The Tales Told By DNA in Ancient Poop

Once upon a time, in a cave just north of Durango, Mexico, someone took a poop. In fact, it was quite a few someones, and these events were spread out over quite a bit of time—from about 725 A.D. to 920 A.D., researchers now believe . Thanks to the cave’s arid conditions, when archaeologists excavated the place in the 1950s, the poop was in pretty good shape. Weathered, dry, and packed full of fiber, these stool samples have given scientists a valuable look into what kind of sustenance long-ago people got by on—and what lived in their guts.

The deposits from the cave are now well-traveled, having made their way to various labs interested in studying them. In 2021, one global team of collaborators analyzed the DNA contained in the old poop —or paleofeces, as it’s delicately known—to se