Is evolution a theory yes or no?

Answer 1

Yes and no.

Evolution is an observed biological phenomenon, and therefore fact.

Evolutionary theory is a model explaining the things we find in Biology and Paleontology in terms of what we know about evolution through genetics and population dynamics.

The point really is not that evolution can be seen as either as theory or as fact, the point is that it is a factual theory; it is a theory which is so well supported by vast quantities of evidence that it would be unscientific and unreasonable to doubt the validity of that theory. Scientists also do not know everything about the evolutionary history of the Earth, or about exactly how evolution takes place, and research into evolutionary biology continues. Theories can be revised. But in the case of Darwin's Theory of Evolution, although many details have been revised, and additional details are likely to be revised, the essential thesis remains, that life does evolve, and that evolution is the process by which the species we observe today on Earth (including the human race) came into existence. Of that, there is no reasonable doubt. Of course, if anyone has a religious belief which compels them to believe otherwise, that is their privilege, but the pious rejection of science does not lead to a better understanding of reality.