What were the first cellular lifeforms on earth? Well according to one biogeologist at a recent Director’s Colloqium at ARC, they were underground dwelling bacteria that obtained their energy from redox reactions involving compounds that were (and some still are) abundant such as iron and hydrogen sulfide.

Why is this important? Well, relatively recent surveys of the surface of Mars have revealed many chemical compounds that the proposed bacteria would have used on earth a long time ago. Such bacteria would not necessarily require the water which is seemingly missing from the Martian surface. We should expect to find out any decade now when they drill the proposed 10km into the Martian crust in search of life and water.

Editor’s Note: Feel free to ask questions in comment box.