This has me wondering if David is trying to find a way to make himself more like the engineers. Perhaps to create a soul of his own. A darker version of Bicentennial Man. Or maybe there are some forms of engineer technology that are simply too organic in nature (DNA/genetic encoding) to be controlled or manipulated by David unless he pulls a Frankenstein. Regardless, I'm starting to think David (and not Shaw) may be the Space Jockey from Alien. Which would mean he succeeds in becoming "a real boy".