- Science says the oldest colour in the world is bright pink.
- The colour was found in pigments extracted from rocks deep beneath the Sahara desert.
- ANU scientists say the pigments are more than one billion years old.
According to research from Australia National University, the oldest colours in the geological record have been discovered — and they’re 1.1 billion-year-old bright pink pigments extracted from rocks deep beneath the Sahara desert in Africa.
The pigments taken from marine black shales of the Taoudeni Basin in Mauritania, West Africa, are more than half a billion years older than previous pigment discoveries.
“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,” says Dr Nur Gueneli from the Australian National University (ANU).
The fossils range from blood red to deep purple in their concentrated form, and bright pink when diluted. The find was announced in the journal PNAS.
Dr Gueneli discovered the molecules as part of her PhD studies. The ANU led the research with support from Geoscience Australia and researchers in the US and Japan.
The researchers crushed the billion-year-old rocks to powder, before extracting and analysing molecules of ancient organisms.
“The precise analysis of the ancient pigments confirmed that 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,” says Dr Gueneli.
Senior lead researcher Associate Professor Jochen Brocks from ANU says that the emergence of large, active organisms was likely to have been restrained by a limited supply of larger food particles, such as algae.
“Algae, although still microscopic, are a thousand times larger in volume than cyanobacteria, and are a much richer food source,” says Dr Brocks from the ANU Research School of Earth Sciences.
“The cyanobacterial oceans started to vanish about 650 million years ago, when algae began to rapidly spread to provide the burst of energy needed for the evolution of complex ecosystems, where large animals, including humans, could thrive on Earth.”