The Flight of the Iguana (13 page)

Personally, I have never seen an okapi, not even in a zoo. My modest research has led me to published descriptions and anecdotes (most of those second- and thirdhand), to a few grainy photographs, and (more often, for some reason) to paintings and drawings. After three days of this, it occurred to me that the okapi might not exist.

Where is the proof, ontological or otherwise? I certainly haven't seen any. For all I know the okapi might be just a droll hoax, like the jackalope. The name itself, maybe, an anagram.
Koipa? O pika? I koap?
To the Pygmies it may stand for a month's worth of meat on the hoof, to the missionaries it may represent a road hazard, to the zookeepers it may be a precious curio, but to the rest of us (at least so it's tempting to conclude) the okapi seems less a real living animal than a riddle.

Something that Norwegian Leo understood, perhaps, from the beginning.

*   *   *

Now, Norwegian Leo is widely noted for his candor. His spontaneous, refreshing, and uncompromising directness. Some would say, his breathtaking bluntness. Once in a bar in Butte, Montana, for example, I witnessed an exchange between Leo and Whisperin' Jack, the famous medical researcher and bon vivant (who figured in a previous volume of these essays). Whisperin' Jack was describing the difficult fact that he himself longed to forsake Connecticut for Montana, while his wife wanted to move to New York City. Leo listened as though sympathetic until Jack was finished, at which point he said, “Then you'll just have to get rid of her.” On another occasion, just after I had been laid off from a job where he and I shared an office wall, Leo (fortified by his boundless sense of loyalty and a fifth of whiskey) phoned the director of the institute for which we both worked, an impeccably pin-striped man whose ghost writer I had been and who was Leo's own boss's boss's boss. Calling at 2
A.M
. on a Wednesday, Leo gave the director a short, trenchant discourse to the effect that firing Quammen had been an act of surpassing stupidity. Then, after identifying himself clearly by name, Leo hung up. He was a skilled engineer; he could always find a new job.

Because of a hundred moments like that, my affection for Leo is as unstinting as his candor. So naturally I flinched just a little when I came upon the evidence, finally, that Leo had suckered me on this whole okapi deal.

Yes, I suspect that the okapi does exist. That's not the issue. There was this other bit of data, tucked in among all the bizarre and less bizarre facts I had been combing through in my sources. One phrase: “. . . and the weight is about 250 kilograms.” Another authority, more conservative, makes that 200 to 250 kilograms. In other words, roughly 500 pounds. This great mooselike, horse-shaped, zebra-striped, short-necked giraffe, which I had envisioned bashing its way crazily through the Zairian bush, kicking out radiators and tumbling thunderously into pitfalls, turns out to be about the same size as an elk. A smallish female.

Not even so hefty as a gnu. Barely bulkier than a tapir. In the same order of magnitude, actually, as a pangolin.

Leo had led me astray. Such a delicate creature couldn't possibly be the largest mammal I'd never heard of. That distinction must still belong to the dugong.

Out on a Limb in the Human Family Tree

The orang-utan is a remote sort of beast. By geography, by behavior, and by the currently prevailing view of its place within primate evolution, this species of ape known as
Pongo pygmaeus
stands apart. Consider: It survives today only on the islands of Sumatra and Borneo; it lives solitarily, not in elaborate social groups like the gorilla or the chimpanzee; it associates with its own kind for mating and infant-rearing but otherwise travels the rainforest treetops alone. And if that's not enough, a zoological encyclopedia will tell you with blustering self-assurance: “Of all the great apes, the orang-utan is the most distantly related to man.”

Pongo's
remoteness is not illusory, but that last statement might be. By the prevailing view, mankind and the chimpanzee are closely related, with the gorilla slightly more distant from us and the orang-utan a far-removed cousin. But the word “orangutan” itself comes from Malayan linguistic roots meaning “forest man,” and a new theory suggests that the label might carry a resonance more factual than poetic. The prevailing view, as Charles Darwin labored to prove, is not
always
the right one.

•   •   •

First, though, the matters of geography and behavior.

The geographic isolation of
Pongo pygmaeus
is easy enough to explain. About two million years ago orang-utans (or orang-utan ancestors) existed not just on Borneo and Sumatra but all across southern Asia. They seem to have been related (though perhaps not by direct descent) to an earlier and more ambiguous primate, an ape-like animal known now from fossil fragments as
Sivapithecus,
dating back about ten million years. The earliest
Sivapithecus
specimen was just part of a left upper jaw, with the teeth in place, discovered a century ago in the Siwalik Hills of India; since then more bits and nuggets of
Sivapithecus
have come out of the same general area—most recently the entire left side of a face, found by David Pilbeam and his colleagues in 1980. As manifest in the various specimens, the
Sivapithecus
creature had spade-like incisors and flat molars with thick enamel, suggesting that it might have fed mainly on fruit, like modern orang-utans. On the other hand, certain aspects of the teeth and the jaws seemed also to hint toward the human line. As early as 1915 scientists were arguing in print about whether these Siwalik fossils should be assigned to the human branch of the family tree or to the orang-utan's.
Sivapithecus
itself disappeared from the fossil record about eight million years ago, leaving no immediate descendants that have been discovered so far. What followed after it, what followed
from
it, remains a mystery.

Roughly six million years later came the prehistoric orangutans, larger than the modern species and possibly more terrestrial, bold enough to descend from the trees and undertake some ambitious travel. Their distribution stretched up into China. During a period of cold climate and lowered sea level they must also have made a peninsular, dry-land crossing from the Asian mainland to what are now the islands of Java, Sumatra, and Borneo. Then around a million years ago primitive humans (in the form of
Homo erectus)
arrived in Southeast Asia, with their primitive but effective methods of hunting. They even reached
Java—as the term “Java Man,” one of many for
Homo erectus,
commemorates. The orang-utans of the mainland and Java were extinguished. But on Sumatra and Borneo—now protected beyond water gaps, safe from
Homo
and other predators—they remained. They adapted to a totally arboreal life. And so they survived to the present day.

Modern orang-utans almost never come down to the ground. They are too large to be as acrobatic as monkeys and gibbons, so they make their way slowly and carefully from limb to limb, tree to tree, gripping with both hands and feet, methodical in their progress, taking no reckless leaps. Despite their great bulk and the energy spent on all that hard climbing, they live almost entirely on fruit. The behavioral solitude of the species, so different from the sociability of other big apes, seems to be a natural requirement of this unique orang-utan ecology.

A British zoologist named John MacKinnon has explained it beautifully, based on his two years of field study in the jungles of Borneo and Sumatra. According to MacKinnon, the orangutan's unsociable behavior is not instinctive but learned. His observations (reported in a long article in the journal
Animal Behavior,
and in several popular books) revealed that juveniles of the species
do
have an inborn interest in playmates of their own kind. Their mothers, though, enforce a strict separation of family groups, dragging youngsters away from each other. Adult males also keep their distance from each other and (except at mating) from the individual females. “But why are adult orang-utans so solitary?” MacKinnon asks. “The answer lies in the distribution of fruit foods in the Asian rainforest.”

The jungles of Borneo contain perhaps three thousand species of tree. Within the range of a single orang-utan there might be 250 species that occasionally bear fruit or some other edible part. This might sound like bountiful pickings for a vegetarian, but the corollary to such breadth of variety is that no species of fruit tree grows in a concentrated clump; the members of any species are
scattered widely through the forest, each one as solitary as the big lonesome ape. “Thus there are large distances between trees that are in fruit at the same time, but the orang-utan is slow-moving and able to search only a small area each day,” writes MacKinnon. A large family or a tribe of orang-utans, traveling slowly as they do, would find no more food in one day than a single orang-utan can, but would have to divide that food among many more mouths. On Borneo especially the orang-utan has few natural predators (except, nowadays, man) from which an alert social group might offer protection, and the task of finding and gathering food requires no cooperative effort. So the animals operate as loners.

There's another fascinating dimension to this outwardly simple life. Full-grown orang-utans can't afford to lumber along randomly through the trees, hoping to blunder upon food; they need to conserve time and energy by systematically visiting one fruiting tree after another. This isn't easy. Some of the rainforest trees bear fruit every few months, some on annual or biannual or multiple-year cycles, and so the pattern of available fruit in a given stretch of jungle is complicated across space and time, by botanical rhythms and signals of readiness and the matter of what species of tree is located where. Orang-utans are faced with learning that pattern, then playing it like a game of Concentration. And they play like winners. Despite covering less area than its smaller and faster competitor, the gibbon, an orang-utan manages to find more fruit. “The orang-utan shows a simply uncanny ability to locate fruit,” writes John MacKinnon, “and his secret is superior brainpower.”

MacKinnon goes further. He rejects the idea that primate intelligence has evolved in direct relation to social complexity, as supposedly reflected in chimp and gorilla societies. MacKinnon's alternative? “The truth is that ape intelligence was evolved in response to the difficulty of locating fruit in tropical rainforests.”

•   •   •

If this seems mildly provocative, an even bolder bit of orang-utan heterodoxy comes now from a scientist named Jeffrey H. Schwartz. Schwartz is a physical anthropologist at the University of Pittsburgh, and unlike MacKinnon he has not devoted years of his life (“constantly being drained by biting flies, ticks and bloodsucking leeches, clinging mud and tearing thorns, oppressive heat and humidity, the growing weight of [one's] pack, regular drenching by tropical downpours, loneliness, hunger, thirst, and despondency,” as MacKinnon reminisces cheerfully) to stalking orang-utans in the wild. Schwartz is a theorist. He does his research in museum collections and libraries. He has focused on primate anatomy, not primate behavior—and in particular on the comparative anatomy of the orang-utan and of that ambiguous fossil ape,
Sivapithecus.
Based on a modest but tantalizing cluster of evidence, he proposes that the orang-utan is our own closest living relative.

It's the chimpanzee and the gorilla, according to Schwartz, that are remote from us
Pongo
and
Homo
types.

A few years ago Schwartz first advanced this theory with an article in the journal
Nature.
Then in 1987 he published a book titled
The Red Ape: Orang-utans and Human Origins,
which presents the idea at much greater (sometimes tedious) length. Schwartz's evidence and his logic are far too complex to be done justice here, in a brief essay. Let it suffice to say that the whole question of primate relationships involves (among other sorts of evidence) anatomical resemblances and molecular resemblances; and that the molecular resemblances
do
seem to link us with chimps, but the anatomical record (especially as manifested in teeth, jaws, and skulls) is another matter. Schwartz argues that the molecular evidence is inconclusive, but that anatomical analysis shows a special kinship between the orang-utan and the human. “
Homo
and
Pongo
are set apart by their low-cusped cheek-teeth and thick molar enamel,” he writes, “as well as by the restriction of the double incisive foramina to a single opening
palatally,” and that's only the start. Never mind what a double incisive foramen is, or why it might pinch down to a single opening through the palate—the crucial point is that humans and orang-utans both have one, and that it does thus pinch down to one opening.