Clues to origins of life

Life may have started in undersea vents

By BBC News Online's Matt McGrath

Scientists claim to have recreated one of the vital steps in the origin of life on Earth.

Their experiments show that a chemical vital to all living creatures can be synthesised from organic and metallic compounds.

Researchers at the Carnegie Institution in Washington DC "cooked" iron sulphide at very high temperatures and pressures.

Pyruvic acid was formed - a key chemical which living organisms use to extract energy from food.

The scientists believe that their experiments create similar conditions to those in hydrothermal vents, a type of geyser found on the ocean floor.

Temperatures in vents can reach 500 C

These underwater "chimneys" spew out a cocktail of basic chemicals at scorching temperatures and under very high pressures.

Many scientists now believe that the most important ingredients in the formation of all life on Earth are found around these vents.

The new research, published in the journal Science, strengthens this view.

The team, led by Dr George Cody, placed samples of iron sulphide inside 24-carat gold capsules.

These tubes were then placed inside what the researchers call "the bomb", a device encased in protective steel plates salvaged from a scrapped battleship.

Hot and Heavy

After subjecting the capsules to temperatures of 250 C and pressures up to 2,000 times greater than the atmosphere, the researchers found pyruvic acid had formed.

The experiments suggest that this process also occurs in a natural setting on the ocean floor.

In hydrothermal vents, where oxygen-poor fluids percolate through a crust containing iron sulphide, "significant concentrations" of pyruvic acid would occur.

Dr Cody believes that the creation of this acid was a critical step in the development of life.

Nasa are taking an interest in this type of research. They believe that it gives them more accurate information on where in the Universe the right conditions exist to create life.

Commenting on the work, Dr Gunter Wachtershauser, a leading researcher in this field, told BBC News Online that the new research was another piece of the jigsaw.

"It means you don't need an ocean to create life," he said.

"All you need is a little water vapour and a lot of volcanic activity."