Archaeological discoveries in South America in the 1980s led to a revision in the timeline of the Bering Strait Theory, throwing the whole theory into doubt. But the dogmatic insistence on a single passageway in a certain time period was also being challenged on many other fronts.
It is generally presumed that the new science of genetics is providing support for the Bering Strait Theory, but that is not necessarily so. The idea that we are all related is a concept well known among American Indians and therefore the fact that new genetic studies are detailing these relationships among humans is not surprising. The question is not so much, “are there relationships?” but do these the new details actually shed light on the movements of populations in the past.
Adding to the confusion surrounding genetic studies is the newness of the science, which has caused genetics to be heavily influenced by the archaeologists, and thus already predisposed to the Bering Strait Theory. More unfortunate has been the use by geneticists of the pseudo- scientific classifications of American Indians proposed by the linguist and Clovis First devotee, Joseph Greenberg, classifications that are completely discredited, but still used in genetic studies. These problems and others have led to the regular publishing of highly contradictory reports, often in the same year. As University of Wyoming anthropologist Nicole M. Waguespack noted, “Genetic studies are currently plagued by equifinality, as it has become clear that multiple scenarios of initial colonization and later population movements can be devised to account for the modern frequencies of American haplotypes.”
The first simple tests for genetic inheritance involved blood groups, discovered by the Austrian biologist Karl Landsteiner in 1901, who named the three then-known types as A, B, and O. In 1919, Ludwik and Hanka Hirschfeld, by sampling soldiers, found that different ethnicities and races had differing frequencies of having one blood type or another. In 1923, two immunologists from Cornell University, Olin Diebert and Arthur Coca, collected blood samples of American Indians, in part to determine “the question of the relation of the American Indian race to the northeastern Asiatic races.” As Margot Lynn Iverson wrote in her book, Blood Types, after they compared their samples to those taken from Asian peoples,
Coca and Diebert anticipated finding similar blood group distributions in the Asian and Indian populations, which would further support the widely held theory that Native Americans had immigrated to the Americas from northeastern Asia. They were surprised to find that, to the contrary, the blood group distributions of the East Asian and American Indian sample groups were quite different.
The American Indians had a very high likelihood of being type O, whereas it was not common in Asians. About one-third of the Asians were type B, but this group was almost non-existent among Indians. In a pattern that would become familiar with genetic studies of American Indian origins, Iverson noted;
Despite not finding similarities between the American Indian and Asian populations, the two researchers interpreted their results as in accordance with the scientific view that Native Americans had traveled to the Americas from Eastern Asia by arguing that the blood group data was evidence of the antiquity of the separation between the two populations, before the mutations causing the A and B blood groups had occurred.
The study by Coca and Diebert did not break down the Indian samples by tribe, a serious flaw in any study. Later studies confirmed that a high percentage of Indians were type O, leading many to conclude that this was the original Indian blood type. This appeared to lend credence to the belief that Indians were one genetic unit, in tune with the perception that the first Indians were a small group of hunters who wandered into the Americas over the Bering Strait. But a report in 1933 threw all of that out the window.
Gustave Matson, a bacteriologist at Washington University in St. Louis, and H.F. Schrader, an Indian Office doctor, did one of the few studies in which the genetic markers of a single Indian nation, in this case the Blackfeet (Piegan), were examined. The report, “Unexpected Differences of Blood Groups in American Indians,” found that the vast majority were type A, and indeed, the more “fullblood” they were, the more likely they were to be type A. They then did another study among the Blackfeet of Canada and found the same result, leading them to conclude that originally the Blackfeet were all type A. Matson and Schrader argued that the results showed that Indians were not originally one homogenous group, and they “suggest the necessity for reconsidering the origin of the American Indian.”
As other genetic markers were developed, they too showed little relationship between American Indians and Asians. The RH blood group system, discovered in 1939, found that American Indians were unlikely to have negative RH factors, the opposite of Asians. Similarly in fingerprint patterns, Indians are more likely to have similar patterns to Caucasians than Asians. Moreover, as in the case of blood types, Indian genetic markers could vary considerably depending on the tribe, dispelling the notion that Indians are one genetic group, and making any conclusion problematic.
THE GENETIC SWAMP
In 1953, James Watson, Francis Crick, Rosalind Franklin, and Maurice Wilkins cracked the genetic code by discovering the structure of DNA. Over the next three decades, scientists would work to identify and place in proper order the thousands of genes that make up DNA strands, leading to the “sequencing” of the DNA in the mitochondria, the small “energy battery” inside of a cell, in 1981. Like radiocarbon dating, sequencing DNA revolutionized, and continues to revolutionize, our understanding of human origins.
In 1991, an international team led by R.H. Ward from the University of Utah and Svante Pääbo from the University of Munich examined the Nuu-Chah-Nulth (Nootka) people of Canada. Their paper, entitled, “Extensive Mitochondrial Diversity Within a Single Amerindian Tribe,” created a stir.
Sequencing of a 360-nucleotide segment of the mitochondrial control region for 63 individuals from an Amerindian tribe, the Nuu-Chah- Nulth of the Pacific Northwest, revealed the existence of 28 lineages defined by 26 variable positions. This represents a substantial level of mitochondrial diversity for a small local population.
This was unexpected, as it would take a long time for this diversity to develop. Given the fixed date of the Bering Strait Theory, the authors could only assume that, “the magnitude of the sequence difference between the lineage clusters suggests that their origin predates the entry of humans into the Americas,” a conclusion that raised even more questions than it answered.
Other, broader studies were encountering similar problems. Because Mitochondrial DNA is passed only from a mother it avoids the gene shuffling that can obscure the evolutionary trail. It also mutates faster than nuclear DNA, allowing researchers to distinguish populations that recently separated and estimate when that occurred. As geneticists began to detect these mutations in different populations, they began to classify them. Although new variations are still being discovered, the basic outlines began to fall in place by the early 1990s.
Divided into “haplogroups” these distinctive sequences were named A to Z in order of their discovery. In very general terms, haplogroup L is found largely in Africa and is believed to be the parent sequence of all modern humans. At some point in the deep past, two groups, M and N, descended from L and, breaking up into numerous subgroups, expanded all over the world, including the Americas. From M, the subgroups C and D, and from N, the groups A, B, and X, are found in American Indians.
These groups are also found in Asia and Europe, and so it was presumed that the Eurasian populations with these same haplogroups were the ancestors of Indians. Even though these haplogroups were the same in both hemispheres, they were not quite identical due to mutations over time, allowing the geneticists the ability to estimate when the DNA in Asia and the Americas had separated from each other. And what they found surprised them.
Investigations by a number of geneticists began to find extremely deep ages for when the DNA splits occurred. Michael D. Brown from Emory University estimated that Haplogroup A divided between 27,000 and 57,000 years ago; Antonio Torroni, professor of genetics at the University of Pavia, Italy, estimated that B split sometime between 26,000 and 39,000 years ago and that D split 32,000 to 47,000 years ago; Theodore G. Schurr, professor at the University of Pennsylvania, estimated that C split between 42,000 and 55,000 years ago, and X split 13,000 to 17,000 years ago. Sandro L. Bonatto from the Catholic University of Rio Grande do Sul, Brazil, summed up the situation, “these results put the peopling of the Americas clearly in an early, pre-Clovis time frame.”
Like the linguistic evidence, which indicates that American Indians have been a separate peoples for at least 40,000 years, the dates for the Bering Strait Theory were “in the wrong ballpark,” in the words of linguist Johanna Nichols. To make matters more problematic, the “coalescent age,” that is the date when the varying genes had been one and not split, in some American Indian haplogroups were older that those of some Asian populations, leading to speculation that migrations may have occurred both back and forth, to and from Asia.
But even with this formidable evidence against it, the Bering Strait Theory would not die. Because it was simply impossible, according to the belief, for American Indians to have migrated before the massive ice sheets blocked their path approximately 30,000 years ago, a new hypothesis was proposed, originally known as the “Three Stage Expansion” but now dubbed the “Beringian Standstill Theory.”
THE THEORY THAT WOULD NOT DIE
Resembling more an invention by Rube Goldberg than a scientific theory, the Standstill hypothesis is a direct result of the genetic evidence, which undercuts the Bering Strait Theory, and it was first proposed in 1997 by the geneticists Sandro L. Bonatto and Francisco M. Salzano. Inthis scenario, the ancestors of Indians migrated to “Beringia,” as the region that surrounds the Bering Strait is called, between 30,000 and 40,000 years ago. They then waited in Beringia–at that time a vast plain that connected Siberia and Alaska–for about 20,000 years until the ice sheets melted, and then around 15,000 years ago made their way into the Americas in time to get to Monte Verde 14,800 years ago.
The Indians, while waiting 20,000 years, also had to be in complete isolation and not genetically mix with other Asian tribes. In this way, the unique genetic mutations would have the time to develop, while at the same time keeping the Paleoindians out of the Americas before 13,000 BC. Geneticists have looked to find a “bottleneck” in genetic growth, and “founder effects,” that is the loss of genetic diversity that occurs when only a small population gives rise to a larger one, that might show there was indeed a 20,000- year wait in Beringia before the expansion into the Americas. This search has produced a number of genetic studies with conflicting results, leaving the whole thing unresolved.
In his February 28, 2014 article in Science magazine, “Out of Beringia?” University of Colorado Boulder researcher John Hoffecker, who is a proponent of the Standstill theory notes, “the weakest link to the Out of Beringia theory is the lack of archaeological evidence.” There is absolutely no sign that humans lived in this region during this time. In addition, this research by the University of Colorado Boulder (and two other universities) found that although the area had “surprisingly mild temperatures” during the summer (for an ice age), it was still cooler than the area is now, which is not particularly hospitable.
The new study actually set the Beringian Standstill Theory back. Digging up sediment cores from that region dated to between 15,000 to 30,000 years ago, they found in the spores of shrubs and other plants, “evidence that central Beringia supported a shrub tundra region with some trees during the last glacial maximum.” But a review in Scientific American argued that, “This kind of vegetation would not have supported the large, grazing animals–woolly mammoth, woolly rhino, Pleistocene horses, camels, and bison” that presumably the Paleoindians would have lived on.
Archaeologists had long held that because there is (under their standards) no archaeological evidence of Indians in the New World before 15,000 years ago, they were thus not here. Yet there is absolutely no archaeological evidence of anyone living in Beringia during the 20,000 years Paleoindians are supposed to have been there, either.
THE MYTH OF SCIENTIFIC FACT
It would appear that different standards of evidence are required, depending on the point of view. Those who would propose an alternative to the Bering Strait Theory must come up with an ironclad case, impeccably documented and researched, and proven beyond all doubt.
Unfortunately, science is only rarely able to prove things with absolute certainty as it normally confines itself to mathematical probability. As the evolutionary psychologist Satoshi Kanazawa put it, “proof is not a currency of science,” and, “the primary criterion and standard of evaluation of scientific theory is evidence, not proof.” However, the demand for “indisputable proof” to overturn a dogmatic stance is one of Aleš Hrdlička’s enduring legacies.
Meanwhile, those who support the Bering Strait Theory may simply present conjectures, even if they have only the slightest evidence and even if these conjectures are often improbable if not impossible.
What makes the dubious nature of the Standstill hypothesis even more unfortunate is that perspectives that do not conform with the Bering Strait Theory, if they are not ignored, are treated with disdain or ridicule, or even savagely attacked. Yet it is the Bering Strait Theory that has historically been a collection of pseudoscientific mythologies, promoted virulently by dogmatists, who have largely held back science and discouraged free expression.
In 1916, in his book, Time Perspective in Aboriginal American Culture, while discussing the science of archaeology, the renowned linguist and a firm believer in the deep antiquity of American Indians, Edward Sapir, offered a thinly veiled criticism.
The method has yielded brilliant results in the study of prehistoric Europe and western Asia and is doubtless destined to teach us vastly more than has yet been disclosed to us about the earlier culture history of the rest of the world. For America, however, the results, while of distinct value as far as they go, have so far been rather more meager than might have been expected. Whether this is due to the nature of the culture history of America itself or to certain defects in the field methods of investigators, I would not venture to decide.
Bruce Bradley, senior lecturer at the University of Exeter, UK, and Dennis Stanford, the former Chair of the Department of Anthropology at the National Museum of Natural History of the Smithsonian Institution, wrote about the Bering Strait Theory in World Archaeology in 2004:
We must remember that these ideas on New World origins are based on informed speculation and are not supported by archaeological evidence. Through time and repetition, and in the absence of any clear alternatives, the theory has become dogma, and ultimately ideology, appearing in all textbook and popular publications.
Bradley and Stanford have proposed instead an equally speculative alternative, that the Clovis culture originated in Europe, not Asia, and that early Paleoindians migrated across the northern Atlantic, not over the Bering Land Bridge. Needless to say, their position is considered to be extremely controversial and their evidence is highly disputed by the paleoanthropological community.
That the science of paleoanthropology, and thus the Bering Strait Theory, were born out of assumptions of Western cultural and genetic superiority is now widely accepted. Anthropologist Michael L. Blakey argued that the father of the modern Bering Strait Theory, Aleš Hrdlička, was among the most influential of the ideological “skull doctors,” and his work was little more than pseudoscientific racism. Yet the unfortunate impact of Hrdlička’s dubious methods continues to this very day.
It is also unfortunate that to the mainstream press, the standard line is recited, that American Indians crossed into this hemisphere from Asia in 13,000 BC through the Bering Strait, as if this is an accepted fact. It seems impossible for scientists to say, “we simply do not know.” It is easier to promote a myth.
One hundred and twenty years ago, paleoanthropologists were faced with what they believed to be a dilemma: chaos or order. In the end they chose order, and in doing so they created the dogma of the Bering Strait Theory. Like most dogmas, it has taken on a life of its own, far beyondwhat its creators could have hoped for or expected. As a theory it continues to grow and mutate, adapting to new circumstances, for no amount of evidence to the contrary will make it disappear.
While there are those who may fear that the loss of a dogma may lead once again to chaos, there are alternatives to chaos or order. As the geneticist Rebecca Cann argued, “rather than make dogmatic statements” we should “encourage the open exploration of this debate” and in doing so, maybe we will find some answers.