THE ERUPTION OF LIFE ON EARTH 1.9 BILLION YEARS AGO
viz. the consequence of a chance meeting from which evolved complex life on Earth, changing the course of life forever.
About 1.9 billion years ago an encounter between an amoeba-like organism and a bacterium led to complex life on Earth. New research finds that this amoeba-like organism engulfed a bacterium that had developed the power to use sunlight to break down water to make oxygen. The bacterium may have been an intended prey, but instead it became incorporated into its attacker's body, transforming it into the ancestor of every tree, flowering plant and seaweed on Earth today.
Paul Falkowski, professor of biochemistry and biophysics at Rutgers University in New Jersey reports that this singular event redirected the evolution of life on Earth. “The descendants of that tiny organism transformed our atmosphere, filling it with the oxygen needed for animals and, eventually humans to evolve.”
Although it had already been deduced that such organisms existed on Earth, the nature of the event has only recently become clear from studies of chloroplasts which absorb sunlight and use its energy to generate nutrients and oxygen.
“It is an astonishing thought that a single random encounter between two tiny cells so long ago could have had such a huge consequence,” said Paul Falkowski.
Nick Lane, a researcher at University College London and author of Oxygen: The Molecule that Made the World, said this information had been emerging. He said, “Oxygen energises all life, and makes it big. Nothing else can provide the energy needed to fuel the demands of multi-cellular organisms. True photosynthesis evolved only once, and the chance encounter that gave rise to plants also happened just once. These were two freak accidents in the 3.5 billion-year history of life on Earth.”
This brief report is from the London Daily Mail of 9 November 2008. A more detailed report from the Sunday Times follows.