<i>Natural selection works on what exists already in a particular animal population (like some camels' ability to last longer without water). It won't sprout wings on the camel, feathers on a frog, or legs on a coconut. <b>That's because camels, frogs, and coconuts do not have the DNA (heredity coding) to produce those other novelties in the first place for natural selection to work on.</b></i>
This is the mistake.
Some camels, frogs etc. <b>do</b> have the genes necessary to sprout wings, grow feathers or whatever. That can happen in two ways. First, genes can sometimes mutate randomly, writing new instructions for building a lifeform. Secondly, when genes are copied there is some chance that an error will occur in the copying process, resulting in a slightly different genetic code.
The changes which produce the feathers or whatever <b>are of exactly the same type</b> as the changes which make camels last longer without water.
If you accept one type of change, you are forced to accept the other, since there is no fundamental difference.