The previous post recounted the unlikely but accepted fossil find of Charles Dawson near his home in Piltdown, England. British paleoanthropologists wanted to believe that the “Piltdown man” was the missing link in human evolution. Mr. P was also widely celebrated in popular culture. He was a rock star. Dawson wanted to be one too.
Skepticism about the fossils’ authenticity, however, came early and in several forms. The fragmented and limited skeletal pieces were missing their most diagnostic portions. (Some said, “How convenient.”) Also, was the gravel bed where Dawson found the fossils as ancient as he indicated, or were the fossils from a more recent era? Were the jaw and cranial fragments from the same species? From the same individual?
Many investigators sought answers, but they had to resign themselves to study casts of the fossils rather than the originals. In 1915, a Smithsonian scientist complained about the inadequacy of studying the casts. Even so, he remarked that the skull fragments and jaw were too different from each other to assume that they were from the same creature. He felt that the skull came from a human, not old, and the jaw from a species of ancient chimpanzee.
Discovery of other human-like fossils in China and Africa in the decades that followed produced conflicting information, and general agreement on how it all fit together was lacking.
During this time, however, Dawson’s reputation and his findings’ major significance remained intact, well after his death in 1916.
The dogma generally prevailed until mid century when the Mr. P was subjected to a new test, fluorine analysis. Fluorine seeps into buried bones from the surrounding groundwater, so fossils from the same animal and resting next to each other will have equal fluorine content. This testing was not undertaken lightly, since small portions of the bones had to be destroyed in the process. The results showed that the skull and jaw fragments contained different levels of fluorine. Additional analyses indicated that the bones were not nearly old enough to be the missing link. Furthermore, the skull was human and the other bones were not human, and under microscopic scrutiny the teeth showed evidence of having been filed down to obscure their origin.
If confirmatory evidence was still needed, it came in 2009. DNA analysis indicated that the teeth and jaw were from an orangutan. A CT scan also revealed an off-white putty covering the bones’ surfaces and sealing interior voids, which were filled with grains of sand. It is likely that the perpetrator weighted the relatively modern bones with sand to give them the heft an expert would expect from a fossil. Finally, the fraudster had stained all the surfaces brown to give the bones an ancient, homogeneous appearance.
Who was the perpetrator? Nobody knows for sure. Conspiracy theories abound. The most likely suspect of course is Charles Dawson. He was an accomplished amateur geologist and archaeologist with knowledge and experience about how ancient artifacts looked. He was discovered to be responsible for some other, small time antiquarian fakes. Dawson also pined for acceptance within the British scientific community and made persistent, but futile attempts to join the Royal Society. He also yearned for knighthood, an honor that bypassed him because of his early death but which was bestowed on several of his contemporaries who studied the Piltdown fossils.
How did this happen and what can we learn? First, as con artists do so well, this fraudster showed his audience what it wanted to see. The experts suspended critical judgement and discounted the red flags in their zeal to accept a British treasure, one that put Britain at the forefront of scientific discovery.
Second, the hoax would have been uncovered much earlier had more investigators been able to examine the actual fossils rather than replicas. By contrast, in every scientific discipline today, there are calls to make the original data, from which investigators drew their results and conclusions, available for all to scrutinize.
Third, fluorine and DNA analysis and CT imaging eventually foiled the fraud. In the future, new means of testing, particularly nondestructive ones, will be forthcoming and capable of re-examining established “facts” with intensified scrutiny.
The lesson that the Piltdown fake teaches is far more relevant and timeless than any insights gained had the discovery been real. It is human nature to see what we want to see, especially when it conforms to our preconceived notions. Instead we should take the evidence for what it is and even then retest its validity from time to time.