Good times led to grisly custom

Increased rainfall may have indirectly prompted development of mummification

A population boom sparked by increased rainfall and a burgeoning supply of seafood may have led members of South America’s Chinchorro culture to start mummifying their dead long before the ancient Egyptians started salt-drying their pharaohs for eternal life.

FACING ETERNITY Chinchorro people invented several mummification styles, including the black mummy technique shown here that was used between 7,000 and 5,000 years ago. After taking apart a person’s dead body, treating and reassembling it, a white ash paste was applied and painted with black manganese. Bernardo Arriaza

Chinchorro hunter-gatherers invented the earliest known mummification procedures about 7,000 years ago, when the group’s population was rising. Increasing numbers of Chinchorro couldn’t help occasionally seeing bodies of dead comrades that had naturally mummified in shallow graves dug in the coastal Atacama Desert of northern Chile and southern Peru, says a team led by ecologist Pablo Marquet of Pontificia Universidad Católica de Chile in Santiago. Those encounters with deceased individuals who seemingly refused to let their bodies decompose inspired the Chinchorro to invent artificial mummification procedures, Marquet and his colleagues conclude in a paper published online the week of August 13 in the Proceedings of the National Academy of Sciences.

Egyptians started mummifying the dead around 4,600 years ago. Chinchorro mummification practices ended about two centuries after that, a time when the weather rapidly turned drier and populations declined in size. In small, dispersed groups, a complex tradition such as artificial mummification became too hard to pass from one generation to the next with any consistency or fidelity to critical methods, the scientists assert.

“Environmental changes are usually associated with the collapse of complex societies,” Marquet says. “But if resources are abundant, environmental change can provide fertile ground for cultural evolution.”

Marquet’s environmental explanation for the invention of Chinchorro mummification practices is plausible but can’t be proven with current evidence, remarks anthropologist Daniel Sandweiss of the University of Maine in Orono. “Perhaps someone who encounters Marquet’s article will be inspired to innovate a new way to test his hypothesis, just as encountering natural mummies in the Atacama Desert may have led Chinchorro people to create artificial mummification,” Sandweiss says.

Evidence from an ice core previously extracted from a mountainous part of Bolivia indicates that increased rainfall between 7,000 and 5,000 years ago along South America’s Pacific coast boosted the availability of fresh water and seafood for Chinchorro people, Marquet’s team reports.

An analysis of remains from 460 previously excavated Chinchorro sites indicated that population numbers rose markedly starting about 7,000 years ago. Chinchorro numbers temporarily dropped around 4,900 years ago before plunging at 4,200 years ago, the researchers say.

As the Chinchorro grew in number, groups spent big chunks of the year in the same camps. People would have regularly seen naturally mummified bodies poking out of shallow, eroding graves, Marquet says.

Many modern hunter-gatherers believe that death is not complete until a body has fully decomposed. Chinchorro encounters with naturally mummified, non-decomposed bodies may have led to a belief in the persistence of a person’s soul via this process, motivating the invention of artificial mummification for religious reasons.

Bruce Bower has written about the behavioral sciences for Science News since 1984. He writes about psychology, anthropology, archaeology and mental health issues.

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