Human, Animal, or Mineral? Ethical Considerations for Studies of Fossilized Hominin Remains

ABSTRACT

Ethical considerations around research and education with modern human subjects, use of human tissue, and studies involving humans are ubiquitous within the global scientific community. This commentary explores considerations around how and whether these types of ethical considerations may apply to hominin fossils. While some might propose that the age of a fossil could be the basis for decisions around their ethical handling, it may be that characteristics or behaviors of the hominins are a more appropriate measure to determine their ethical status. These types of ethical considerations have recently been examined in other historical human tissues, such as mummies and ancient DNA, with these ethical explorations being driven by a recognition of evolving ethical perspectives around the world. Thus, there is both the precedent and stimulus for the paleoanthropology community to revisit current ethical practices within the profession. Doing so would help identify and establish standards that are reflective of global perspectives around the contemporary ethical management of hominin fossils, and potentially assist in aligning these practices with other disciplines that work with both hominin fossils and human tissues.

1. Introduction

The recently published special issue of The Anatomical Record on the Sima de Los Huesos paleoanthropological site is fascinating (Arsuaga et al. 2024) as it provides vivid details about a collection of over 7000 fossilized bones from a minimum number of 29 hominin individuals. While the authors often refer to these materials as human or human‐like, these and other publications (Xia et al. 2024) are notable for the absence of ethical statements concerning the human‐like nature of the specimens. Recently, such statements have become more common in other fields of scholarship that study modern human subjects and their remains, such as anatomy education, bioanthropology, and museum curation (AAA 2024; Cornwall, Hildebrandt, et al. 2024), reflecting appropriate respect for, care, and management of human tissues (Cornwall 2016; Jones 2019; Cornwall, Hildebrandt, et al. 2024). Noting the increase in ethical practice in fields that engage with modern human remains, an interesting question arises: at what point in our past should ethical considerations and approaches begin to treat remains as human, thus suggesting ethical approaches that align with those applied to the more recently deceased? This commentary presents suggestions for exploring when, how, and why different levels of ethical standards could be considered appropriate for fossilized remains, and how these practices could be facilitated.

2. Contemporary Ethical Standards in the Management of Hominin Fossils

The first research responsibility listed in the Code of Ethics of the American Association of Biological Anthropologists (AABA) (formerly the American Association of Physical Anthropologists [AAPA]) is, “Anthropological researchers have primary ethical obligations to the people, species, and materials they study and to the people with whom they work. These obligations can supersede the goal of seeking new knowledge and can lead to decisions not to undertake or to discontinue a research project when the primary obligation conflicts with other responsibilities, such as those owed to sponsors or clients” (AAPA 2003, 3). This statement and others like it are essential to maintaining the dignity of the human study subjects. There are current examples of anthropological recommendations for the ethical treatment of human tissues (AAA 2024; Stantis et al. 2023) as well as for the ethical use of ancient DNA (aDNA) (Alpaslan‐Roodenberg et al. 2021; Caron et al. 2020; Fleskes et al. 2022; Gibbon et al. 2024; Kaestle and Horsburgh 2002) and isotopic analysis of fossils (Stantis et al. 2025). However, these recommendations do not yet explicitly extend to all hominin fossils. Given reflection on contemporary ethical management of human tissue, it is therefore valuable to explore whether ethical considerations could also apply to the latter, even more so as the law clearly sees them as worthy of protection.

There are strict legal regulations governing the acquisition, storage, and treatment of vertebrate fossils in the United States. Other countries also have laws overseeing the fossils in their jurisdictions, with some less stringent than others. However, the primary purpose of these regulations appears to be protection of the fossils as items of scientific significance, not necessarily the ethical protection of the individuals who were fossilized. For example, the Society for Vertebrate Paleontology (SVP) outlines in its Code of Ethics both mandatory standards and aspirational standards for the collection, management, and study of vertebrate fossils. While indisputably an important benchmark for the field, these guidelines stop short of the rigorous ethical standards that typically apply to modern human remains. For example, regarding specimen study, the SVP guidelines state, “When working with specimens, we will treat all collections with respect, and will follow all relevant institutional policies for their preservation and use.” While certainly an important minimum standard, there might be room for further ethical consideration of hominin remains beyond basic respect and institutional guidelines.

This perception may be changing, at least in the AABA, which recently released a position statement in opposition to an incident in which fossils of the hominins Homo naledi and Australopithecus sediba were sent into space, seemingly for the purpose of publicity (AABA 2023). The statement reads “Taking original fossils of rare human ancestors, especially a holotype and a paratype of two species, into space puts them at risk of destruction for no clear scientific reason […] Additionally, there is concern about the use of fossils for individual promotional activities, and the ethical questions and potential conflicts of interest that arise from such activities.” (AABA 2023). Such comments demonstrate existing concerns and specifically highlight the existence of ethical issues around the use—or potential misuse—of fossilized hominin remains within contemporary scientific practice and suggest that additional ethical discussion is warranted. Since classifications of fossils and archeological artifacts vary across countries, finding a universally applicable solution for ethical handling could be challenging. However, this does not mean that ethical priorities could not be discussed or formulated, or that standards could not be developed and adopted by international or national associations and upheld by the journals associated with these groups.

3. Human, Animal, or Mineral?

One of the first issues of interest is the categorization of hominin fossils. Fossilized materials are the actual physical remains or are nearly exact duplicates, and paradoxically, they are simultaneously both human, yet not‐human. Are they human remains, remains of human‐like ancestors, or are they simply representations of human tissues in mineral form? A modern example of this conundrum is the recent development of 3D printing of human tissues. These 3D prints contain no actual human tissue yet are virtually identical representations. Many in the anatomical ethics community consider these representations to have the same or similar ethical weight as the real tissue from which they were derived (Alves‐Cardoso and Campanacho 2022; Campanacho and Cardoso 2024; Carew et al. 2023; Cornwall 2016; Cornwall, Hildebrandt, et al. 2024; Schug et al. 2021; Smith and Hirst 2019). A similar consideration could be applied to mineralized or permineralized fossils.

There is an extensive debate in the paleoanthropological community about how to define “human uniqueness,” whether it be taxonomic (e.g., Homo sapiens only) or through hallmarks of cultural and/or cognitive modernity (e.g., language, burial of the dead, art, capacity for knowledge acquisition; d'Errico and Stringer 2011; Henshilwood and Marean 2004). The Sima de Los Huesos hominins apparently demonstrated some of the key characteristics typically associated with human‐like modernity, such as intentional burial of the dead, care for the disabled, control of fire, and symbolic thought (Arsuaga et al. 2024). Notably, they were deposited in a concentrated arrangement on a distinct sedimentary level and in association with apparent grave goods, suggesting they employed funerary practices (Carbonell and Mosquera 2006).

The further back in time one looks in the hominin fossil record, the less these so‐called “human” characteristics are apparent. Does this matter for the ethical treatment of these materials, especially given the fact that it is now widely understood that H. sapiens is not the only species with culture and not the only one to bury their dead or even to practice elaborate mortuary rituals (Carbonell and Mosquera 2006; d'Errico and Stringer 2011; Henshilwood and Marean 2004; Rendu et al. 2014)? At what point in hominin evolution should these remains be treated with the same or similar types of ethical considerations as those of modern H. sapiens? For example, should ethical considerations start with the origin of our own genus, Homo, while recognizing that some of the earlier Homo species lacked the so‐called hallmarks of human modernity? Alternatively, should fossil hominin materials that show clear evidence of intentional burial or other funerary rituals receive the same ethical considerations given to modern human remains, regardless of whether they belonged to H. sapiens? It could be suggested that a hominin (of any species) that was intentionally buried by conspecifics (members of the same species) or displayed evidence of other conspecific thanatological responses might require more nuanced ethical considerations than the excavation of other vertebrate fossils that were deposited by natural processes.

4. Age Is Just a Number

It has been suggested that the further removed remains are from the people of today, the more likely they are to lose ethical consideration, as noted by scholars examining German collections of modern human remains. These scholars considered human tissues from the 19th century, removed from today by three or four generations, as having lost proximity to living groups or individuals and therefore being owed reduced or no ethical protections (German Medical Association 2003). Other scholars who have worked with much older individuals have argued that they clearly exhibited human‐like traits—including burial practices, vocalization, oral language, and artistic expression—and that these characteristics raise questions around whether these individuals should also have ethical protection (Kaufmann and Rühli 2010; Kreissl Lonfat et al. 2015; Sørensen 2019). In the case of hominin fossils, their age alone may not be a useful criterion. Rather, cultural as well as social practices and skills might be more valuable criteria (Figure 1). Presently, the greater scientific community has no agreed‐upon understanding around when or why ethical standards should occur with human or human‐like remains, and discussions that attempt to determine what ethical standards should be implemented, when these should be enforced, and why these should be practiced across a timeline continuum would be a welcome conversation.

FIGURE 1.

Logarithmic scale indicating the years before present at which fossilized hominin remains have been found and comparing that with burial rituals, dissection, and other uses of the deceased. The lower part of the figure describes a continuum that reflects the range in the level of detail of ethical statements that may occur due to the nature of the human remains, and the suggested level of detail of ethical statements related to the age of the remains. The figure is intended to stimulate discussion around when ethical practices should change for any “human‐like” remains, fossilized or otherwise, and what factors may be used as justification for these changes.

5. Ethical Standards, Transparency, Culture, and Global Community Practice

While the guidelines recently developed by anatomists and anthropologists rely strongly on the inclusion of communities of care in the implementation of ethical practices around human remains, they also grapple with the question of identifying such communities and developing ethical practices where such communities cannot be found (AAA 2024; Cornwall, Champney, et al. 2024). The priorities formulated in these recommendations focus on the consistent application of ethical standards. These standards encourage transparency around good ethical practice that aims at developing global community standards which reflect a shared understanding of the appropriate treatment of human remains.

These priorities—if not the guidelines themselves—might be helpful to consider in the context of the treatment of fossil hominins and their sometimes‐ambiguous human‐like status. The paleoanthropological community could consider when applying such guidelines and statements to hominin species are appropriate and could acknowledge this by the inclusion of an ethical statement that describes the specific ethical considerations for those fossils (Figure 1, lower portion). A possible solution is that paleoanthropological associations convene a task force that can study these issues and recommend guidelines for the ethical treatment of fossil hominin species. This task force could be composed of a diverse group of stakeholders including paleoanthropologists, museum curators, bioethicists, vertebrate paleontologists, and interested members of the public from all regions of the world, especially those where large concentrations of fossils are found. If consensus recommendations were adopted by the associations, they could encourage or even require that they be followed by their journals, thus assisting in their adoption.

6. Conclusion

The application of contemporary ethical standards in the use and management of human tissues within the clinical sciences is expected and is legally required in some jurisdictions. While the situation in paleoanthropological studies of fossil hominins is complicated by their ambiguous status as human, yet not‐human, and a lack of direct descendant communities, these hominin individuals immortalized in fossilized remains perhaps deserve to be acknowledged in some way that is different to fossils from other species. Even if it is difficult to determine precisely what ethical practices should be applied to these remains (Sørensen 2019), the issue should be discussed and revisited throughout the larger paleoanthropological community to assist in the identification of criteria that define when and how ethical practices may apply.

While undertaking conversations around what “contemporary ethical treatment of hominin fossils” looks like would undoubtedly be challenging, other professions such as anatomy and bioarcheology have already embarked on a similar journey to ensure contemporary ethical practice reflects our modern, pluralistic society. It also helps ensure good ethical practice by revisiting any existing standards to make certain they remain fit for purpose. Challenges for such projects exist in the form of current practices being entrenched, diverse ethical perspectives around fossils and hominins, differing cultural and philosophical perspectives about hominins and fossilized remains, and a lack of shared definitions. There may also be concerns that “ethical consideration” will add more work for research teams, though this is both speculative and not necessarily the case when refining definitions and providing clarity may actually assist or promote streamlined research practice. The perceived “difficulty” of this process does not mean the task should be avoided. Conversations around ethical practices will promote consistency, a shared understanding of concerns, and encourage interdisciplinary conversations, all of which bring benefits to the profession.

This commentary encourages the paleoanthropological community to consider standards and statements for the respectful treatment of hominin fossils and to help remind the scientific community that those who were fossilized were living, breathing individuals who may have contemplated their existence and enjoyed the beauty of the world. Among the relevant questions to ponder are: what ethical considerations different forms and ages of fossils should receive, and what specific characteristics could be suitably used in determining these considerations? Discussions that can assist in defining the term “human” in an ethical context are necessary, considering biological and cultural thresholds, and determining how ethical treatment may differ between human and nonhuman remains. Conversations around the applicability of these topics to contemporary ethical standards across other professions would be valuable to inform a continuum of ethical care and ensure a transparency of practice in and around not only fossilized remains, but very old human remains. Presently, there is no established or agreed‐upon “point in time” where, how, or why ethical standards change in the management of human and human‐like remains, and clarity around these ethical transitions would be highly useful for many professions. Furthermore, agreement about what constitutes “respectful treatment” would ensure consistency of practice among different professions, while conversations around the cultural context of fossilized remains would assist in the development of practices that can guide nuance around adoption or modification of other proposed ethical standards. As paleontologists and others who work with fossilized hominins continue their studies, they are encouraged to contemplate these ethical considerations and develop standards that respect their hominin study subjects. This would help ensure the level of dignity and respect that is appropriate for the ethical protection of humans, human remains and these human‐like species.

Author Contributions

Thomas H. Champney: conceptualization (lead), writing – original draft (equal), writing – review and editing (equal). Heather F. Smith: conceptualization (supporting), writing – original draft (equal), writing – review and editing (equal). Sabine Hildebrandt: conceptualization (supporting), writing – original draft (equal), writing – review and editing (equal). Jon Cornwall: conceptualization (supporting), visualization (lead), writing – original draft (equal), writing – review and editing (equal).

Conflicts of Interest

Jon Cornwall, Sabine Hildebrandt, and Thomas H. Champney are all members of the Federative International Committee for Ethics in the Medical Humanities (FICEM), the ethics committee of the International Federation of Associations of Anatomists. Jon Cornwall is the Chair of FICEM. Sabine Hildebrandt is a member of the Human Remains in Harvard Museum Collections Research Review Committee. She receives royalties from her book “The Anatomy of Murder.” Thomas H. Champney was a member of the American Anthropological Association's Ethical Treatment of Human Remains Commission. Thomas H. Champney oversees the South Florida Body Donation Program, is entrusted with the care of human remains in this program and serves on the University of Miami's Anatomical Advisory Committee. Heather F. Smith is the Editor‐in‐Chief of The Anatomical Record. She is Director of the Menefee Paleontological Project and holds an active Paleontological Resources Use Permit from the U.S. Bureau of Land Management for collection of Cretaceous fossil vertebrates.

Champney, T. H. , Smith H. F., Hildebrandt S., and Cornwall J.. 2025. “Human, Animal, or Mineral? Ethical Considerations for Studies of Fossilized Hominin Remains.” American Journal of Biological Anthropology 187, no. 3: e70085. 10.1002/ajpa.70085.

Data Availability Statement

The authors have nothing to report.