What is the world’s oldest colour?

Scientists have revealed the world’s oldest colour - a billion-year-old bright pink.

The pigments were discovered when researchers crushed ancient rocks found in a marine shale deposit beneath the Sahara desert in the Taoudeni basin in Mauritania, West Africa, reports The Guardian.

“The bright pink pigments are the molecular fossils of chlorophyll that were produced by ancient photosynthetic organisms inhabiting an ancient ocean that has long since vanished,” said Dr Nur Gueneli, who discovered the molecules as part of her PhD studies at the Canberra-based Australian National University (ANU).

Subscribe to The Week

Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.

SUBSCRIBE & SAVE

Sign up for The Week's Free Newsletters

From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.

From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.

Sign up

The university’s Professor Jochen Brocks told the BBC that the discovery was as amazing as finding fossilised dinosaur skin that still has its original colour.

“These are actual molecules, the oldest coloured molecules in the world,” Brocks said. “And the molecules we’ve found were not from a large creature but microscopic organisms because animals didn’t exist at that time. That’s the amazing thing.”

The rocks were found about ten years ago by a mining company looking for oil under the desert. “They drilled a hole several hundreds metres deep and they hit a deep, black, oily shale,” Brocks continued. “It turned out to be 1.1 billion years old.”

The significance of the pigment discovery is “not just the coolness of having old, pink stuff”, he added, but also helps to solve a “very major puzzle about life” – why large, complex creatures appeared so late in Earth’s history.

Although the Earth is about 4.6 billion years old, animal-like creatures only emerged about 600 million years ago. When the researchers analysed the structure of the pink molecule, they were able to find what had produced them – tiny cyanobacteria.

“Tiny cyanobacteria dominated the base of the food chain in the oceans a billion years ago, which helps to explain why animals did not exist at the time,” Brocks explained.

“Life only became bigger about 600 million years ago because before that there was no sufficient food source.”

The research has been published in Proceedings of the National Academy of Science of the United States of America.