The amoeba pattern is way of creating notes and schemas using an iterative process.
It helps answer the question - "how do I organize my notes in Dendron when I don't know the topic/hierarchy ahead of time"?
In a nutshell, the Amoeba pattern says to lump everything into a single note until it becomes obvious what the potential groupings might be. Dendron provides a bunch of features (eg. extract note via selection, hierarchy refactoring, schemas, hierarchal graphs) that make it easy to do this. You can see an example of this workflow in action here.