No Biochemical Barriers: Difference between revisions

** An aversion comes up as a [[Noodle Incident]] in ''[[Death Star]]''.

{{quote|"How was I to know your kind can't eat sweetweed?"

"Not a chance, Green-Eyes." }}

* Averted in ''[[Fallen Dragon]]'' by Peter F. Hamilton, where alien ecosystems are completely incompatible with human biochemistry—meaning the first step in colonizing a new world is to kill all the native flora.

* Most of the aliens in the ''[[Men in Black (film)|Men in Black]]'' films and [[Men in Black (animation)|the cartoon]] get along fine without special respirators, although there are exceptions: one species risked premature aging in earth's atmosphere, while "Atlantis" (actually a [[Ancient Astronauts|sunken space ship]]) is a posh resort for (salt)water-breathing aliens. When Agent Jay is surprised at the fish-like aliens, Agent Kay [[Lampshade Hanging|lampshades]] this with "You think ''all'' aliens breathe oxygen?"

* [[Lampshade Hanging|Lampshaded]] and played hilariously straight in ''[[Galaxy Quest]]'', when [[Cloudcuckoolander|Tech Sargent Chen]] opens the door of the ship while it's on an alien planet:

Chen: (sniffing a few times) Seems okay. }}

* Present ''and'' subverted (and generally just plain [[You Fail Biology Forever|screwed up]]) in M. Night Shyamalan's ''Signs''. Aliens are seen walking around on Earth apparently sans any kind of protection whatsoever, but then turn out to be fatally allergic to water. ([[Fridge Logic|But let's not go into why hydrophobic aliens would decide to invade a planet 75% covered with water, nor how they managed to run through a misty cornfield at night]].)