Jack July

3.5 billion-year-old stromatolites composed of fossilized cyanobacteria in Glacier National Park.

From the wikipedia page on abiogenesis, the arisal of life on earth from inanimate matter.  At 4.5 billion years old, the Earth plenty of time to think things over before the animalcule party arrived.

It has been shown that simulating the conditions of the early earth allows for the spontaneous synthesis of certain molecules necessary for life, though such spontaneous generation has not been demonstrated for other molecules (or for other planets). To prove the feasibility of biological self-assembly from non-biological precursors, several groups aim to synthesize entire proto-cells, hypothetical precursors to self-replicating bacteria, for example.  Some of the problems encountered involve the generation of lipids for membranes, the self-nucleation of enclosed vesicles to delineate a distinct internal chemical environment, and the passage of nucleic acids through membranes and into the protocellular space, where they can act as information storage molecules, or, as in the case of ribozymes, can catalyze chemical reactions.  Harvard’s Jack Szostak, who won the Nobel Prize today for unrelated work, leads this field and has some excellent simulations of nucleic acid passage and lipid growth here.