Cannibalism and Human Evolution

Model of a female Homo antecessor of Atapuerca practicing cannibalism by Jose Luis Martinez Alvarez from Asturias, España via Wikimedia Commons.

One of my aunts was once asked during an interview for a position in the criminal justice field “Is there any kind of criminal you don’t feel you could work with?”

“Yes,” she replied. “Have you ever seen ‘The Silence of the Lambs?’ I don’t do cannibals.”

My aunt is an extremely kind woman, who cheerfully works with hardened criminals without batting an eye. Her refusal to work with this class of criminals—along with a long list of lurid horror movies–illustrates how repugnant our society finds cannibalism. We view it as highly deviant and pathological, limited to the worst of people (such as Jeffrey Dahmer). But at the same time, exceptions have been carved out for when this practice is considered appropriate. In cases of starvation, cannibalism for survival purposes is generally accepted as a necessity, such as the final Franklin expedition when sailors had to eat their own shipmates, or in 1972 when members of a Uruguayan rugby team stranded in the mountains of Argentina were forced to eat their dead teammates. Cannibalism has also been tolerated for medical reasons, such as during the 16-18th centuries, when elite Europeans who condemned the practice by ‘uncivilized’ societies engaged in it themselves, consuming Egyptian mummies, fresh human blood, and ground up bones.  Today, some American women eat their own–or other women’s– placentas after childbirth, believing it has healthful or spiritual benefits. And symbolic or literal cannibalism forms an integral part of religious traditions around the world, including Christianity.

Speaking to the strength of this taboo,  I would expect people who engage in these exceptions might push back against the idea that they are cannibalistic practices, despite their meeting the definition*.  But, as we will discuss here, cannibalism has been a part of human cultures since long before we became modern H. sapiens. Bioarchaeologists identify cannibalism in the archaeological record by a suite of characteristic modifications to the skeleton, including:

• Defleshing cutmarks
• Longitudinal breakage patterns similar to those seen on butchered animals (to extract nutritious bone marrow)
• Tooth marks from gnawing
• “Pot polish”: characteristic polishing that is the result of bones coming into contact with a cooking vessel while being boiled

Biochemical analysis can also give insights into the practice of cannibalism. The presence of human myoglobin within human coprolites indicates the consumption of human tissues. And using biochemical analyses, Trujillo-Mederos et al. (2015) were able to determine that the remains of eighteen people killed and eaten in rituals at the Late Preclassic Period site of Tlatelcomila, near present-day Mexico City, were cooked in a variety of ways (including boiling and grilling) and eaten with chilies.

Anthropologists generally distinguish between two types of cannibalism: “endocannibalism,” in which the consumed individuals are from the same group as those who eat them, and “exocannibalism” in which people outside the group are consumed. The former has been interpreted as being motivated by a variety of factors, including spirituality, honor, bereavement, and social control. The latter is more often interpreted as an act of violence or contempt. (Carbonell et al. 2010).

As in contemporary groups, this practice in past groups was motivated by a variety of reasons including starvation, warfare, and ritual.  It can be difficult to distinguish between the latter two motivations from skeletal remains unless there is clear archaeological context (Larsen 2015). For example, the Upper Paleolithic Magdalenian assemblage at Gough’s Cave site shows extensive modifications to the bones including gnawing and cutting, but also the fashioning of skull-cups from the crania, suggesting “that cannibalism was probably not survival cannibalism but a customary one that included ritual practices involving the shaping of human skulls into skull-cups.” (Bello et al. 2015).

However Mays and Beattie (2015) note that starvation-motivated cannibalism in the archaeological record can be identified by patterned modification to skeletal elements:

Survival (or starvation) cannibalism generally follows a sequence in which body parts requiring least effort in processing are utilised first. Initially, flesh is cut from an articulated corpse, and large muscle groups are often targeted. If further calories are needed, there may be corpse dismemberment and, finally, processing of bones to extract fat from medullary cavities and cancellous bone (Read, 1974; Turner & Turner 1999; Rautman & Fenton, 2005). If cold conditions favour preservation of the corpse, this may potentially allow sustenance to be obtained over a prolonged period (Read, 1974; Rautman & Fenton, 2005).

Bioarchaeologists have identified cannibalistic practices in many ancient societies—so many, in fact, that a comprehensive overview is way beyond the scope of this blog post. But what particularly interests me is just how ancient it is: symbolic cannibalism is seen (as mentioned above) at the Upper Paleolithic Gough’s Cave site in England, and cannibalism was also not at all uncommon among archaic humans.

The oldest evidence for cannibalism comes from the ~1 million year old H. antecessor remains at the Gran Dolina site at Sierra de Atapuerca, Spain.  Neandertal remains from Krapina in Croatia (~130,000 YBP), Moula-Guercy cave and Les Pradelles in France, Zafarraya and El Sidrion in Northern Spain, and the early modern H. sapiens from the Herto site in the Middle Awash region of Ethiopia (~160,000 YBP) also all show bone modifications consistent with butchering.  And a recent paper by Rougier et al. (2016) adds additional evidence that Neandertal cannibalism was widespread. Neandertal remains reanalyzed from the Troisième caverne from Goyet (Belgium), which date to 40,500-45,500 cal YBP, show evidence of butchering for both food and the creation of bone retouchers (used to modify stone tools) . It is unknown whether the use of Neandertal remains for retouchers was a symbolic act, or simply expediency**.

So although we may shudder at the thought of eating people, the archaeological record shows us that cannibalism has actually been an integral part of human evolutionary history. Exactly how it may have shaped our evolution is unclear. Certainly it has allowed individuals to survive under extreme circumstances; could it have preserved populations that would have otherwise gone extinct? It’s tempting to speculate that this might have been a crucial survival strategy in the case of H. antecessor, but additional evidence is needed.

Oh, and my aunt? She got the job, and has been working to improve the lives of incarcerated people since. She hasn’t had to work with any cannibals.

*As a cradle Catholic, I’ve often engaged in one such practice, but without an anthropological perspective I would never have characterized the Eucharist as a cannibalistic act, despite that being the literal meaning behind the doctrine of transubstantiation!

**as a side note, mitochondrial DNA recovered from remains at Troisième caverne show them to be genetically similar to other Neandertals from Feldhofer (Germany), Vindya (Croatia), and El Sidrón (Spain). This finding of similarity over wide geographic distances supports one current hypothesis that Neandertals had an extremely low effective population size.

References and further reading

Bello SM, Saladié P, Cáceres I, Rodríguez-Hidalgo A, Parfitt SA. 2015. Upper Palaeolithic ritualistic cannibalism at Gough’s Cave (Somerset, UK): The human remains from head to toe. Journal of Human Evolution 82: 170-189.

Carbonell E, Cáceres I, Lozano M, Saladié P, Rosell J, Lorenzo C, Vallverdú J, Huguet R, Canals A, and de Castro JMB. (2010). Cultural Cannibalism as a Paleoeconomic System in the European Lower Pleistocene. Current Anthropology 51 (4): 539-549

Larsen CS. 2015. Bioarchaeology: Interpreting Behavior from the Human Skeleton, 2^nd edition. Cambridge Studies in Biological and Evolutionary Anthropology, Cambridge University Press.

Larsen CS 2014 Our Origins: Discovering Physical Anthropology, third edition. W.W. Norton & Company: New York.

Mays S, Beattie O. 2015. Evidence for End-stage Cannibalism on Sir John Franklin’s Last Expedition to the Arctic, 1845. International Journal o fOsteoarchaeology doi: 10.1002/oa.2479.

Rougier H, Crevecoeur I, Beauval C, Posh C, Flas D, Wißing C, Furtwängler A, Germonpré M, Gómez-Olivencia A, Semal P, van der Plicht J, Bocherens H, Krause J. 2016. Neandertal cannibalism and Neandertal bones used as tools in Northern Europe. Sci Rep 6:29005 doi: 10.1038/srep29005

Trujillo-Mederos A, Bosch P, Pijoan C, Mansilla J. 2015. Savory recipes and the color of the Tlatelcomila human bones. Archaeometry 58(4): 688-704. DOI: 10.1111/arcm.12178