The word theory means different things to different people in different contexts, with little consistency, so what folllows is only how it should be read in connecftion with evolution. A theory is an explanation, and the theory of evolution is an explanation for the diversity of living things and the successive appearance of fossils in rock strata.
Okay. But, where are the transitional forms in the fossil record which is what one would expect if the theory of evolution was true as Darwin himself stated? In his own day, Darwin knew the fossil record did not support his theory but he hoped the transitional forms would eventually be found. Now, after 150+ years of digging the situation has not changed but has only gotten worse for Darwinism. You like to talk about the mathematical probability of the theory of evolution. What is the mathematical probability that if the theory of evolution were true and upon the millions upon millions or billions of fossils in the fossil record spanning millions or billions of years, there is not a single undisputed supposed transitional form fossil or that the abrupt appearance of all the variety of species in the fossil record leave no trace of their supposed evolutionary development? From the evolutionary standpoint, the probability that the fossil record should lack a clear trace of transitional forms or fossils of any kind, defies any credible explanation.
Further, it is an explanation based entirely on observation.
Macroevolution has never been observed nor even if it was happening now could it be observed. Yet, you say “Further, it [the theory of evolution] is an explanation based entirely on observation.” What we actually observe in the real world as opposed to the imaginary world of Darwinism is tigers begetting tigers, horses begetting horses, humans begetting humans, and so on. Rodents morphing into whales, dinosaurs into birds, and the rest of the fossil record interpreted according to the theory of evolution, is an interpretation based on
imagination, not on observation.