and by the way, what if we were planted by others? IMHO, it's just as good a theory as evolutionism and creationism (by the goddess, i don't like 'isms'). just as logical and unprovable.
Hmm... I would not lump creationism, evolution, etc., together like that. Evolution is clear based on fossil records, DNA, and other evidence. Creation has no evidence whatsoever. But aliens planting life on earth? Sure, that's certainly possible. But it would have had to happen a VERY long time ago, and it doesn't negate the fact that evolution has caused all of the species we now see on the planet.
So far there's no evidence to support that conclusion, so it would be safer/better NOT to believe in it (until such evidence is found).