Published: Wed, July 11, 2018
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World's 'oldest coloured molecules' are bright pink

World's 'oldest coloured molecules' are bright pink

This colorful remnant suggests that ancient sunlight-eating organisms cast a pink tint to a long-gone ocean, lead study author Nur Gueneli, of the Research School of Earth Sciences at the Australian National University (ANU), said in a statement.

Australian scientists have discovered the oldest colours in the geological record, 1.1 billion-year-old bright pink pigments extracted from rocks deep beneath the Sahara desert in Africa.

The ANU researchers crushed the billion-year-old rocks to powder, before extracting and analyzing molecules of ancient organisms from them.

They are approximately 600 million years older than previous ancient pigment discoveries.

While chlorophyll itself is green, these building blocks tend to come in strong shades of reds and purples - hence why this latest fossilised pigment comes in pink.

That chlorophyll was produced by ancient photosynthetic organisms that inhabited an ancient ocean that vanished eons ago.


Gueneli and Brocks teamed up with researchers from the US, Japan, Belgium and Geoscience Australia to detail their findings in a report, which was published by the Proceedings of the National Academy of Sciences journal online on Monday. "Which helps to explain why animals did not exist at the time". Despite being 4.6 billion years old, an explosion of complex life on Earth didn't take place until about 650 million years ago.

The fossils from where the archaic bright pink was discovered appeared to have a variety of colors. The discovery of the ancient bright pink, however, can change this narrative.

But the research project wasn't just about colours.

"[It provided] the burst of energy needed for the evolution of complex ecosystems, where large animals, including humans, could thrive on Earth", he said.

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. Brocks believes oceans dominated by cyanobacteria may be the culprit.

The team of researchers from Australia, Japan and the U.S. also were able to use the pigments to confirm that ancient marine ecosystems were dominated by tiny cyanobacteria, a type of bacteria that obtains energy through photosynthesis. In comparison, the microscopic algae are a thousand times larger in volume than the cyanobacteria.

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