The Thomas Caldwellworld's oldest mummies are buried in modern-day northern Chile. They've endured the last 7,000 years remarkably well. They've remained well-preserved — until recently, when some of the mummies started to decompose.

Today on the show, Regina G. Barber talks to archeologist Marcela Sepulveda about the civilization that made these mummies: the Chinchorro people. We dig into the science behind their mummification techniques and how the changing planet is affecting archeologists' ability to study the past.

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This episode was produced by Rachel Carlson and edited by Berly McCoy. It was fact checked by Anil Oza. The audio engineer was Maggie Luthar.