A Prometheus Theory of Evolution.

[Ballzanya]

Spoiler

The initial scene makes it seem as if they initiate some sort of DNA chain reaction to allow life to flourish, in general. But the film makes it clear they have some sort of exact match to human genes (which doesn't make too much sense, either, because... Look at them).

[close]

I can't quite remember exactly, i need to see the scene again (can't find it on you tube). But I seem to recall the opening scene of the film panning over green hills. If how I remeber it is true then life already existed on the planet, atleast in a vegtative state. Either way I am of the opinion that the engineers didn't introduce all life to the planet. Just the evolutinary cycle that would either, eventually lead to humans or eventually lead to all vertebrates and/or mammals in general.

The problem with this is that the evolution of more complex mammals like ourselves was totally contingent on the dinosaurs being wiped out by an asteroid impact. You kind of can't just rewind evolution on earth and get the same results. We weren't inevitable, nor could an intelligent source control exactly how things would evolve, if all that source did was set the initial seeds of life lose on the planet.

[Nero the Jackal]

They only created humans, not all life so dinosaurs getting wiped out and everything before man could still have happened, remember that the film purposefully makes us question this and characters in the film are equally bewildered.

[Aceburster]

  New theory...

  The Engineers used Earth as a testing ground for creating and building forms of bio weapons and other genetic experiments. Once they were done experimenting they flooded the planet to sanitze it because its rude to leave your crap lying around all over the universe once you are done playing with it.

  The head Engineer overseeing the experiments on Earth felt so strongly about his work that he stayed behind and sacrificed himself as the waters receeded to give Earth a fair chance. The other Engineers had no idea that he had also sabotaged their urns of genetic material to kill them all so that they couldnt come back and ruin Earth. He left a painting on a cave wall so that man would eventually find the answers about his beginnings not realizing that another Engineer might survive.

  The Last Engineer wakes up and realizes all his bros are dead, his urns have been tampered with and there are Space Monkeys in his ship that he could have sworn were wiped out on Earth.

  He rampages and the Space Monkeys run screaming covered in space goo and not understanding that they were never meant to live.

[Nero the Jackal]

Heh that is actually not a bad theory and it is kind of fitting.

[GreatKnower]

  New theory...

  The Engineers used Earth as a testing ground for creating and building forms of bio weapons and other genetic experiments. Once they were done experimenting they flooded the planet to sanitze it because its rude to leave your crap lying around all over the universe once you are done playing with it.

  The head Engineer overseeing the experiments on Earth felt so strongly about his work that he stayed behind and sacrificed himself as the waters receeded to give Earth a fair chance. The other Engineers had no idea that he had also sabotaged their urns of genetic material to kill them all so that they couldnt come back and ruin Earth. He left a painting on a cave wall so that man would eventually find the answers about his beginnings not realizing that another Engineer might survive.

  The Last Engineer wakes up and realizes all his bros are dead, his urns have been tampered with and there are Space Monkeys in his ship that he could have sworn were wiped out on Earth.

  He rampages and the Space Monkeys run screaming covered in space goo and not understanding that they were never meant to live.

This is actually similar to the sumerian accounts of dialogue between Enlil and Enki regarding the humans before the flood.

in this case, Enki is the sacrifice engineer and Enlil is the sleeping jockey