I think they should have used this article about 'human's closest living relative, the chimpanzee' as part of that 'last of the human genome has been mapped' or whatever it was tagline in the Doom trailer; but then they would have had to bring in chimpanzees, and that would have complicated things. And made it a lot scarier. You know, monkeys - creepy. That, and the phrase 'shotgun sequencing approach' is fun.
      Tangentially, that whole thread of worlds mixing by mistake or otherwise seems interesting. Let's explore it! In the aforementioned Doom, it's been told that I know of as a science community (operating within a corporation) that opens a portal for monetary gain; through that portal come the aliens/entities that either a) are actually demons or b) the slightly more interesting take the form of demons in order to scare and manipulate world leaders through offers of power. Interesting points: our reality is not itself inherently altered, and the link between the monetary purpose of opening the original portal and the corruption-by-power end result.
      In Stephen King's short story, "The Mist," the mix-of-worlds in question originates in a military base (purpose unknown). First, reality itself is altered - this manifests in the form of a mist, which isn't really a mist but a kind of meta-static that resulfts from the mixing of worlds. Then the creatures from the other reality manifest within the mist, which leads to the horror elements concerning the isolated survivors of the resulting mayhem. The interesting thing about this one to me was that it's the only one off the top of my head I can think of where there is minimal fighting-back, as it were, and more purely panic and base survival - perhaps because it is also the one where reality is inherently altered?
      In the Half-Life games, the mix is the created by a scientific community working under the aegis of the military/shady-government-elements, again, purpose unknown (supposedly scientific). The story begins with survival/panic, but leads into fighting-back, but then (like Doom) repeats the cycle after world domination. Here reality itself is not altered, but for all intents and purposes humanity's social and cultural reality is altered when they reduced to a slave race by the other reality. And there, I think it rises above its parallel, Doom, in interesting complexity, as the obliquely altered reality creates panic/survival elements and at the same time leaves room for the more romantic fighting-back.

Word of the Day that I think would be cool to put into contemporary use: aedile - an elected official of ancient Rome who was responsible for public works and games and who supervised markets, the grain supply, and the water supply