You yourself can join in the good fight without even unplugging your television. Just take a day or an hour each month to think carefully about something that nobody else deems worthy of contemplation. Break stride. Wander off mentally. Pick a subject so perversely obscure that it can’t help but have neglected significance. If everyone else is thinking about the sad and highly visible deaths of seven astronauts, think about the Scottsboro Boys. If everyone else is thinking about the Super Bowl, think about a quiet little story called “The Loneliness of the Long-Distance Runner.” If everyone else is busy despising Ferdinand Marcos, devote a few minutes of loathing to Fulgencio Batista. Or think about earthworms.
Think about the Australian species, Megascolides australis, that grows ten feet long and as big around as a bratwurst. Think about Lumbricus terrestris, familiar to soil scientists as the common European earthworm and to generations of American boyhood as the night crawler, nowadays gathered at night by professional pickers on Canadian golf courses and imported into the U.S. for a total value of $13 million per year. Think about how hard it is to tell front from rear, especially so since they can back up. Think about the curious reproductive arrangement of earthworm species generally, hermaphroditic but not self-fertilizing, so that each one during the act of mating provides sperm for its partner’s eggs while receiving back the partner’s sperm for its own eggs; now imagine having a full sister whose mother was your father. Think about the fact that these animals can regenerate a lost head. Think about the formation of vegetable mould, and the relentless swallowing, digesting, burrowing, and casting off of waste by which earthworms topple and bury the monuments of defunct civilizations while freshening the soil for new growth. Think about how sometimes it’s the little things that turn the world inside out.
THE THING WITH FEATHERS
Is It a Bird,
Is It a Dinosaur,
or Is It Much More?
For today, a brief verbal Rorschach: What is the thing with feathers?
Don’t rush your answer. Take some time. Allow your mind to billow and glide. If you’ve already said “A bird, of course. A bird is the thing with feathers,” your test results indicate a latent aptitude for work as a punch-press operator. The question is just possibly a good bit more complicated.
Hope, according to Emily Dickinson, is “the thing with feathers” that perches in the soul, singing a tune without words. Woody Allen disagrees. “How wrong Emily Dickinson was!” he has written in a published selection from the Allen notebooks. “Hope is not ‘the thing with feathers.’ The thing with feathers has turned out to be my nephew. I must take him to a specialist in Zurich.” It can get highly confusing, as you see, and even more so when you consider that an international group of distinguished paleontologists convened during the summer of 1984 in the small town of Eichstätt, Bavaria, to haggle among themselves on the very same issue. What is the thing with feathers?
Those scientists, divided raucously on particulars, did have one point of consensus. They were all concerned with a creature called Archaeopteryx.
Archaeopteryx is simply the oldest thing with feathers that mankind has ever unearthed. It was an animal. It is known from just six fossil specimens. It lived about 160 million years ago, in the heyday of the dinosaurs. It was first discovered in the early years of the Darwinian revolution and played a crucial role in giving impetus to that revolution, yet it remains today one of the pivotal unsolved riddles of paleontology. It had a long bony tail, it had teeth, it had the skeletal anatomy of a small dinosaur—and it had feathers, exactly like those of a modern bird.
This much is indisputable, literally written in stone. Say anything more about Archaeopteryx, and you have taken a controversial position.
• • •
There is no question today, among paleontologists, that birds evolved originally from a line of reptilian ancestors. Skeletal anatomy alone is enough to show a close kinship between modern birds and certain primitive reptiles. But the intermediate stages in that transmogrification are rather more of a mystery. No one knew what sort of creature might have been the missing link between reptile and bird—until the discovery of Archaeopteryx.
The first Archaeopteryx specimen ever recognized was just the impression of a single feather, preserved with startling precision in a piece of limestone. It turned up in 1861 at a rock quarry near the Bavarian village of Solnhofen, not far from Eichstätt, and announced itself to the world like the portentous opening chord of an overture to a wild opera. It had defied the odds, that feather, captured with photographic fidelity in the same fine-grain limestone that made Solnhofen rock highly valued for lithographic printing. It was the size and shape of a primary feather from the wing of a pigeon, and one German scientist wrote of it blandly as evidence of a fossil bird. Then almost immediately there came a related find from the same area of Solnhofen limestone. This one was a full skeleton, thoroughly fledged with the same sort of feathers; the anatomy otherwise, though, seemed purely dinosaurian. It was dubbed Archaeopteryx, a reasonably safe formulation meaning “ancient wing.”
The Origin of Species had been published just two years before, and the notion of a transitional form between reptiles and birds (between any two groups of creatures) was as provocative as any idea in European science. To the anti-Darwinists (mainly churchmen and conservative scientists) Archaeopteryx had to be either a bird, period, or a reptile, period, or else it was some sort of sick-minded hoax. To the Darwinists it was precisely the sort of missing-link evidence that could give dramatic support to their theory. What is the thing with feathers? The disputation began.
In 1877 a second complete Archaeopteryx was uncovered, again from the Solnhofen quarries. Evidently the animal had been fairly abundant in this area during the late Jurassic period, when those fine-grain limestone strata were being laid down. This second full specimen—preserved in a natural pose, showing excellent detail on both bones and feathers—was recognized as a rare scientific treasure and snatched up for a museum in Berlin. One expert has said of it: “The Berlin Archaeopteryx may well be the most important natural history specimen in existence, perhaps comparable in value to the Rosetta stone.” Maybe so, but the hieroglyphics in question here still haven’t been conclusively deciphered.
Three more specimens have been found in this century, none nearly so graphic as the Berlin fossil, but all nonetheless precious. The second of those had actually been dug up back in 1855 (near Eichstätt, once again) and incorrectly identified for 113 years as a pterodactyl. The last showed only the faintest feather impressions, which were overlooked, and it spent two decades mistakenly labeled as Compsognathus, which is a small dinosaur.
To say that Archaeopteryx is known from “just six fossil specimens” might be somewhat misleading. For such a delicate creature, a species with small bones and fragile feathers that disappeared 160 million years ago, six decent specimens amounts to a lot. Thanks to a convergence of accidents—six individual deaths, occurring at just the right place and time to be preserved within fine-grain sediments, and later discovered largely because mankind had a commercial reason for excavating those same sediments—Archaeopteryx is exceptionally well represented within the fossil record. Between it and the next-oldest bird or bird-like fossil there stretches a gap of ten million years, and not nearly so much is known about that next-oldest relative. Disproportionally well documented, Archaeopteryx nevertheless (or maybe therefore) raises a disproportionate number of questions.
To paleontologists this creature is by now a familiar riddle. But, familiar or not, it’s still very much a riddle.
• • •
How did flight begin among birds?
Why did it begin?
Were the dinosaurs warm-blooded or cold-blooded?
Is a chicken more closely related to a crocodile or to Tyrannosaurus rex?
Did feathers come into existence for aerodynamic reasons or as insulation to keep body heat in—or maybe to serve as adjustable reflectors that kept heat out?
Were the predecessors of birds runners or tree climbers? Were they jumpers or were they gliders?
Did warm-bloodedness evolve two separate times—once in our mammal lineage and once among birds—or did we all inherit that handy attribute from a frisky two-legged dinosaur?
Did the dinosaurs ever really go extinct? Or do they survive among us today, in discreet and more humble forms such as Turdus migratorius, the robin? Are feathers merely the means that allowed dinosaurs, while becoming smaller, to stay warm?
If a bird can fly, why can’t I?
• • •
To each of those questions the Archaeopteryx evidence is central. But that evidence is as resonantly ambiguous as a good haiku poem. Read from it what you will. Prove with it what you can. That’s what the scientists have been doing with it for a century and a quarter. And it isn’t their fault that Archaeopteryx lies there, sphinx-like, on its beige limestone slabs, granting many answers but no certainty.
The runners-versus-climbers controversy is a good example. From the time of Darwin right up through the Eichstätt conference in 1984, this has been one of the most fundamental dichotomies within the range of interpretations of Archaeopteryx. Some paleontologists have insisted that Archaeopteryx evolved from a tree-climbing dinosaur, which jumped from its high perches, then later developed gliding ability, then finally flew. Others have argued that Archaeopteryx came from the ground up, a fleet bipedal runner that stretched out its arms, leaping and sailing, until it developed the wing power to get airborne. These two schools of opinion know themselves respectively as the arborealists and the cursorialists. If you are an arborealist on the subject of Archaeopteryx, your professional attitude inclines toward polite but dogmatic scorn for all misguided cursorialists. And vice versa.
The arborealists point out that flight of some kind or another, from modest gliding to powered flapping, has evolved separately no less than sixteen times among the nonavian vertebrate animals—that is, in four distinct groups of flying fishes, in one frog, in two groups of extant reptiles as well as the pterosaurs, in two kinds of flying squirrels, in bats, and in three kinds of marsupials, not to mention a few other weird little kamikaze mammals that neither you nor I have ever heard of. Among those sixteen instances, all but the flying fish and maybe the pterosaurs are known to have gotten their start as tree climbers. The force of statistical probability, as well as the force of gravity, seems to favor the arborealist side.
So what? say the cursorialists. Evolution is not roulette. And besides, they say, the case of feather-assisted bird flight is obviously a drastic exception to the general pattern—peregrine falcons and hummingbirds are spectacularly proficient, after all, while those poor cloddish “flying” frogs and lizards and squirrels are still careening down half out of control and slamming themselves into tree trunks. Furthermore, say the cursorialists, it is hard to imagine Archaeopteryx doing much tree climbing with those long primary feathers sticking way out past its foreleg claws. Try opening your car door while wearing an outfielder’s mitt on each hand, and you’ll appreciate the problem.
To all of which the arborealists, of course, have ready rebuttals.
The first of the arborealists was none other than Othniel C. Marsh, a preeminent figure in American paleontology during the nineteenth century, and one of the two principals behind the great wild dinosaur wars that were fought out between rival collectors in frontier Montana and Wyoming. (The other paleontological warlord was Edwin Drinker Cope, and it’s a bizarre story all to itself.) Concerning the evolution of flight, Marsh argued: “In the early arboreal birds, which jumped from branch to branch, even rudimentary feathers on the forelimbs would be an advantage as they would tend to lengthen a downward leap or break the force of a fall.” Arguing the other view, among the first of the cursorialists, was Franz Baron Nopcsa von Felso-Szilvas, an elusive but unmistakably demented Hungarian who happens to be my own personal favorite in the paleontological pantheon. Baron Nopcsa was a brilliant prodigy who made significant contributions toward the study of Archaeopteryx until certain other interests pulled him aside toward Albania, motorcycle touring, and death.
Nopcsa was born in Transylvania, always a good sign. He published his first paleontological monograph as a university freshman, and thereafter turned into an arrogant snot. Somehow he became infatuated with the geography and ethnography of Albania. He learned the dialects, amassed a huge library of books about the country, made many visits; eventually he offered himself for the position of King of Albania, based on what he considered his surpassing competence for the job, but the Hapsburg overlords picked someone else. During World War I he served the Austro-Hungarian Army as a spy along the Romanian border, letting his hair grow and dressing as a Romanian peasant. He spoke the languages. He passed. Much later, when he was bored and impoverished, his baronial lands having been confiscated in the peace settlement, he took off on a long motorcycle ramble with his male lover, an Albanian named Bajazid. Finally, in April 1933, for reasons we’ll never know, Nopcsa came to the end of his tether. He slipped Bajazid a mickey, shot him through the head, then put the pistol to himself. But before he died—in fact, it was way back in 1907—Baron Nopcsa had published a paper titled “Ideas on the Origin of Flight.” The central datum was of course Archaeopteryx.
Nopcsa wrote: “We may quite well suppose that birds originated from bipedal long-tailed cursorial reptiles which during running oared along in the air by flapping their free anterior extremities. By gradually increasing in size, the enlarged but perhaps horny hypothetical scales [would] . . . ultimately develop to actual feathers; this epidermic cover would also raise the temperature of the body, and thus help to increase the mental and bodily activities of these rapacious forms.”
Nopcsa was just deranged enough (well, maybe more than enough) to be a bold, original thinker. In suggesting an earth-bound Archaeopteryx that flapped its feathered arms to help itself gain speed as it ran, he had broken through a basic assumption in the debate over whether feathers evolved first for insulation or for gliding—the assumption that, if those earliest feathers served any aerodynamic purpose, the purpose must have been flight. But ground travel too involves aerodynamics. Ask any designer of racing cars; ask anyone who rides touring motorcycles.
For three quarters of a century Nopcsa’s view was dismissed as nonsensical. Ground-travel aerodynamics seemed an unlikely precursor to feathered flight since, as soon as the animal made that next little evolutionary leap, becoming airborne, it would have lost all the running leverage from its legs; losing that leverage, it would have achieved a net decrease instead of a net increase in speed, and therefore also a net decrease in its prospects of survival. The gap between feather-assisted running and feather-assisted flying seemed evolutionarily unbridgeable. But now again the notion of ground-travel aerodynamics is being given some careful thought.
One of the hot new ideas on the subject, as of the 1984 conference in Eichstätt, is that maybe Archaeopteryx used its arm feathers as rudders, for changing direction erratically as it ran along. Assisted by aerodynamic rudders, this little beast might have streaked out a wild zigzag path across the floor of Cretaceous forests, escaping from bigger and faster predators.
The cursorialists at Eichstätt were intrigued. The arborealists were not swayed. The disputation goes on.
• • •
What is the thing with feathers? It might be a dinosaur dressed for warmth in a chicken suit. It might be the earliest bird, hot-blooded and flapping its way from tree to tree. It might be your nephew or mine or Woody Allen’s, in need of a visit to Zurich. It is a mystifying cross between fowl and reptile, a chimera sculpted in fossil stone—an oxymoronic creature that actually lived and died, rather like Baron Nopcsa himself.
It perches on the soul, this thing, singing a tune without words.
We call it Archaeopteryx. The name is Latin, standing for: Thank God there are some riddles we can’t solve.
NASTY HABITS
An
African Bedbug Buggers the Proof-by-Design
A fellow named Duane T. Gish was in town here last week, playing his practiced role in a debate on the subject of “scientific creationism” versus evolutionary theory. I didn’t go. It was dollar night at the movies. But now I regret having missed a precious opportunity, since just the next day, in my random reading, I came upon an account of the startling deportment of the hemipteran insect Xylocaris maculipennis, an animal that demands pondering by creationists and evolutionists alike. A question-and-answer period followed the debate, but with me off watching Peggy Sue Got Married and pushing popcorn into my face, the important Xylocaris maculipennis question never got asked of perhaps the one human being most qualified to attempt an answer. Namely, Duane T. Gish.
Duane T. Gish, as it turns out, is a famous (some would say, notorious) man, vice president and leading spokesman of the Institute for Creation Research, which is a fundamentalist think tank based in Santee, California. He travels across America arguing the creationist viewpoint—that the Earth is only 10,000 years old, that evolution is an atheistic delusion, that the myriad types of plants and animals which some of us think of as evolved species were all in fact created individually by God—and according to most reports he is a glib and effective debater, a man of some charm, good with crowds and capable of making fools of opponents who underestimate his intelligence. He holds a doctorate in biochemistry and seems possessed, if the photos do justice, of a bad toupee. A country slicker, is what you might call him. Xylocaris maculipennis is an African bedbug. There had to be more than blind coincidence involved in bringing this man and this insect both into my purview during the same week, but the precious opportunity nevertheless slipped past me. Dr. Gish was packed and gone to the next town before I could solicit his thoughts concerning X. maculipennis and the Proof-by-Design.
The Flight of the Iguana Page 3
