This is a topic I find particularly interesting, and something I would like other people to be able to talk about: The biology of Pokémon. Thinking about Pokémon in a scientific, realistic sense. How exactly does Pokémon physiology work? For example...
The bulb on Bulbasaur's back, how does it interact with the animal part?
Why does Charmander have a flame coming out of its tail?
When Squirtle sprays water out of its mouth, where the heck does it come from?
What exactly are TMs and HMs, and how do they work?
What exactly happens when a Pokémon evolves?
The following link has a few articles on the subject, and I wanted to share it with all of you. http://www.kyogrelair.net/pfiles/files.htm
So, let's open it up. What are your theories on the biology of Pokémon?