Gravity and evolution - both 'just theories"

Thanks, Phong, for telling me about this terrific article - UBC geneticist proves evolution:
Here is how it ends -

Since Darwin published Origin of Species in 1859, many religious leaders have gone to great lengths to convince the public that the concept of evolution is a theory, not a scientific fact. Their reasons for this are understandable: evolution stands in direct opposition to Biblical mythology. When I asked Darren Irwin whether his research had established evolution as a fact, his answer was enlightening: "Scientists are never able to completely prove any theory. Science is a process by which incorrect theories are shown to be incorrect, leaving us with the theories that are most consistent with the evidence. The theory of evolution is one of the most successful theories ever, in the sense that it is highly consistent with abundant evidence. We understand the mechanisms by which evolution operates, and these mechanisms have actually been observed on short time scales. This establishes evolution as a more successful theory than the
theory of gravitation. The theory of gravitation is also consistent with evidence, but we don't yet know how it works. The theory of gravitation, however, does not contradict religious doctrine, and so is universally accepted. "