million years toward the here and now. The planet has been fraught with offspring for a few billion years, in fact, and the majority fail to complete the marathon, their collapses occurring invisibly and ages before they’d have come into view of the grandstands. Indeed, most of the dinosaurs whose fragments we’re familiar with cannot leap the steeple from the Mesozoic Era to the Cenozoic, and the next contestants tread upon their fossils. Some who do survive the marathon do not survive as they began it. Eohippus, for instance, drops out, leaving the modern horse to deliver the mail. A given lizard may streamline every thousand centuries or so, sloughing a dozen or more precedent semblances on its way, dumping ballast for the long haul. Certain amphibians carry the baton legless ancestors brought the first half-million generations. Meanwhile, a few mischievous species prominent in the Holocene stretch slipped in recently, perhaps ducking in from behind a dying herd during that catastrophe’s distraction; some would say their success is tempered by the deceit. The fittest are left standing, slithering, soaring, or treading water at the ever-receding finish line, leaving immeasurable time and carnal tonnage in their wake.
Tolstoy wrote that happy families are all alike. From the long view of biology, unhappy families are all alike, too. Been there. Been them.
A second viable diagram shows Creation coursing in several unpredictable directions from a hypothetical seminal event. Call it biology’s own version of the Big Bang. Here the way species spread from the center recalls how cracks in the windshield can continue for years after it’s been struck by a BB or a pebble a truck kicked up. Whatever existed during the first eons—that rudimentary zodiac—was presumably packed close to the core, after which the traces of random gambits, impasses, and mysteriously juried amendments to the constitution of life on Earth become visible. Everything about this depiction is unsettling: not only the unlucky animals born too close to the epicenter but all successive creatures as well are perched precariously over faults, which, based on what we know of faults, are liable to grow. Logic dictates that because those fractures have persisted for so long, we, too, will eventually tumble in after the majority.
Then there is the so-called Tree of Life, a metaphor bequeathed to us by Darwin himself. Many find this the most appealing of the three models: whereas the racetrack model emphasizes lethal competition and the shattered glass model accident, the Tree of Life is a community roost, consolingly organic, with a different beast blooming from every bud. Single-celled animals hug the trunk, while increasingly complex organisms roost and ramify further out. Trilobites and other unimaginably ancient entities verified only by the barest carbon outlines make the oldest claims nearest the bole, with millions of insects and other biological minutiae infesting ground level with them. The lower branches are hung with cuttlefish and tube coral, decked with plankton, caterpillars, and blood stars as if to celebrate a Christmas held millennia before the arrival of the putative guest of honor. A jungle of more advanced vertebrates nest in the canopy—as in New York City, priority manifests as altitude—until finally, Man, having alighted last, rides highest of the higher mammals; he commands the branch closest to heaven, his eminence depending on the slightest twig.
These models are models of necessity: they ordain a trackable past and a reasonably foreseeable future for every constituent, from plants to prime ministers, from mollusks to Machiavelli, from algae to Elvis. It’s safe to say that they are not the only options. Once the standing committee rescinded the biblical image of the ark, with every current animal and animal to come coupled in its impossible cargo, once the suspicion arose that our souls are not outsourced by the Lord Himself, there must have been other proposals that received a hearing. Consider a layout on the order of the London Underground, with each species stationed on its isolated platform; some will catch expresses, some will get stuck on local lines, and some bygone animals will remain stranded altogether. Picture the whirling Earth as a centrifuge whose populations separate and resolve. What about an Escher-inspired digestive system, whose contents are constantly being circulated, absorbed, or expelled? Or a bank of elevators. A miraculously engendering rainfall that precipitates everyone in its spill. The interstate highway system. A charm bracelet. The ultimate gumbo. An immense Pachinko game, whose random paths and probabilities our advents take. The interstices of the U.S. Tax Code—how many have perished trying to navigate its narrows?—or the financial agent’s ledger, in which each of us is listed as a credit and a debit together, as once and future dust. Try the declension of government powers, with its Hobbesian population vying for perks and office space, and with its cubicles checked and balanced against one another. A theater, whose structured seating chart ranges from the simplest groundlings to the lucky personages occupying the royal box. Then again, maybe Creation comes down to a construction as common as boxes stacked in a closet. (Going by such a diagram, with all species wrapped in boxed sets, it is obvious that caskets are the main thing living things share.) These and a hundred other wayward arrangements might serve the idiosyncrasies science encounters.
All this proves is that the details of evolution (whether God, the devil, or any engineer is in the details or not) are maddeningly obscure, like an argument in a distant room. Life has been conceived in the conditional tense. We might think of these depictions as “whether patterns,” if we may be pardoned the pun. Because in a sense every animal update puns on the shape and function of its parent, by punning ourselves we are merely borrowing from evolution’s own figurative history, anyway. Out of the ocean’s endless approaches and approximations life began, and ever since, approaches and approximations describe its perpetuation and perpetuate its description.
Given a choice of metaphors, I prefer a flip book: even though agile handling provides the illusion of a smooth evolution, closer inspection reveals gaps in the manuscript, which current findings in the fossil record confirm. The gaps, though, are what gall us most. The unseen shoving that upsets the queue. Some species prevail, some are plowed over, and if nothing else is known for certain, it is clear that it isn’t virtue that got us and any other chosen taxonomy through the gate.
One might say, in an attempt to appease the creationists, that the Tree of Life doesn’t fall far from the apple. Breaks in the terrestrial manuscript, however, do not mean that creationists win the day, much less the definition of time. If the evolutionists’ version of the world is based on generation after generation of subtle paraphrase, the creationists’ is a stupor of continuity plagiarized verbatim from God. No said-and-done scheme they might devise accommodates any organic scrap we’ve encountered so well as the incremental Genesis evolution subscribes to.
The ascension of cells, whether envisioned as a race, a ripple effect, or a totemic orchard, may conclude with humanity, but recent studies make mankind look less and less mandatory. Lest we get too smug about our fifteen seconds of geologic dominance, Stephen Jay Gould reminds us that “progress does not rely (and is not even a primary thrust of) the evolutionary process.” The same disclaimers go for Homo sapiens. Organisms earn no extra credit for complexity. There is no special award for gorgeousness, either. Human supremacy, for what it’s worth and so long as it lasts, smacks of some vague exchange of favors behind the scenes. The history of habitation is narrated as a bildungsroman, and human beings are the author, hero, and happy ending. But once we “see the Earth again, / Cleared of its stiff and stubborn, man-locked set,” as Wallace Stevens’s angel of reality advises we do, existence becomes a shell game. Furthermore, fossil evidence is hearsay that doesn’t automatically hold up in court, and whatever chart we employ is an elaborate confession of extenuating circumstances. And when we add to that the fact that man’s recent reign has lasted, oh, about two percent as long as the frog’s did, it’s pretty hard to muster much arrogance.
Scientists bandy the beaks of finches and debate the opalescence of the inshore squid, but surely there is no more relevant concern for the layman than by what sort of ape the scientists themselves were fathered. In Herzog, Saul Bellow’s hero devotes one of his notorious mental letters to the issue of our issue: “Latest intelligence from the Olduvai Gorge in East Africa gives grounds to suppose that man did not descend from a peaceful arboreal ape, but from a carnivorous, terrestrial ape, a beast that hunted in packs and crushed the skulls of prey with a club or femoral bone.” Even if genetics
