Researchers have created one of the first scans of a mummified human from southern Africa using computerized tomography (CT), also performing the first successful aDNA (ancient DNA) extraction from a partially mummified body that is estimated to be 200 years old.
Samples taken from the mummy, which was found in 2008 by patrol staff wrapped in animal skin in the Tuli block of Botswana, were recently examined in specialized aDNA laboratories in Zurich.
The project, led by Maryna Steyn, head of the School of Anatomical Sciences at the University of the Witwatersrand (Johannesburg), involved collaboration with research teams from the University of Zurich, University of Pretoria and University of Botswana.
Steyn and co-author Frank Rühli explained that this was the first mummy to be discovered in Botswana, although some mummified remains have been located in neighboring South Africa. These particular remains are those of an older male adult, who appears to have been interred in a constricted position.
Ethnographic studies throughout the region indicate a general trend wherein the bodies of deceased leaders being gradually dried over a low fire before burial. The ritual also involved wrapping the body in animal hide, similar to the one found encasing the Tuli mummy - but the Tuli mummy appears to have been preserved by accident, due in part to the dry climate of the region.
Steyn and Rühli described the delicate process of performing the CT scans and aDNA analyses: "Modern imaging techniques have opened up a whole new world when it comes to mummy studies," they wrote. "CT scans are frequently used, though it can be a risky process - the mummy can be damaged during transportation and scanning. The scientists involved usually wrap the mummy and wear gloves as much as possible so that the mummy isn't physically damaged."
The radiological and molecular findings of the CT scans revealed that the internal organs were not preserved. The degenerative changes caused by advanced osteophytosis in the spine point to the mummy's older age. Although the cause of death could not be established by the scans, the body does not show signs of injury.
The aDNA analysis established that the Late Iron Age man was likely genetically connected to the modern-day Sotho-Tswana or Khoesan people living in the region, which is not a surprising analysis but still marks an important development in the usage of aDNA technology and in the ethnographic history of the region.
Mummified human remains are important sources of information regarding past populations, often helping scientists to better understand local population genetics. Additionally, despite the challenges posed by handling the delicate remains, Steyn and Rühli noted, "CT scans give us the chance to get really important medical and archaeological information through non-invasive examinations."
The study was recently published in the South African Journal of Science.
