Scientists discovere world’s oldest colour

Earth's oldest biological colour discovered in rocks beneath Sahara Desert

World's oldest colours shed light on mystery of life on Earth

An global team of researchers from Australia, Japan, the United States and Belgium has successfully extracted bright pink biological pigments from 1.1-billion-year-old marine sedimentary rocks of the Taoudeni Basin in Mauritania, West Africa.

Australian researchers have uncovered the world's oldest biological colour in the Sahara desert, in a find they said today helped explain why complex life forms only recently emerged on earth.

The pigments are fossilised molecules of chlorophyll produced by sea organisms, Australian scientists said.

As described in a paper published by the journal PNAS, found fossils (sent to ANU from an oil company that discovered the rocks a decade ago) range from blood red to deep purple in their concentrated form, and bright pink when diluted.

As part of the research, the billion-year-old rocks were crushed to powder and the molecules of ancient organisms were extracted and analyzed.

According to senior lead researcher Dr. Jochen Brocks, an associate professor at ANU, the limited supply of large food particles like algae in these ancient oceans likely restrained the emergence of large, active organisms. It's hard to say since the organic pigments that produce color typically degrade over time.

As we read in Luke Henriques-Gomes' yarn for The Guardian, Australian National University's Nur Gueneli made the thrilling discovery as a PhD student.

Researchers said the pink pigment they discovered would have originally appeared blue-green to the human eye. "[Gueneli] came running into my office and said, 'look at this, ' and she had this bright pink stuff..." These cyanobacteria had a great run for 500 million years or so, which is more than enough time to pull off wearing pink. Prof Brocks said this contributed to understanding on the evolution of life forms on Earth. Gueneli explained these microorganisms once dominated the base of the food chain in the oceans a billion years ago.

At first, scientists thought it had to do with a lack of oxygen, but it turns out that may not be the case.

"Algae, although still microscopic, are 1000 times larger in volume than cyanobacteria, and are a much richer food source", Dr Brocks said. Despite being 4.6 billion years old, an explosion of complex life on Earth didn't take place until about 650 million years ago.

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