Hmm...flowing liquid, lakes, hydrocarbons.....wouldn't is be cool to find some little bugs swimming around? [video=youtube;msiLWxDayuA]https://www.youtube.com/watch?v=msiLWxDayuA[/video]
From my novice perspective the answer to your question above is it's just a matter of time. Although it is possible, it's unlikely Earth is an anomaly out of zillions of opportunities in the Universe for life to exist. If it can happen on Earth why not throughout the Universe? After all, everything in the Universe came from the same singularity...so why not 'bugs' everywhere? Sure things were a little violent after the BB, but once the dust settles and the environment became more habitable, and this includes habitats many of us cannot fathom, and allowing for a few billion years of evolution, I'm thinking bugs everywhere...