Surgical amputation of a limb 31,000 years ago in Borneo

The prevailing understanding of medical evolution posits that the Neolithic Revolution (approximately 10,000 years ago) spurred advancements in prehistoric medical practices due to novel health problems arising from settled agricultural life. The oldest known surgical procedure was believed to be a left forearm amputation on a European Neolithic farmer (Butchers-Boulancourt, France) dating back 7,000 years. This required advanced anatomical knowledge and skill, establishing a benchmark for complex medical acts. However, this paper presents evidence pushing back the timeline significantly. The discovery of skeletal remains (TB1) from Liang Tebbo cave in Borneo, Indonesia, reveals a young individual who underwent an extensive lower leg amputation during childhood (aged 6-9 years), before burial approximately 31,000 years ago. This predates previously known examples by a substantial margin. Liang Tebbo is known for its early rock art, further contextualizing this finding. The unexpected discovery suggests that sophisticated medical practices existed amongst at least some modern human foragers in tropical Asia long before the Neolithic transition, challenging existing narratives about the development of medical knowledge and skills in prehistoric societies. The study aims to document this remarkable finding and discuss its implications for our understanding of human history and the evolution of medicine.

The literature review section focuses on previous research concerning early examples of surgical interventions and the prevailing understanding of medical practices in pre-Neolithic foraging societies. It highlights the Butchers-Boulancourt amputation as the previously accepted oldest known example of a complex surgical procedure, emphasizing the technical skill and anatomical knowledge it required. The authors also discuss the common perception that healthcare systems in prehistoric foraging societies were rudimentary, typically involving plant-based remedies, but with limited complex surgical intervention beyond basic procedures like wound suturing or trepanation. The review sets the stage for the unexpected discovery in Borneo and its implications for overturning the established timeline and understanding of medical development in prehistoric human populations.

The methodology section details the archaeological excavation and dating techniques used in the study. The researchers excavated a 2m x 2m trench in Liang Tebbo cave, uncovering the skeletal remains of TB1. The burial context was carefully documented using laser scanning and photography. The skeleton's completeness (75% bone integrity) allowed for a thorough anatomical examination and age estimation using epiphyseal fusion, pubic symphysis, auricular surface analysis, and dental formation techniques. The individual (TB1) was determined to be a young adult (19-20 years at death) of indeterminate sex. Dating methods included accelerator mass spectrometry (AMS) radiocarbon dating of charcoal samples found above and below the burial layer, providing a stratigraphic minimum and maximum age for the burial. A combined uranium-series and electron spin resonance (ESR) dating was also conducted on a mandibular molar, providing an independent age estimate. The age estimates from various methods were integrated into a Bayesian chronological model to refine the age range. The analysis of the skeletal remains focused specifically on the left leg, where the amputation was evident. Detailed examination of the bone morphology, radiography, and microscopy were used to determine the nature of the amputation, healing process, and potential causes. Statistical analysis may have been conducted to compare TB1's stature to other prehistoric populations, as indicated in the supplementary materials.

The key finding is the evidence of a surgical amputation of the left lower leg of TB1, dated to approximately 31,000 years ago. The complete absence of the left foot and the clear remodeling of the distal ends of the tibia and fibula demonstrate a successful healing process following a clean surgical amputation. The bone morphology indicates the amputation occurred in childhood, allowing for sufficient time for bone remodeling and healing before death at approximately 19–20 years of age. The lack of infection suggests a high level of surgical skill and possibly the use of antiseptic techniques. Radiocarbon dating of charcoal associated with the burial produced a date range of 31,519 to 30,437 cal. BP, with a mean of 30,978 cal. BP. Uranium-series and ESR dating of a molar yielded an age estimate of 25.4 ± 3.3 thousand years old, consistent within the error margin of the radiocarbon dating. The Bayesian analysis incorporated all dating evidence, further supporting the age of the burial. The precise nature of the amputation, the absence of infection, and the successful healing process strongly suggest deliberate surgical intervention, rather than accidental trauma or animal attack. This pushes back the known timeline for complex surgical procedures by a considerable margin.

The discovery of a 31,000-year-old surgical amputation challenges the established understanding of the evolution of medical practices. It demonstrates that sophisticated surgical skills and medical knowledge were present in at least some foraging populations in tropical Asia well before the advent of agriculture. This finding significantly predates previously known evidence of such advanced surgical capabilities and overturns the long-held assumption that complex medical procedures were primarily associated with settled agricultural societies. The advanced surgical techniques, apparent antiseptic practices, and successful healing of the amputation highlight the significant level of medical knowledge and skill possessed by the community to which TB1 belonged. The findings have broader implications for understanding the cognitive and social capacity of Late Pleistocene hunter-gatherers, highlighting their adaptive and technological capabilities. The discovery provides a powerful counterpoint to Eurocentric narratives of the development of medicine, showing that sophisticated medical knowledge and practice evolved independently across different parts of the world.

The discovery of a surgically amputated limb on a 31,000-year-old skeleton from Borneo represents the oldest known example of a successful surgical procedure, significantly shifting our understanding of the development of medicine. This finding necessitates a reassessment of the assumed link between complex medical practices and the Neolithic Revolution, suggesting that advanced medical knowledge and skill existed in some foraging populations thousands of years earlier than previously thought. Future research should focus on further investigation of archaeological sites in the region, seeking evidence to support the widespread practice of complex surgical procedures amongst these early human populations. Further investigation into the potential use of antiseptic techniques during the amputation would be particularly valuable.

While the evidence strongly suggests a surgical amputation, there remains the possibility of alternative interpretations of the bone morphology. Though unlikely, some level of uncertainty remains concerning the exact surgical techniques employed. The limited sample size, with only one individual exhibiting the amputation, prevents generalization to the entire population. Furthermore, the reliance on radiocarbon and uranium-series dating methods introduces some degree of inherent uncertainty to the age estimation. Future studies may benefit from employing additional dating techniques to further refine the age estimation and provide more certainty.