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human
[Prometheus/Alien: Covenant/Alien: Resurrection/AvP] Why did the Engineers want to destroy Earth? Do we know whether or not David 'invented' the zenomorphs from the virus; and also, is Ripley 8 not arguably the ultimate species that David had intended to create from the virus?

1. We see the Engineer at the beginning sacrifice himself in order to create life on Earth. So they seeded Earth, and *Prometheus* verifies that they seeded life. But why were they carrying a virus that was going to destroy all fauna on the Earth? Were they just terraforming Earth and were going to wipe out all animals life in order to kill off any intelligent life forms that spawned there, and then colonize it themselves with new animals or something?

2. Did David actually invent the zenomorphs? I've seen at least one video that theorizes that he didn't, that he created a subspecies but that the zenomorphs were already in the virus DNA if allowed to grow in that way.... But *Covenant* seems like it suggests this: that David in fact created the zenomorphs as a "perfect organism," then was able to take over the Covenant in order to use the new planet as a colonizing step for him to diminish the rest of human DNA through the use of the zenomorphs (him planning that they'd eventually get sent back to Earth.) And actually, I think that this explains a lot about the original series, as well. If David has been living and working toward his goal as Creator on Origae-6, using the deadly terraforming virus created by the Engineers to breed his colony of weird alien soldiers, then he might have had the ability to:

\-help create AIs that are sympathetic toward the biology of the aliens (which happens in *Aliens*, iirc)

\-use machinery to encourage aliens to spread all over the galaxy, thinking they'd make their way to humans and potentially any surviving Engineers

\-*maybe* take over the Weyland corporation.... I was thinking that if David ends up seeking power for its own sake then he might end up like a dictatorship type of person.

But this seems to contradict AvP. One youtuber suggests that David didn't invent the zenomorphs, which contain the same DNA as the original virus; rather, he used Engineer technology to alter their physical expression of their genes - so the black zenomorphs and facehuggers are 'natural' but the white zenomorphs are David's own creation, a mutated style of the black ones. So I don't know. Is this stuff resolved yet, or do we have to wait for another sequel?

Is it worth mentioning that Ripley 8 might be the perfect organism that David had intended to create - that is, being a mixture of the "dying species" of humanity, alongside the *intended* example of biological perfection?
gpt
1. They presumably thought that earth had failed, they probably didnt like what humans were doing. Also, i think they only created humans, not life as we know it. IIRC we are never given a date on when the first scene happens, and it seems weird that they would come back 4 billion years later only to die a few years after. Seems unlikely we would time their extinction so perfectly.

as for 2, i dont think he created xenomorphs, i think that was the natural final state of the black goos evolution, becasue it seems to create similar beings to every part of the xenomorphs life cycle. It created some kind of cheastbuster with shaw, which then evolved into some kind of facehugger, which then spat out some kind of xenomorph. similarly, when exposed to engineers, it tried to create some kind of xenomroph too. 

So, i think the black goo is just the first step in creating the bioweapon that was the xenomorphs, and what david does is just is just followed the path laied out before him in the goos genetics. So he didnt create them, just made his own version, which is why it looks a bit different from the others we have seen. So no, david is not connected to the events of the OG movies. Oh, and AVP isnt canon to the alien movies. 

I think the black goo is the unfinished work that the engineers did, becasue its a very undiscrimiate bioweapon that also taints the planet it attacks. So they refined it into the xenomorphs which will only kill large living beings, perfect for an attack on humans or similar beings. The black goo is a weapons of mass destruction, and it leaves traces while the xenomorphs will eventually starve and die.