[LeeE (OP)]

Our Moon has clearly been a factor in the evolution of life on Earth, with many species possesing physiological cycles synchronised to the luner cycle, but it seems to me that it may have had an even greater influence in the development of life upon Earth due to the great tidal range it can cause in large bodies of water.  Because the tides can expose and then re-cover large areas of land on such a frequent and regular basis I can't help thinking that this must have been an enormous factor in the emergence of life from the oceans on to the land.

Now it's generally considered that our Moon is probably very atypical in terms of it's size when compared with the body it orbits (the Earth) and so, if this is the case, could the rate of evolution, especially with regard to the emergence of life on land, be a lot higher on Earth than is likely to be the case on other life supporting planets in the universe?

If so, how would this alter our estimates of intelligent life elsewhere in the universe?

[another_someone]

The existence of the large moon, not only in terms of tidal flows, but also in terms of the effects it had on the crust of the Earth that allowed the moon to be formed, clearly must have had an enormous consequence upon the development of life on this planet.

The trouble with judging how this must effect the probability of life (intelligent or otherwise) on other planets is that until we find such life, we cannot really judge what range of conditions are conducive to life (nor even do we have a good unambiguous definition of what life is, let alone what intelligent life is).

At present, we are in the situation of a man sitting in a car at a red traffic light.  He can see the red traffic light, so he knows that traffic lights can be red, but until he sees the colours of the traffic light change, he cannot say what other colours the traffic light might be.  We know that life can exist on Earth, and we know the environment on Earth is somewhat exceptional (we don't know exactly how exceptional, but exceptional it is), but we cannot say under what other situations life can also exist.

At very least, we should have a clear and unambiguous definition of what intelligent life is, which we lack.