Dinosaur Evolution

Dinosaur Evolution

I saw my first dinosaur skeleton in the late 1950s at the Natural History Museum in London on a family trip. I remember it as huge, alien, and dead; but undeniably impressive. I have seen many more such skeletons since. It has always seemed to me that a lot of evolution separates us from the dinosaurs: a great deal must have happened since then, distinguishing us from these big primitive lizards. We are far more advanced. But I have recently come to the conclusion that this is wrong: not much evolution has occurred since the dinosaurs. Evolution has been fairly static, not progressing much. We are under the illusion that we are far more advanced than they. To see this, consider the following thought experiment: suppose that dinosaurs still existed and have their own natural history museums, and suppose they contain the fossilized remnants of hominid skeletons, lovingly reconstructed. Wouldn’t the dinosaurs be under the impression that these long-dead creatures were not much to write home about? They are just a bunch of lifeless bones. Of course, they seem markedly unimpressive. It is only when you add flesh to the bones, and movement, and all the rest that the creature springs to life. A human skeleton is far from a full-blooded human being—and similarly for dinosaurs. This image problem has been somewhat rectified in recent years by animation: we get to see the dinosaurs as they originally lived and moved, more or less. They have come to life for us. And now it seems to me that the gap between us and them is not as large as I imagined. It now strikes me that rather little evolution has occurred between the time of the dinosaurs and our time; indeed, that this evolutionary time period has the character of a plateau. The animals of today have hardly advanced at all compared to the animals of the dinosaur’s epoch. In fact, we might even detect a decline in evolutionary development: the dinosaurs were really the peak of evolutionary success, from whose heights there has been a gradual (or abrupt) descent. They were the best animals that have ever lived, judged by biological standards—the greatest, the tops, numero uno.

Let’s recall some basic evolutionary facts. Life on Earth began around 3.5 billion years ago, soon after the planet was formed. It wasn’t until about 300 million years ago that dinosaurs appeared: it took an extremely long time before they evolved. When they did, they ruled the planet for over 200 million years. They had eyes, ears, noses, brains, locomotion, strength, resilience, social intelligence, and a whole suite of biological adaptations. At that time, they were the clear pinnacle of the evolutionary process. Then why did they go extinct? We know the answer: because of a giant meteor that happened to strike the earth and unleash mass extinction. If that had not happened, they very likely would still be here, only bigger and better, perhaps with language, art, science, and the rest. It would be a dinosaur planet. Humans would probably not even exist. The dinosaurs went extinct because of bad luck not bad design. They had good genes, but you can’t argue with a giant meteor landing on your house. There was nothing wrong with them adaptively; they were survivors par excellence. Now it has only been about 300 million years since they evolved—nowhere near as much time as it took for them to evolve. That is a short time to make major biological steps forward. If we consider the non-human animals now existing on the planet, we are not going to be much impressed with their edge over the dinosaurs; surely, if the dinosaurs came back, they would soon dominate the species that supplanted them (not counting us). Even the most brilliant of apes is not going to out-survive the dinosaurs. Later species are no match for reborn dinosaur species. You see what I mean about being the peak.

But what about us, you protest: aren’t we superior to the dinosaurs? Could they overrun us? The first point to make is that we are special: the other species now existing are not superior to dinosaurs. Evolution has not in general produced species superior to the dinosaurs; we are really a freak accident (what with language etc.). The trend has not been towards superior species. Second, we tend to exaggerate our uniqueness and ignore our vulnerabilities. Who knows how much longer we will last? What would happen if we lost our vaunted technologies? We are not so darn impressive “in the wild”. Third, our biology is basically the same as that of much more ancient species: we haven’t evolved any new adaptations that dramatically improve our survival chances—extra senses, impenetrable skin, total immunity to disease, etc. We are basically the same old body plan that has been around forever: eyes, legs, mouths, etc. There just hasn’t been enough time to develop radically new body plans, indestructible internal organs, high-speed brains. Face it, we are not that different from dinosaurs anatomically. We have cleverer brains, it is true, but that is no guarantee of survival superiority and might indeed be our downfall (a meteor made dinosaurs extinct, our own brains might make us extinct). In any case, we are hardly the zoological norm: the world is not full of recently evolved species that are streets ahead of the dinosaurs. One might be forgiven for supposing that since the dinosaurs nothing very interesting has happened zoologically. If anything, there has been a decline. That could certainly happen if the world becomes less hospitable to animal life, because of temperature changes, pollution, meteor bombardments, etc. There is no guarantee that species will keep improving and outshine their ancestors. What if the only creatures that can survive on planet earth are ants and termites?

The opinion I have come to, then, is that evolution has not been up to much lately. The same might be said of civilization. The ancient Greeks were the pinnacle of civilization; the dinosaurs were the pinnacle of evolution. The past was better than the present. More cautiously, we should not assume that the extinct animals whose skeletons we sometimes see are somehow less sophisticated biologically than current animals (including us). Nothing much has changed biologically since the time of the dinosaurs. It is an illusion to suppose otherwise.[1]

[1] It was watching a PBS documentary “Walking with Dinosaurs” that most immediately triggered these reflections. You get to see dinosaurs as they actually lived not as skeletons propped up in a museum. Their variety is also well-depicted. These are not lumbering clods or dim grass-munchers. They have sharp eyes, agile movements, and obvious intelligence. They are in no way inferior to the animals of today.