The Piltdown Hoax

In 1912 Charles Dawson a collector of antiquities for the British Museum found the first of two skulls which apparently validated this hypothesis. The specimens were found in deposits that were thought to be Pliocene in age (5 million to 2 million years ago) near Piltdown, England. The fossil was exactly what the paleontological community expected, the large brain and high forehead of a modern human with an ape-like mandible. British paleontologists championed the find (that Britain was the cradle of humankind was almost too good to be true), while the French and American scientific communities remained skeptical. In 1917, an additional fossil from the same site was reported. It had supposedly been found in 1915 by Dawson, who had died in 1916. Once again fragments of a skull and mandible were found, and again the proportions were the same, large brain/ape-like mandible. Once could have been a chance happening or a mistake by a researcher. Twice, however, seemed to convert the skeptics. A reconstruction of "Piltdown Man" is pictured below from a cast in the Smithsonian collection.

But scientific work in other parts of the world was beginning to uncover evidence of a different pattern of human evolution. The discovery of the "Taung Child" in South Africa (Australopithecus africanus) in 1924 showed early humans that were not big-brained apes but rather bipeds (walking on two legs) with brains roughly the same size as modern chimpanzees'. The Peking Man (Homo erectus) discoveries in the 1920's and '30's at Zhoukoudian (="Choukoutien ") in China, where as many as 40 individuals were discovered, showed human ancestors more recent than the proposed Piltdown Man, yet they had nearly identical body proportions to modern humans, with jaws that did not resemble ape jaws at all, and brains that were still smaller and shaped differently than modern humans'. But because Piltdown fit the expected result, new fossil finds were held up to Piltdown for verification. Many researchers, including the noted British anatomist Sir Arthur Keith, soundly rebuked the claims of researchers whose work cast doubt on the validity of the Piltdown finds (such as Raymond Dart in South Africa and Eugène Dubois in Indonesia).

As time went on, there continued to be finds, that were inconsistent with the Piltdown material. The evidence for small-brained bipeds became more and more overwhelming. Piltdown was pushed further and further to the side as discoveries were made, particularly in Africa, of early humans that contradicted the large brain/ape-like jaw combination found in Piltdown. It was not until 1949 that fluorine ion testing (a test that measures the amount of fluorine ions taken into bone as it lays in the ground; this can be used to determine ages of bones) proved that the finds could not possibly be Pliocene in age, and therefore not of an ancient ancestral species. The final blow came in 1953, at a congress of paleoanthropologists, when the possibility of a deliberate forgery was first openly considered. Upon re-examination, it was found that molars of the mandible had been deliberately filed to near perfect flatness in order to fit to the teeth of the upper jaw. To make the specimens appear to be ancient, the bones had been stained in an iron solution and the canine tooth in the mandible on the first Piltdown skull had even been painted brown . The bones, it was later determined, were from a modern human (cranium) and an orangutan (mandible).

The evidence was there the entire time. Any researcher could have looked at the teeth with a microscope and noticed an artificial wear pattern, or the fact that one tooth had a coat of paint on it. But why didn't anyone recognize this forgery? One reason is that beacause Piltdown affirmed many scientists' hypotheses, they were reluctant to put it under scientific scrutiny that might have proved it wrong. Museums prominently displayed casts of Piltdown as scientific fact. Ales Hrdlicka, a leading anthropologist here at the Smithsonian, was one of the few scientists to question whether the jaw and cranium went together. But even here in our museum there was an exhibit on display: "Evolution of the Bony Chin" -- from chimpanzee through Piltdown Man to modern humans! -- see to the right. The Piltdown mandible is the second from the top. Many researchers not associated with the forgery simply saw what they wanted to see in Piltdown. Publications on the "ape-like qualities" of the cranium of Piltdown were not uncommon, and these were authored by trained anatomists looking at a fully modern human cranium.

The implication of Piltdown for science is not an important triumph over a forgery; it took science four decades to look through a microscope to see that the teeth had been filed and painted. Rather, it is a reminder to us all of the responsibility we, as scientists, have to the confront evidence that supports our ideas with the same level of scrutiny we would apply to evidence contradicting our beliefs.

One very important questions still remains of the Piltdown scandal...Why?

Was this a deliberate forgery? Could it have simply been a prank gone terribly wrong? And exactly who was involved (remember Charles Dawson died before the second Piltdown skull was revealed to the public)?

A thorough examination of these questions and all of the history behind the Piltdown hoax is available at the Piltdown Man Homepage. Check this site out.