Carl Sagan once did a rough statistical estimate of the chances
of life elsewhere.
In the equation, worst case estimates were plugged in to
all the variables.
Even when it was all calculated with these downgraded numbers,
the experiment pointed towards the universe containing life somewhere
in significant numbers.
Now my view is that if we took that as our starting position
and then looked back on ourselves we get this:
Life here, science tells us is the result of evolution of several hundred
million years.
Edit:
Evolution also tells us that we consider ourselves superior to every other
species below us, and we take it upon ourselves to choose which
inferior species survive or not...basically on a whim.
Several hundred million years is just a blink of an eye in the age
of the universe.
Then finally, if that's how we view our species below us, imagine how
another civilisation superior to ours would probably view us?
And also remember that since the invention of radio transmission
and subsequent television and everything else we broadcast, that
the bubble of these transmissions is something like 75 or 100 light
years big now....
I'd be worried
Steve