Deciphering how an ancient person lived and died is based heavily on the context of the buried body or mummy, including the soil around the gravesite, artifacts present in the grave and if nothing else, the location of the remains. What happens when there is no context? With skeletal remains or even bone fragments, which is primarily what is found at many burial sites, there is some information that can be derived but mummies that include tissue as well as bone offer a greater opportunity to learn about a deceased individual’s life. A recently published PLOS ONE article of a bog body identified using analyses across several scientific fields demonstrates how we can uncover the story of a person who lived several centuries ago based on her mummified remains.
This mummy was on display at the Bavarian State Archaeological Collection, where it had been transferred from the Anatomical Institute of the Ludwig-Maximilians University in 1970. Based on the dark brown color of the mummy, she was tentatively identified as a bog body from the moor regions around Munich. Inconsistent with this identification were the preserved outer shape with intact bone structure, the body in a squatting position and her hair in long braids. Based on these differences, which suggested the body may not be European in origin, a multidisciplinary team worked to identify who she was. However, this work was complicated by the fact that the mummy had suffered some damage including the loss of both lower legs due to the bombing of Munich during World War II.
Panzer et al. examined the body and noted the condition, position, any defects and other physical characteristics. Of note were a transverse defect above the left eye and the thick, brown to reddish hair in plaits tied off with tiny ropes. Based on their initial observations, the researchers knew they had a female body with an estimated height of 167cm (just under 5 feet, 5 inches).
To examine the mummy further, a CT scan was used to examine bone and other tissue present. This method offers a view in three dimensions, not simply a flat view like that seen in X-rays. Here the mummy gives us some interesting information. Based on skeletal characteristics (e.g., no demineralization of bone), the team suggested the individual was 20–25 years of age. Even more interesting was an extra bone found in the skull called an Inca bone, named for the South American people who typically exhibit this characteristic anatomy. While the external survey of the female mummy did not reveal much facial deformation, the CT scan showed that the skull was not intact and in fact, there were numerous bone fragments inside what remained of the skull, suggesting massive facial trauma. Further histological analysis of bone and cartilage confirmed how well the skeleton had been preserved and showed no abnormalities in those tissues.
Soft tissue like tongue, lungs, heart and gastrointestinal tract could also be seen in the CT scan but did not fill the chest or abdomen like they do in living humans. The scientists observed that both the heart and rectum walls were thickened and the lumen distended, suggesting that the woman suffered from Chagas disease. This disease is caused by the parasite Trypanosoma cruzi, which is transmitted to animals and people by blood-sucking insects and found only in the Americas. Based on this diagnosis, small samples of rectal tissue were taken for further analysis. Using histology, Panzer et al. saw extensive fibrosis (connective tissue) in the muscle tissue and positive staining with an anti-Trypanosoma cruzi antibody. In contrast, staining to detect residual bleeding and fungi yielded negative results. Using a rectal tissue sample, researchers extracted DNA and amplified a 220bp portion of the ubiquitous β-actin gene (to confirm DNA was isolated) and a T. cruzi-specific fragment of 330bp. Only one of the two samples exhibited the T. cruzi fragment. Sequencing of the PCR product resulted in a 74bp sequence with a 97% identity to the expected fragment defined by the primers used.
Microscopic analysis showed the hair shaft was normal and pigmented brown. Hair was also used to examine the woman’s diet. Carbon isotope analysis suggested a diet of C4 plants (e.g., maize) with carbon levels similar to those found in other South American mummies. Nitrogen isotope analysis revealed a diet with high levels of nitrogen like that found in individuals who consume marine animals. The PLOS ONE article referenced other research that had showed similar nitrogen levels for Inca mariners in northern Chile and southern Peru. The combination of C4 plant and marine diet suggested the coast of southern Peru or northern Chile to Panzer et al. The fibers binding the woman’s braids were identified as hair from alpacas or llamas, animals found only in the Americas and known to be important to Incans.
When was this woman alive? C14 analysis dated her to 1451–1642 AD. This range coincides with the Inca Empire, which was active from 1438–1533 AD along the Pacific coast of South America from Ecuador to central Chile.
Multiple lines of evidence indicated this mummy was South American in origin and her diet, the Inca bone of her skull and the fiber binding her braids allowed the research team to pinpoint a more specific location. Histological and molecular evidence lend credence to the chronic T. cruzi infection diagnosis. And the fragmentation of the skull suggests she was struck in the face prior to death. Incans were known for sacrificing young people as part of their religion so she could have been one such sacrifice. Taking all the data together, we can say that the mummy was a young Inca woman from the Pacific coastal region of South America who suffered from chronic Chagas disease and may have died as the result of a ritual homicide about 500 years ago.
The authors of the PLOS ONE article were able to learn more about this unknown mummy displayed in a German museum and uncovered an incredible story. Describing who she was, where she lived and how she lived and died gives her context despite her move from New World to Old World, making her more than just a mummy identified as a bog body from Germany. The multidisciplinary tools and analysis used to identify this Inca woman were impressive, and I look forward to seeing these techniques used with other anonymous bodies to answer the questions who, what, where, why and how.
Panzer, S., Peschel, O., Haas-Gebhard, B., Bachmeier, B.E., Pusch, C.M. and Nerlich, A.G. (2014) Reconstructing the Life of an Unknown (ca. 500 Years-Old South American Inca) Mummy – Multidisciplinary Study of a Peruvian Inca Mummy Suggests Severe Chagas Disease and Ritual Homicide. PLOS ONE PMID: 24586848
Latest posts by Sara Klink (see all)
- Identifying the Ancestor of a Domesticated Animal Using Whole-Genome Sequencing - September 16, 2020
- Using the Power of Technology for Viral Outbreaks - August 12, 2020
- Small Changes With Large Consequences: The Role of Genetic Variance in Disease Development - July 15, 2020