The evolution of the human race is my evidence. See my above post. To summarize... if we can go from cavemen to technologically advanced ( relatively speaking ) in 10000 years, which is an absurdly small amount of time, universally... Then what of the possibilities of life that was advanced over a million years ago. We know it must be out there, somewhere, right? There is no way Im going to believe the whole god damn universe is evolving in tandem with the human race, technology wise. No way. If it is, then I challenge science to explain that?!
Neither agreeing with you nor disagreeing with you here, just throwing something out there.
How do we know that other civilisations that exist/could have existed are not as destructive as us humans. War is human nature, so why not the nature of any other advanced civilisation?
For all we know, every civilisation that has ever existed could have waged war on each other, like we humans do, and wiped themselves out? After all, we're not too far from that outcome. One crazy leader pressing the big red button and the shit could hit the fan and before you know it, hundreds of red buttons are being pressed and the planet is turned into an inhospitable wreck of nuclear fallout.
Not to mention that as technology advances, so does the deadliness of armoury.
You see what i'm getting at?