A short history of nearly everything (60 page)

So instead the name and credit for the discovery of the first early humans went to the Neander Valley in Germany—not unfittingly, as it happens, for by uncanny coincidenceNeander in Greek means “new man.” There in 1856 workmen at another quarry, in a cliff face overlooking the Düssel River, found some curious-looking bones, which they passed to a local schoolteacher, knowing he had an interest in all things natural. To his great credit the teacher, Johann Karl Fuhlrott, saw that he had some new type of human, though quite what it was, and how special, would be matters of dispute for some time.

Many people refused to accept that the Neandertal bones were ancient at all. August Mayer, a professor at the University of Bonn and a man of influence, insisted that the bones were merely those of a Mongolian Cossack soldier who had been wounded while fighting in Germany in 1814 and had crawled into the cave to die. Hearing of this, T. H. Huxley in England drily observed how remarkable it was that the soldier, though mortally wounded, had climbed sixty feet up a cliff, divested himself of his clothing and personal effects, sealed the cave opening, and buried himself under two feet of soil. Another anthropologist, puzzling over the Neandertal’s heavy brow ridge, suggested that it was the result of long-term frowning arising from a poorly healed forearm fracture. (In their eagerness to reject the idea of earlier humans, authorities were often willing to embrace the most singular possibilities. At about the time that Dubois was setting out for Sumatra, a skeleton found in Périgueux was confidently declared to be that of an Eskimo. Quite what an ancient Eskimo was doing in southwest France was never comfortably explained. It was actually an early Cro-Magnon.)

It was against this background that Dubois began his search for ancient human bones. He did no digging himself, but instead used fifty convicts lent by the Dutch authorities. For a year they worked on Sumatra, then transferred to Java. And there in 1891, Dubois—or rather his team, for Dubois himself seldom visited the sites—found a section of ancient human cranium now known as the Trinil skullcap. Though only part of a skull, it showed that the owner had had distinctly nonhuman features but a much larger brain than any ape. Dubois called itAnthropithecus erectus (later changed for technical reasons toPithecanthropus erectus ) and declared it the missing link between apes and humans. It quickly became popularized as “Java Man.” Today we know it asHomo erectus .

The next year Dubois’s workers found a virtually complete thighbone that looked surprisingly modern. In fact, many anthropologists think itismodern, and has nothing to do with Java Man. If it is anerectus bone, it is unlike any other found since. Nonetheless Dubois used the thighbone to deduce—correctly, as it turned out—thatPithecanthropus walked upright. He also produced, with nothing but a scrap of cranium and one tooth, a model of the complete skull, which also proved uncannily accurate.

In 1895, Dubois returned to Europe, expecting a triumphal reception. In fact, he met nearly the opposite reaction. Most scientists disliked both his conclusions and the arrogant manner in which he presented them. The skullcap, they said, was that of an ape, probably a gibbon, and not of any early human. Hoping to bolster his case, in 1897 Dubois allowed a respected anatomist from the University of Strasbourg, Gustav Schwalbe, to make a cast of the skullcap. To Dubois’s dismay, Schwalbe thereupon produced a monograph that received far more sympathetic attention than anything Dubois had written and followed with a lecture tour in which he was celebrated nearly as warmly as if he had dug up the skull himself. Appalled and embittered, Dubois withdrew into an undistinguished position as a professor of geology at the University of Amsterdam and for the next two decades refused to let anyone examine his precious fossils again. He died in 1940 an unhappy man.

Meanwhile, and half a world away, in late 1924 Raymond Dart, the Australian-born head of anatomy at the University of the Witwatersrand in Johannesburg, was sent a small but remarkably complete skull of a child, with an intact face, a lower jaw, and what is known as an endocast—a natural cast of the brain—from a limestone quarry on the edge of the Kalahari Desert at a dusty spot called Taung. Dart could see at once that the Taung skull was not of aHomo erectus like Dubois’s Java Man, but from an earlier, more apelike creature. He placed its age at two million years and dubbed itAustralopithecus africanus , or “southern ape man of Africa.” In a report toNature , Dart called the Taung remains “amazingly human” and suggested the need for an entirely new family,Homo simiadae (“the man-apes”), to accommodate the find.

The authorities were even less favorably disposed to Dart than they had been to Dubois. Nearly everything about his theory—indeed, nearly everything about Dart, it appears—annoyed them. First he had proved himself lamentably presumptuous by conducting the analysis himself rather than calling on the help of more worldly experts in Europe. Even his chosen name,Australopithecus , showed a lack of scholarly application, combining as it did Greek and Latin roots. Above all, his conclusions flew in the face of accepted wisdom. Humans and apes, it was agreed, had split apart at least fifteen million years ago in Asia. If humans had arisen in Africa, why, that would make usNegroid , for goodness sake. It was rather as if someone working today were to announce that he had found the ancestral bones of humans in, say, Missouri. It just didn’t fit with what was known.

Dart’s sole supporter of note was Robert Broom, a Scottish-born physician and paleontologist of considerable intellect and cherishably eccentric nature. It was Broom’s habit, for instance, to do his fieldwork naked when the weather was warm, which was often. He was also known for conducting dubious anatomical experiments on his poorer and more tractable patients. When the patients died, which was also often, he would sometimes bury their bodies in his back garden to dig up for study later.

Broom was an accomplished paleontologist, and since he was also resident in South Africa he was able to examine the Taung skull at first hand. He could see at once that it was as important as Dart supposed and spoke out vigorously on Dart’s behalf, but to no effect. For the next fifty years the received wisdom was that the Taung child was an ape and nothing more. Most textbooks didn’t even mention it. Dart spent five years working up a monograph, but could find no one to publish it. Eventually he gave up the quest to publish altogether (though he did continue hunting for fossils). For years, the skull—today recognized as one of the supreme treasures of anthropology—sat as a paperweight on a colleague’s desk.

At the time Dart made his announcement in 1924, only four categories of ancient hominid were known—Homo heidelbergensis, Homo rhodesiensis, Neandertals, and Dubois’s Java Man—but all that was about to change in a very big way.

First, in China, a gifted Canadian amateur named Davidson Black began to poke around at a place, Dragon Bone Hill, that was locally famous as a hunting ground for old bones. Unfortunately, rather than preserving the bones for study, the Chinese ground them up to make medicines. We can only guess how many pricelessHomo erectus bones ended up as a sort of Chinese equivalent of bicarbonate of soda. The site had been much denuded by the time Black arrived, but he found a single fossilized molar and on the basis of that alone quite brilliantly announced the discovery ofSinanthropus pekinensis , which quickly became known as Peking Man.

At Black’s urging, more determined excavations were undertaken and many other bones found. Unfortunately all were lost the day after the Japanese attack on Pearl Harbor in 1941 when a contingent of U.S. Marines, trying to spirit the bones (and themselves) out of the country, was intercepted by the Japanese and imprisoned. Seeing that their crates held nothing but bones, the Japanese soldiers left them at the roadside. It was the last that was ever seen of them.

In the meantime, back on Dubois’s old turf of Java, a team led by Ralph von Koenigswald had found another group of early humans, which became known as the Solo People from the site of their discovery on the Solo River at Ngandong. Koenigswald’s discoveries might have been more impressive still but for a tactical error that was realized too late. He had offered locals ten cents for every piece of hominid bone they could come up with, then discovered to his horror that they had been enthusiastically smashing large pieces into small ones to maximize their income.

In the following years as more bones were found and identified there came a flood of new names—Homo aurignacensis, Australopithecus transvaalensis, Paranthropus crassidens, Zinjanthropus boisei,and scores of others, nearly all involving a new genus type as well as a new species. By the 1950s, the number of named hominid types had risen to comfortably over a hundred. To add to the confusion, individual forms often went by a succession of different names as paleoanthropologists refined, reworked, and squabbled over classifications. Solo People were known variously asHomo soloensis, Homo primigenius asiaticus, Homo neanderthalensis soloensis, Homo sapiens soloensis, Homo erectus erectus, and, finally, plainHomo erectus .

In an attempt to introduce some order, in 1960 F. Clark Howell of the University of Chicago, following the suggestions of Ernst Mayr and others the previous decade, proposed cutting the number of genera to just two—AustralopithecusandHomo —and rationalizing many of the species. The Java and Peking men both becameHomo erectus . For a time order prevailed in the world of the hominids.[47]It didn’t last.

After about a decade of comparative calm, paleoanthropology embarked on another period of swift and prolific discovery, which hasn’t abated yet. The 1960s producedHomo habilis , thought by some to be the missing link between apes and humans, but thought by others not to be a separate species at all. Then came (among many others)Homo ergaster, Homo louisleakeyi, Homo rudolfensis, Homo microcranus, andHomo antecessor , as well as a raft of australopithecines:A.afarensis, A. praegens, A. ramidus, A. walkeri, A. anamensis , and still others. Altogether, some twenty types of hominid are recognized in the literature today. Unfortunately, almost no two experts recognize the same twenty.

Some continue to observe the two hominid genera suggested by Howell in 1960, but others place some of the australopithecines in a separate genus calledParanthropus , and still others add an earlier group calledArdipithecus . Some putpraegens intoAustralopithecus and some into a new classification,Homo antiquus , but most don’t recognizepraegens as a separate species at all. There is no central authority that rules on these things. The only way a name becomes accepted is by consensus, and there is often very little of that.

A big part of the problem, paradoxically, is a shortage of evidence. Since the dawn of time, several billion human (or humanlike) beings have lived, each contributing a little genetic variability to the total human stock. Out of this vast number, the whole of our understanding of human prehistory is based on the remains, often exceedingly fragmentary, of perhaps five thousand individuals. “You could fit it all into the back of a pickup truck if you didn’t mind how much you jumbled everything up,” Ian Tattersall, the bearded and friendly curator of anthropology at the American Museum of Natural History in New York, replied when I asked him the size of the total world archive of hominid and early human bones.

The shortage wouldn’t be so bad if the bones were distributed evenly through time and space, but of course they are not. They appear randomly, often in the most tantalizing fashion.Homo erectus walked the Earth for well over a million years and inhabited territory from the Atlantic edge of Europe to the Pacific side of China, yet if you brought back to life everyHomo erectus individual whose existence we can vouch for, they wouldn’t fill a school bus.Homo habilis consists of even less: just two partial skeletons and a number of isolated limb bones. Something as short-lived as our own civilization would almost certainly not be known from the fossil record at all.

“In Europe,” Tattersall offers by way of illustration, “you’ve got hominid skulls in Georgia dated to about 1.7 million years ago, but then you have a gap of almost a million years before the next remains turn up in Spain, right on the other side of the continent, and then you’ve got another 300,000-year gap before you get aHomo heidelbergensis in Germany—and none of them looks terribly much like any of the others.” He smiled. “It’s from these kinds of fragmentary pieces that you’re trying to work out the histories of entire species. It’s quite a tall order. We really have very little idea of the relationships between many ancient species—which led to us and which were evolutionary dead ends. Some probably don’t deserve to be regarded as separate species at all.”

It is the patchiness of the record that makes each new find look so sudden and distinct from all the others. If we had tens of thousands of skeletons distributed at regular intervals through the historical record, there would be appreciably more degrees of shading. Whole new species don’t emerge instantaneously, as the fossil record implies, but gradually out of other, existing species. The closer you go back to a point of divergence, the closer the similarities are, so that it becomes exceedingly difficult, and sometimes impossible, to distinguish a lateHomo erectus from an earlyHomo sapiens , since it is likely to be both and neither. Similar disagreements can often arise over questions of identification from fragmentary remains—deciding, for instance, whether a particular bone represents a femaleAustralopithecus boisei or a maleHomo habilis .

With so little to be certain about, scientists often have to make assumptions based on other objects found nearby, and these may be little more than valiant guesses. As Alan Walker and Pat Shipman have drily observed, if you correlate tool discovery with the species of creature most often found nearby, you would have to conclude that early hand tools were mostly made by antelopes.

Perhaps nothing better typifies the confusion than the fragmentary bundle of contradictions that wasHomo habilis . Simply put,habilis bones make no sense. When arranged in sequence, they show males and females evolving at different rates and in different directions—the males becoming less apelike and more human with time, while females from the same period appear to be movingaway from humanness toward greater apeness. Some authorities don’t believehabilis is a valid category at all. Tattersall and his colleague Jeffrey Schwartz dismiss it as a mere “wastebasket species”—one into which unrelated fossils “could be conveniently swept.” Even those who seehabilis as an independent species don’t agree on whether it is of the same genus as us or is from a side branch that never came to anything.