This is different from the theory of evolution or the theory of electromagnetism. It's a smaller things, like an assumption. Evolution, also in biology, is a more encompassing set of ideas. So the theoretical framework has a hierarchy. Perhaps at the top is a Kuhnian paradigm or a Lakatosian research program.

Does this hierarchy different between sciences, though? Like, how hard is it to take a new assumption and grow it into a fully-fledged theory? Biology is more complex than physics, with more "facts" and forms to understand. Evolution is different from electromagnetism because it doesn't limit as much. EM clearly prescribes what's possible and what isn't, whereas evolution doesn't make the distinction so clearly.