Every so often we like to check in with news about the color pink. There’s the recent Janelle Monáe single and the fact that “pink” used to mean a yellow color, but we’ve found out something particularly cool about pink. It turns out that the first color of life on Earth was pink.
Dr. Nur Gueneli of the Australian National University made the surprising discovery. She had pulverized some ancient rocks to see if there happened to be remains of any organisms that had been fossilized. She mixed the rock with a solvent and expected the material would turn gray or black. Instead it turned bright pink.
It turns out the rocks contained fossils of cyanobacteria. Cyanobacteria is often called “blue-green algae” even though it’s not a true algae. As you might guess from its name, cyanobacteria is a bacteria — and the only type of bacteria to photosynthesize. In fact, it was the chlorophyll the cyanobacteria needs to photosynthesize that provided the pink pigment.
The pigment is the oldest ever discovered — dating back 1.1 billion years. (And yes, that’s billion with a B.) The oldest organic pigment that had been previously discovered was only about 500 million years old. Associate professor Jochen Brocks compared the discovery to hypothetically finding a bit of fossilized dinosaur skin that still had its original color.
Amazingly, the discovery of the first color of life on Earth could also answer another mystery. Scientists have long wondered why complex life didn’t appear until 650 million years ago. Previous theories were that there wasn’t enough oxygen on the early Earth to support life. But recently, it’s been discovered that there, in fact, was enough oxygen. So what gives?
It turns out that the cyanobacteria could have been too plentiful and blocked other organisms from evolving. Brocks explained, “Algae, although still microscopic, are 1000 times larger in volume than cyanobacteria, and are a much richer food source. 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.”
Are you surprised that the first color of life on Earth was pink?
Featured photo by Lannon Harley/Australian National University