Superbugs from Hell - Evolution Re-Visited

For centuries, people thought life was created in the Garden of Eden by God. Then along came Charles Darwin with his theory of evolution, and spoilt that cosy image. Darwin gave a convincing account of how all life on Earth has gradually evolved from simple microbes. However, he left open the question of how life got started in the first place. Now scientists are sure they are close to solving that mystery too, and the answer looks set to inflame passions once again.

Chemists have long tried to make life in a test tube, by simulating the conditions of the primeval Earth. Envisaging an ancient pond laced with minerals and bathed in solar radiation, researchers pinned their hopes on finding a chain of reactions that would transform a lifeless chemical soup into a primitive organism.

Chicago chemist Stanley Miller blazed the trail in the early 1950s by zapping a noxious brew of gas and water with electricity. Others have tried different formulae. Unfortunately, after fifty years of experimentation, the results are disappointing. Some of the simpler building blocks of life, like amino acids, are readily made, but the building itself - a living cell - remains as elusive as ever.

Deep-sea Life

Now a radical new theory could explain the lack of progress. Scientists increasingly suspect that the tepid pool scenario is wrong, and that life didn't start on the Earth's surface at all. This change of mind stems from the startling discovery of bizarre micro-organisms, dubbed superbugs or extremophiles, that inhabit some of our planet's most extreme environments.

Credit - Hencoup Enterprises.American chemist Stanley Miller surveys the contents of a flask where primitive gases have been zapped by an electric spark. For many years, scientists assumed this was how life started on Earth: now, many have doubts.

In the late 1970s, a research submarine called Alvin was sent to the bottom of the Pacific Ocean to explore a string of volcanic vents known as 'black smokers'. These chimneys on the sea floor spew forth superheated water rich in dusky chemicals. The investigators were astonished to find many exotic life forms clustered around the searing effluent in pitch darkness, including weird-looking crabs and giant tube worms.

Most remarkable of all were bacteria that inhabited the hot zone itself, thriving in the disgorging fluids at temperatures in excess of 100^oC. Previously, nobody believed that any life could survive above the normal boiling point of water. These superbugs lie at the base of the food chain. They are primary producers, turning inorganic material from the hot vents directly into biomass, without the need for sunlight.

Subterranean Bugs