Just on the if evolution was true the universe would be full of life point, there are many scenarios where life exists and we would have ZERO chance of ever knowing about it.
1) Life may exist elsewhere but not be intelligent. The planets around other stars may be full of trees and flowers and even bunny rabbits but there is no way of us knowing.
2) Life may exist elsewhere, be intelligent but unable to broadcast detectable signs. There may be small, blue, furry creatures on Alpha Centauri, but if they don't use radios (or point giant lasers at us or something) then there is no way of us knowing they're there.
3) Life may exist elsewhere, be intelligent, be broadcasting signals like crazy but:
3a) Be too far away for their signals to have reached us in the short time we've been listening.
3b) The signals from another civilisation may have washed over planet Earth 1,000 (or 10,000 or 100,000) years ago but then stopped due to them wiping themselves out.
3c) Life may exist elsewhere, be intelligent, be broadcasting within range right at this moment but in a way that we can't detect or interpret as a signal.
4) Life may exist elsewhere but be so different from life on earth that we wouldn't recognise it as life. Maybe deep space is teeming with life that forever avoids the death dealing heat of star systems.
And so on and on.
I'm afraid that although that illustration was pleasingly non-borgian it is still as flimsy as a tramps pants.
