There seems to be an element of the Texas Sharpshooter fallacy here, in that you are calculating (I do not know how accurately) the odds of what did happen happening, rather than the odds of something similarly interesting happening.
The DNA codes for spatial arrangements of cells in the form of functional bio-structures. A heart valve is one such arrangement, while the ear is another. In between you have a nearly infinite number of junk arrangements. You can't just wave a magic wand of mutations and jump from one bio-functional arrangement of cells to another, and than claim - natural selection did it!
But mutations often do get us from one functioning organism to another. These mutations are of course not caused by natural selection, but they are preserved by it.