Evolution before life

I was reading today that life on earth was probably an inevitable consequence of an abundance of organic chemicals, forming either around geothermal vents deep in the ocean, or in shallow pools at the ocean's edge. Either way, it's an interesting prospect. It seems that these chemicals were subject to evolutionary pressure before the first self replicating molecules even came into existence. That the most unstable molecules in this soup were selected against, in favour of the more stable, such as citric acid. This in turn paved the way for other molecules to use the stable molecules as foundations on which to attach themselves, until complex, self replicating molecules such as RNA became possible.

Evidence for this hypothesis is not hard to find. It forms the metabolic backbone of every living cell in existence. Fossils in our very own bodies. Cool, huh?