The world is our home?

I often wonder how different we humans are, in comparison to other creatures on earth. Physically, the nearest relative species we can find are the apes. Psychologically, we surpass every other known creature by leaps and bounds. Socially, we are a world apart.

Recently, one of my co-author posted a scientific report suggesting that aliens may be present amidst us disguising as one like us, and are probably studying our planet to rule, or even destroy us.

I was so amazed by this report that i got into a discussion with her on it, and i recalled another such report which suggested that human life may have originated in outer space and reached earth via a meteorite crash. I asked, "If this later report is to be believed, why can't it be that we are the aliens the former report is suggesting?

Though, it took a lighter note from there, all concurred that we may be the actual aliens and to our own credit, we came in peace!

I, now wonder, if by chance it is true and we are the aliens (and why not! We are different as i pointed out earlier, and we are super-interested in outer space and life on other planets unlike other creatures!)
So, if it is so, which is our home planet?
Where is it?
Is it still out there? Or destroyed like Spock's?

But questions of higher importance and impact are,
As inhabitants it is our duty to protect and nourish it, but is it right now to pollute, destroy and flounder it?
How acceptable is it now to treat the other creatures (probable native or real inhabitants of earth) which such cruelty and recklessness?
How justified is it now to fight, kill and crush each other for pieces of land and earthly possessions, which isn't even ours to say?

And, even if the otherwise is the actual truth, are not my questions still relevant? And at the least, worth a serious thought?