Bully for Brontosaurus (46 page)

Osborn described the tooth of
Hesperopithecus
as “a second or third upper molar of the right side of a new genus and species of anthropoid.” Osborn did lean toward human affinity, based both on the advice of his colleague Gregory (see point three below) and, no doubt, on personal hope and preference: “On the whole, we think its nearest resemblances are with…men rather than with apes.” But his formal description left this crucial question entirely open:

An illustration from Osborn’s article of 1922, showing the strong similarity between worn teeth of
Hesperopithecus
and modern humans.
NEG. NO. 2A17804. COURTESY DEPARTMENT OF LIBRARY SERVICES, AMERICAN MUSEUM OF NATURAL HISTORY
.

3.
Encouragement of further study
. If Osborn had been grandstanding with evidence known to be worthless or indecipherable, he would have made his public point and then shut up after locking his useless or incriminating evidence away in a dark drawer in the back room of a large museum collection. Osborn proceeded in exactly the opposite way. He did everything possible to encourage further study and debate, hoping to resolve his own strong uncertainties. (Osborn, by the way, was probably the most pompous, self-assured S.O.B. in the history of American paleontology, a regal patrician secure in his birthright, rather than a scrappy, self-made man. He once published a book devoted entirely to photographs of his medals and awards and to a list of his publications; as an excuse for such vanity, he claimed that he harbored only a selfless desire to inspire young scientists by illustrating the potential rewards of a fine profession. “Osborn stories” are still told by the score wherever vertebrate paleontologists congregate. And when a man’s anecdotes outlive him by more than half a century, you know that he was larger than life. Thus, the real news about
Hesperopithecus
must be that, for once, Osborn was expressing genuine puzzlement and uncertainty.)

In any case, Osborn reached out to colleagues throughout the world. He made numerous casts of
Hesperopithecus
and sent them to twenty-six universities and museums in Europe and North America. As a result, he was flooded with alternative interpretations from the world’s leading paleoanthropologists. He received sharp criticisms from both sides: from Arthur Smith Woodward, describer of Piltdown, who thought that
Hesperopithecus
was a bear (and I don’t mean metaphorically), and from G. Elliot Smith, another “hero” of Piltdown, who became too enthusiastic about the humanity of Osborn’s tooth, causing considerable later embarrassment and providing creationists with their “hook.” Osborn tried to rein both sides in, beginning his
Nature
article with these words:

Moreover, Osborn immediately enlisted his colleague W. K. Gregory, the acknowledged local expert on primate teeth, to prepare a more extensive study of
Hesperopithecus
, including a formal comparison of the tooth with molars of all great apes and human fossils. Gregory responded with two detailed, technical articles, both published in 1923 with the collaboration of Milo Hellman.

Gregory followed Osborn in caution and legitimate expression of doubt. He began his first article by dividing the characters of the tooth into three categories: those due to wear, to subsequent erosion, and to the genuine taxonomic uniqueness of
Hesperopithecus
. Since the first two categories, representing information lost, tended to overwhelm the last domain of diagnostic biology, Gregory could reach no conclusion beyond a basic placement among the higher primates:

In the second and longer article, Gregory and Hellman stuck their necks out a bit more—but in opposite directions. Hellman opted for the human side; Gregory for affinity with “the gorilla-chimpanzee group.”

4.
Gathering of additional data
. Osborn knew, of course, that a worn and eroded tooth would never resolve the dilemma of
Hesperopithecus
, no matter how many casts were made or how many paleontologists peered down their microscopes. The answers lay in more data buried in the sands of Nebraska, and Osborn pledged, in his diatribe against Bryan, to make the earth speak further:

To his professional audiences in
Nature
, Osborn made the same pledge with more detail: “We are this season renewing the search with great vigor and expect to run every shovelful of loose river sand which comprises the deposit through a sieve of mesh fine enough to arrest such small objects as these teeth.”

Thus, in the summers of 1925 and 1926, Osborn sent a collecting expedition, led by Albert Thomson, to the Snake Creek beds of Nebraska. Several famous paleontologists visited the site and pitched in, including Barnum Brown, the great dinosaur collector; Othenio Abel of Vienna (a dark figure who vitiated the memory of his fine paleontological work by later activity in the Austrian Nazi party); and Osborn himself. They found abundant material to answer their doubts. The earth spoke both audibly and distinctly, but not in the tones that Osborn had anticipated.

5.
Retraction
. After all this buildup and detail, the denouement can only be described as brief, simple, and conclusive. The further expeditions were blessed with success. Abundant new specimens destroyed Osborn’s dream for two reasons that could scarcely be challenged. First, the new specimens formed a series from teeth worn as profoundly as
Hesperopithecus
to others of the same species with crown and cusps intact. The diagnostic pattern of the unworn teeth proclaimed pig rather than primate. Second, the unworn teeth could not be distinguished from premolars firmly residing in a peccary’s palate found during a previous expedition. Osborn, who was never praised for a charitable nature, simply shut up and never mentioned
Hesperopithecus
again in his numerous succeeding articles on human ancestry. He had enjoyed the glory, but he let Gregory take the heat in a forthright retraction published in
Science
(December 16, 1927):

Why should the detractors of science still be drawing such mileage from this simple story of a hypothesis swiftly refuted by science working well? I would divide the reasons into red herrings and a smaller number of allowable points. The red herrings all center on rhetorical peculiarities that anyone skilled in debate could use to advantage. (Debate, remember, is an art form dedicated to the winning of arguments. Truth is one possible weapon, rarely the best, in such an enterprise.) Consider three good lines:

1. “How can you believe those evolutionists if they can make monkeys out of themselves by calling a pig a monkey?” As a trope of rhetoric, given the metaphorical status of pigs in our culture, the true affinity of
Hesperopithecus
became a blessing for creationists. What could possibly sound more foolish than the misidentification of a pig as a primate. My side might have been better off if
Hesperopithecus
had been, say, a deer or an antelope (both members of the order Artiodactyla, along with pigs, and therefore equally far from primates).

Yet anyone who has studied the dental anatomy of mammals knows immediately that this seemingly implausible mix-up of pig for primate is not only easy to understand but represents one of the classic and recurring confusions of the profession. The cheek teeth of pigs and humans are astonishingly and uncannily similar. (I well remember mixing them up more than once in my course on mammalian paleontology, long before I had ever heard the story of
Hesperopithecus
.) Unworn teeth can be told apart by details of the cusps, but isolated and abraded teeth of older animals are very difficult to distinguish. The
Hesperopithecus
tooth, worn so flat and nearly to the roots, was a prime candidate for just such a misidentification.

A wonderfully ironic footnote to this point was unearthed by John Wolf and James S. Mellett in an excellent article on Nebraska Man that served as the basis for my researches (see bibliography). In 1909, the genus
Prosthennops
was described by W. D. Matthew, Osborn’s other paleontological colleague at the American Museum of Natural History, and—guess who—the same Harold Cook who would find
Hesperopithecus
ten years later. They explicitly warned their colleagues about the possible confusion of these peccary teeth with the dentition of primates:

2. “How can you believe those evolutionists if they can base an identification on a single worn tooth?” William Jennings Bryan, the wily old lawyer, remarked: “These men would destroy the Bible on evidence that would not convict a habitual criminal of a misdemeanor.”

My rejoinder may seem like a cavil, but it really isn’t. Harold Cook did send but a single tooth to Osborn. (I do not know why he had not heeded his own previous warning of 1909. My guess would be that Cook played no part in writing the manuscript and that Matthew had been sole author of the statement. An old and admirable tradition grants joint authorship to amateur collectors who often find the material that professionals then exploit and describe. Matthew was the pro, Cook the experienced and sharp-eyed local collector.) Osborn sought comparative material in the Museum’s collection of fossil mammals and located a very similar tooth found in the same geological strata in 1908. He added this second tooth to the sample and based the genus
Hesperopithecus
on both specimens. (This second tooth had been found by W. D. Matthew, and we must again raise the question of why Matthew didn’t heed his own warning of 1909 about mixing up primates and peccaries. For Osborn showed both teeth to Matthew and won his assent for a probable primate identification. In his original description, Osborn wrote of this second tooth: “The specimen belonged to an aged animal and is so water-worn that Doctor Matthew, while inclined to regard it as a primate, did not venture to describe it.”)

Thus the old canard about basing a human reconstruction on a single tooth is false. The sample of
Hesperopithecus
included two teeth from the start. You might say that two is only minimally better than one, and still so far from a whole animal that any conclusion must be risible. Not so. One of anything can be a mistake, an oddball, an isolated peculiarity; two, on the other hand, is the beginning of a pattern. Second specimens always provide a great increment of respect. The Piltdown fraud, for example, did not take hold until the forgers concocted a second specimen.

3. “How can you believe those evolutionists if they reconstruct an entire man—hair, skin, and all—from a single tooth?” On this issue, Osborn and Gregory were unjustly sandbagged by an over-zealous colleague. In England, G. Elliot Smith collaborated with the well-known scientific artist Amedee Forestier to produce a graphic reconstruction of a
Hesperopithecus
couple in a forest surrounded by other members of the Snake Creek fauna. Forestier, of course, could learn nothing from the tooth and actually based his reconstruction on the conventional rendering of
Pithecanthropus
, or Java man.