Now, if random mutations are the stuff, why do they actually exist? What makes it so that such allegedly random mutations can even happen? If you keep the random element of it, it's hard to make sense of it, but if you, for a second, consider the possibility that it's not random at all, then it makes perfect sense. The trees are too high, giraffes grow a longer neck. Of all the random stuff giraffes could have grown, it had to be a long neck. And you're going to say: "Well, if they had grown a fifth leg, it would have been useless and they would have died." Right enough, but in that case we would have found those skeletons of badly failed random mutations. Thing is, we don't! And when we do find odd mutations, they're mutations of the kind that the two-headed goat had. A fifth leg would not have changed the giraffes' situation much, but it would have survived long enough to procreate somewhat, and would have left us a good number of five-legged specimens. They haven't, because this particular mutation never took place. It was only the really useful mutation that took place.