Quote Originally Posted by Az.
i heard the other day that life on earth may have come from another planet, for example bits of mars fall on earth quite often so if one of these rocks had some sort of life on it then it may breed and evolve....

so i was thinking maybe we started off on another planet burnt it out and with no other hope of survival packed a rock with dna or whatever and shot it into space in the desperate hope that it would land on another planet and go from there....
Well, there's no ruins of a previous civilization on mars, and they would have just sent actually colonists rather than DNA if they had to evacuate. unless you meant any planet, not just mars.