Re: Tidal forces required in early evolution
One of the steps in evolution most overlooked is that the eukaryotic cell is actually most likely a symbiont of several separate "ancestor-organisms", of which one, the mitochondrium, even still has its' own DNA and reproduces separately within the cell.
Something along the lines of that mechanism still exists today,where ( very anaerobic) methanobacteria survive in an oxygen environment by living in the creases of the cell walls of E.Coli bacteria, occasionally temporarily being incorporated as "organelles" within the host body itself. ( and giving rise to the rather rare, but fun, "lightable fart". Ain't biology fun.. ;) )
As far as I can remember the biggest influence the moon has on the earth with regards to the "sustainability of life" is that it stabilises the earth's spin with regards to the ecliptic plane, creating an environment that is more stable than it would be without. Then again, we don't see Mars, or any other planet flipping its axis of rotation all around, so ymmv there.
Never been too fond of the tides-enabling-life/driving evolution theory, given that the moon at the crucial time was a lot closer to the earth, and the tides it created were a bit more frequent and.. prominent.. than the gentle stuff the moon gives us nowadays.