1.43 billion year old microbe fossil supports deep-sea origin of life

Geologists have discovered 1.43 billion-year-old fossils of deep-sea microbes, providing more evidence that life may have originated on the bottom of the ocean.

Washington, Aug 4 : Geologists have discovered 1.43 billion-year-old fossils of deep-sea microbes, providing more evidence that life may have originated on the bottom of the ocean.

The ancient black smoker chimneys, unearthed in a Chinese mine, are one billion years older than similar fossils previously identified. They are also nearly identical to the archaea- and bacteria-harbouring structures found today on seabeds.

Black smoker chimneys develop at submerged openings in the Earth's crust that spew out mineral-rich water as hot as 752 degrees Fahrenheit (400 degrees Celsius). Bacteria that don't depend on sunlight or oxygen move into the fragile chimneys that grow around the vents and feed on the dissolved minerals. The stony chimneys can grow more than 50 feet (15 meters) tall, but retrieving even a modern chimney sample is extremely difficult, as they're fragile and can crumble when touched.

"These are remnants of the oldest living types of life forms on the planet. Some people like to call it life in extreme environments. These bacteria pretty much live on a different planet compared to conditions we live in," said Timothy Kusky, a geologist at Saint Louis University and co-author of the new study describing the fossils.

Kusky said the fossils offer "tantalizing suggestions" that life developed near deep-sea hydrothermal vents and not in shallow seas, as other evidence have suggested.

The age and size of the chimneys will help scientists understand how ancient hydrothermal vent growth and the development of life on the sea floor might be interconnected, he said.

"This discovery offers scientists valuable on-land samples for geological and geo-biological research," Livescience quoted him as saying.

The findings appear in the current issue of the journal Gondwana Research.

ANI