http://www.telegraph.co.u...2008/01/31/scilost131.xml
By Roger Highfield, Science Editor
Last Updated: 7:01pm GMT 31/01/2008

A lost city at the bottom of the ocean contains chemical traces that suggests it could have been the cradle of life on Earth.




The towering structures of the Lost City are nearly pure carbonate, the same material as limestone in caves
Some believe the right ingredients for life made their way from outer space. Darwin thought it emerged in a "warm little pond" and others have looked for answers on the sea floor.

Now evidence to back the latter submarine idea has emerged from the "Lost City" which lies at a depth of 2,600 feet, where creamy white to grey spires, pinnacles and 18 storey chimneys teem with microscopic marine life, as a volcanic system on the Atlantic sea floor that gradually pushes America and Britain apart.

The temperature and composition of fluids from a group of underwater hot springs there that are heated by the slow cooling of the underlying rocks, called a hydrothermal vent field, are similar to those predicted to have occurred during the early years of life on Earth.

Today, a team reports that hydrocarbons - the stuff of oil and gas and molecules critical to life - are routinely being generated by the simple chemical interaction of seawater with the rocks under the Lost City in the mid-Atlantic.

Being able to produce building blocks of life makes these sites, which are found in the world's oceans, even stronger contenders as places where life might have originated on Earth, according to Dr Giora Proskurowski and Prof Deborah Kelley, two authors of a paper in the journal Science.

Hydrocarbons, molecules with various combinations of hydrogen and carbon atoms, are key to cellular life. For instance, cell walls can be built from simple hydrocarbon chains and amino acids are short hydrocarbon chains hooked up with nitrogen, oxygen or sulphur atoms.

"The generation of hydrocarbons was the very first step, otherwise Earth would have remained lifeless," says Dr Proskurowski.
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An analysis has ruled out a living origin for the hydrocarbons, which are the stuff of oil and gas reserves which, in turn, formed from the remains of prehistoric marine plants and animals that sank to the sea bed. But in the case of the Lost City, the ultimate source of the hydrocarbons is non living.

"The detection of these organic building blocks from a non-biological source is possible evidence in our quest to understand the origin of life on this planet and other solar bodies," Proskurowski says.

Could this mean the world's reserves of oil and gas have been underestimated, chiming with an idea popularised by the scientist Thomas Gold that non living geological processes can make petroleum? "I'd speculate that petroleum accumulation at Lost City-type deep sea system is unlikely," says Proskurowski.

The Lost City hydrothermal vent field is about 2,300 miles east of Florida, on the Mid-Atlantic Ridge. Microorganisms there thrive in alkaline vent fluids, some nearly as caustic as liquid drain cleaner. This contrasts to the previously studied black-smoker vents where organisms have adjusted to acidic water.

Lost City microbes dine on methane and hydrogen instead of the carbon dioxide that is the key energy source for life at black-smoker vents.

The towering structures of the Lost City are nearly pure carbonate, the same material as limestone in caves. The structures drape the cliffs at Lost City and range from the size of tiny toadstools to the 18-story column, named Poseidon, that dwarfs most known black smoker vents by at least 100 feet.

The field was named Lost City in part because it is on top of a submerged mountain named Atlantis and was discovered by chance during an expedition on board the research vessel Atlantis.

The Atlantic Ocean is not old enough to mark the start of life on Earth.

Who told you the Atlantic Ocean was present in the start of life on Earth..??
:headscrat

No one, I just remember hearing that the Atlantic is some 200 million years old, but that is less than half as old as life on Earth.

sm.....life on earth is supposedly close to 3.5 billion years old.....and mega fauna (larger multi-celled life)...is close to 700 million years old.....so life is far older than the Atlantic which is still getting wider.

There is similar hydrothermal vents near the Galapagos Islands as well in a near by rift zone similar to the ones off of Florida. The Galapagos Rift was discovered in the late 1970s and life forms there do not used photosynthises but a process called chemosynthises.....its a fascinating topic.