I'm not sure you can separate Natural Selection and Evolution so readily....

If natural selection "weeds out" the weakest of a species they are not, logically, identical to the rest of the species. Say, for example, redheads were being "weeded out" because the predator can see them more easily. They are redheads because, even though they are the same species, their DNA differs from the blond and dark haired people. In a way they are already a "sub-species". Should the environment remain the same, (the predators remain), then, eventually, the redhead's genetic material would be removed from the species DNA - thus the extinction of the "sub-species". The DNA of the species as a whole has changed - no redheads - thus the species has evolved. But it was achieved by natural selection.

Evolution produced the "error" in the code that threw redheads. Natural selection threw out the redheads because the "code" was not a successful branch. The code has been re-altered. It would be quite possible that, at some time in the future, the "code" errors again and begins throwing redheads and, if the predators have gone, (because they can't catch enough food now the redheads have gone), that the redheads could succeed.

Or am I completely nuts?

Oh Hush...