How the Piltdown Man skull became the greatest hoax in anthropology

In the early 20th century, people were interested in finding the 'missing link' in human evolution because they believed that discovery would give clear proof for the theory of evolution and help to fill gaps in scientific understanding of human origins. 

The theory of evolution, which was first proposed by Charles Darwin in the mid-19th century, had gained widespread acceptance among scientists by the early 20th century. 

However, there was still much to learn about the details of human evolution: particularly about the transition, 'the link', from apes to humans. 

Finding this 'missing link' was seen as an important way to bridge that gap and give clear proof for the theory of evolution. 

In addition, people believed that finding the missing link would help to answer basic questions about who we are and our place in the natural world.

As the story goes, in 1911 amateur archaeologist and lawyer Charles Dawson was given a fragment of a skull by a workman at a gravel pit in Piltdown, Sussex, England. 

Dawson believed it might be a significant find and he kept searching the site and found more fragments. 

In 1912, he asked for help from British Museum paleontologist Arthur Smith Woodward to continue his excavations. 

Together, they claimed to have found more skull fragments, a jawbone, teeth, and early tools believed to belong to the remains of a previously unknown hominid species, the supposed 'missing link.'

The two men shared their findings with the scientific community at the Geological Society of London in December 1912, when Dawson claimed that the bones were at least 500,000 years old. 

He argued that the remains came from a stage in human evolution when the brain had grown in size but the jaw had stayed primitive. 

The Piltdown Man was then formally named Eoanthropus dawsoni meaning 'Dawson's dawn man' in honour of its discoverer Charles Dawson. 

The discovery, which was known as the Piltdown Man, was widely celebrated and quickly considered one of the most important finds in the study of human evolution. 

An artist called John Cooke was hired to reconstruct the Piltdown Man's skull in 1913, an image that was widely shared and added to the discovery’s credibility. 

Prominent anatomist Sir Arthur Keith became one of the most vocal supporters of the Piltdown Man find and he used it to back his idea that the development of a large brain came before other human evolutionary traits. 

Most importantly, at the time the discovery also boosted British national pride by suggesting that England was the birthplace of early human evolution.

However, some scientists were doubtful from the start, noting the differences between the human-like skull and the ape-like jaw. 

Further doubts about the Piltdown Man appeared in the 1920s. 

The age of the bones was questioned, and some scientists suggested they might be much younger than first thought. 

Others noted that the jaw and the skull looked like they belonged to different hominid species. German anatomist Franz Weidenreich examined the Piltdown fossils in 1923 and openly said the skull was a mix of a modern human and an ape jaw. 

Other scientists pointed out that the teeth looked very different from the skull. 

Despite these criticisms, the Piltdown Man continued to be seen as proof of human evolution for several decades. 

It was not until the 1950s that the hoax was finally exposed.

In 1953, new dating techniques showed that the bones were only a few hundred years old, not hundreds of thousands. 

Two types of absolute dating were used to uncover the Piltdown Man hoax. They were called fluorine dating and radiocarbon dating. 

Fluorine dating was still fairly new at the time and it had been improved by Kenneth Oakley. 

It was a way of working out how old bones are by measuring how much fluorine they have taken in from the ground. 

The more fluorine in a bone, the longer it has been in the ground. 

The breakthrough happened when scientists Kenneth Oakley, Wilfrid Le Gros Clark and Joseph Weiner used fluorine dating, which was a method that showed the bones were much younger than people had thought.

Radiocarbon dating is another method that checks the amount of carbon-14 in a sample to work out its age. 

Later, radiocarbon dating confirmed that the skull and jawbone were modern, less than 1,000 years old. 

Together, these dating methods proved that the Piltdown Man was a fake and not the ‘missing link’ people thought it was. 

The skull turned out to be from a modern human, only about 600 years old.

Also, scientists tested the nitrogen levels in the bones and found that the jawbone came from a young orangutan. 

The jawbone had been tampered with to hide where it came from and it had been broken near the middle and the teeth were filed to look more like human ones. 

The skull pieces and the altered jawbone had also been stained with iron and chromic acid to make them look older and match the colour of the local gravel. 

The exact place where the orangutan jawbone came from wasn't clear, but it definitely wasn't from the Piltdown area. 

The discoveries were published in the journal Nature on November 21, 1953, and they ended the hoax for good. 

By then, over a dozen other hominid fossils, including Java Man and Peking Man, had been found in Asia and Africa. These fossils didn’t match Piltdown Man and showed it couldn't be real.

No one knows for sure who faked the Piltdown Man. 

The trick was so detailed and clever that some people think more than one person was involved. 

Still, a few people have been named as possible suspects. 

The most obvious is the discoverer of the Piltdown Man, Charles Dawson. 

But some experts have also pointed to other scientists from that time, like Arthur Smith Woodward and Pierre Teilhard de Chardin. 

After he had helped with the digs, Jesuit priest de Chardin later stepped away from the discovery, a move that made people wonder if he was involved.

Over time, some even blamed Sherlock Holmes creator sir Arthur Conan Doyle. 

He lived in Sussex when the bones were found and he was known to be into archaeology. 

But there’s no solid proof for any of these ideas. 

A big study in 2016 said that Charles Dawson probably acted alone. 

DNA tests showed that both the canine and molar found at the Piltdown sites came from the same orangutan, most likely from Borneo. 

The study also found that the bones and teeth had Piltdown gravel and dental glue inside them and they had the same kind of fake staining and wear and this showed that someone had faked them on purpose. 

In the end, the collected forensic and chemical evidence supported the idea that Dawson was behind the hoax and had tricked scientists for years.

Whoever was behind it, the Piltdown Man hoax is a warning about the risks of wishful thinking and cheating in science. 

It lasted for more than 40 years, which made it one of the longest-running and most harmful scientific fakes in history. 

When the hoax was uncovered, it made scientists question their methods and look more carefully at how they study fossils. 

It also started serious discussions about honesty in science and how peer review should work. 

One sad result was that the hoax delayed the recognition of real ancient human fossils, like Australopithecus africanus, which was discovered in 1924 by Raymond Dart. 

The Piltdown Man case became a clear example in science of why it’s important to be sceptical and use different types of evidence before accepting unexpected claims. 

Even though the hoax slowed down the study of human evolution for a long time, it helped in the end and it pushed scientists to come up with better ways to investigate and check their findings.