The Missing Link

Eoanthropus dawsoni.

This is one of the most famous hominids ever discovered. But certainly for the wrong reasons.

It was 1912. Very few hominid fossils had so far been found. Neanderthal Man in 1856; Cro Magnon Man in 1869; Java Man in 1890; Peking Man in 1903; Heidelberg Man in 1908. Each of these discoveries had added a small piece to the great puzzle of modern man’s origins, but there was still no clear species that represented a clear link in the evolution between ape and man.

In a way, that changed with the 1912 discovery of the fossil remains of a hominid — identified as eoanthropus dawsoni after the man who discovered them — that clearly showed a mix of features between ape and man. Found in quarries in Sussex, England, the skull was similar to that of modern man, but would hold only a brain about two-thirds the size of a modern brain. And the jawbone was decidedly more apelike. The combination supported the theory that the evolution between ape and man would begin with the brain so that the skull would evolve before the jaw into a form closer to what exists today.

There were skeptics, mostly among French and American paleontologists. But there were also those who saw the discovery as a critically important one, particularly British paleontologists in a pique of nationalist pride. But as time went on and further hominid fossils were discovered, it became increasingly difficult to fit eoanthropus dawsoni into the developing framework of human evolution. Experts perhaps puzzled over it at times, recognizing it as anomalous.

It would be forty years before the discovery of the fossils — made in the quarries of Piltdown — would be discovered to be a fraud. It was an elaborate hoax perpetuated by someone whose identity remains a mystery today, even though there are various theories about who it might have been. Certainly the fossils had been carefully prepared to make them look far older than they actually were, and it was with the use of much more modern dating techniques that the fraud was ultimately exposed. The preparations clearly required knowledge about the techniques that paleontologists would use in analyzing the fossils, making the hoax seem elaborate and almost sinister.

The four-decade episode of Piltdown Man is an instructive one, exposing the limits that may exist with scientific analyses and the ability of some to exploit those limits to mislead.

The more recent episode of “Climategate” is an attempt to suggest that a similar hoax is being perpetuated by some climate scientists today. The episode began in November of last year when a variety of emails and documents were hacked from the University of East Anglia’s Climatic Research Unit computers. Through a rather selective citation of isolated phrases out of context from stolen documents, a scandal was orchestrated, accusing the scientists who were quoted of colluding in a campaign to withhold scientific information, to manipulate data, and to interfere with the peer-review process in order to perpetuate a hoax of increasing global temperatures.

One particular focus of the allegations has been language in an internal email related to the famous “hockey stick” graph that shows sharply increasing global temperatures in modern times. It is a private email written between two scientists and needs to be understood in that context. It undoubtedly refers to a “trick” used to “hide the decline.” But scientists use the word “trick” to describe something clever or insightful to deal with a difficult issue — not as something deceptive. And the decline that is referred to is well-known in dendroclimatology in which the properties of annual growth rings of trees are used to infer temperature changes.

The fact is that since about 1960, tree-ring data has tended to suggest a decline in global temperatures at a time when direct instrumental measurements of temperatures show that it has clearly increased. Before 1960, tree-ring proxy measurements are consistent with other proxies for temperature change at least back to about 1600 AD. Something is obviously amiss with tree-ring proxy measurements, at least after 1960, although the reason for the divergence is not understood. What the Climategate scientists were referring to in their exchange was a known way of dealing with this inconsistency. It is important to recognize that they were not “fooling” anyone — the anomaly with tree-ring data is well-known among climate experts, as is the statistical “trick” used to legitimately reconcile the different types of data.

Yesterday, a British panel exonerated the scientists involved in Climategate, even as it criticized them for some reluctance to release computer files supporting their work. “[W]e find that their rigour and honesty as scientists are not in doubt,” the review states. This is the third review to clear the scientists of allegations of fraud and the vice-chancellor of the university has now expressed his hope that this will “finally lay to rest the conspiracy theories, untruths and misunderstandings that have circulated.”

The history of Piltdown man reminds us that we need to be on guard against scientific misconduct and fraud. But we also need to be on guard against unwarranted allegations of such misconduct when there is no sustainable evidence to show it is there.