It’s easy to read too much into the scant evidence that remains of ancient rituals, particularly when the believers -- and the victims -- left no written records. But in the case of the Incas, who flourished half a millennium ago in the heights of the Andes, archaeologists have been piecing together a persuasive story of a religion that involved the sacrifice of children, who were apparently drugged into submission and left to die on cold mountain tops. Because of the dry, frigid climate, many of the bodies did not decompose. Instead they were mummified, leaving behind forensic clues to ancient murders. Last week in Nature, Erika Check Hayden wrote about a particularly fascinating study. By analyzing the hair of three of these Ice Children (for background information, see Sharon Begley’s 1995 article in Newsweek) scientists found metabolites left behind from ingesting alcohol and coca leaves, which contain the alkaloid cocaine. Analyzing the hair, centimeter by centimeter, the scientists concluded that the oldest child, a 13-year-old girl, had been given ever larger doses of the drugs as her killing approached.
The levels of metabolites in her hair, for instance, increased about a year before her death and then shot up to very high levels about a month and a half before she died — her hair recorded the highest level of coca ever found in Andean archaeological remains, says John Verano, a biological anthropologist at Tulane University in New Orleans, Louisiana.
Andean mummies have also been an important source for studying ancient diseases, including cancer. I describe some of the cases in my article in the current issue of Discover: The Long Shadow. (It is no longer behind a pay wall and free for all to read.) The mummy of a Chilean boy had a rare tumor called a rhabdomyosarcoma on his face, and nine Peruvian mummies bore the marks of melanoma. Another striking case involved a middle-aged woman from the Chilean Andes. Here is how I describe her in The Cancer Chronicles:
Her desiccated body was buried in a mummy pack along with her possessions: three woolen shirts, some feathers, corncobs, a wooden spoon, a gourd container, and a metal crucible. . . . Her hair reached down her back in a long braid tied with a green cord. There were lesions in her spine, sternum, pelvis. On top of her skull, cancer had chomped a ragged hole 35 millimeters across. Cancer had feasted on her right femur, shortening her leg.
The diagnosis was metastatic carcinoma, and the pattern of its spread suggested that the cancer had begun in her breasts. Whether they died of disease or natural causes or were murdered to appease imaginary gods, thousands of Andean mummies have been discovered. Studying them systematically would provide an unprecedented wealth of information about cancer and how prevalent it was in times past. And that would give science an ever sharper picture of cancer's causes -- how much is endemic and inevitable and how much is amplified by modern life. @byGeorgeJohnson For a preview of The Cancer Chronicles, including the table of contents and index, please see the book's website. @byGeorgeJohnson