Again with the talk about "proof". You cannot prove a scientific theory. Theories are conceptual models that tie facts together; there is no threshold of evidence beyond which a theory ceases to be a theory. For a "scientific recognized body" to declare any theory a fact would be contrary to the very notion of science. That goes for any theory you care to name: evolution, general relativity, quantum electrodynamics, the atomic theory of matter, and so on.
But as a quirk of language would have it, there is a fact of evolution. The quirk is that the term "evolution" means two quite different things: the change of species over time, and the spontaneous appearance of those changes through mutation and natural selection. The second is the Darwinian theory of evolution, to which you referred. The first is simply a raw fact about the universe that the Darwinian theory of evolution seeks to explain. This fact, unfortunately and confusingly, is also referred to by the term evolution. The truth of this fact (independent of the mechanism by which it occurs) is seen on the small scale by the careful observation of the change in the morphology of organisms and their genes over time; it is seen on the large scale by observing such changes in the fossil record.