Okay, 96 pages and all I see is: "they can't", "not in this universe", "he said that in the audio commentary..." and stuff.
1st of all, when Mr. Scott was creating Alien he wasn't thinking of any sequels, he was thinking on some good shit: how this would look, how scary is this shit. Or he and his friend are having a joint and think: "Tail over Lambert's leg - scary as hell, I would shit my pants, yeah, f**king A, I gotta put this down..."
Then there was no mythology, correct me if I'm wrong, but the whole universe got wind up after Aliens, ya know comic books and stuff.
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Aliens are f**king animals, ya know, they can adapt not only because they are perfect, but because it's nature and some simple lizards can change their sex if their mate is dead or gone because it is a f**king instinct to reproduce.
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Stop posting all these things about bad ideas and stuff, if the directors, producers and writers think that this is a good idea, they may be right.