(I'm sorry if these questions have been answered before, but I can't find the answers if they have. I will grow in my knowledge and ability to use the site as I go.)
How did Shaw's offspring, which she ripped from her body just in time using the autosurgery equipment, grow to such tremendous size without ingesting a significant amount of other biomass? Doesn't that violate some principle about creation of mass from nothing? Is it supposed to have found some Snacky Smores in a bulkhead compartment or something? This has always bothered me.
Also, how is the Engineer's DNA supposedly identical to our own, when we are so different from them? Do they just take vitamins as children or something? If our DNA is identical, does that mean that, say, chimps have a big chunk of Engineer DNA too?
If the Engineers seeded our planet with their DNA, how did we get it? Was there some early hominid, whose DNA was overlaid and 100% replaced with the Engineer DNA-- and if so what accounts for the somewhat gradual changes in the fossil record? It seems to me that too many questions are raised by the supposed 100% match with the Engineer DNA, even if one tries to explain it away with non-chromosomal genetic factors.
Perhaps most importantly, who the hell keeps quiet about black micro-eels in one's eyeballs?