The truth about "Nebraska Man"

As I made my way around the lab table during my last human osteology practical, examining the yellowed and cracked teeth in the hopes that I'd be able to tell an upper molar from a lower one, I came across a particularly strange tooth. I had been told by the professor that 3rd molars ("wisdom teeth") can be strange and don't always conform to the rules that makes identifying other molars comparatively easy, but this specimen was simply bizarre. The arrangement of cusps and folds on the crown of the tooth didn't correspond to any of the diagrams I looked over the night before, and the roots of the teeth were even stranger. Could this tooth have come out of the mouth of a human?

Even though I wasn't able to positively identify the tooth, I discovered that I had given the right answer on the test; the tooth was not from a human. While no one was sure what the tooth actually was or where it came from (the collection as a whole is in a poor state), it most likely came from a pig. If I had said that the specimen was from a human, though, it would not have been the first time that someone made such an error. In 1922 a single tooth was discovered in Nebraska that would provide the basis for "Nebraska Man," a hypothetical hominid that fit nicely with the social & political aims of AMNH president Henry Fairfield Osborn.

Much to the embarrassment of Osborn and other researchers that had studied and defended Hesperopithecus, the tooth turned out to be from a peccary rather than any primate, and this cautionary paleoanthropological tale is celebrated amongst creationists as they feel it proves the dishonestly and feeble-mindedness of evolutionary researchers as a whole. As with any other piece of evidence a creationist may marshal, however, the story of the "discovery" of Hesperopithecus is a complex mesh of political, social, and institutional factors that ended up creating a man from a molar.

My introduction to Hesperopithecus and the accompanying controversy came (oddly enough) from creationists. As a response to a post critical of creationism that I wrote last year, I was sent a standard laundry list of "problems with evolution" by young earth creationist Paul Humber (author of Evolution Exposed). It was standard Gish gallop all the way through, but one particular assertion caught my attention;

We should not trust our origins to a pig's tooth. Nebraska Man also became part of scientific literature, but it was a colossal, scientific blunder-based on a single, pig tooth. Sir Grafton Elliot, an anatomist, commissioned a painting of this "creature" which appeared in the Illustrated London News.

Leave it to creationists to continue to blame scientists for a drama that is generally regarded as an embarrassing footnote, a mistake that I had never heard discussed outside of creationist circles. My first introduction to "Nebraska Man" came from a copy of Duane Gish's The Amazing Story of Creation I had purchased two years ago in an attempt to educate myself about creationist dogma. Gish's treatment of Nebraska Man is relatively short, and reads as follows;

In 1922 a single tooth was discovered in western Nebraska. The tooth was shown to one of America's foremost fossil experts, Dr. Henry Fairfield Osborn, professor at Columbia University. Dr. Osborn and other American experts were very excited by the appearance for this tooth. They declared that they could see, in that tooth, certain characteristics intermediate between ape and man. In fact, they weren't quite sure whether it was from an ape-like man or a man-like ape. He was given the official name of Hesperopithecus, became popularly known as Nebraska Man, and was presented as evidence that man had evolved from apes. In 1922, the Illustrated London News published a picture of Nebraska Man, his wife, and the tools they were using-all based upon the discovery of one single tooth!

A few years after the discovery of the tooth, some additional bones of the creature were discovered and Nebraska Man turned out to be neither an ape-like man nor a man-like ape. He turned out to be a pig! That's right-Nebraska Man was nothing more than a pig's tooth!

If we were to believe Gish and Humber, we would assume that a multitude of scientists endorsed Nebraska Man, only to have all of evolutionary science a black eye when the true identity of the molar was realized. How could a hominid be dreamed up and so heavily endorsed based upon just a single tooth? The truth is that Nebraska Man was never widely accepted or endorsed, and passed quickly and quietly from the scientific literature.

Historical context is key to understanding the tale of Nebraska Man. The tooth that gave rise to all this controversy was discovered in 1922, two years before the Taung specimen (the first scientifically described fossil of Australopithecus africanus) was discovered in South Africa and three years before Raymond Dart published the details of that famous fossil in Nature. Even then, researchers were skeptical of an African origin for humans, and different figures proposed different hypotheses based upon the remains of Neanderthals, Homo erectus, and Cro-Magnon grade Homo sapiens then known.

H.F. Osborn, perhaps the principal player in this story, thought that humans had evolved in Asia, but that modern humans were unrelated to any fossil forms (each had their own line of descent on an evolutionary bush and did not represent transitions). As outlined in the book An Agenda for Antiquity, though, Osborn's views of evolution (especially human evolution) were widely rejected, his main contribution to science being building a vertebrate paleontology program at the AMNH when laboratory science was growing in popularity elsewhere.

Whether or not Osborn's views were accepted by scientists isn't as important as the fact that Osborn was a known proponent of evolution, and during the time that Nebraska Man came to life Osborn was engaged in a paper battle with William Jennings Bryan. In 1923 Osborn published a book The Earth Speaks to Bryan, a short appeal for the marriage of evolution & religion as well as an attack on Bryan's views, my second edition (1925) copy featuring a dedication to John Scopes and an opening chapter about "The Tennessee Trial." Indeed, Osborn viewed himself as no less religious than Bryan, yet he abhorred Bryan's rejection of evolution and felt that evolution and religion complimented each other perfectly. According to Osborn;

The moral principle inherent in evolution is that nothing can be gained in this world without an effort; the ethical principle inherent in evolution is that only the best has the right to survive; the spiritual principle in evolution is the evidence of beauty, of order, and of design in the daily myriad of miracles which we owe our existence.

These beliefs perhaps best sum up Osborn's view of a purposeful, teleological evolution combined with his support for eugenics and his religious zeal. Reading such views now, I cannot help but think that it might have been a good thing that Osborn never made it to Dayton to testify on Scopes' behalf (although he did make a number of public appearances with Scopes when the defendant visited New York City, see Edward Larson's Summer for the Gods for an excellent summary of the trial). This is beside the point, though. Bryan, "The Great Commoner," was born in Nebraska, and I imagine that Osborn would have been overjoyed when he thought he had discovered a representative of "early man" from that very state. Again in The Earth Speaks to Bryan, Osborn wrote;

It is noteworthy that shortly after his pledge to accept the Truth appeared in 1922 ["truth is truth and must prevail." - Bryan in the New York Times, Feb. 26, 1922], the Earth spoke to Bryan and spoke from his own native State of Nebraska, in the message of a diminutive tooth, the herald of our knowledge of anthropoid apes in America. This Hesperopithecus tooth is like the "still small voice"; its sound is by no means easy to hear. Like the hieroglyphics of Egypt, it requires a Rosetta Stone to give the key to interpretation. Our Rosette Stone is comparison with all the similar grinding teeth known, collected from all parts of the world, and described or figured in learned books and illustrations. By these means this little tooth speaks volumes of truth-truth consistent with all we have known before, with all that we have found elsewhere.

Such a snippet does not do justice to the rise and fall of Nebraska Man, though, and in his piece "An Essay on a Pig Roast" (collected in Bully for Brontosaurus) Stephen Jay Gould ably put together the history of how Hesperopithecus came to be. According to Osborn's paper "Hesperopithecus, the First Anthropoid Primate Found in America," Harold Cook wrote to Osborn the day before Bryan's irritating article appeared in the New York Times, noting that he had found a tooth in Nebraska "that very closely approaches the human type." (Cook actually tried to contact paleontologist Frederick Loomis, but received no reply). Osborn, perhaps feeling like God had favored him over Bryan, replied and received the tooth on March 14, 1922, and he wrote back to Cook about his thoughts upon opening the package;

The instant your package arrived, I sat down with the tooth, in my window, and I said to myself: "It looks one hundred per cent anthropoid." I then took the tooth into Doctor Matthew's room and we have been comparing it with all the books, all the casts and all the drawings, with the conclusion that it is the last right upper molar tooth of some higher Primate, but distinct from anything hitherto described. We await, however, Doctor Gregory's verdict tomorrow morning; he certainly has an eagle eye on Primate teeth. . . . We may cool down tomorrow, but it looks to me as if the first anthropoid ape of America had been found by the one man entitled to find it, namely, Harold J. Cook!

[W.D. Matthew and W.K. Gregory were Osborn's top scientists at the AMNH and both strongly disagreed with many of Osborn's ideas about evolution despite their close personal ties. See An Agenda for Antiquity for a fuller elucidation of their relationships to Osborn.]

Despite the excitement, Osborn was not entirely sure where the fossil tooth fit. Writing in a paper published in the American Museum novitates, Osborn concludes that Hesperopithecus is close to humans but unlike any known hominid species;

...it would be misleading to speak of this Hesperopithecus at present as an anthropoid ape; it is a new and independent type of Primate, and we must seek more material before we can determine its relationships.

Still, Osborn was clearly excited about the find, and the presence of a badly worn tooth collected in 1908 that appeared to correspond with Cook's tooth bolstered the case for Nebraska Man. Another paper published by Gregory, Matthew, and Milo Hellman backed up Osborn's claims, putting Hesperopithecus as an intermediate form between Dryopithecus and Sivapithecus on a phylogenetic tree that would probably give any modern anthropologist a chuckle or two. Something more noteworthy about the paper is subtler and can only be appreciated with the benefit of hindsight; in the faunal list of the fossils found in the same location as Cook's tooth, the authors list Prosthennops cf. serus, a name that will take on great significance shortly.

Gregory and Hellman published another more detailed analysis that same year (1923), as well, the main purpose of both the elaborative papers being to defend the hypothesis that Hesperopithecus was some unknown form of human. Indeed, rather than being universally accepted, other researchers proposed all sorts of other possibilities that Gregory, Matthew, and Hellman worked to refute. Competing hypotheses asserted that the tooth more likely belong to a monkey, a bear, a rodent, a carnivore, or (my personal favorite) that it was "An incus bone of a gigantic mammal," but the AMNH researchers held fast to their interpretation.

Being that Gregory was Osborn's go-to-guy from primates, he put in much of the work behind defending Hesperopithecus, but in 1927 he would also be the scientist that would admit that Nebraska Man never existed. In a letter published in Science, Gregory summarizes the research that went into Cook's tooth, admitting that a search to find more material of Hesperopithecus turned up teeth of an extinct peccary relative called Prosthennops, leading him to sincerely doubt the reality of Hesperopithecus. A post-script by Gregory to the letter drives the final nail in the coffin for Nebraska Man;

Last summer (1927) Mr. Thomson made further excavations in the exact locality where the type of Hesperopithecus haroldcookii was discovered. A number of scattered upper and lower premolar and molar teeth were found in different spots, but every one of them appears to me to pertain to Prosthennops, and some of these also resemble the type of Hesperopithecus, except that the crown is less worn. Thus it seems to me far more probable that we were formerly deceived by the resemblances of the much worn type to equally worn chimpanzee molars than that the type is really a unique token of the presence of anthropoids in North America.

Images can often be more powerful than words, however, and the restoration of Nebraska Man in the Illustrated London News made an embarrassing situation all the worse when the true owner of Cook's tooth was discovered. The infamous artwork resulted from a collaboration between G. Elliot Smith and artist Amedee Forestier, and Osborn did not think highly of it. As quoted in Gould's essay, Osborn considered a reconstruction based upon one tooth to be irresponsible;

Such a drawing or 'reconstruction' would doubtless be only a figment of the imagination of no scientific value, and undoubtedly inaccurate.

Although he was right in this respect, the sting from the controversy prevented Osborn from mentioning Hesperopithecus ever again, a fossil hominid that lived and died in the scientific literature in a span of 5 years. While Osborn was a bit overzealous and probably should have waited to publish until he was able to find some more material (his debates with Bryan probably spurring him on to get news of the find out as fast as possible), the quick turnaround of Hesperopithecus represents science at its best. Osborn thought he had something spectacular on his hands, published it, set his top researchers to the task of studying it, organized a search for more material, and ultimately accepted defeat (even if he never publicly admitted as much). Other researchers were skeptical, aired their objections, and the call for more research and fossil material ultimately refuted the hypothesis in only half a decade. As Gould notes in his essay;

The story of Hesperopithecus was certainly embarrassing to Osborn and Gregory in a personal sense, but the sequence of discovery, announcement, testing, and refutation-all done with admirable dispatch, clarity, and honesty-shows science working at its very best. Science is a method for testing claims about the natural world, not an immutable compendium of absolute truths. The fundamentalists, by "knowing" the answers before they start, and then forcing nature into the straightjacket of their discredited preconceptions, lie outside the domain of science-or of any honest intellectual inquiry. The actual story of Hesperopithecus could teach creationists a great deal about science as properly practiced if they chose to listen, rather that to scan the surface for cheap shots in the service of debate pursued for immediate advantage, rather than interest in truth.

Keeping in mind that Bully for Brontosaurus has been available since 1992, now costing a whopping $0.86 for a used copy from Amazon.com, Paul Humber is either not interested enough in science to bother to read up on the subject of Hesperopithecus or he already knows the real story behind the myth and continues to be deceitful in his attempts to proliferate creationism. Neither is acceptable, and neither represent the actions of someone who truly understands science. Creationists often pay lots of lip-service to their supposed love for science, but is such professed affection genuine? If they do not care to spend 15 minutes reading an essay that clears up their various misconceptions about a long-forgotten piece of paleontological lore, do they really employ their minds in an attempt to understand the natural world?

Rather than being an Achilles' Heel for evolutionary scientists, the tale of Hesperopithecus serves as a valuable example of how science should be done. Great care should be taken with hypotheses, and corrections should be swift and forthright (even if Osborn didn't participate in this aspect of the process). Science has changed so much in my lifetime, even moreso in the past hundred years (and so forth throughout history), and we would be fools to think that every new paper or discovery holds an instant and permanent truth. If we give our assent to the "infallibility" of one hypothesis or another then we are no better than the creationists. The great strength of science is how it not only allows for mistakes, but thrives on their correction, and there is no blasphemy or sacrilege in questioning what has come before.

References;

Gould, S.J. (1992) Bully for Brontosaurus,.W.W. Norton & Company, New York.

Gregory, W.K. (1927) "Hesperopithecus Apparently Not an Ape Nor a Man." ScienceVol. 66 (1720) pp. 579-681

Gregory, W.K.; Hellman, M. (1923) "Further notes on the molars of Hesperopithecus and of Pithecanthropus." Bulletin of the AMNH. Vol. 48 (13), pp. 509-530

Gregory, W.K.; Hellman, M.; Matthew, W.D. (1923) "Notes on the type of Hesperopithecus haroldcookii Osborn." American Museum novitates No. 53, pp. 1-16

Larson, E.J. (2006) A Summer for the Gods. Basic Books, New York.

Osborn, H.F. (1922) "Hesperopithecus, the first anthropoid primate found in America." American Museum novitates No. 37, pp. 1-5

Osborn, H.F. (1925) The Earth Speaks to Bryan. Charles Scribner's Sons, New York.