As it currently stands, there exist many Pokemon[^1]-related phenomena that are unexplainable by basic physics or biology. For example, there are many mysteries surrounding the breeding aspect of Pokemon. Why can forms such as Skitty and Wailord breed and produce offspring, despite the size difference. Why can forms like Gastly breed at all, despite being mostly made of gas?
Other phenomenon that can't be explained with today's science is the Pokemon evolution. Evolution is a rapid process, during which a lot of matter is created de novo, despite having no apparent source from which that matter may appear.
This theory is an attempt to explain most of the Pokemon phenomena. It's work-in-progress, since I'm still figuring out how it would fit into known phenomena.