Bizarre bacteria that can survive in boiling water and dine on minerals containing copper, gold and zinc could provide clues to our ancestry.

Some of these remarkable life forms - called 'extremophiles' - were recently collected by CSIRO scientists in an eerie landscape of smoking undersea chimneys, north of Papua New Guinea.

There is mounting evidence that the first life on earth was similar to these bacteria," says Dr Joanna Parr, from CSIRO's Division of Exploration and Mining, whose team is studying the chimneys formed by volcanic activity below the seafloor, and the life forms associated with them.

When life first arose, conditions are believed to be similar to what we see now around these deep sea volcanoes - high temperatures, intense pressures, darkness and no free oxygen.

Scientists are keen to study these bacteria because they are the basis of a food chain that does not use photosynthesis," says Dr Parr. "Instead they 'chemosynthesise', producing energy from hydrogen sulphide."

"The hydrogen sulphide is bound up with sulphides of iron, copper, silver, gold and zinc and is deposited by hot fluids as they emerge on to the seafloor forming chimney-like structures up to two kilometres below the sea.

The bacteria are also being investigated for possible industrial applications. The idea is that if the bacteria are capable of separating metals from the sulphide minerals they're normally found in, then they could be used in ore processing.

"First of all, though, we need to find out if we can take them out of their home environment and use them on land. The microbiologists at Land and Water are working on this and they're pretty optimistic."

Dr Parr is among a number of scientists speaking at a Public Symposium next week looking at the nature and evolution of life, and whether there is life outside the Earth.