[zeebeecee]

Well so far we do not know, so again this is just speculation. Your guess might be as good as mine. There does not seem to be any serious scientific results in this direction, other than nonsense like the Drake equation.

I think the variety among the possibilities for other intelligent species (if any) would far outweigh the number of them. Hence it might be probable that there would exist two similar ones, but it would be very improbable that any of them would be similar to humans.

The point about "communicating" with a piece of rock was exactly that we cannot communicate them. Even if we would run into an alien species (which seems unlikely), it seems very improbable that any meaningful communication could happen.