The Super-Ancient Origins of Your Blue Jeans

Peruvians were creating distinctive indigo-blue cotton fabrics long before the pyramids were built.

For archaeologists in the far-off future, two-legged cotton garments dyed with indigo will be classified as one of the most common human adornments of the 20th and 21st centuries. In typical archaeological fashion, these "jeans" will be assigned various subcategories, such as "skinny" or "bootcut," and their geographic ubiquity will be held up as evidence for rapid globalization of trade and culture during the time period.

These future "jeanaeologists" will also point back to an intriguing report, published today in Science Advances, that shows that humans were already dyeing cotton with indigo at least 6,000 years ago.

This discovery came as a surprise to the researchers who analyzed eight fragments of cotton textiles excavated at Huaca Prieta, a site in northern Peru that was occupied between 14,500 and 4,000 years ago. The torn and cut textiles appeared to have belonged to bags or containers, and most were no more than a foot square.

"The textiles were originally very, very dirty," says archaeologist Jeffrey Splitstoser, an expert in textile structures and co-author of the research paper. "You could see blue in some of the samples but they were mostly grey. You know how your blue jeans fade over time? Well, these were like 6,000-year-old blue jeans." (Read how ancient Peruvians were making popcorn 6,700 years ago.)

Researchers used high-performance liquid chromatography to identify the presence of plant-based indigo dye in five of the eight fabric samples, which ranged in age from 6,200 to around 1,500 years old.

Until this discovery, the earliest-known indigo-dyed textiles were from Egypt's Fifth Dynasty and dated to approximately 2400 B.C.

Researchers believe that cotton was domesticated independently in several parts of the world, including South Asia, the Middle East, and Mesoamerica. Peru's northern coast, however, is believed to be the earliest area of cotton domestication. The region's native cotton, Gossypium barbadense, is also known as Pima cotton, and the strain became a backbone of modern cotton industry hybrids, says Splitstoser.

"South Americans really did contribute to [the history] of blue jeans," Splitstoser adds.

Read This Next

The most ancient galaxies in the universe are coming into view
‘Microclots’ could help solve the long COVID puzzle
How Spain’s lust for gold doomed the Inca Empire

Go Further

Subscriber Exclusive Content

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet