"Graham Cairns-Smith, a chemist at the University of Glasgow in Scotland, has speculated for many years that life on our planet may not have started with organic (carbon-based) molecules. He suggests life may have begun with inorganic ingredients, such as clay minerals that can carry heritable information in the stacking sequence of their sheets of atoms. Such 'clay organisms' might be able to replicate, Cairns-Smith argues."

For the serious science geek find out more about "Spontaneous Formation of Cellular Chemical System that Sustains Itself far from Thermodynamic Equilibrium" here (pdf).