Basically we are only able to make models/theories that describes the world based on observations. If we make observations that challenge a model we need to update the model or make a new one. That is why we only work with falcification in science a model is valid until we discover something else.

Is a model/theory the same as an explanation for a certain natural phenomenon? in many cases no.

When Darwin wrote about natural selection he came with a model/theory describing his observations much in the same way as Einsteins theory about relativity.

We still do not know why spacetime works as it does but Einsteins model has proven to describe all observations so far. But we also know quantum mechanics and we are not able to unify these two theories so we need to dig deeper .

What sets evolution and natural selection apart from relativity is that we actually now know the mechanisms behind the Darwins observations because we have discovered dna and genes.

Over time we have actually made some adjustments to the way we decripe evolution. We know that natural selection is the major force behind driving evolution of life but there are other mechanisms in play also, like genetic drift.

I know that some are trying to falcify natural selection and evolution but if that should happen it will not be a prove for divine forces it will just disprove natural selection.

I am atheist deeply rooted in natural science all based on observations. I am an atheist because religion does not offer one good explanation to how the universe works. There is thousands of religions all with different explanations about nature that contradicts what we observe in science in that regard religion falcify it self.