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America Before

Page 13

by Graham Hancock


  A number of other researchers seized on the apparent temporal discrepancy to discount Anzick-1 as a Clovis individual,36 but Fiedel’s comment on contamination proved prescient. In June 2018, a year after his Quaternary International paper, a new study by scientists at the Oxford Radiocarbon Accelerator Unit was published in Proceedings of the National Academy of Sciences (PNAS) under the headline “Reassessing the Chronology of the Archaeological Site of Anzick.”37 The study reminds us that “in radiocarbon dating, contamination can be a major source of error” but adds that “methodological improvements” since the original dating work at Anzick was done “have seen a significant effect in dating accuracy and reliability.”38 After applying these new methods the study concludes, contrary to previous findings, that “Anzick-1 is temporally coeval with the dated antler rods. This implies that the individual is indeed temporally associated with the Clovis assemblage.”39

  We’ll return to the mysterious end of the Clovis culture in later chapters. Meanwhile there’s a second reason why Anzick-1’s “Clovis connection” is of immediate relevance to our quest here—which is that although Clovis did, at the limits of its range, extend into some northern areas of South America, its heartland was in North America.40 Intuitively, therefore, we would expect the Montana infant, a Clovis individual, to be much more closely related to Native North Americans than to Native South Americans. Further investigations, however, while reconfirming that Anzick-1’s genome had a greater affinity to all Native Americans than to any extant Eurasian population,41 revealed it to be much more closely related to native South Americans than to Native North Americans! 42

  Morten Rasmussen of Denmark’s Centre for GeoGenetics and Pontus Skoglund of the Department of Genetics at Harvard Medical School seek to explain the anomaly by arguing that the ancestors of the First Americans must have split into two separate groups—they label them “the NA and SA lineages”—before entering the Americas, “with the Anzick-1 individual belonging to the SA lineage.”43

  That seems reasonable enough on the face of things until we stop to consider the spectacle of these two groups, sharing common ancestry but already genetically distinct, racing into the Americas on parallel and nonconverging tracks, one heading straight for South America, the other staying in North America—yet never, throughout this process, making sufficiently enduring contact with one another to compromise their separateness or leave a trace in the genetic record. This seems to deny human nature and simply doesn’t make sense in lots of ways even before we get to the fact that Anzick-1, the most ancient representative of the “SA lineage” so far studied by science,44 wasn’t found anywhere near South America but in North America and, indeed, in Montana, which, 12,600 years ago, was about as far north as you could get before you hit the great Cordilleran ice sheet.

  A PECULIAR SIGNAL FROM DOWN UNDER

  IN SUMMARY, ANZICK-1 IS A paradox clothed in a conundrum, wrapped up in a mystery—an individual in a North American Clovis culture grave who is closely related to Native South Americans, to the Siberian Mal’ta population, and to ancient western Europeans. Because the South American lineage to which he belonged shared a common ancestor with the North American lineage, the geneticists found nothing in the data to challenge their long-held view that the settlement of the Americas, both North and South, had been accomplished from northeast Asia by a single founding population—albeit one that divided itself into two streams.

  A year later, however, in September 2015, Pontus Skoglund, his senior colleague Professor David Reich of the Department of Genetics at Harvard Medical School, and other leading experts in the field announced in the pages of Nature that they had found new evidence in South America, and specifically in the Amazon rainforest, that called for a rethink:

  Here we analyse genome-wide data to show that some Amazonian Native Americans descend partly from a Native American founding population that carried ancestry more closely related to indigenous Australians, New Guineans and Andaman Islanders than to any present-day Eurasians or Native Americans. This signature is not present to the same extent, or at all, in present-day Northern and Central Americans or in a 12,600-year-old Clovis-associated genome, suggesting a more diverse set of founding populations of the Americas than previously accepted.45

  We’ve already done the groundwork on the “12,600-year-old Clovis-associated genome” the researchers speak of here. The reference, of course, is to Anzick-1, that paradoxical infant, swaddled in mystery, who we know was more closely related to Native South Americans than to Native North Americans. What the new study adds to this is that there was a previously unsuspected structure within the SA lineage, including at least one sub-lineage—to which Anzick-1 did not belong—that was more closely related to Melanesian Papuans and Australian Aborigines than to any extant Native American population.

  South Americans, notably in the Amazon rainforest, share ancestry with Australasian and Melanesian populations not seen in Mesoamericans or North Americans. (After Nature, “Genetic Evidence for Two Founding Populations of the Americas,” September 3, 2015).

  There is no trace of this lineage in most modern Native Americans, and—it’s worth driving this point home—no trace either in the ancestral population represented by Anzick-1. Nevertheless, the investigators continued to be confronted by a peculiar and distinctive “Australasian signal,” showing genetic relatedness to “indigenous groups in Australia, Melanesia, and island Southeast Asia,”46 calling attention to itself in the genomes of Native Americans from the heart of the Amazon jungle. The Surui and Karitiana tribes, speaking languages belonging to the Tupi family, proved to have a peculiarly close connection to Australasians, as did the Ge-speaking Xavante of the central Brazilian plateau.47

  Such a signal was completely unexpected given the vast distance between Australasia and the Amazon and the absence of any overland DNA trail. Skoglund and Reich therefore subjected it to particularly rigorous testing, applying four different methods of statistical analysis to compare the genomes of 30 Central and South American peoples with the genomes of 197 other populations from around the world.48 “We spent a really long time trying to make this result go away,” Skoglund explained, “but it just got stronger.”49

  In the end “a statistically clear signal linking Native Americans in the Amazonian region of Brazil to present-day Australo-Melanesians and Andaman Islanders” was confirmed.50

  “It’s incredibly surprising,” commented David Reich. “There’s a strong working model in archaeology and genetics, of which I have been a proponent, that most Native Americans today extend from a single pulse of expansion south of the ice sheets—and that’s wrong. We missed something very important in the original data.”51

  What was missed, Reich and Skoglund argue, was nothing less than the fingerprints of a lost lineage—a second founding population of the Americas. It is very old,52 in their view, and almost all traces of it have been overwritten almost everywhere by later genetic “noise.” That we can still detect it at all among isolated peoples in the Amazon is probably because their genomes have been subject to less admixture and introgression than most.

  The investigators have given their “putative ancient Native American lineage” a name: “Population Y” after Ypykuéra, which means “ancestor” in the Tupi language family.”53

  And they come to a very clear, if tantalizing, conclusion: “A Population Y that had ancestry from a lineage more closely related to present-day Australasians than to present-day East Asians and Siberians likely contributed to the DNA of Native Americans from Amazonia and the Central Brazilian Plateau.”54

  But how, when, and where did this contribution occur?

  One possibility that Skoglund and Reich consider is that the patterns of genomic variation of present-day Amazonians could be explained if a large proportion—up to 85 percent—of their ancestry derived “from a population that existed in a substructured northeast Asia, and was similar to the main lineage that gave rise to other Native Americans while
retaining more Australasian affinity.”55

  In other words, congregating in that original northeast Asian—that is, Siberian—melting pot we are now being asked to envisage not only people with European genes and people with east Asian genes, but also people with Australasian genes. Neanderthals were part of the mix, too, interbreeding vigorously with Homo sapiens, and there were people carrying Denisovan genes and of course the Denisovans themselves. We’re asked to see these groups as essentially divided and separate from one another—despite the obvious evidence of their liaisons—and we’re asked to accept that they remained divided and separate, already conveniently prearranging themselves into what would become the “NA” and “SA” lineages, as they trekked across the Bering land bridge.

  The endlessly flexible boundaries of such an improbable model seem perfectly adapted to explain away any potentially boat-rocking data. It’s not surprising, therefore, to find a hermetically sealed and hitherto invisible “Australasian lineage” being tacked on to the mongrel pedigree of the First Americans as soon as the inconvenient presence of Australasian genes in the midst of the Amazon jungle needed to be explained and normalized. Nor is it surprising to see the hypothetical “Population Y,” identified as the bearer of those genes, depicted as heading straight to South America to oblige without leaving any of its DNA along the way among the North American populations with which it would surely have had to mingle.

  Perhaps because of the impracticality of some of these ideas, Skoglund and Reich conclude with an offbeat alternative. “The patterns of genomic variation of present-day Amazonians,” they point out, seemingly off the cuff, could also be explained “by as little as 2% admixture from an Australasian-related population, that would thus have penetrated deep inside the Americas without mixing with the main ancestral lineage of present-day Native Americans.”56

  In other words, on this view, what has been preserved in those isolated, unadulterated Amazonian genomes that speaks to an ancient connection with Australasia might not be the traces of a full-scale migration but something more like a one-off settlement by a relatively small group.

  In the next chapter we’ll consider the profound implications of this scenario for our understanding of American prehistory.

  A SIGNAL FROM THE DREAMTIME?

  SKOGLUND AND REICH’S PAPER IN Nature reporting the presence of Australasian genes in certain populations in the Amazon is titled “Genetic Evidence for Two Founding Populations of the Americas.”1 It was first published online on July 21, 2015 (ahead of the print edition, which appeared on September 3, 2015).

  On precisely the same day (before appearing in print in the journal Science on August 21, 2015), another team of researchers, led by Maanasa Raghavan and Eske Willerslev, both of the Centre for GeoGenetics at the University of Copenhagen, published the online version of a paper titled “Genomic Evidence for the Pleistocene and Recent Population History of Native Americans.”2 Unlike Skoglund and Reich, who see two founder populations in the data, Raghavan and Willerslev see only one, arriving in “a single migration wave from Siberia no earlier than 23 thousand years ago and after no more than an 8000-year isolation period in Beringia.”3

  Raghavan and Willerslev several times drive home the point that the data they present “are consistent with a single initial migration of all Native Americans”4 along a route from Siberia via Beringia and that “from that single migration, there was a diversification of ancestral Native Americans leading to the formation of northern and southern branches.”5

  This is all very neat, tidy, and in certain ways reassuring for those American archaeologists—a majority—still reeling from posttraumatic shock following the collapse of the Clovis First dogma. Of course they would have to be in a state of rigid and unyielding denial to continue to shrug off the perfect storm of evidence from genetics and from sites like Topper, Cactus Hill, and Monte Verde that relegated Clovis to the trash can of history. But at least their favored route—from Siberia, across the Bering land bridge—remains intact and not only that, but Raghavan and Willerslev’s paper also endorses the currently fashionable “Beringian standstill” model.

  If only the geneticists had ended their paper there, archaeological contentment with it would have been complete. However, because they are good scientists, Raghavan and Willerslev—just like Skoglund and Reich—could not ignore the persistent “Australasian signal” that kept cropping up in the data:

  We found that some American populations—including the Aleutian Islanders, Surui, and Athabascans—are closer to Australo-Melanesians as compared with other Native Americans, such as North American Ojibwa, Cree, and Algonquin and the South American Purepecha, Arhuaco, and Wayuu. The Surui are, in fact, one of the closest Native American populations to East Asians and Australo-Melanesians, the latter including Papuans, non-Papuan Melanesians, Solomon Islanders, and South East Asian hunter-gatherers such as Aeta.6

  As we’ve seen in previous chapters, the archaeological mainstream is an intensely conservative and territorial scholarly community, resistant to change, whose deeply embedded prejudices deny that our “Stone Age” ancestors could have possessed anything other than the most primitive and rudimentary technological abilities. For orthodox thinkers, it is literally inconceivable that prehistoric settlers from the general vicinity of Papua New Guinea could have crossed the entire width of the Pacific Ocean to South America, and thence made their way to the Amazon to leave evidence of their presence in the DNA of people still living there today.

  What’s paradoxical about this position is that—admittedly after a hard-fought struggle—no one in the mainstream now would seriously dispute that our ancient hominid ancestors were capable of undertaking successful open-water voyages to colonize new lands.7 We’ve seen how the presence of Denisovan DNA on both sides of the Timor Straits and both east and west of the Wallace Line confirms that migrations across stretches of open water up to 90 kilometers wide were indeed taking place at least 60,000 years ago—a position already supported by a mass of other evidence.8

  Likewise, and significantly earlier, bones and artifacts of Homo erectus dated to 800,000 years before the present have been found on the Indonesian islands of Flores and Timor, again making open-water crossings by these supposed “subhumans” a certainty even during periods of lowered sea level.9

  All of this has long ago been conceded. Despite the passage of close to a million years since Homo erectus first sailed to Flores, however, what archaeology does not concede is that the human species could have developed and refined those early nautical skills to the extent of being able to cross a vast ocean like the Pacific or the Atlantic from one side to the other. In the case of the former, extensive transoceanic journeys are not believed to have been undertaken until about 3,500 years ago, during the so-called Polynesian expansion.10 And the mainstream historical view is that the Atlantic was not successfully navigated until 1492—the year in which, as the schoolyard mnemonic has it, “Columbus sailed the ocean blue.”

  Indeed, the notion that long transoceanic voyages were a technological impossibility during the Stone Age remains one of the central structural elements of the dominant reference frame of archaeology11—a reference frame that geneticists see no reason not to respect and deploy when interpreting their own data. Since that reference frame rules out, a priori, the option of a direct ocean crossing between Australasia and South America during the Paleolithic and instead is adamant that all settlement came via northeast Asia, geneticists tend to approach the data from that perspective.

  This is the case with Raghavan and Willerslev. First, as we’ve seen, they concede the presence within the data of “a distant Old-World signal related to Australo-Melanesians and East Asians in some Native Americans.”12 But, second, they go on to downplay the implications of this with the following interpretation:

  The widely scattered and differential affinity of Native Americans to the Australo-Melanesians, ranging from a strong signal in the Surui to a much weaker signal in no
rthern Amerindians such as Ojibwa, points to this gene flow occurring after the initial peopling by Native American ancestors.13

  Here’s how they arrive at this interpretation of the data:

  They trace the source of the strong Australasian signal in the Amazon to “gene flow”—the transfer of genetic variation from one population to another.14

  They propose that this gene flow reached Amazonian peoples such as the Surui from northern Amerindian populations such as the Aleutian Islanders and the Athabascans, and they appear to favor particularly a “route via the Aleutian Islanders,” since the latter “were previously found to be closely related to the Inuit who have a relatively greater affinity to East Asians, Oceanians, and Denisovans than Native Americans.”15 They hypothesize that the “complex genetic history” of the Aleutian Islanders perhaps “included input from a population related to Australo-Melanesians through an East Asian continental route [i.e., from Siberia across the Bering land bridge], and this genomic signal might have been subsequently transferred to parts of the Americas, including South America, through past gene flow events.”16

  The problem I have with all this is that these hypothetical “past gene flow events” somehow left a strong DNA signal in the Amazon, one of the remotest and most inaccessible parts of South America, while leaving next to no signal at all in North America, which—whether the genes were carried by people who traveled on foot or by people who island-hopped and coasted from the Aleutians in simple watercraft—would surely have involved interactions with North American populations before any interactions with South American populations took place—and therefore presumably should have left a DNA signal in North America at least as strong as the signal found in the Amazon.

 

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