The very first scene in Prometheus, the sacrifice of the Engineer to create new life, the are a few observations worth mentioning. The "Chemical of Creation" is enclosed in a container, there is a symbol on the lid of the container which appears to be a tree, as in the tree of life and knowledge. As mentioned in an excellent post earlier, this substance is the key element for the films, as they continue to develop. The version commonly known as the Black Goo, is a corrupted form, derived from the original compound (theory). The next detail, is that new life is literally derived from the dust of the Engineer, another symbol in biblical creation, the dust which is in reality the mutated DNA from which life will evolve. (Sacrifice/Creation) A question which bothers me, Why do Engineers need to create life in this fashion? Why not just colonize? In AC, mankind will preserve its species through colonization. (Preservation) The Engineers have the means and the technology to get to new worlds and colonize. Unless, they are not able to reproduce normally. Mankind, the offspring of the Engineers, has this gift.
In Prometheus, David asks Holloway the existential question, why do you think man created me? Man is creating AI not to develop the perfect life form, not to replace mankind, but to serve mankind, to be subservient and obedient, no matter how evolved, to occupy a place just below man. (Hierarchy) In the AC prologue Peter Weyland, in an interesting exchange, demonstrates this, putting David "in his place", by telling him to get his tea, which is right next to Weyland. Does this plant a seed in Davids mind?
Why did the Engineers make mankind? Could it be possible in the overall arc of the story, that Engineers created mankind to eventually replenish and replace them once we were fully evolved. (Preservation) Why was the Xenomorph created and why did the Engineers, or a faction of the Engineers wish to eradicate mankind? As mentioned in previous posts, mankind is (in the eyes of some Engineers) weak, arrogant, selfish, cruel, and fueled by greed (this is symbolized by Weyland in Prometheus). Could it be possible that this faction views mankind as unworthy, (disobedient), to be the eventual successors to Engineers, even if mankind was derived from Engineers? This breakaway faction takes the "Chemical of Creation" and corrupts it, modifying it to develop a new species not simply to eradicate mankind, but to replace them. This new species was a development which combined the pathogen Black Goo, and genetically enhanced, bio-mechanoid Engineers. This new species will correct the flaws and short comings of mankind. In the Prometheus Ampule Room, the large head is could be the leader and creator of the new species, the Xenomorphs will be the "saviors" of the Engineers. (Speculation/theory)
But there appears to be a cycle at work here, Man creates AI and considers himself God, AI creates (replicates) a new species and considers himself God, the Engineer faction creates the Xenomorphs, and again take the role of God. It feels as if there is a disintegration of Hierarchy, everyone aspires to be God.
In AC, in his conversation with Walter, David makes allusions to Shelly, Byron, and Milton. This is not only a clear link to Prometheus, but could be a potential harbinger to future events. There are two Shelly's, Percy and Mary. Percy Shelly's work referenced in AC is Ozymandias. In general terms, Ozymandias reminds me of the Roman Empire, built to achieve greatness and glory, only to fall into decline, collapse, and ruin. (was this the fate of the Engineer society?) Mary Shelly, Frankenstein. In the story, Victor Frankenstein, playing God, takes the role of creator. In his mind, his creation will not only be superior, but will worship and honor him like a father. Victor Frankenstein is a rebellious character, however his actions are not morally acceptable, instead of advancing society with his creations, he simply destroys with the intention of populating the world with his creations. (This not only applies to David, but the faction of Engineers) Lord Byron, whose famous dramatic work, Cain, is the biblical story of Cain murdering his brother Abel. (David -Walter?) All of these writers were part of the Romantic Period of writers. Aside from being contemporaries, they were all influenced by John Milton, who wrote Paradise Lost. But unlike Milton, this group interpreted Paradise lost as a celebration of Satan, who they considered rebellious hero, who defies the power of God. (Disobedience) In AC David tells Walter the famous line from Paradise Lost, "It is better to rule in hell than to serve in Heaven". Is this all a coincidence? Not likely. The themes from Paradise Lost are littered in Prometheus. Is this a metaphor for the backstory and resolution of this story arc? The elements, Creation, Sacrifice, Disobedience, Conflict in Hierarchy, are identical themes.
I too agree with previous posts, that David is not the original creator of Xenomorphs, but he is replicating the work of the faction Engineers, since he has acquired the knowledge and clearly disdains mankind. He has not been able to replicate because he is not using the same ingredients. In Paradise lost, Satan loses his perfection by the changes in his appearance. David is showing signs of a mental descent, when he confuses Shelly and Byron talking to Walter and his erratic behavior with Daniels, he is losing his "perfection". If this is a cycle, do Davids creations turn on him eventually? (speculation)
What caused the events of LV-223 which saved mankind? Were the Engineers victims of their creations or was there sabotage involved? Was there a savior to mankind? Some theories say the Ampule Room in Prometheus (mural room) was booby trapped with the black goo.
On LV-426, it would not be consistent with events already revealed, that David is the Space Jockey. If the story line is altered, this would be a mess. Until now, LV-426 has not made an appearance. The next chapters may move the story there. There have been interviews suggesting a great war is approaching. Between who??
Will the movies all connect or will they reach Alien in the timeline, and then side step?