I recall hearing of an interesting theory about "the greys" aliens possibly being human beings coming back in time, studying their ancient ancestors (us) from the past. I believe that there is lifeforms in the universe besides what's on Earth, and I do believe that time travel could be realized in the future... but I'm not really sold on the alien theory. I can make some connections, though, from an evolutionary stand point. Long lanky fingers from centuries of electronics use. Big, dark eyes and pale skin from centuries of being indoors, away from the sun... or even a lack of sun perhaps due to nuclear winter. Hell, an inevitable nuclear war could alter our DNA enough to change appearances in just a few short generations. Interesting stuff to think about.