Piltdown

Early evolutionary scholars, including Darwin, anticipated that fossils of our earliest ancestors would be ape-like. However, before the fossil record was as rich as it is today, it was widely assumed that hominins evolved large brains before they evolved humanlike bodies. It was as if hominins decided with their keen intellects to walk upright (as if "up" is "right") and to use tools with their freed hands. Because of the evidence on record now, we know that bipedalism first arose about 6 Mya in tiny-brained hominins that did not make stone tools and the major expansion of the hominin brain did not occur until after 2 Mya.

This early hypothesis about brain size and its fervent following, coupled by a willingness to believe that the first brainy humans originated in Great Britain, made the notorious fossil specimen known as "Piltdown Man" such a powerful hoax.

Between1908 and 1912, a series ofpaleontological and archaeological discoveries were made near the village of Piltdown in Sussex, southern England. Among the remains of long extinct mammals like hippos and rhinos was a humanlike piece of skull bone and an ape-like fragment of a jaw that Charles Dawson (an amateur antiquarian and paleontologist of considerable repute) named "Eoanthropus dawsoni." Many scholars were happy to accept Piltdown Man (as it was nicknamed) because it showed that big brains evolved early as a cornerstone of human evolution and that big-brained humans evolved first in England.

There was never full scientific agreement about how to fit Piltdown Man into the hominin family tree or about how to reconstruct the anatomy because there was a lack of comparative material at the time. Even when additional hominin fossils were discovered in China and Africa in the 1920s and 1930s they lacked preservation of the same parts for comparison and, furthermore, more and more hominin fossils showed that humanlike teeth evolved early while human brain size evolved much later. With the accumulation of evidence elsewhere, the Piltdown anomaly became frustrating and embarrassing to science.

With the advent and application of new technologies in the 1940s, the Piltdown problem began to unravel like a mystery. Fluorine analysis proved the skull bone and the jawbone were not from the same individual. After an animal dies the nitrogen in its bones is replaced by fluorine that is absorbed through groundwater. The levels of fluorine would have been the same in the two bones if they had been from the same animal, but they were different. Furthermore, uranium dating analyses showed that the bones were younger than 50,000 years old, which is much too recent for an ape-man.

In 1953 Joseph Weiner, Kenneth Oakley, and Wilfred Le Gros Clark published "The solution of the Piltdown problem" in the Bulletin of the British Museum of Natural History. Their analysis showed that the Piltdown jaw was from a young female orangutan and the cranium had belonged to a modern human. Piltdown was no more than a fake made to appear ancient with an artistic application of staining chemicals. Microscopic analysis showed that the teeth had been filed down to appear more ambiguous and human. The part of the jaw that articulates with the skull had been broken off to disguise that the two could not possibly fit together.

Although a hoax like Piltdown Man could not happen in this day and age, the culprit of the Piltdown forgery is still unknown. Charles Dawson is probably the best guess since he was responsible for the various discoveries at Piltdown and he was also associated with incidences of artifact fraud at other sites. However, the list of suspects continues to grow and includes author Sir Arthur Conan Doyle who participated in the Piltdown excavations, as well as Martin Hinton, a former fossil curator at the British Museum (Natural History). Recently discovered leftover laboratory materials tell of Hinton's preoccupation with the geologic processes that tarnish and stain fossils, and he could have been Dawson's accomplice in the forgery.

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