Unofficial SJG Archive

The Unofficial Stephen Jay Gould Archive

Unofficial SJG Archive



Lesson of the Dinosaurs: Evolution Didn't Inevitably Lead to Us

by Stephen Jay Gould


F
othing crystallizes commitment quite so well as righteous anger. When I was ten, I got into a fierce argument with a friend at summer camp about whether humans and dinosaurs had lived together—he thought yes; I knew no (and by a good 60 million years). We bet a candy bar (camp currency) and agreed to abide (by foolish and habitual trust) in a grown-up's affirmation. Not a soul at the camp knew the answer, so we had to wait for parents' day. My folks didn't show that weekend; his dad insisted that people and dinosaurs had lived together—hadn't I ever seen Alley Oop, he asked. I had to pay. My anger, a thousand chocolate bars later, remains undimmed.

Such a travesty of justice couldn't occur today (outside the community of fundamentalists, who sink dinosaurs, along with wicked humanity, in Noah's flood). Dinosaur consciousness is far too high, and too general. No randomly chosen garden-variety adult would be so uninformed. Dinosaurs are riding high in both the popular and professional community. Are the reasons for this joint acclaim related?

Dinosaurs have flooded kiddie culture and spilled over to adult life. Tyrannosaurs have almost displaced flamingos in Key West T- shirt emporia. Dinosaur dolls, models, clocks, even toilet paper holders, are inundating the world of kitsch, while games, books, and anatomically correct plastic skeletons bombard the upscale market of "educational toys." (I leave aside, for some other time, the issue of whether such a surfeit is pure blessing. I'm too young, I trust, to glory in the old days when men were men and thought their Neanderthal forebears rode bareback on brontosaurs—but too much of anything can remove mystery and provoke demotion to the ordinary. The dinosaur nuts of my childhood shared a rare and secret passion for something arcane—and we had to search out every tidbit of knowledge. Dinosaurs are now ubiquitous in a child's world. They've become scenery or furniture—a stage of early life for all to enjoy and supersede.)

This public acclaim is matched by renewed interest among professionals—a result, largely, of a new and coherent interpretation (spearheaded by Bakker and Horner, the appropriate foci of the foregoing article) that has revised our view of the lives and fortunes of these most prominent prehistoric beasts.

The so-called age of mammals has persisted, so far, for the 60 million years since dinosaurs died. Dinosaurs, by contrast, were the dominant large animals of our continents for more than twice this span of time.

Despite this proven record of success, the traditional view cast dinosaurs as stupid, slow, inefficient, and torpid—overgrown cold-blooded reptiles of little brain, so bloated that the largest could only survive in the buoyant waters of swamps and marshes.

A pushover, no doubt, for superior animals. But if so, how couldwe account for the basic and long known fact that pierced this tradition and cried for recognition—but largely went unacknowledged? Mammals didn't evolve late in the reign of dinosaurs, immediately using their newly evolved wile and wool to launch dinosaurs on their path to death (by eating their eggs, or whatever). Mammals evolved at the same time as dinosaurs and lived for more than 100 million years—twice the span of their later success—as small creatures in the nooks and crannies of a world dominated by dinosaurs.

Bakker and Horner provide an elegant and coherent solution to this paradox. We were wrong. Dinosaurs were sleek, anatomically efficient, probably warm-blooded creatures with complex social behaviors and average-sized brains for reptiles of their bulk. This new, archetypal dinosaur is a great improvement on the old stereotype for public fascination. Yet while the sleek new model helps to promote public acclaim (all the world loves a winner, cliches about underdogs notwithstanding), the full implications have yet to be assimilated—and they're both disturbing and wonderfully enlightening.

Dumb and torpid dinosaurs fit well with our most cherished notion of evolution as progress leading inevitably to us. But in the new view, dinosaurs are as worthy as mammals (only different) and their success (apparently beyond the power of mammals to challenge) implies that life doesn't proceed in lockstep toward increasing efficiency and mentality, eventually (and inevitably) to culminate in us.

The new view of dinosaurs adds a third component to the Bakker-Horner duo of anatomical efficiency and behavioral complexity: the recognition that extinction is no sign of ineptitude but the inexorable result of life on an uncertain planet. Both Bakker and Horner accept this view of extinction but oppose the most congenial argument in its favor, the idea that an extraterrestrial impact (the ultimate bolt from the blue) triggered the coordinated extinction of dinosaurs with some 50 per cent of marine species. (I might add that I disagree with Bakker and Horner here.)

And so, dear reader, you can't have it both ways. All knowledge and novelty comes at a price. You may have your sleek new dinosaur as a better icon for pop culture, but you'll have to accept its implication for the history of life and for our own species. We didn't have to evolve at all. Life is a series of complex and unpredictable events, not a straight and narrow path to progress. Wind back the tape of life to the midst of dinosaurian hegemony, and let it play again (but without asteroidal or cometary impact). This time perhaps, as we reach our own day, no tyrannosaur graces a T-shirt. Rather, great-grandson of tyrannosaur gazes down at his feet and wonders how those odd little furry things continue to eke out such a marginal life in his glorious world.


[ Stephen Jay Gould, "Lesson of the Dinosaurs: Evolution Didn't Inevitably Lead to Us" Discover 8 (March, 1987): 51. ]


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