The appendix does not evolve. The organism evolves. Logically, the genes encode proteins that respond to the local microenvironment. And that's it. The cells ha

The appendix does not evolve. The organism evolves. Logically, the genes encode proteins that respond to the local microenvironment. And that's it. The cells have no idea where they are, other than subtle cues from their neighbors. Imagine trying to build a city with no localization input except accelerometry. Theoretically, works fine. In practice, eh, there are some odds and ends left over.