The knotted, intricately braided string was like no other anthropologist Sabine Hyland had ever seen. Called a khipu, such devices were typically made and used by Inca elite to record astronomical events, take the census and maybe even collect taxes. And this one was “beautifully made, with fine braiding and variation in cord size,” Hyland says. She recalls thinking, “this is so beautiful, it must be royal.”
But a single strand of hair woven into the cord tells a very different story. A chemical analysis reveals the owner’s diet and likely location, pegging the person as a commoner from the Andean highlands, researchers report August 13 in Science Advances.