Although keen on decipherment, Hyland admits that Inca khipus might represent more of a “proto–writing system” still coming into being when the Spanish invasion disrupted its development.

Nearly 500 years after the collapse of the largest empire in the Americas, a single bridge remains from the Inca's extraordinary road system – and it's rewoven every year from grass.

Around 1500, the Inca Empire ran for over three thousand miles (5,000 km) down the Andes, and ruled over 12 million people from the Pacific Coast to the Amazonian jungle.

The Inca was led back to Cusco in a golden chain and sentenced to death. Chiefs from across his grandfather’s empire crowded the balconies, rooftops, and hillsides.

These writing systems, then—including, possibly, Inca khipus—could illuminate how and why our ancestors first adopted written language: a record of one of the most consequential changes in ...