3.4 billion years ago. Certain to send fundies scrambling for their fucking bibles.
http://www.nytimes.com/2011/08/22/scienc...TE&ei=5043
http://www.nytimes.com/2011/08/22/scienc...TE&ei=5043
Quote:A team of Australian and British geologists have discovered fossilized, single-cell organisms that are 3.4 billion years old and that the scientists say are the oldest known fossils on earth.
Their assertion, if sustained, confirms the view that life evolved on earth surprisingly soon after the Late Heavy Bombardment, a reign of destruction in which waves of asteroids slammed into the primitive planet, heating the surface to molten rock and boiling the oceans into an incandescent mist. The bombardment, which ended around 3.85 billion years ago, would have sterilized the earth’s surface of any incipient life.