Evolution in the VERY beginning

Explaining abiogenesis is not strictly an evolution question.The two most common hypotheses appear to be:

• Spontaneous generation. The chemical reactions in the early earth happened to created suitable organic material. Whether the first proto life would have required DNA or RNA is not certain. Perhaps it just started with a mix of proteins.
• Panspermia. The earth was seeded from organic material that happens to be floating around in outer space.

There really isn't much evidence to go on. If space explorations reveal other earth-like planets (in other star systems), then whether there is life on those planets might give us information on how life started here.

That's a misunderstanding of why panspermia is proposed by some people.One possibility for abiogenesis is that a chemical reaction spontaneously generated the first primitive life form. Such a chemical reaction is highly improbable, as I am sure you agree. But you have to multiply the tiny probability by the number of trials (possible circumstances where the reaction could have occurred). If the result of this multiplication is near 1 (or higher), then it is very likely that it happened at some time.What the panspermia thesis would allow, is that we can consider not just the number of trials on earth, but the number of trials on all planets in the cosmos, and over a longer period of time than the earth has existed. It changes the computation of the probability.In the extreme case, assume that the universe has existed for ever. Then it could be that life has existed for ever, and is spread from old dying planets to new young ones, as in panspermia. In that case we never have to explain how life started, because life always was. It's my impression that panspermia theories were first proposed at a time when a steady state cosmology was being seriously considered.

RAZD - Building Blocks of Life