In the wee hours of the morning in a lab in Amherst, Massachusetts, geoscience graduate student Rob D’Anjou sat looking over test results, a pot of coffee nearby. He’d been pulling long days to analyze two narrow columns of silt, mud, and other sediment cored from the bottom of Lake Liland in Arctic Norway, and, frustratingly, was seeing no sign of the molecules with which he’d been hoping to reconstruct the temperature and precipitation records during the lake’s last 7,000-odd years.
There were a number of other substances in the cores, though. And some of those other substances, he realized with a jolt, looked familiar. He turned to a cache of chemistry papers and, with their help, confirmed his suspicion: He was looking at human fecal sterols, the last chemical hurrah of poop. And these feces were decidedly ancient ones, manufactured, as it were, starting more than 2,000 years ago.
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