Does chlorophile run through The Engineers' veins?

You are right, that is why you can for instance use the dna of a deep ocean creature to make your organs fluorescent... we are the branches of come from the same tree...

@loseyourname You just have "blinded me with science" lol

My theory is that the Engineers are looking to expand. We've seen they are capable of breathing (and probably thrive) in atmospheres humans are comfortable with - so they pick planets orbiting in habitable zones around stars similar to theirs and seed them with life. The black goo is a mutagen that breaks apart the Engineer DNA into basic proteins and reassembles them randomly, leading to all manner of life to evolve (though because there are no plants or other animals to consume in the beginning, plant life survives and evolves first). This results in a somewhat predictable outcome - the planet breeding life (albeit new and never before seen species) that over great amounts of time terraform the planet to something we'd recognize as Earth-like. The only problem is something unexpected happened on Earth itself - instead of lumbering animals and plants (and beyond all odds) a second evolution of their kind happened. They view humanity as an inferior life form, but one that could potentially rise to be a threat (the way humans view David/automatons - synthetic industry is "buried" by second gen synthetic revolt a la Alien: Resurrection as they "didnt like being told what to do"). So they decide to cull Earth by bombarding it with goo to reset the process. This also explains why the Engineer acted so angrily/deperately. His people were assigned to re-boot earth, but now he is being awoken by the very race he was ordered to destroy. In essence - it may already be too late from the Engineer's point of view as humanity has developed space-flight and a level of technology that could pose a threat. One hole in this idea is that we've seen how the goo mutates some organisms into horrible monsters/zombies. Perhaps this is part of the plan - the end-stage xenomorphs wipe out all other life forms, and then the engineers come in with the raid (the thing in the green crystal?) that inhibits/destroys all the xenos. A giant mop-up on a planet-wide scale that lets the whole process start over.

Good points made, i would like to add maybe the engineers just seeded human life, because humans are the dominant "gods' on each, we run just about everything. And possibly the engineers want to destroy us out of jealousy. Heres why, obviously where ever the engineers inhabit it doesn't allow them to evolve, but where we inhabit it allows us to essentially evolve. So to have the ability to evolve the engineers want to inhabit earth so they can evolve, only to make themselves "better". Also since earth allows us to evolve, and they currently can't for some reason, they find us as a threat, so they simply want to wipe us out, because they don't want what they've created to "over power" them..

@ParkerN "i would like to add maybe the engineers just seeded human life, because humans are the dominant "gods' on each, we run just about everything." It could be, but then what about the Neanderthals and our cousins the chimps?

@Alienpuzzle "Yes, essentially tho if the engineers created humans, maybe the neandrethals and chimps were already around, and the engineers came when they inhabited the earth, and instead of neandrethals or chimps evolving into humans, we were immediately created by the engineers, since our dna is so similar to theirs..."

Yeah, you kind of have to take it literarily, not literally. No possible explanation holds up for very long to scientific scrutiny. It's obvious to me they seeded all life on Earth, which is fine. Throwing DNA and other organic macromolecules into the primordial stew would eventually do that given the right conditions. But resulting in a single species 3.5 billion years later with an identical genome to the original seed? That's not the way it works, but I forgive that because it seems to be such a common misconception that evolution works toward some particular goal with some species more "evolved" than others that I expect a writer to make that mistake. On the other hand, the hypothesis that they only seeded human life is much worse. First, we see DNA dumped into a waterfall. They didn't dump it into ape gametes. The intro clearly shows single-celled organisms developing in the water, not human zygotes developing inside ape wombs. Moreover, we share almost all of our genome with every other living thing on the planet. Most of our genes don't code for bipedalism, large brains, and hairless skin. They code for storing energy in ATP, wrapping phospholipid bilayers around organelles, and protein synthesis, things that every single living creature does in basically the same way. We are very clearly related to and descended from the same things as everything else on this planet. We weren't made from a batch of DNA imported from another planet. Whatever created us created everything else, too.

Are you asking, "Why doesn't the Engineer look like a Pterodactyl, a Troodon or a Triffid?" I agree with you. :)