In Part 3 of our exclusive series we looked at how the new science
of paleoanthropology was being used in Europe while infighting paralyzed
it in America when Ale Hrdlicka, stepped forward to end the
disputations and promote professionalism and respectability.
By the 1920s, the Bering Strait Theory, and in particular the
idea that American Indians had settled in the New World less than
5,000 years ago, had become a rigid dogma that no scientist who
valued their career would dare to challenge.
In the end, it was a group of amateurs who exposed the charade.
In 1908 George McJunkin, an African-American cowboy born the son
of former slaves, was tending cattle at the Crowfoot Ranch near
Folsom, New Mexico, when he discovered the remains of an animal
that had been uncovered after a recent flood. He recognized the
bones as a bison, and surmised that it was of some ancient type.
McJunkin informed a local blacksmith and amateur naturalist,
Carl Schachheim, who then informed his friend and fossil hunting
companion, Fred Howarth, a banker. After visiting the site, they
tried repeatedly to interest paleontologists into excavating it
without success. Finally, their persistence paid off in 1926, when
Harold J. Cook and Jesse Dade Figgins of the Denver Museum of Natural
History agreed to take a look. They quickly found, not only extinct
bison, but spear points. This was a "kill site," the results of
a hunt. Since the established dogma insisted that kill sites of
extinct animals did not exist, they worked very, very carefully,
hoping to find somethinganythingthat might be conclusive.
On August 29, 1927, an ancient stone spear point was found embedded
between the ribs of an extinct bison. This was clearly no accident.
Recognizing the importance of the discovery, the find was left intact
in the ground to be witnessed by as many eminent archaeologists
as they could muster. Although he tried, Hrdlicka could not reject
this. The indisputable evidence had surfaced, and one glass floor
had been shattered.
With the acceptance of the Folsom point, it became clear that
humans were in the Americas more than 5,000 years ago. No longer
hamstrung by the need to overturn dogma, a flurry of sites were
discovered in the next few years which began to change the picture
of ancient America. In 1932, near Clovis, New Mexico, a site was
uncovered that featured the same type of spear point found at Folsom,
and then digging deeper, a different and older set of spear points
were found. Humans had been in America at least 10,000 years or
more. It had been 68 years since the Europeans accepted the antiquity
of humans, but finally, the American paleoanthropologists had joined
It is important to note that it was not the discovery of human
remains, so emphasized by Hrdlicka, but of human tools in the right
context, that changed the perceptions of the past. This was also
the case in 1859 in Europe, when the stone tools of Brixham and
the Somme led to the acceptance of human antiquity. The value to
science of human remains in certain cases may be important, but
it has not been decisive.
But if the time frame for human antiquity in the Americas had
changed, the story had not. The Bering Strait Theory remained the
unchallenged assumption. The line was drawn hard and fast once again,
this time at 10,000 BC.
"Clovis First," the new version of the Bering Strait Theory,
was based on the presumption that the Paleoindian culture that had
produced the spear points found at the Clovis site were the first
settlers. In part, this was because of the Clovis site itself, which
had in layer after layer revealed thousands of years of settlement
history, but nothing was found in the layer beneath the Clovis culture.
The other factor was the growing awareness among paleoanthropologists
that the presumed pathway between Asia and the Americas, the Bering
Strait, may not have always been open, but may at times have been
By 1932, geology had progressed to the point that an accurate
map of the giant ice sheet could be drawn with reasonable certainty.
A general consensus had developed among geologists that the glaciers
were impassible approximately 30,000 years ago and very likely through
to 10,000 years ago, about the time when the Clovis culture was
beginning. The Clovis First Theory naturally dismissed the idea
that Paleoindians might have arrived before 30,000 years ago (before
the Last Glacial Maximum or LGM).
In 1933, the Canadian geologist William Alfred Johnston proposed
that when the glaciers began melting, they broke into two massive
sheets, one centered on the Pacific Coast and Rocky Mountains (later
named the Cordilleran ice sheet), and the other, now known as the
Laurentide ice sheet, covering the rest of Canada all the way to
the Atlantic Ocean. In between these two massive ice caps, people
might have been able to walk from Alaska down into the United States.
Two years later, the Swedish-American geologist Ernst Antevs dubbed
this route, the "ice-free corridor."
The date when the melting of the ice sheets opened the ice-free
corridor, believed to be around 13,000 BC, seemed to give just enough
time for the Clovis culture to walk from Alaska and spread all across
Retiring in 1942 as head of the anthropology department of the
National Museum, a position he had held for almost 33 years since
replacing William Henry Holmes in 1909, Hrdlicka died the following
year. His legacy, however, continued. The Bering Strait Theory,
now in its new incarnation, Clovis First, was upheld with equal
dogmatism by a new generation of paleoanthropologists who had grown
up with no other perspective.
Bend it like Beckham
As new scientific methods began to play an important role
in the examination of artifacts, new battles began almost immediately.
Radiocarbon dating, developed in 1949 by Nobel Prize-winning chemist
Willard Libby, revolutionized archaeology. By measuring the decay
of a radioactive isotope of carbon, carbon 14, in any dead organic
matter such as bones, wood, or plants, Libby found an approximate
way to date when it had died.
During the construction of a dam in Lewisville, Texas the remains
of a bison were uncovered in 1949, leading to a series of excavations
that continued until the dam was finished and the site inundated
in 1957. The excavations, as archaeologists Wilson W. Crook, Jr.,
and R.K. Harris wrote in the journal American Antiquity, "yielded
remains of more than 21 hearths of an ancient campsite of early
man. An extensive Upper Pleistocene fauna has been recovered, much
of it actually burned within the hearths themselves, and the remainder
closely associated with camp refuse, along with certain distinctive
artifacts." What created a stir was that two of the hearths were
radiocarbon dated at more than 37,000 years old.
Since this flew in the face of the Clovis First Theory, the
findings were instantly attacked. But given the indisputable (at
that time) radiocarbon dating, that was not going to be easy to
do. The archaeologists Robert F. Heizer and Richard A. Brooks (both
of whom did not visit the site) responded in the Southwestern Journal
of Anthropology in a manner that would have made Ale Hrdlicka
The evidence for association of stone tools with the hearths
is insufficient to provide a valid case for arguing that the hearths
are the result of human agency. If we are to accept the proposition
that man has been in the New World for more than 37,000 years, the
least we can demand is that the evidence for the belief be unambiguous.
They then proposed that the hearths were actually ancient nests
of wood rats, an idea so absurd on its face (presumably the wood
rats also cooked the extinct animals found burned in the hearths),
that the whole matter was dropped and ignored. Since it could not
be disputed, the Lewisville site was consigned to the academic dustbin.
Twenty-five years later, as archaeologists gained experience
with radiocarbon dating and learned that a contamination of samples
or other factors could influence the dates given, the geologist
D. L. Johnson proposed that maybe the Lewisville site had been contaminated
by lignite (brown coal) from nearby outcroppings of the Woodbine
Formation, which was around 70 million years old. A dry spell in
1979 had allowed for a new excavation and so material from the Lewisville
site was sent for reanalysis.
Unfortunately for the Clovis First Theory, a report produced
in 1985 by a team from the Illinois State Geological Survey headed
by Richard H. Shiley, entitled "Moessbauer Analysis of Lewisville,
Texas, Archaeological Site Lignite and Hearth Samples" found that
whatever was burned in the hearths, it was not Woodbine lignite.
The rare earth composition of Woodbine Formation lignite and
its corresponding ash are very similar to one another, but are not
similar to the soil or hearth samples. The rare earth composition
of the surrounding soil follows the same pattern as that of the
hearth. From this data, it is reasonable to provisionally conclude
that the Woodbine Formation lignite was not burned in the hearths.
A second test then found that, "pyrite combustion products were
not detected using X-ray diffraction." Pyrite, found in lignite,
when burned should generate a byproduct, but none were found. Whatever
was burned in the hearths was not lignite.
A third test, now using Moessbauer spectroscopy, also did not
find pyrite byproducts in the charcoal of the hearths tested, but
did find trace amounts of hematite, a pyrite byproduct, in the sediment
lining of one of the hearths, hearth 22, a hearth that had been
excavated in 1979, after the site had been submerged by the reservoir.
The Moessbauer test did not find traces of lignite in the hearths
excavated in the 1950s by Crook and Harris. By all rights, the radiocarbon
dates of more than 37,000 years still stood.
The team, clearly disappointed it had not come up with the expected
result, put the best face it could on its findings.
The use of the Moessbauer spectroscopy, on the other hand, produced
positive results. Hematite, a pyrite combustion product, was found
in hearth 22. We concluded that there is some support for the hypothesis
that Woodbine Formation lignite was burned in this hearth, thus
increasing the apparent age (radiocarbon date) of the hearth material.
Thankfully the tepid "some support for the hypothesis" was all
that was needed. Few were going to bother to read the actual report
and nobody wanted to dispute its conclusions. Lewisville was pronounced
as having been contaminated by lignite and was no longer a problem
for the Clovis First Theory.
The orthodoxy was stronger than ever. No longer under Hrdlicka's
iron grip, it was now self-policing. Whatever the scientific data
might say, the conclusions would somehow support the theory. Any
site that promised to be earlier than Clovis was going to be subject
to unrelenting scrutiny until something was found wrong with it.
New evidence would be "bent" towards upholding the Bering Strait
The established dogma could still only be overturned by "indisputable
proof," the nature of this proof being defined by the dogmatists
themselves. Despite the discovery of the Folsom point in 1929, the
same intellectual stubbornness that Hrdlicka had fostered continued
to stunt paleoanthropology.
Strait Theory, Pt. 5: The Theory Comes Crashing Down"