umsonstigkeit’ – i.e., a free gift, given undeservedly, i.e., gratuitously – medical science tends to be tempted by what Illich terms scientistic ‘black magic’, taking over (expropriating) the life and the death of the patient in increasingly technological ways, a point underscored in the concluding section on the commercial prospects of xenotransplants using factory farm or mass-produced (and already for some time) human-pig mosaics or chimeras. (shrink)

In their recent paper in this journal, Zümrüt Alpinar-Şencan and colleagues review existing dignity-based objections to organ markets and outline a new form of dignity-based objection they believe has more merit: one grounded in a social account of dignity. This commentary clarifies some aspects of the social account of dignity and then shows how this revised account can be applied to other perennial issues in bioethics, including the ethics of human embryo research and the ethics of creating part-human (...) chimeras. (shrink)

This paper addresses several questions related to the nature, production, and use of animal-human (a-h) chimeras. At the heart of the issue is whether certain types of a-h chimeras should be brought into existence, and, if they are, how we should treat such creatures. In our current research environment, we recognize a dichotomy between research involving nonhuman animal subjects and research involving human subjects, and the classification of a research protocol into one of these categories will (...) trigger different ethical standards as to the moral permissibility of the research in question. Are a-h chimeras entitled to the more restrictive and protective ethical standards applied to human research subjects? We elucidate an Aristotelian-Thomistic metaphysical framework in which to argue how such chimeras ought to be defined ontologically. We then examine when the creation of, and experimentation upon, certain types of a-h chimeras may be morally permissible. (shrink)

Recent advances in the technology of creating chimeras have evoked controversy in policy debates. At centre of controversy is the fear that a substantial contribution of human cells or genes in crucial areas of the animal’s body may at some point render the animal more humanlike than any other animals we know today. Authors who have commented on or contributed to policy debates specify that chimeras which would be too humanlike would have an altered moral status and (...) threaten our notion of ‘human dignity’. This setting offers a productive opportunity to test the notion of human dignity and to emphasize some of its weaknesses as an ethical tool. Limiting chimerism experiments on the basis of whether or not it undermines or challenges human dignity implies a clear demarcation of those characteristics which are typically, and importantly, human. Evidence of our evolutionary ties and behavioral similarities with other animals seem to annul all attempts to define the uniquely human properties to which human dignity may be attributed. Hence, it has been suggested that the particular moral status associated with humans cannot be explained for beyond an intuitive basis. In what follows, we will argue that the difficulties inherent in the notion of human dignity lie not in the impossibility to acquire a list of properties which are unique to humans, but rather in the difficulty to demonstrate the moral relevance of these properties, and particularly the relevance of their being human. We offer an alternative interpretation of the concept of dignity which is not necessarily related to being human. (shrink)

The creation of chimeras by introducing human stem cells into nonhu- man animals has provoked intense concerns. Addressing objections that appeal to human dignity, I focus in this essay on stem cell research intended to generate human neurons in Great Apes and rodents. After considering samples of dignity- based objections from the literature, I examine the underlying assumption that nonhuman animals have lower moral status than personsFwith particular attention to what it means to speak of higher (...) and lower moral statusFbefore evaluating the chimera research in question. I argue that (1) such experiments involving Great Apes should be prohibited out of respect for the research subjects and (2) such experiments involving rodents may or may not be permissible, depending on how we answer unresolved questions regarding rodents’ moral status. In the end, concerns about human dignity prove insignificant. (shrink)

In this paper, I argue for the modest claim that people's apparent indifference to animal pain may not be predicated upon speciesism. I defend that claim by developing an analogy between current attitudes toward at least some non‐human animal pain — that which pigs endure while having their tails ‘docked’— and our culture's indifference to the pain that male human infants experience while being circumcised. And I conclude that to convince more of their philosophical and social critics, ‘animal (...) liberationists’ need to spend more time analyzing the pain that non‐human animals experience and defending its moral significance, rather than assuming that such pain is significant and then simply arguing that unnecessary forms of it exist. (shrink)

One argument Robert and Baylis do not raise in their article on the creation of interspecies chimeras using human cellular material is that the creation of these chimeras would, or could, offend human dignity. Yet, human dignity is one of the most common concerns raised in public debates, academic arguments, and policy documents regarding biotechnology in general, and the creation animal-human chimeras in particular. … The concept is ill-defined within bioethics and … risks (...) being dismissed as meaningless or uselessly vague. However, this lack of definition should not yet cause us to abandon or ignore human dignity. At least in arguments about creating chimeras, an examination of what may be meant by appeals to human dignity can uncover important concerns or arguments that are not captured by other formulations of the debate. (shrink)

Research with human–animal chimera raises a number of ethical concerns, especially when neural stem cells are transplanted into the brains of non-human primates . Besides animal welfare concerns and ethical issues associated with the use of embryonic stem cells, the research is also regarded as controversial from the standpoint of NHPs developing cognitive or behavioural capabilities that are regarded as “unique” to humans. However, scientists are urging to test new therapeutic approaches for neurological diseases in primate models as (...) they better mimic human physiology than all current animal models. As a response, various countries have issued reports on the topic. Our paper summarizes the ethical issues raised by research with human–animal brain chimeras and compares the relevant regulatory instruments and different recommendations issued in national reports from three important European research nations: Germany, Switzerland and the United Kingdom. We assess and discuss the focus and priorities set by the different reports, review various reasons for and perspectives on the importance of the brain in chimera research, and identify critical points in the reports that warrant further specification and debate. (shrink)

In “Human‐Animal Chimeras: The Moral Insignificance of Uniquely Human Capacities,” Julian Koplin explores a promising way of thinking about moral status. Without attempting to develop a model in any detail, Koplin picks up Joshua Shepherd's interesting proposal that we think about moral status in terms of the value of different kinds of conscious experience. For example, a being with the most basic sort of consciousness and sentience would have interests that matter morally, while a being whose consciousness (...) featured the riches of loving affection, say, might have greater moral status and therefore deserve some sort of priority if the interests of the two beings conflicted. This approach represents an improvement over the more common, transparently anthropocentric habits of thinking about moral status, whether in connection with evaluating human‐animal chimera research, deciding what one can ethically eat, or pursuing some other moral inquiry. (shrink)

Discussions about whether new biomedical technologies threaten or violate human dignity are now common. Indeed, appeals to human dignity have played a central role in national and international debates about whether to allow particular kinds of biomedical investigations. The focus of this paper is on chimera research. I argue here that both those who claim that particular types of human-nonhuman chimera research threaten human dignity and those who argue that such threat does not exist fail to (...) make their case. I first introduce some of the arguments that have been offered supporting the claim that the creation of certain sorts of chimeras threatens or violates human dignity. I next present opponents' assessments of such arguments. Finally I critically analyze both the critics' and the supporters' claims about whether chimera research threatens human dignity. (shrink)

Human‐animal chimeras—creatures composed of a mix of animal and human cells—have come to play an important role in biomedical research, and they raise ethical questions. This article focuses on one particularly difficult set of questions—those related to the moral status of human‐animal chimeras with brains that are partly or wholly composed of human cells. Given the uncertain effects of human‐animal chimera research on chimeric animals’ cognition, it would be prudent to ensure we do (...) not overlook or underestimate their moral status. However, to assess moral status, we first need to determine what kinds of capacities are morally relevant. The standard view holds that it matters, morally, if chimeric animals develop uniquely human cognitive capacities. I argue that this view is mistaken, highlighting three problems with it: that we can think of examples of uniquely human cognitive capacities that are not morally significant, that we can think of examples of morally significant cognitive capacities that are not uniquely human, and that evidence that some cognitive capacity is shared with nonhuman animals does not undermine claims that this capacity is morally significant. We need a better framework for thinking about the moral status of part‐human beings. (shrink)

: The transplantation of adult human neural stem cells into prenatal non-humans offers an avenue for studying human neural cell development without direct use of human embryos. However, such experiments raise significant ethical concerns about mixing human and nonhuman materials in ways that could result in the development of human-nonhuman chimeras. This paper examines four arguments against such research, the moral taboo, species integrity, "unnaturalness," and human dignity arguments, and finds the last plausible. (...) It argues that the transfer of human brain or retinal stem cells to nonhuman embryos would not result in the development of human-nonhuman chimeras that denigrate human dignity, provided such stem cells are dissociated. The article provides guidelines that set ethical boundaries for conducting such research that are consonant with the requirements of human dignity. (shrink)

Moral status is the moral value that something has in its own right, independently of the interests or concerns of others. Research using human embryonic stem cells implicates issues about moral status because the current method of extracting hESCs involves the destruction of a human embryo, the moral status of which is contested. Moral status issues can also arise, however, when hESCs are transplanted into embryonic or fetal animals, thereby creating human/ nonhuman stem cell chimeras. In (...) particular, one concern about chimera research is that it could confer upon an animal the moral status of a normal human adult, but then impermissibly fail to accord the animal the protections it merits in virtue of its enhanced status. Understanding the public policy implications of this ethical conclusion is complicated by the fact that certain views about the moral status of the embryo cannot legitimately be used to justify public policy decisions. Arguments like those employed in the abortion debate for the conclusion that abortion should be legally permissible even if abortion is not morally permissible also support, to a more limited degree, a liberal policy on hESC research involving the creation of chimeras. (shrink)

In their feature article, ‘Moral uncertainty and the farming of human-pig chimeras,’ Koplin and Wilkinson argue that there is a tension between thinking that creating pig-human chimaeras with partly humanised brains as a source of organs for transplantation as morally problematic because of the uncertainty of their moral status and thinking that the raising normal pigs for food is not morally problematic because of the certainty concerning their moral status.1 Koplin and Wilkson claim that the reasons that (...) we are uncertain about the moral status of human-pig chimaeras with partly humanised brains also apply to normal pigs. Our moral uncertainty derives from philosophical uncertainty concerning the characteristics that convey moral status and epistemological uncertainty concerning the extent to which pigs with partly humanised brains or normal pigs possess such characteristics. If we think it is morally problematic to create pigs with humanised brains for organ transplantation, we should also think it is morally problematic to raise normal pigs for food, given our uncertainty about the moral status of both kinds of animals. Their view implies that it would be inconsistent to have moral qualms about creating pigs with humanised brains for organ transplantation but to no such misgivings about raising pigs for food. While I find Koplin and Wilkson’s arguments …. (shrink)

Human–nonhuman chimeras have been the focus of ethical controversies for more than a decade, yet some related issues remain unaddressed. For example, little has been said about the relationship between the origin of transferred cells and the morally relevant capacities to which they may give rise. Consider, for example, a developing mouse fetus that receives a brain stem cell transplant from a human and another that receives a brain stem cell transplant from a dolphin. If both (...) class='Hi'>chimeras acquire morally relevant capacities as a result of transplantation, and if those capacities are indistinguishable, should the difference in cell origin matter to how we classify these creatures? I argue that if morally relevant capacities are easy to detect, cell origin is irrelevant to how the chimera ought to be treated. However, if such capacities are hard to detect, cell origin should play a role in considerations about how to treat the chimera. (shrink)

The prospect of creating and using human–animal chimeras and hybrids that are significantly human-like in their composition, phenotype, cognition, or behavior meets with divergent moral judgments: on the one side, it is claimed that such beings might be candidates for human-analogous rights to protection and care; on the other side, it is supposed that their existence might disturb fundamental natural and social orders. This paper tries to show that both positions are paradoxically intertwined: they rely on (...) two kinds of species arguments, “individual species arguments” and “group species arguments,” which formulate opposing demands but are conceptually interdependent. As a consequence, the existence of HACHs may challenge exactly those normative standards on which the protection of HACHs may eventually be based. This ethical paradox could constitute the ultimate source of the “moral confusion” that some authors have suspected HACHs to provoke. (shrink)

Cerebral organoid models in-of-themselves are considered as an alternative to research animal models. But their developmental and biological limitations currently inhibit the probability that organoids can fully replace animal models. Furthermore, these organoid limitations have, somewhat ironically, brought researchers back to the animal model via xenotransplantation, thus creating hybrids and chimeras. In addition to attempting to study and overcome cerebral organoid limitations, transplanting cerebral organoids into animal models brings an opportunity to observe behavioral changes in the animal itself. Traditional (...) animal ethics frameworks, such as the well-known three Rs (reduce, refine, and replace), have previously addressed chimeras and xenotransplantation of tissue. But these frameworks have yet to completely assess the neural-chimeric possibilities. And while the three Rs framework was a historical landmark in animal ethics, there are identifiable gaps in the framework that require attention. The authors propose to utilize an expanded three Rs framework initially developed by David DeGrazia and Tom L. Beauchamp, known as the Six Principles (6Ps). This framework aims to expand upon the three Rs, fill in the gaps, and be a practical means for assessing animal ethical issues like that of neural-chimeras and cerebral organoid xenotransplantation. The scope of this 6Ps application will focus on two separate but recent studies, which were published in 2019 and 2020. First, they consider a study wherein cerebral organoids were grown from donors with Down syndrome and from neurotypical donors. After these organoids were grown and studied, they were then surgically implanted into mouse models to observe the physiological effects and any behavioral change in the chimera. Second, they consider a separate study wherein neurotypical human embryonic stem cell-derived cerebral organoids were grown and transplanted into mouse and macaque models. The aim was to observe if such a transplantation method would contribute to therapies for brain injury or stroke. The authors place both studies under the lens of the 6Ps framework, assess the relevant contexts of each case, and provide relevant normative conclusions. In this way, they demonstrate how the 6Ps could be applied in future cases of neural-chimeras and cerebral organoid xenotransplantation. (shrink)

In this work I present a detailed critique of the dignity-related arguments that have been advanced against the creation of human–nonhuman chimeras that could possess human-like mental capacities. My main claim is that the arguments so far advanced are incapable of grounding a principled objection against the creation of such creatures. I conclude that these arguments have one, or more, of the following problems: they confuse the ethical assessment of the creation of chimeras with the ethical (...) assessment of how such creatures would be treated in specific contexts, they misrepresent how a being could be treated solely as means towards others’ ends, they fall short of demonstrating how humanity’s dignity would be violated by the creation of such entities, and they fail to properly characterise the moral responsibilities that moral agents have towards other moral agents and sentient beings. (shrink)

Human eggs for basic, fertility and stem-cell research are in short supply. Many experiments that require their use cannot be carried out at present, and, therefore, the benefits that could emerge from these are either delayed or never materialise. This state of affairs is problematic for scientists and patients worldwide, and it is a matter that needs our attention. Recent advances in chimera research have opened the possibility of creating human/non-human animal chimeras intended for human (...) gamete production (chimeras-IHGP). In this paper, I examine four arguments against the creation of such chimeras and prove that all of them are found wanting. I conclude by showing that there is a strong moral reason for scientists to pursue this research avenue. (shrink)

The article aims to present issues arising out of differences in the way that the terms chimera and hybrid are defined in legal systems and by natural sciences in the context of mixing human and animal DNA. The author analyses the different approaches to defining these terms used in various legal systems, dividing them into groups in light of conclusions reached from examining definitions used in natural sciences. The distinction is used to answer the question of which approach to (...) definitions applied by legislators is the best way to handle the subject of human-animal organisms, given the need to balance their impact on medicine and the ethical concerns that arise. (shrink)

The burgeoning field of biomedical research involving the mixture of human and animal materials has attracted significant ethical controversy. Due to the many dimensions of potential ethical conflict involved in this type of research, and the wide variety of research projects under discussion, it is difficult to obtain an overview of the ethical debate. This paper attempts to remedy this by providing a systematic review of ethical reasons in academic publications on human-animal chimera research. We conducted a systematic (...) review of the ethical literature concerning human-animal chimeras based on the research question: “What ethical reasons have been given for or against conducting human-animal chimera research, and how have these reasons been treated in the ongoing debate?” Our search extends until the end of the year 2017, including MEDLINE, Embase, PhilPapers and EthxWeb databases, restricted to peer-reviewed journal publications in English. Papers containing ethical reasons were analyzed, and the reasons were coded according to whether they were endorsed, mentioned or rejected. Four hundred and thirty-one articles were retrieved by our search, and 88 were ultimately included and analyzed. Within these articles, we found 464 passages containing reasons for and against conducting human-animal chimera research. We classified these reasons into five categories and, within these, identified 12 broad and 31 narrow reason types.15% of the retrieved passages contained reasons in favor of conducting chimera research, while 85% of the passages contained reasons against it. The reasons against conducting chimera research fell into four further categories: reasons concerning the creation of a chimera, its treatment, reasons referring to metaphysical or social issues resulting from its existence and to potential downstream effects of chimera research. A significant proportion of identified passages fell under Category C. We hope that our results, in revealing the conceptual and argumentative structure of the debate and highlighting some its most notable tendencies and prominent positions, will facilitate continued discussion and provide a basis for the development of relevant policy and legislation. (shrink)

The momentum of advances in biology is evident in the history of patents on life forms. As we proceed forward with greater understanding and technological control of developmental biology there will be many new and challenging dilemmas related to patenting of human parts and partial trajectories of human development. These dilemmas are already evident in the current conflict over the moral status of the early human embryo. In this essay, recent evidence from embryological studies is considered and (...) the unbroken continuity of organismal development initiated at fertilization is asserted as clear and reasonable grounds for moral standing. Within this frame of analysis, it is proposed that through a technique of Altered Nuclear Transfer, non-organismal entities might be created from which embryonic stem cells could be morally procured. Criteria for patenting of such non-organismal entities are considered. (shrink)

Developments in biological technology in the last few decades highlight the surprising and ever-expanding practical benefits of stem cells. With this progress, the possibility of combining human and nonhuman organisms is a reality, with ethical boundaries that are not readily obvious. These inter-species hybrids are of a larger class of biological entities called “chimeras.” As the concept of a human-nonhuman creature is conjured in our minds, either incredulous wonder or grotesque horror is likely to follow. This paper (...) seeks to mitigate those worries and demotivate reasonable concerns raised against chimera research, all the while pressing current ethical positions toward their plausible conclusions. -/- In service of this overall aim, first, I intend to show that chimeras are far less foreign and fantastic in light of recent research in the lab; second, I intend to show that anti-realist (so-called “constructivist”) commitments regarding species ontology render the species distinction (i.e., the divide between human and nonhuman) superfluous as a basis for ethical practice; and third, I discuss some prevailing dignity accounts regarding the practical ethics of the creation, research, and treatment of chimeras. Consequently I intend to show that the adoption of this particular set of views (constructivist ontology, capacity-based ethics) in conjunction with recent research ought to justify a parallel with what we accord to humans persons, and that trajectory allows for cases of moral permissibility. (shrink)

This work was supported, in part, by a Stem Cell Network grant to Françoise Baylis and Jason Scott Robert and a CIHR grant to Françoise Baylis. We sincerely thank Alan Fine, Rich Campbell, Cynthia Cohen, and Tim Krahn for helpful comments on an earlier draft of this paper. Thanks are also owed to Tim Krahn for his research assistance. An earlier version of this paper was presented to the Department of Bioethics and the Novel Tech Ethics research team. We thank (...) the participants at each of these meetings for their helpful comments. (shrink)

I respond to Monika Piotrowska's argument against anthropocentric theories of moral status that they yield disparate moral verdicts about parallel cases of embryonic stem cell transplantation. I argue that anthropocentric theories of moral status may not fall prey to this problem because embryonic stem cell transplantation may constitute creation rather than mere enhancement.

Many people find the notion of blending humans and nonhumans together to create animals whose brains are composed entirely of human brain cells disturbing. I argue that these moral qualms lack adequate justification. I consider a number of reasons for objecting to the creation of such chimeras and argue that none of these reasons withstand scrutiny. I argue that the only plausible objections to these chimeras would require that they possess morally significant properties that would be lacked (...) by similar, non-chimeric animals, but that there is no good reason to think this would be the case. (shrink)

In this paper I explore some of the moral issues that could emerge from the creation of human–nonhuman chimeras capable of human gamete production and human pregnancy. First I explore whether there is a cogent argument against the creation of HNH-chimeras that could produce human gametes. I conclude that so far there is none, and that in fact there is at least one good moral reason for producing such types of creatures. Afterwards I explore (...) some of the moral problems that could emerge from the fact that a HNH-chimera could become pregnant with a human conceptus. I focus on two sets of problems: problems that would arise by virtue of the fact that a human is gestated by a nonhuman creature, and problems that would emerge from the fact that such pregnancies could affect the health of the HNH-chimera. (shrink)

The aim of this paper is to critically examine David Shaw, Wybo Dondorp, and Guido de Wert’s arguments in favour of the procurement of human organs from human/nonhuman-primate chimeras, specifically from great-ape/human chimeras. My main claim is that their arguments fail and are in need of substantial revision. To prove this I first introduce the topic, and then reconstruct Shaw et al.’s position and arguments. Next, I show that Shaw et al.: failed to properly apply (...) the subsidiarity and proportionality principles; neglected species overlapping cases in their ethical assessment; ignored the ethics literature on borderline persons; and misunderstood McMahan’s two-tiered moral theory. These mistakes render an important part of their conclusions either false or problematic to the point that they would no longer endorse them. Finally I will briefly mention a possible multipolar solution to the human organ shortage problem that would reduce the need for chimeras’ organs. (shrink)

: Experiments involving the transplantation of human stem cells and their derivatives into early fetal or embryonic nonhuman animals raise novel ethical issues due to their possible implications for enhancing the moral status of the chimeric individual. Although status-enhancing research is not necessarily objectionable from the perspective of the chimeric individual, there are grounds for objecting to it in the conditions in which it is likely to occur. Translating this ethical conclusion into a policy recommendation, however, is complicated by (...) the fact that substantial empirical and ethical uncertainties remain about which transplants, if any, would significantly enhance the chimeric individual's moral status. Considerations of moral status justify either an early-termination policy on chimeric embryos, or, in the absence of such a policy, restrictions on the introduction of pluripotent human stem cells into early-stage developing animals, pending the resolution of those uncertainties. (shrink)