Evolutionary proof is limited to, as an example, the ability of a bird to adapt to environment, including food sources by differences in size, beak shape, strength and structure etc. This enabled several different kinds of birds to live together, each within its own niche, living on the ground or high in the trees or on cliffs and every where in between; living off of all different kinds of food sources. Where there was competition for a specific food source, the stronger bird survived and displaced the weaker.
Species adaptive change is proven; I have seen it in genetics laboratories. Microevolution if you will… this could be a hard coded adaptive ability suppressed within species genes as a survival mechanism awakened when required due to extreme changes in environment and NOT evolution at all as SS has suggested but had a difficult time stating. For instance in the human, there are several organs that are responsible for the elimination of waste, AND several processes including defecation, urination, perspiration, regurgitation etc., where when one begins to fail another takes over or aids in the process… a built in redundancy to allow the survival of the organism.
The study of vast physical differences within groups of like organisms is what Darwin based everything on and it is severely flawed, as are all evolutionary theories of macroevolution. There is no proof of a species morph into another species.
Darwin based his theory on extrapolating to a beginning in the primordial soup... which is not and never will be proven.