Maybe humans didn't evolve from a different Living creature.... I was thinking the other night that maybe Aliens are the one who lived in this earth LONG LONG time ago. They had advance technology and went to another planet to live because of maybe they know a natural cause, supernova, or iceage and etc. going to hit earth. They camed back later and maybe mate with amphibians or other humanoid creatures and we were born...... JUST a guess, please comment me about my theory.