[JurijD]

Back to the original debate:

Simple life:
I still think that life in one form or another will be very common in our galaxy. By this I mean some form of lower single-celled life. Bacteria, protozoa etc. etc. (if cells will even be the building blocks of life on other worlds... who know !) I base this on the discoveries we made in the Last few decades. Life has turned out to exist in the most unusual places... at the bottom of the sees, in vulcanos, 10km unde ground etc. etc. where the temperature, pressure and other conditional extremes challange our usual perception of a life friendly environment. I wouldn´t be at all surprised if we found bacteria living under ground on Mars and perhaps even Venus... the moons of Jupiter, Saturn and perhaps even further out.

Complex life: The evolution of multicelular organisms requires a certain environmental stability that earth provided. But obviously the more complex life gets the more rare it will be because the more complexity an organism has the greater are its envirnomental requirements. So I´m pretty sceptical that we will find complex multicelular organisms in our solar system... perhaps on Mars, Titan or Europa... but I doubt it.

Intelliget life: Lets put the early hominids as a base line. Anything more evolved is intelligent anything less is not. By this cretaria if we found some form of aliend dolphin it would not be an intelligent life form.... Noone can really answer this question, as I pointed out erlier. I wouldn´t be surprised if our galaxy had 1.000.0000 intelligent species in it and neither if we were the only one. This is because I cannot make a realistic approximation of the number for myself... its just not possible, the Drake and the Rare Earth equations are a bunch of §%!%"§ ... they can give whatever results you want, depends how optimistic you are so they are virtually useless.

Conclusion:
I think theis question will only be answered when we have explored our entire galaxy... or have enocountered an alien race that will share its knowledge with us. since both events are very unlikely I think this post could hang around for a very long time...