In Part 4 of our exclusive series we looked at how the Bering
Strait Theory by the 1920s had become a rigid dogma that no scientist
who valued their career would dare to challenge.
For most of the 20th century, new discoveries of American Indian
origins that cast doubt on the Bering Strait Theory were either
dismissed or ignored. But as the technology of science marched on,
the cracks grew deeper and deeper.
An unintended consequence of the atmospheric testing of atomic
weapons during the Cold War was that by the 1960s it had doubled
the amount of radioactive carbon 14 in the environment, and this
"bomb pulse" was showing up on the instruments that were used for
radiocarbon dating. This led scientists to suspect that the amount
of carbon 14 that is found in the environment might not have always
been constant, possibly leading to wrong dates.
By the mid-1980s, dendrochronologists, those that study and
date tree-rings, had manage to piece togetherby matching the
tree-rings of long-living species such as the bristlecone pine with
those of ancient treesan unbroken string of tree-rings over
7,000 years old. Since dendochronology can give extremely accurate
dates, often to the year, matching the two dating systems found
exactly that, that the amount of C14 fluctuated and that many radiocarbon
dates had to be adjusted.
For Clovis First advocates, this presented a real problem, for
the new calibrated radiocarbon dates pushed back the Clovis culture
almost 2,000 years. It meant that the oldest reliably dated Clovis
site, in Aubrey, Texas, which was radiocarbon dated at 11,590 years
ago, was now approximately 13,490 years old. The Paleoindians would
have had to race through the Ice-free Corridor to get to Texas in
But the new radiocarbon dates would give even more bad news.
Geologists, also recalibrating their radiocarbon data, began to
refine their estimates for when the massive ice sheets began to
melt, and found them adjusting their dates between 500 and 2,000
years earlier. The Ice-free Corridor was now certainly impassable
13,000 years ago and possibly as late as 12,000 years ago. This
meant that there was no way the Paleoindians could have walked over
from Asiaor if they had, they would have had to done so 20,000
years earlier, a non-starter for the theory's advocates. A central
thesis of the Bering Strait Theory was now toppled, for if the Clovis
culture was indeed the first peoples in the Americas, they had to
have come by boat.
A Polynesian Interlude
The use of boats had always been rejected by the Bering
Strait advocates, because it opened up other possible routes of
migration, such as Europe or Polynesia. Thus they had dismissed
any contacts between Polynesians and American Indians (and many
continue to dismiss evidence of prehistoric contacts), because it
would undercut the contention that "primitive people" could not
cross the oceans, and that walking across the Bering Strait was
the only possible way that Paleoindians could have come to the Americas.
But the presumption that primitive people cannot sail the ocean
is a belief born out of the social evolutionary theories of Herbert
Spencer and Lewis Henry Morganthat societies inexorably evolve
to greater complexity and skill. Since the Europeans were unable
to cross the oceans until the 16th-century, no one else should have
been able to do so earlier.
Yet the evidence for pre-Columbian contact between Polynesians
and American Indians has always been strong. Before the Bering Strait
Theory assumed its dogmatic status, many scientists believed it
and few rejected it out of hand. As early as 1837, scientists such
as John Dunmore Lang, a prominent Presbyterian minister and Australian
politician, proposed Polynesian voyages to America. In his book,
Origins and Migrations of the Polynesian Nation, Lang dismissed
the Asian-American connection, stating that "there is no evidence,
and not the slightest probability, of any emigration having ever
taken place from Asia to America by the Behring's [sic] Straits."
Ever since the first proposer of this particular route for the
discovery and settlement of America announced his great idea to
the world, the learned of all nations, including such names as Humboldt
and Dr. Robertson, have caught and adopted that idea and followed
in his wakeas blindly, indeed, and as unintelligently as a
flock of sheep follows its leader.
Lang, who traveled throughout the Pacific and into the Americas,
argued, in a large part through linguistic evidence, that the Polynesians
originated in Malaysia and spread across the ocean in a pattern
largely confirmed 150 years later by genetic evidence.
Many of Lang's ideas were fanciful, but no more so than any
one else's at the time. He believed the Polynesians landed near
Copiapo in Chile in some distant past and from there colonized the
Americas. The historian George Bancroft (whose dubious accomplishments
include instigating the Mexican War as acting Secretary of War under
President James Polk), wrote about Lang's theory in 1841 in his
influential book, History of the Colonization of the United States,
"It would not be safe to reject the possibility of an early communication
between South America and the Polynesia world." The distinguished
French naturalist Jean Louis Armand de Quatrefages also considered
American voyages likely in his 1866 work, The Polynesians and Their
There was little doubt in those days that the Polynesians could
have made a trans-Pacific voyage. The early settlement of Hawaii,
more than 2,500 miles from the northernmost islands of French Polynesia
and over 3,000 miles from Tahiti, required a tremendous feat of
sailing and navigation. European explorers often recorded meeting
Polynesian sailors in the open ocean, including an encounter in
1615 by the Dutch navigator, Willem Cornelisz Schouten, who came
across a party of Polynesians in a double-hulled ship more than
3,000 miles from their home in the Marianas.
Lang noted physical and cultural similarities between the two
peoples, many of which today would be seen as the result of simple
prejudice, but others, such as similar types of fishhooks, canoes,
and harpoons used by Indians in California, Chile, and among the
Polynesians, were not to be dismissed lightly.
The most important evidence was biological. As early as 1770,
Spanish explorers wrote that maize, manioc, and white potatoes,
all indigenous to the Americas, had been grown on Easter Island.
Similar varieties of coconuts, bottle gourd (calabash), bananas,
and chickens, were all seen as evidence of voyages back and forth.
Most significantly, the sweet potato, clearly indigenous to the
Americas, was found across Polynesia, including Hawaii and New Zealand.
In 1866, in the journal Botany, the German botanist Berthold Carl
Seemann wrote that the Polynesian name for sweet potato, "Kumara
or umara, of the South-Sea Islanders, is identical with cumar, the
Quichua name for sweet potato in the highlands of Ecuador."
As if that evidence was not indisputable enough, in 1841, while
digging through an ancient Inca temple in Cuzco, Peru, the director
of the National Museum of Lima, Mariano Eduardo de Rivero, and the
Swiss explorer, Johann Jakob von Tschudi, discovered a distinctive
"green amphibole stone ax," that was soon identified as a Maori
patu-pounamu, or jade war club, from New Zealand. But as the Bering
Strait Theory became predominant in the late 19th-century, the idea
of Polynesian-American contact began to lose favor.
By the early 20th-century, only a few anthropologists, such
as Roland Dixon, were willing to accept, and even then only half-heartedly,
that trans-Pacific voyages by Polynesians might have occurred. Thor
Heyerdahl's highly celebrated voyage from South America to Polynesia
in the light raft Kon-Tiki in 1947, along with his equally celebrated
but extremely doubtful ideas of Polynesian origins, created a huge
scientific backlash that basically killed any lingering discussion
of trans-oceanic contact.
But the Polynesians did sail to the Americas. Recent DNA studies
of sweet potatoes and chickens now confirm that they were traded
before contact with Europeans. A flurry of recent articles, including
"The Polynesian Gene Pool: an Early Contribution by Amerindians
to Easter Island," published in the Philosophical Transactions of
the Royal Society in 2012; a 2013 article from the Proceedings of
the National Academy of Sciences, entitled "Identification of Polynesian
mtDNA Haplogroups in Remains of Botocudo Amerindians from Brazil;"
and a 2010 article in Current Geonomics, "The Origin of Amerindians
and the Peopling of the Americas According to HLA Genes: Admixture
with Asian and Pacific Peoples" have pretty much settled the debate
for everyone except the most dogmatic Bering Strait advocates.
The new version of the Bering Strait Theory, what is now known
as the "Coastal Migration," has the first Americans using boats,
presumably small primitive craft that then skirted the massive ice-sheets
along the coast on their way to Aubrey, Texas. But that assumption
completely dismisses the reality of the region of the Bering Strait.
As it is presently, even without being surrounded by the massive
ice-sheets that would have reached out well into the open ocean
back then, the seas around the Bering Strait are among the most
treacherous on the planet. European explorers had, for 200 years
after they had already circumnavigated the globe, attempted to reach
the area without success, failing time and time again because their
ships were not capable of even coming close to it, much less crossing
it. Navigating those seas requires tremendous technological skill,
every bit as daunting as crossing the open ocean.
One could argue, using the example of European or Polynesian
voyages, that it would have been just as easy for Paleoindians to
have crossed the Pacific or Atlantic, than to try to sail or paddle
the seas around the Bering Strait. The presumption had been that
Paleoindians walked across a land bridge into the Americas because
they were incapable of doing anything else, but if Paleoindians
did indeed use boats 15,000 years ago, then they could have come
Time Waits for No One
Now that it became evident that the land passageway
to the Americas was effectively blocked, even during the Clovis
period, the Bering Strait Theory should have died a natural death,
but being a dogma and not a scientific theory, its advocates would
simply not let go. After Ale Hrdlicka's retirement in 1942
from the National Museum, a number of sites potentially older than
Clovis had been excavated, but all had been vigorously challenged
by a new generation of archaeologists, and all had been dismissed.
The demand for "indisputable proof," whatever that might entail,
was simply too great an obstacle to overcome. But one man had figured
out the game, and in doing so, brought down the Clovis First version
of the Bering Strait Theory.
In 1976, Tom Dillehay, an American anthropologist who at that
time was working at the Universidad Austral de Chile, began excavating
an ancient site in southern Chile. Quickly recognizing the antiquity
of this site, his excavation became arguably the most meticulous
ever undertaken. It had to be, for when he first announced his findings
in 1988, and claimed that the samples of wood from houses, charcoal
from hearths, and other artifacts that he had excavated had been
radiocarbon dated to be almost 15,000 years old, it sent a massive
shock wave through the archaeological community. It meant that this
site in South America was more than 1,000 years older than any accepted
site in North America. Dillehay's findings were immediately and
bitterly attacked by the Clovis First advocates, but he had expected
it, and the detail and quality of his work made his conclusions
virtually irrefutable. Despite this, it took almost 10 years for
the archaeological community toextremely grudginglyaccept
the Monte Verde site.
The fact that the oldest site in the Americas was located almost
8,000 miles from the presumed gateway did not go unnoticed. One
might have assumed that if the Bering Strait Theory were correct,
and Paleoindians migrated from Asia, then the sites in South America
would be much younger than those in North America, and the further
north one excavated, the older the sites would be. But that had
never been the case, as the accepted sites in Canada were even younger
than those in the U.S. Indeed the archaeological evidence was pointed
towards a migration, but a migration the other way.
With Clovis First now dead and with it the Ice-Free Corridor,
Coastal Migration was now the only alternative. The new dates from
Monte Verde had pushed back human occupation of the Americas to
14,800 years ago, but geologists had already determined that 17,000
years ago the coastal route was completely blocked by ice from Russia
all the way to Seattle. The Paleoindians would have had to have
sailed a distance of almost 3,000 miles alongside the massive ice
sheets without being able to land. Even 16,000 years ago the coastal
route would have been largely clogged with ice. Once again the Paleoindians
would have had to race, this time in tiny boats through treacherous
waters, if they were to reach Monte Verde in time to leave traces
of their occupation.
The line was drawn once again by the Bering Strait advocates
at 15,000 years ago, and it could not go back much further than
that without the collapse of the whole theory. So this meant that
according to the newest version of the Bering Strait Theory, the
Paleoindians essentially sailed down the coast directly to Monte
Verde, Chile, before later deciding to settle in the Americas. But
as absurd as that idea was, new evidence was making even that far-fetched
Strait Theory, Pt. 6: DNA, Blood Types and Stereotypes