On Aliens

So Aliens are basically humans from the future who have travelled back to time to warn humanity of something.

If you look at the widely popular imagery associated with aliens - the big head to body proportion difference, the big eyes, can be simply attributed to human evolution. For example, it is a scientifically proven fact that the size of the human skull is increasing and will continue to do so. Because there is such less activity that we do with our bodies, there will come a time when humans will figure the most optimised body type - small, runs on less energy.
Scientists also predict that the humans of future will all be pale wheatish in colour with big round eyes. This is because there will come a day when all races of the earth would've finally mingled completely!
Another few hundred thousand years and the earth is dying as pollution, nuclear waste completely blocks the sun out. Its darkness everywhere. Consequently, the eyes become 'black' with the pupils dilated fully to soak in more light and the skin becomes leathery thick to withstand the harsh temperature fluctuations.
So yes, those 'aliens' who crashed at Roswell and have been sighted all over the world, are just us from the future!!
Now that's a theory.