Mummifying the dead is a funerary rite that has been practiced for thousands of years in many locations across the world.
A new discovery reveals that we may have been underestimating exactly how widespread the practice has been. Bones that show signs of deliberate mummification have been found across Southeast Asia and southern China, with ages dating back to the pre-Neolithic period up to 12,000 years ago.
That's several thousands of years older than the cultures best known for mummification, the Chinchorro people of Chile, who were mummifying their dead 7,000 years ago, and the ancient Egyptians, who were practicing the craft 5,600 years ago.
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The reason we might have missed it? The technique used by the earlier Asian cultures is quite different from the more well-known mummification practices. According to a team led by archaeologist Hsiao-chun Hung of the Australian National University, the individuals in their study were slowly smoked over an open fire for long stretches of time.
This practice is similar to burials seen in Australia and New Guinea at a slightly later date, suggesting a cultural link via shared funerary rites.
"Our burial samples from Southeastern Asia highlight a remarkably enduring set of cultural beliefs and mortuary practices that persisted for over 10,000 years among hunter-gatherer communities who were related through their craniofacial attributes and genomic affinities to Indigenous New Guinea Highland and Australian populations," the researchers write in their paper.
Archaeologists had previously noticed that a large number of pre-Neolithic burials across a wide geographical region that includes Southeast Asia and southern China have a lot in common. In many, the individual is curled in a crouching or fetal position, tightly bound in place. Moreover, many of these burials show some burning of the bones.
How these cultures processed their dead for burial, and how they achieved the distinctive burial postures, have been open questions. Hung and her colleagues postulated that the remains were smoke-dried, in a similar manner to how some New Guinea Highlands cultures process their dead to this day.
The research team's examination involved 69 bone samples from 54 pre-Neolithic burials, dating between 4,000 and 12,000 years ago, from 11 different sites across southern China, northern Vietnam, and Indonesia.
These bones were subjected to X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). XRD is particularly effective at detecting changes to the structure of the bone that occur under temperatures higher than 500 degrees Celsius (932 Fahrenheit). FTIR is better for detecting bone changes induced by exposure to lower temperatures.
Five of the samples did not return reliable FTIR results, which left 64 samples. Most of these – around 84 percent – showed evidence of heat exposure. Some of the bones also had soot deposits, while different bones taken from the same individual returned different values, suggesting that the heating was applied selectively. There were also cut marks on some of the bones.
Based on their findings, the researchers believe that the process was similar to the modern-day rites of the Dani people in New Guinea. The deceased individual is tightly bound before being suspended over low, smoky fires for periods of weeks to months. Cuts on the bones could indicate cuts made for drainage or disarticulation purposes.
Once the individual is sufficiently mummified, the burial rites can continue. For the Dani people, that involves open-air displays; for pre-Neolithic cultures, it appears to have been burial.
These findings suggest that deliberate mummification is far more widespread around the world, more complex and varied, and older than we thought.
"The tradition of smoked mummification serves as compelling evidence of long-term cultural persistence between ancient Southeastern Asian and ethnographic Papuan and Australian mortuary practices. Furthermore, archaeological findings suggest that this tradition may have been known among hunter-gatherer societies across a vast region, for many millennia, extending from northeastern Asia and Jomon Japan to western Oceania and Australia, and possibly farther," the researchers write.
"Through this practice, the smoked and preserved remains of the deceased allowed people to sustain physical and spiritual connections with their ancestors, bridging time and memory."
The research has been published in The Proceedings of the National Academy of Sciences.