The Giraffe's Long Neck.



I am very suspicious of the giraffe's long neck. Well, more to the point, I am suspicious of our explanations of how it got that way. In fact, to get down to the nitty-gritty, I am suspicious of the theory of evolution.

Just to make sure you know where I'm coming from, I do not subscribe to any organized religious faith or belief. In particular, I am not a fundamentalist Christian who rejects evolution as contrary to the "Word of God." On the contrary, I believe that evolution of living forms is well established both in the geological record and in our modern experience. But what is not well established, at least in my mind, is the theory of the mechanism by which life evolves.

My biology teacher told me long ago (and I think biology teachers are saying just about the same thing today), that the neck of the giraffe grew longer and longer over many generations because to do so was an advantage in obtaining food from the tops of trees. It was an example of "survival of the fittest" and evolution through "natural selection." Even my child's brain wondered if such were so, why all leaf eating animals didn't have long necks. And, since there are still a lot of herbivores around with short necks, why are there not giraffes with short necks? After all, it is obvious that it is not so much the survival of the fittest as it is the survival of the fit. Even a lot of unfit creatures manage to struggle along, reproducing their own just in time and in just enough numbers to avoid extinction, but only barely so. Along that line, have you ever seen a giraffe drink from a stream? Talk about leg splits. So ungainly. I'd hardly call that an advantage. It seems to me that it's far more likely that giraffe has to eat leaves from the tops of trees because its neck is so long, rather than its neck grew long just so that it could eat from the tops of trees.

As I grew older and devoted most of my serious scholarly thinking to physics (much easier than biology), I continued to puzzle over the puzzle. I had lots of questions.

If suddenly there appeared among a herd of normal-necked giraffes, one with a mutation-induced extraordinarily long neck, don't you think it would have been ejected from the herd post haste? Suppose it were a guy giraffe. Would any sensible girl giraffe mate with it? And even if she were stupid enough to do so, what would their offspring look like? Maybe some with normal necks, some with medium long necks, and some with really long necks, like dad's. But unless that long-necked mutated gene were extremely dominant, it would eventually wash out. After lots of generations it would have been drowned in the gene pool.

So what might have happened? Perhaps a mutated gene for a long neck did appear in a proto-giraffe. Again, assume the proto-giraffe was male and that he seduced a "normal" female, probably much against her wishes. She ends up with some offspring with long necks. But the male and long-necked offspring are run out of the herd. They go off on their own and interbreed and after a few hundred years or so, we have a herd of long-necked giraffes.

But this does not explain what happened to the normal-necked variety, who were certainly better equipped to drink from streams even if they couldn't eat the tops of trees.

In a nutshell: If the mutation stays with the herd, the mutation washes out. If the mutation leaves the herd and interbreeds with like kind, it may become a separate species, but the original species remains.

In mulling over the puzzle, I thought that something must direct evolutionary change within the species. Okay, you are thinking I'm about to introduce "Divine Intervention." But I'm not. What I'd like to suggest is probably something as unlikely. What I think may happen is that there are genes (or something) that direct evolutionary processes. All the features of the giraffe (not just the long neck) were programmed in genes in the proto-giraffe and in the proto-proto-giraffe (etc.) and these genes directed slowly evolving changes that have produced our present species. As long as the species is extant, the evolutionary process continues, not by accident but by design, even though the design may not make much sense.

It may be that this "evolutionary gene" shuts off when the species becomes eminently successful in surviving, thus explaining why cockroaches have been around, unchanged, a lot longer than we have.

As long as I'm off on this bent, let me ask how crows feeding off road-kill on the Interstate learned to get out of the way of cars approaching at 70 mph, just in the nick of time, while squirrels are too dumb to avoid getting run over on residential streets where cars go much slower. I'm wondering how natural selection and survival of the fittest could have trained the crow in such a short time. And I'm still waiting for natural selection and survival of the fittest to breed a squirrel with enough sense to get out of the way.