TWO FAMOUS DEBUNKERS OF EOLITHS
paleoanthropology, we sometimes encounter the definitive debunking report-one
that is used again and again to invalidate certain evidence. In the case of
European eoliths, there are two good examples of definitive debunking reports.
These are H. Breuil' s paper claiming that
pseudoeoliths were formed by geological pressure in the French Eocene
formations at Clermont (
Henri Breuil conducted investigations he thought would put an end to the eolith
controversy. In his often cited report, he said he found flints resembling
stone tools in the Thanetian formation at Belle-Assise, near
Can geological pressure really create the effects observed by Breuil? Leland W. Patterson, a modern authority on stone tools, says that pressure flaking very rarely produces clearly marked bulbs of percussion. It usually takes an intentionally directed blow.
Breuil probably selected for illustration his best examples of flakes found in contact with the parent block of flint. But the flaking and retouching on them is far cruder than on the cores and flakes selected by Breuil as examples of pseudoeoliths. Breuil said all the effects resulted from natural geological pressure flaking. But he would have been justified in making such a statement only if he had found the flakes from better looking eoliths in contact with their parent blocks of flint. And this he did not do.
The unsatisfactory nature of Breuil's geological pressure hypothesis becomes even clearer when we consider what Breuil called "two truly exceptional objects, of which the site of discovery, in the interior of the beds, is absolutely certain."
said the first object was virtually indistinguishable from an
Azilio-Tardenoisian grattoir, or end scraper. Scientists generally attribute
Azilio-Tardenoisian stone implements to Homo sapiens sapiens in the Late
Pleistocene of Europe. In describing the second exceptional object, Breuil
compared it to tools found at Les Eyzies, a Late Pleistocene site in
Breuil's paper is still cited as proof that eoliths are natural rather than artificial productions. This kind of citing is a very effective propaganda technique. After all, how many people will bother to dig up Breuil's original article and see for themselves if what he had to say really made sense?
definitive 1910 report came before most of J. Reid Moir's discoveries in
important element in the eolith controversy was the platform angle test,
promoted by Alfred S. Barnes. Barnes, who defended Moir in the 1920s, later
became opposed. In 1939, he delivered what many authorities still regard as the
death blow to Moir's English eoliths. But Barnes did not limit his attention to
Moir. In his study, titled "The Differences Between
Natural and Human Flaking on Prehistoric Flint Implements," Barnes also
considered stone tool industries from
Supporters of eoliths generally argued that natural forces could not produce the kinds of chipping observed on the objects in question. Barnes looked for some measurable way to demonstrate whether or not this was so. For this purpose, Barnes chose what he called the angle platform-scar. "The angle platform-scar " he said, "is the angle between the platform or surface on which the blow was struck or the pressure was applied which detached the flake, and the scar left on the tool where the flake has been detached." In genuine human work, the angle would be acute. Natural fractures would, he said, yield obtuse angles.
Barnes's description of the angle to be measured somewhat ambiguous. We have
spoken with experts on stone tools at
To be effective, the measurement had to be applied not to a single specimen, but to a large sample of specimens from the industry in question. Barnes stated that a sample "may be considered of human origin if less than 25% of the angles platform-scar are obtuse (90 degrees and over)." Having established this, Barnes delivered a devastating conclusion: none of the eoliths he examined, including those of Moir, were of human origin. Interestingly enough, it appears that Moir himself was aware of the Barnes criterion and believed his specimens were within the required range. But for Barnes, and almost everyone else in the scientific community, the controversy was over.
in mainstream circles the controversy about the eoliths and other Tertiary
stone tool industries had long since ceased to be a burning issue. With the
discoveries of Java man and
close examination, it appears that Barnes's definitive debunking report may be
in need of some debunking itself. Alan Lyle Bryan, a Canadian anthropologist,
wrote in 1986: "The question of how to distinguish nature facts from
artifacts is far from being resolved and demands more research. The way the
problem was resolved in
example of an industry that apparently does not conform to the Barnes criterion
is the Oldowan, from the lower levels of the
In light of the views presented by Bryan and others, it is clear that wholesale rejection of the Eolithic and other early stone tool industries by application of the Barnes criterion is unwarranted.