Bizarre creatures found in mine living off fool’s gold could unpick how life began

'What we are finding is so exciting — like ‘being a kid again’ level exciting.'

Sulfur-breathing creatures that feed on fool’s gold in caves have been found thousands of feet below the earth’s surface - a discovery which scientists say has the potential to unlock the secrets of how life began on earth and how it might survive on other planets.

Undisturbed for as long as 2 billion years, the Kidd Mine in Canada is the deepest area ever explored on land by humans and home to the oldest known reservoir of water on the planet .

Life has continued to thrive in the cave and others like it despite being sealed off from the world in a state of never-ending darkness.

Now a research team from the University of Toronto overseen by acclaimed geologist Barbara Sherwood Lollar, have found single cell organisms had managed to survive in the waters of the Kidd Mine by feeding from the chemicals produced by interaction between the reservoir and the surrounding rocks.

In particular, Pyrite, known as fool’s gold, was found to be sustaining the life forms – which have evolved to not require oxygen or sunlight.

“It’s a fascinating system where the organisms are literally eating fool’s gold to survive,”Dr Sherwood Lollar told NBC News. “What we are finding is so exciting — like ‘being a kid again’ level exciting.”

The discovery helps to unpick the puzzle of how deep water organisms can survive as scientists look to hidden sealed caves and other areas to unpick the earth’s deep biosphere – dubbed the “underground galapagos”.

A 2018 report from the Deep Carbon Observatory estimated that the number of cells living deep below the earth’s surface stands at five-hundred-thousand-trillion-trillion.

They weigh 300 times more than every human on the planet combined.

And with low levels of energy available to the organisms, many of their metabolisms have slowed dramatically, leaving microbes to potentially survive for thousands of years without changing, offering a window into an ancient biological world.

Dr Sherwood Lollar’s team are now looking to sequence the genes of the organisms, which they will then compare to others deep underground to see if they share a family tree, and how different they are from one another – a study that could help science unlock the secret of where, and how, life began on Earth.

Commenting on Charles Darwin’s theory that life on earth developed in a “warm little pond”, she added: “There’s absolutely no reason why it could not have been a warm little rock fracture”.

Studies into the creatures could also help scientists understand how alien life could survive on other planets where oxygen is not readily available.

However, Dr Sherwood Lollar emphasised there was still plenty to discover about the earth before considering the rest of the solar system.

She added: “There are fundamental principles on which the planet operates that we’re still just beginning to figure out. There are still amazing discoveries to be made.”