Perhaps I used the wrong term, but everything that has happened or will ever happen in the universe is completely natural. This includes things like serial killers. It is survival of the fittest however, if you read my last post (the one I edited) it should make more sense.
I can see where you're coming from, and I hope I didn't come off as attacking your statement. I just get really excited.... (sorry)
Either way (although I know this shouldn't be a morality debate) I just want to clarify that in some ways it won't be survival of the fittest. Not to take a movie too seriously, but let's take District 9 (the film) as an example. The aliens who cohabited in South Africa were intellectually, anatomically, and technologically much more advanced than humans. If we are applying survival of the fittest, then in that movie, the whole planet would've been wrought in destruction due to THEIR hand. It all depends on intent. A much superior civilization will lose if ti chooses not to fight back, and I think, in essence, this is the problem with society thinking they can use Darwinism as an excuse to expand and conquer. Since i am very into morality and epistemology, I try to veer off of any decision which may plant the very seeds of our own destruction, and messing with other life forms for purely selfish reasons could be the catalyst for such an event (such as our severe exploitation of the earth...)
On the other hand, I can see the whole "put your own family rather than the neighbors'" bomb shelter anology. Although to paint a better picture, it would be "steal the neighbor's bomb shelter and put your family in it" if we are discussing the debate still (and not human instinct).
If we can find a planet that can sustain millions of lives that is empty of life EXCEPT for water and vegetation, then let's go! But of course this is an impossible scenario. Where there is water, there are bound to be anything from microbes to sophisticated life forms that we are displacing. Personally, if the world ends and we did not expand through space, I say it is the end of our race. Some species are meant to be instinct one day as in the cycle of life and death. (now THAT is the works of natural selection/true survival of the fittest)
/edit
Preserving humanity is great, but not if you end up losing your humanity in the process.
Incidentally, paraphrasing commander Shepard is my hobby.
i think you're beginning to sound a bit like nietzche