How did giraffes come to have long necks?

I’m always thrilled whenever I rediscover by chance a typical Richard Dawkins gem like this one.

A nice old-fashioned answer is that God, knowing that He had cunningly placed the most tasty leaves at the top of tall trees, designed giraffes with extra long necks so that they would have no trouble in reaching this good food.

A less religious answer is that, over a certain period of time, Nature caused the necks of giraffes to grow longer and longer, because Nature was smart enough to realize that hungry giraffes would be needing bigger necks to attain leaves that were moving higher and higher.

Well, that god-free answer is closer to the truth, but we still need to improve the wording. We merely have to introduce a pair of freak events. So, let’s go. At a certain point in time, most giraffes had medium-sized necks, whereas a minority of freaky giraffes were born with slightly longer necks. At about the same time, during a few freak seasons, leaves happened to grow so high that all normal giraffes with shorter necks couldn’t reach them. These poor animals gradually died of starvation. Only the freaky longer-necked giraffes survived and bred children who, like their parents, had long necks. Longer necks had started out as just a random happening… but they soon became a matter of life or death.