This is the second post in a series discussing the recent publication of a 12,500 year old genome from Montana. You can find the first post here.
In the weeks following the publication of the complete genome from a Clovis child, there’s been a lot of press coverage of this study and its possible implications. I want to discuss a bit of the media coverage on this subject, since it raises issues that I think science journalists need to consider more carefully.
First of all, to recap the major findings of the original study (discussed in more detail at the link above):
1. Anzick-1, the 12,500 year old Clovis child whose genome Rasmussen and colleagues sequenced, is very closely related to living and ancient Native Americans.
2. Anzick-1 is more closely related to Siberians than other Eurasian groups.
3. Anzick-1 is more closely related to Central and South American Native American groups than to some North American groups.
4. The results from Anzick-1′s genome fit with the scientific consensus about the peopling of the Americas. This consensus encompasses the results of decades of archaeological, genetic, and paleoclimate research.
Unfortunately, several press reports chose to find controversy in a decidedly non-controversial story by giving undue weight to problematic “alternative” explanations of Native American origins, including the Solutrean hypothesis, and other “European contributions” to Native American ancestry.
The Solutrean hypothesis rejects the consensus view by researchers that the ancient Native American Clovis peoples were descended from ancestors who lived in Beringia (who themselves were descended from ancient peoples who lived in Siberia). Instead, its proponents suggest that Clovis peoples are descended from a group of people living in France during the Solutrean period (21,000–15,000 years before present) who migrated across the Atlantic and spread westward across North America. They point to similarities in the stone tool technologies of the Solutrean and Clovis peoples as the main support of this idea. (These “similarities” in tool shape are vigorously rejected by most American archaeologists. I won’t go into a discussion of the details here, because that’s not my field, but if any archaeologists wish to in the comments, please feel free!).
In addition to extravagant claims based upon problematic dating and superficial similarities between tools, a serious problem with the Solutrean hypothesis is that its claim of an ancient European origin for Clovis also predicts that we would find a significant genetic contribution from ancient Europeans into ancient Native American populations. We don’t. All ancient and modern Native Americans possess mitochondrial (maternally-inherited) and Y-chromosome (paternally-inherited) lineages that are descended from those found in peoples of Siberia. They are not found in ancient or modern Europeans. Comparisons of bi-parentally inherited nuclear markers also show a close relationship between all Native Americans and Siberians, not Europeans.
What about haplogroup X?
X is mitochondrial haplogroup that has been cited as evidence of a trans-Atlantic genetic contribution. Some say that it’s evidence of a European migration, and others claim that it’s evidence of an ancient Israelite migration (including the makers of the 2011 documentary “Lost Civilizations of North America”). In the latter case, interviews of archaeologists, historians, and geneticists who work on Native American history and prehistory were edited to make it sound like they supported the idea that haplogroup X was evidence of a pre-Columbian migration of Israelites to the Americas. The scholars responded by writing a series of articles refuting the documentary’s claims in Skeptical Inquirer (“Civilizations Lost and Found: Fabricating History”). Specifically, in this article one of them (my current advisor, Deborah Bolnick) discusses haplogroup X, and I encourage you to go read it. The main points are:
–Haplogroup X is widely distributed throughout Eurasia.
–The particular lineage found in North America, X2a, is specific to Native Americans. It not closely related to X lineages found in Europe or in the Middle East.
–X2a is roughly the same age as other Native American-specific haplogroups (Perego et al. 2009), which fits a model of simultaneous expansion from a single source, and would not likely be the case if it was a much older lineage expanding from Europe.
The interpretation of X2a as evidence of a European genetic contribution is not accepted by geneticists specializing in the study of Native American origins. This was carefully considered as a hypothesis a decade ago by our field, and rejected based on a strong body of evidence. Many of us are mystified that it’s recurring now, given that it was thoroughly debunked so long ago.
Unfortunately, the majority of media reports about the Clovis child’s genome chose to give undue weight to the Solutrean hypothesis and/or his “European connections”. I saw two major types of this reporting. The first, like this Reuters article presented the debate as if there were equal weight to both sides, an example of false equivalency that we see quite often in science coverage of controversial topics (and which I explicitly tried to warn reporters against when I was being interviewed on the subject). The second, like this article in der Spiegal “Montana Boy: Bones Show Ancestral Links to Europe”, emphasized the Anzick-1′s genetic affinities with the recently published genome from the ancient Siberian “Mal’ta child” (Raghavan et al. 2013) as evidence of European ancestry. (They specifically suggest that he may have German ancestry). That they chose to do so is puzzling. Shared ancestry between an ancient Native American and an ancient Siberian individual from the Lake Baikal region is a totally unsurprising result and fits within our consensus models for the peopling of the Americas. But Spiegal’s interpretation of this as a “European link” to Native Americans is inaccurate. The Mal’ta individual shows shared ancestry with a broad distribution of Eurasian populations, not just modern Europeans. Furthermore, the Mal’ta child lived 24,000 years ago, and the genetic landscape of that time period was almost certainly unlike the genetic landscape of today. To say that the Mal’ta child was “European” is to inappropriately apply a modern description of genetic variation backwards to a time when genetic diversity patterns in Europe likely were very different: by that logic, it would be just as accurate to say that modern Europeans are “Siberian”!
Emphasizing the “European connections” to the ancient Native American genome seems at first glance to be a particularly bizarre approach, because the genome showed absolutely nothing new in this context; it fit all expectations for what Clovis genetic diversity should look like if the standard migration model from Siberia to the Americas (via Beringia) was correct. So why did they choose to report it this way?
I think one possibility is that such alternative explanations are very appealing to reporters, as they evoke the concept of “lost civilizations” and add a touch of mystery and drama to what might otherwise be rather dry genomics papers. And it doesn’t help that we geneticists sometimes aren’t careful about thinking through the implications of emphasizing some aspects of our results over others. When we don’t provide appropriate anthropological context for our results, it’s easy to misunderstand them. What journalists may not be aware of is that there is a long and unsavory tradition in the United States–going back to the very earliest days of European colonization–of attempts to insert Europeans into Native American history. These attempts have taken many forms, as Feder and colleagues (2011) discuss:
“Even restricting ourselves to just North America, the list of such claims is long—though evidence is short—and includes: Celtic kingdoms in the northeastern United States thousands of years ago (Fell 1976); Coptic Christian settlements in ancient Michigan (based on the so-called Michigan Relics) (Halsey 2009); Roman Jews in Arizona (the Tucson Artifacts) (Burgess 2009); the Lost Tribes of Israel in Ohio (the Newark Holy Stones) (Lepper and Gill 2000); and strange mixtures of various ancient Old World peoples secreted in hideouts in the Grand Canyon in Arizona (“Explorations in Grand Canyon” 1909) and in a cave in southeastern Illinois (Burrows Cave) (Joltes 2003). These claims are predicated essentially on the same notion: ancient Europeans, Africans, or Asians came to the Americas long before Columbus and long—perhaps thousands of years—before the Norse; they settled here and had a huge impact on the native people but then somehow became lost, both to history and to historians.”
This recent round of media attention is merely the latest iteration of a long tradition of emphasizing completely unsubstantiated hypotheses of European contributions to Native American prehistory. The fact is that they run counter to the consensus of over a century of research by hundreds of scholars in multiple disciplines. But that seems to be precisely what makes them attractive–the media is very fond of the story of the lone scientist (or group of scientists) radically challenging the dominant scientific paradigm. But they are doing so with complete unawareness—or worse, disregard—for the ways in which this narrative has been used over the past several centuries as a tool to de-legitimize Native Americans’ connections to their own history.
Some ideas that buck the scientific consensus are brave and new and bold and right, like the idea that Clovis peoples weren’t the first inhabitants of the Americas.
But most are brave and new and bold and wrong, like the notion that skulls with intentional cranial deformation belong to aliens or an unprecedented new hominid species.
In this case, not only does speculating about European genetic or cultural contributions to Native American history run completely counter to existing genetic and archaeological evidence, it buys in to a long and unfortunate tradition of asserting problematic external explanations for Native American achievements. As Feder et al. (2011) put it:
“Native Americans were fully capable of developing complex and sophisticated cultures on their own without help from other societies. The archaeological record of North America clearly shows the indigenous development of the technologies, art, architecture, social systems, subsistence practices, and engineering accomplishments seen in native America. There is no archaeological or biological evidence for the presence of interlopers, and there is no need for their presence in explaining the archaeology of native America.”
Dear journalists, please delve a bit deeper into the history of research into American prehistory before trotting out discredited theories. Mavericks love to tout their iconoclasty as evidence that they’re right, but you know that’s not how science works. Ideas live or die based on whether they’re right or wrong, and the Solutrean hypothesis is simply wrong.