The giraffe did not grow a longer neck so that it could reach the leaves. There was a genetic mutation (a birth defect or retrovirus or whatever) that resulted in the sudden appearance of the giraffe. The giraffe was well suited to survive in its environment, and so it was not deselected by natural selection.
There is another example of blind worms in a cave. True story. There are two species that are identical except that one glows in the dark. What is the advantage to glowing in the dark? None. The key is that there is neither an advantage nor a disadvantage to glowing in the dark for such a worm. Thus, both types of worms exist side by side in the same environment, without one of them becoming extinct.
There is another example of blind worms in a cave. True story. There are two species that are identical except that one glows in the dark. What is the advantage to glowing in the dark? None. The key is that there is neither an advantage nor a disadvantage to glowing in the dark for such a worm. Thus, both types of worms exist side by side in the same environment, without one of them becoming extinct.
