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Dear Guardian Editors,

Bradley comments (Raff comments below in bold):

Contributor Bruce Bradley, University of Exeter

I resent the need frequently to reply to the same false and misleading assertions about our hypothesis and the dogma put forth by some critics.  Our time and intellectual efforts would be better spent doing the research.  The production of this documentary sponsored primary research and, for this, we are grateful.

“…European…” We (Stanford, Bradley and Oppenheimer) use the term European as a geographic reference and nowhere do we use it as a cultural indicator.  We do not speak of ‘Europeans’ migrating to the New World during the glacial maximum.  Palaeolithic peoples in what is now Europe were not ‘Europeans’ as they are defined today (with the possible exception of the Basque). We never say or imply that Palaeolithic peoples from the Basque Refugium were white or resembled the majority of modern Europeans.  In fact, recent genetic analysis indicates that at least one Palaeolithic person (‘Cheddar Man’) had dark skin.

“…who see it as a means of denying Native Americans an ancestral claim on their land” This may be the case for some ‘white nationalists’ but has no basis in law.  In the United States Native rights are based on treaties between Nations not on who was there first.  This statement implies that we subscribe to the denial of Native rights.  We do not.

“…the idea behind the Solutrean hypothesis is part of a long tradition of Europeans trying to insert themselves into American prehistory; justifying colonialism by claiming that Native Americans were not capable of creating the diverse and sophisticated material culture of the Americas”  This is utter nonsense.  How are the origins of Native Americans and their capability of creating diverse and sophisticated material culture any different if they came from Europe or Asia? I find the whole tenor of this line of discussion unsettling in its own clear ‘racist’ overtones.  How is the (assumed) ancestry of the authors or producers of the documentary relevant to the content?  This, in itself, is a racist comment and the recurrent implication is that we are racists and I am thoroughly offended.

“Clovis tools, the first recognized stone tool tradition in the Americas” This is inaccurate, as Across Atlantic Ice clearly incorporates well-established older than Clovis archaeological evidence (Chapter 4).  That Raff uses this now out-dated view, clearly puts her in the old “Clovis First” camp.  Does she deny the evidence of all older-than-Clovis evidence?

“The notion that the ancestors of Native Americans were not the first or only people on the continent…”

How does the Solutrean Hypothesis deny Native American ancestry any more than the Out of Asia Hypothesis, which latter we also accept?  Raff is stating a Creationist belief that Native Americans originated exclusively in the Americas. 

“…nor did they include any critical perspectives from indigenous peoples”

I suggest that Raff does a bit of background research.  Are there any published critiques by Native Americans of the Solutrean Hypothesis?  This shouldn’t include social media or blogs where anybody can say anything.  I suggest she reads Clovis vs. Beringia: Europe or Siberia? A Review of Across Atlantic Ice, by Ruth Hopkins • in Indian Country Today July 9, 2012. 

“While supporting the agenda of white nationalists was not the intent of the producers or of the scientists involved, it would have been appropriate for the documentary to take a stand against it, and I and many archaeologists are disappointed that they did not” I will leave this to be answered by CBC but acknowledging these issues in this documentary would have been counterproductive and brought attention to the claims of the white supremacists.  I think the choice of actors in the reenactments were clearly made to avoid the perception that the Solutrean Hypothesis is promoting the idea of white Europeans colonizing the Americas. If in her studies Raff discovers evidence of non-Asian ancestry in pre-Columbian Native American populations will she suppress this for the sake of her perception of political correctness?  It seems she might.

“Bruce Bradley and Dennis Stanford, proponents of the Solutrean hypothesisbase it on the claim that the North American Clovis stone spear points are the technological descendants of a subset of those made by the Upper Paleolithic southwestern European Solutrean peoples. Specifically they cite fact that both are made by a technique known as “overshot” flaking as evidence for their common origin. From this starting point, Bradley and Stanford propose a hyperdiffusionist scenario in which a group of Solutreans migrated across the Atlantic Ocean to North America via an “ice bridge” approximately 20,000 years before present (YBP)”

At best this is an outdated misrepresentation of our research and worse, a clear example of minimal research and ‘cherry-picking”.  Clovis technology and tools were very complex and specific (Bradley et al.2010) as were Solutrean (Aubry et al. 2008). In Across Atlantic Ice we presented, at length, the evidence we used to compare pre-Clovis, Clovis and Solutrean artifacts and technology, not just Clovis points.  The claim that we base our interpretations primarily on the technique of overshot flaking has been made (Eren et al 2013) and specifically refuted (Lohse et al. 2014).   We discussed all of the 47 technological traits we used to construct an archaeological cultural matrix for a cluster analysis (Across Atlantic Ice Figure 6.4).  This analysis was challenged and it was suggested that a better statistical technique would be cladistical analysis.  We have since done this using an expanded matrix of 47 technological traits and 40 ‘archaeological cultures‘, resulting in a nearly identical dendrogram.  Both analyses show the similarities and differences between the technological traits of the archaeological cultures. 

“…hyperdiffusionist scenario…” unnecessary hyperbole

“Archaeologists have taken a hard, long look at this idea and dismissed it on the basis of insufficient evidence” Raff only cites three sources in her references, including Across Atlantic Ice, yet it is clear that either she hasn’t actually read it or she has chosen to misrepresent its contents.  The other archaeological source is outdated.  To claim that the Solutrean Hypothesis is invalid and has been thoroughly evaluated and rejected by most archaeologists is an unsupported claim.  Where is a statistically valid survey published?  The book was peer reviewed and published by a credible University Press (California) and was selected by a panel of renowned scientists to receive a Smithsonian Institution Secretary’s Research Prize “For exemplary scholarship and outstanding contribution towards the increase and diffusion of knowledge” February 8, 2016.  This hardly relegates it to the category of ‘popular culture’ implied by Raff.

”There’s a serious time gap between when the Solutreans could have crossed the Atlantic via the ice bridge (~20,000 YBP) and when Clovis tools begin to show up in the archaeological record (~13,000 YBP). This means that they would have made the points in exactly the same way for 7,000 years” This is an extremely outdated critique (Straus et al 2005 and rebutted by Bradley and Stanford 2006).  This statement denies all pre-Clovis evidence, which latter is now accepted by many serious scholars. Again, we show this in Across Atlantic Ice (Figure 7.10) which clearly indicates a complete chronological continuum between Solutrean, pre-Clovis and Clovis.  While not unique to the Corckran site included in the documentary, the obtained dates from it correspond to Solutrean dates.  What is Raff’s evidence of this claimed time gap?

“Nowhere else in the Americas do we see technologies and cultures existing unchanging for that length of time” This is another outdated assertion and indicates Raff is unaware of recent publications relating to cultural continuity in South America (Okumura and Araujo 2014; Araujo et al. 2017)  It is also a false statement, in that we acknowledge that there were changes in aspects of form and manufacturing technology between Solutrean and Clovis (for example change from bipointed to indented base bifaces and fluting). It is also disingenuous of Raff not to acknowledge that we discussed chronological and geographic variations within Solutrean archaeological cultures.

“There is no evidence of boat use, or tools used for making boats at Solutrean sites” This is another unsubstantiated assertion by Raff.  There are numerous examples of indirect evidence of early use of watercraft (see Van de Noort 2012 for a discussion of early boat technologies) only one of which was included in the documentary.  Where is the study that defines what stone tools were used to build boats?  What does Raff propose needs to be included in stone tools and technologies to build a skin boat?  There are numerous ethnographic and archaeological examples of stone tool-using people building boats, these should be cited and a case made that Solutrean tools were incapable of building boats. There are Palaeolithic archaeological cultures following Solutrean (for example Magdalenian, Mesolithic, etc.) which most archaeologists agree had boats, yet for most there is no direct evidence. What do their tool kits include that are more specific to boat building than Solutrean tools?

“The existence of a year-round “ice bridge” across the Atlantic during the Last Glacial Maximum is not supported by paleoclimate data. Instead, sea ice in the Atlantic would most likely have been seasonal, with a connection between North American and Europe only a few months out of the year” Has Raff not read Across Atlantic Ice? This issue is discussed in detail in Chapters 8 and 9. We do not assert a year-round ice bridge but instead discuss seasonal variations.  The North Atlantic environment seems to be the focus of all her attention yet it is curious how the issue of how people may have managed to cross and survive in eastern Asia during the glacial maximum is just assumed rather than evidenced.  Except for the Ushki site on the Kamchatka Peninsula (Goebel et al. 2003), dated to the end of the Pleistocene (contemporary with Clovis and therefore not ancestral), there is no direct evidence of shelters, yet we assume that they must have had them to survive.  Were the terrestrial conditions in western Beringia (the coldest place on earth including Antarctica) all that different from what would have been present in the Basque Refugium or on the North Atlantic?  People were adapted to and surviving in the glacial environment in all of these areas. Average temperatures, winds, etc. do not define long term possibilities or probabilities.  Over the 3,000 to 5,000 year span of the last glacial there were many ‘windows of opportunity’.  As scientists we should let the evidence lead us and not preclude options because of preconceived notions of past peoples’ capabilities (Raff accuses us of not crediting the ingenuity of Native Americans but clearly has little regard for the intelligence of any ancient peoples in this respect).  If indirect evidence is used to propose watercraft for Australia 65,000 or Crete 200,000 years ago (Strasser et al. 2011) or even Flores Island which was first colonized over 1 million years ago by archaic toolmakers (Brumm et al. 2016), or shelters in glacial Beringia we should use the same criteria for anywhere else, including Europe, the Atlantic and the Americas.

“As Strauss [mispelled] (2000) puts it, “One or two technical attributes are insufficient to establish a cultural link or long-distance interconnection.”- This quote is taken from an article (Straus 2000) that was published prior to our publication of the hypothesis.  It was based on an inaccurate newspaper article. As discussed above, this is not applicable to our research.  In Across Atlantic Ice we used 47 flaked stone technological traits not “one or two” (see book Appendix).  Then of course there are the stylistic (see Figure 6.3), use and other attributes that were considered. All of this is covered and since the book was published in 2012 more correspondences between some Solutrean and pre-Clovis artefacts have been identified (eg. shouldered and plane-face points).  While not specific to Raff, the example of convergence/independent invention using pyramids put forth by Waters in the documentary received spontaneous laughter by a group of South American postgraduate archaeological students. What an absurd example and in no way applicable to our multidisciplinary evidence.  The assertions of independent invention, chance or convergence need to be supported by evidence just as much as those of historical connection.  This has not been done by Raff, Waters or any other critics of our hypothesis.

“Radiocarbon dates of Clovis sites do not show a pattern one would expect if people diffused into North America from the east coast, as postulated by Stanford and Bradley” This is a useful line of evidence only if one accepts the Clovis First Hypothesis.  If what we define as Clovis wasn’t the first archaeological culture (see Stanford and Stenger 2014; Waters and Stafford 2007) it is likely that Clovis was not a single population but rather a material culture that could have been adopted by any number of previously existing groups with differing genetic and cultural backgrounds, whether they originated from the East or West. See Bradley and Collins 2016 for one possible (testable) hypothesis.  Even if one dogmatically insists on accepting Clovis as first, the dating does not exhibit any evidence of a northwest to southeast cline as one would expect from a Beringian origin hypothesis.  In fact, all current evidence of the early passage of people through the ice-free corridor indicates they were going north not south.  For example, the fluted point evidence in Alaska (Goebel et al. 2013) is interpreted as being derived from continental North America. 

“…including the only known ancient individual buried in association with Clovis tools” If there is a case of ‘bad science’ in the search for the origins of people in the Americas, this is it.  The recent claim that the Anzick cache was a Clovis burial and that the genetic make-up of the supposedly ‘associated’ child’ disproves the Solutrean Hypothesis (Rasmussen et al.2013) is ridiculous.  As an archaeologist, I am unable to question the genetic analysis and leave this to others, however, the archaeological evidence and the contextual-associative interpretations of the Anzick child are highly suspect (Oppenheimer et al. 2014).  The circumstances of the find and recovery of materials from the Anzick site make any claims of specific contexts impossible to determine.  Critics of pre-Clovis sites are quick to dissect all claims of context and reject anything they see as less than perfect.  However, when it comes to the Anzick evidence the same critics seem to disregard any issues relating to contextual integrity.  What makes the small number of human bones a burial?  Does red ochre staining really indicate direct temporal association between the human remains and the Clovis artefacts in spite of the fact that radio carbon dating indicates that they weren’t contemporary even at 2 sigma?  If the Anzick ‘evidence’ were used to claim a pre-Clovis occupation it would be rightfully summarily dismissed.  Yet, because it suits the claims of Clovis being of Asian origin it is accepted and used to ‘disprove’ any possible early origins from Europe.  A single ‘data point’ to define all Clovis ancestry! Absurd and very bad science.

“The Ice Bridge unfortunately relied on cherry-picking of data to support the ideas of Bradley and Stanford” This is an absolutely false, defamatory and misleading assertion.  In Across Atlantic Ice we made great efforts to include as many lines of evidence as we could define.  Our archaeological evidence was based on entire assemblages of artefacts that were in no way ‘cherry-picked’.  You just need to read it first to evaluate our data. What is it that Raff claims we omitted in our ‘cherry-picking’?

“You must build your models based on evidence you have, not evidence you wish you had” In this we agree and we are confident that our evidence is sound, multidisciplinary and peer reviewed. The Solutrean Hypothesis is the only current hypothesis with a wide multidisciplinary range of data that explains both the archaeological and the evolving genetic evidence of the peopling of the eastern seaboard of North America.  If the ‘Everybody out of Beringia as the only migration Hypothesis’ has as wide a range of supporting evidence we strongly encourage somebody to publish it rather than just continue to assert it. Curiously, it is geneticists that propose a ‘ghost’ population in Eastern Eurasia to account for the total lack of X haplogroup let alone the ancestral pre-19,000 year old X2 root group (Oppenheimer et al. 2014).  If this isn’t ‘evidence you wish you had’ what is?

References and further reading- Raff presents a pathetically minimal set of references to support the claims made in her submission.  Straus (not Strauss) 2000 is missing. Many of Raff’s criticisms have already been dealt with in peer-reviewed publications, which she is either unaware of or has ignored.   It is even worse because it is evident that she hasn’t read Across Atlantic Ice, or she has willfully chosen to misrepresent its contents.  I have had numerous first year British undergraduate students, with no previous archaeological background, write more considered, critical (pro and con) and accurate appraisals of the Solutrean Hypothesis than this.  Had they submitted their essays with this slim a set of references and numerous misrepresentations they would have received poor marks indeed.


Araujo, Astolfo G.M., R.O.F. Santos Pugliese, Mercedes Okumura

(2017) Extreme cultural persistence in eastern-central Brazil: the case of Lagoa Santa Paleoindians. Anais da Academia Brasileira de Ciências,

Aubry, T, B. Bradley, M. Almeida, B. Walter, M. Neves, J. Pelegrin, M. Lenoir, M. Tiffagom

(2008) Solutrean laurel leaf production at Maitreuax: an experimental approach guided by techno-economic analysis. World Archaeology 40(1):48-66, Routledge.

Bradley, Bruce A. and Michael B. Collins

(2016) Imagining Clovis as a Cultural Revitalization Movement, Paleoamerican Odyssey, Center for the Study of the First Americans pp. 247-255.


Bradley, B., Collins, M., Hemmings, CA.

(2010) Clovis Technology.  International Monographs in Prehistory No. 17.  Ann Arbor, MI.


Bradley, Bruce A. and Dennis J. Stanford

(2005) The North Atlantic ice-edge corridor: A possible Palaeolithic route to the New World. World Archaeology 36(4):459-78.

Brumm, Adam, Gerrit D. van den Bergh, Michael Storey, Iwan Kurniawan, Brent V. Alloway, Ruly Setiawan, Erick Setiyabudi. et al.

(2016) Age and context of the oldest known hominin fossils from Flores. Nature 534; 249-253                                                                          

Eren, Metin I., Robert J. Patten, Michael J. O'Brien, and David J. Meltzer

(2013) Refuting the technological cornerstone of the Ice-Age Atlantic crossing hypothesis.  Journal of Archaeological Science 40(7):2934–2941.

Goebel, Ted, Heather L. Smith, Lyndsay DiPietro, Michael R. Waters, Bryan Hockett,

Kelly E. Graf, Robert Gal, Sergei B. Slobodin, Robert J. Speakman, Steven G. Driese,

David Rhode

(2013) Serpentine Hot Springs, Alaska: results of excavations and implications for the age and significance of northern fluted points. Journal of Archaeological Science 40:4222-4233.

Goebel, Ted, Michael R. Waters, Margarita Dikova

The Archaeology of Ushki Lake, Kamchatka, and the Pleistocene Peopling of the Americas (2003) Science  Vol. 301, Issue 5632:501-505.

Hopkins, Ruth

A Review of Across Atlantic Ice, Indian Country Today July 9, 2012. 

Lohse, John C., Michael B. Collins, Bruce Bradley

(2014) Controlled Ove 37:507-32.rshot Flaking: A Response to Eren, Patten, O'Brien, and Meltzer. . Lithic Technology 39:46-54.

Okumura,Mercedes and Astolfo Araujo

(2014) Long-term cultural stability in hunter-gatherers: A case study using traditional and geometric morphometric analysis of lithic stemmed bifacial points from Southern Brazil. Journal of Archaeological Science 45:59-71.

Oppenheimer, Stephen, Bruce Bradley, Dennis Stanford

(2014) Solutrean hypothesis: genetics, the mammoth in the room.  World Archaeology 46(5):752-774.

Rasmussen, M., S. Anzick, M. Waters, P. Skoglund, M. DeGiorgio, T. Stafford, Jr, S. Rasmussen, et al.

(2014) The genome of a Late Pleistocene human from a Clovis burial site in western Montana. Nature 506:225–229. 

Stanford, Dennis J. & Bruce Bradley

(2012). Across Atlantic Ice: The Origin of America’s Clovis Culture. Berkeley: University of California Press.

Stanford, Dennis J. and Alison T. Stenger

(2014) Pre-Clovis in the Americas: International Science Conference Proceedings.  CreateSpace Independent Publishing Platform; Smithsonian Institution edition.

Strasser, Thomas, Curtis Runnels, Carl Wegman, Eleni  Panagopoulou, Floyd Mccoy, Chad Digregorio, Panagiotis Karkanas, NickThompson

(2011)  Dating Palaeolithic sites in southwestern Crete, Greece. Journal of Quaternary Science,pp. 553-560.

Straus, Lawrence G.

(2000) Solutrean Settlement of North America? A Review of Reality.  American Antiquity


Straus, Lawrence G., David J. Meltzer, Ted Goebel

(2006) Ice Age Atlantis? Exploring the Solutrean-Clovis “connection”.  World Archaeology 37:507-32.

Van de Noort, Robert

(2012) North Sea Archaeologies: A Maritime Biography, 10,000 BC - AD 1500. Oxford University Press, USA.

Waters, Michael R. and Thomas W. Stafford, Jr

Redefining the Age of Clovis: Implications for the Peopling of the Americas. 

(2007)  Science Vol. 315, Issue 5815, pp. 1122-1126.  


Oppenheimer Comments (responding to Raff comments below in italic):

Contributor Stephen Oppenheimer, Oxford University

As a participant in the above documentary, I am surprised to see the Guardian publish such a biased, inaccurate, defamatory and misleading review offered by Jennifer Raff, a participant in the Ice Bridge film.

The accusations of racism against other participants, the producer and CBC start off immediately in the article subtitle ending:

A recent Canadian documentay promoted a fringe idea in American archaeology that’s both scientifically wrong and racist.

The ‘racist’ accusation is untrue and defamatory. The repetitive racist accusations are at odds with Raff’s own later acknowledgement:

While supporting the agenda of white nationalists was not the intent of the producers or of the scientists involved, it would have been appropriate for the documentary to take a stand against it, and I and many archaeologists are disappointed that they did not.

Why should the documentary makers and participants defend themselves against an absurd post hoc accusation of racism? That view is the review author’s own perspective. The first paragraph also calls the ideas portrayed within the Solutrean Hypothesis “…unsettling, unwise,…” emphasizing the racist accusation against the documentary makers and other participants.

The second paragraph continues with new false accusations:

First, in addition to the scientific problems with the Solutrean hypothesis which I’ll discuss shortly, it’s important to note that it has overt political and cultural implications in denying that Native Americans are the only indigenous peoples of the continents.

In what way do the academics Dennis Stanford and Bruce Bradley, who constructed the Solutrean Hypothesis, do that, except in reviewer’s imagination? It may well be, as she claims, that white Nationalists have such perceptions, but later in the paragraph, she comes back with another false accusation against Stanford and Bradley, but including the film producers this time:

… the idea behind the Solutrean hypothesis is part of a long tradition of Europeans trying to insert themselves into American prehistory; justifying colonialism by claiming that Native Americans were not capable of creating the diverse and sophisticated material culture of the Americas.

Again, it is wrong to make that slur against co-participants, particularly in the use of the term ‘sophistication’? The shoe is on the other foot here. The writer appears, in the following passage, to think people living over 18,000 years ago were not sophisticated enough to have a seafaring culture:

Although the Ice Bridge documentary makes much of an image of a fish and an auk in a French cave, it is a bit of a stretch (to say the least!) to claim that this is sufficient to demonstrate a sophisticated seafaring culture, capable of crossing the Atlantic.

Raff’s position here seems, in its presumption of a lack of Upper Palaeolithic sophistication, to share the derogatory attitudes wrongly attributed to Stanford and Bradley. In contrast, like most archaeologists studying the Palaeolithic elsewhere, Stanford and Bradley, do indeed accept that boats would have been necessary over the past 50-60,000 years, for a range of founding migrants to reach New Guinea and Australia for instance, as well as Crete.

It seems above, that a key element of the Guardian review is an attempt to leverage Raff’s very personal opposition to the Solutrean hypothesis by linking the documentary and its participants to white racists. Raising that spectre here, is not a new tactic. It appears to be using white supremacists as a valid reason for seeking to suppress i.e. censor, enquiry into the Solutrean Hypothesis. The last point is indeed suggested by a number of your own Guardian readers. Ironically, a recent claim derived from the ancient DNA of ‘Cheddar Man’, suggests western Europeans might have been dark-skinned, until relatively recently,(~10,000 years ago).

Naturally, I concentrate above, on the initial, repeated false accusations of racism, connected with the white-supremacist issue, occupying a quarter of the article, since they could have been picked up by a moderator. It would not have taken specialist knowledge, to have recognised the specious accusations in the racist arguments, which were certainly picked up by many of your readers in the comments. Such an insult to First Nations co-participants on the film, reflects badly.

As mentioned above, Stanford and Bradley are falsely accused of

…justifying colonialism by claiming that Native Americans were not capable of creating the diverse and sophisticated material culture of the Americas.

In the very next sentence the producers receive the same treatment:

Unfortunately, the producers of the documentary deliberately chose not to address this issue head-on, nor did they include any critical perspectives from indigenous peoples.

While these accusations are vexatious and creative and have no value except to longstanding convictions, they affect more than the producers and film participants like Bruce Bradley, Dennis Stanford and myself. Maybe she didn't view the whole film before making these particular accusations and didn’t realise who her other co-participants were? One of the key senior participants of the film was Dr Louis Lesage, biologist and senior figure in the Huron Wendat Nation.

Dr Lesage did find potential virtue in the Solutrean Hypothesis and said so in the film. This was because parts of the hypothesis coincided with an ancestor story of his own Nation, in which his ancestors had arrived from the East across a lake of salt water.

Furthermore, Dr Lesage, brought to England particular, provenanced, precontact remains of his Nation's ancestors for genetic analysis, with the formal approval of his own Nation's council. The hand-over of the box of remains to the researchers in England was filmed. The remains themselves were not filmed, out of respect. Also filmed, was the explanation of the imperative requirement given by Dr Lesage to the researchers to show every respect, offer reassurance and verbal explanation of what they were doing and to what purpose, throughout their work, as if they were still living (to which the researchers enthusiastically agreed). The film also has a section in which Dr Lesage and myself discuss the preliminary mitochondrial DNA results. Due to the time constraints of the film schedule, the bulk of the remaining comparative analyses of the rest of the genome in the same samples are still in process.

In this context, it is unfortunate that Raff chooses, to make blanket white racist accusations and assertions concerning the involvement of CBC and other participants in the film, but to ignore the voluntary participation of the Huron Wendat, as if their decision, roles and opinions did not count in her discourse.

I sincerely hope that she can formally apologise to Dr Louis Lesage and his Nation for insulting their views and decisions and those of their representative in the way she has done.

There are other assertions, inaccuracies and bias throughout the article, a few of which I address here in order of appearance. Bruce Bradley has dealt with the archaeology and I only add a couple of comments here:

1) The claim: “Archaeologists have taken a hard, long look at this idea and dismissed it on the basis of insufficient evidence” clearly refers to archaeologists who agree with Raff, for instance in her belief in the long-defunct Clovis-First paradigm. Bruce Bradley deals with this old conviction in his commentary. Raff may be surprised to find out how many New World archaeologists have now moved on from ‘Clovis-First’. A number that I have met, have now seen the Solutrean-matching, Parsons Island (Maryland, USA) stone tool assemblages such as shown in the film and have radically changed their views about the Solutrean Hypothesis based on the new archaeological evidence.

2) In Raff’s explicit adherence to the 50+year-old Clovis-First, single-entry theory, she presumably dismisses all recent archaeological evidence for humans south of the ice, before c. 13,000 years ago (see Bradley’s commentary above), and thus either indicates how little she accepts of recent work in New World archaeology or, maybe, how little she has read of the recent literature, particularly from South American archaeologists.

3) Moving onto the genetics, Raff dismisses any evidence for ancient West Eurasian genetic ancestry in the New World:

Geneticists, too, have tested the Solutrean hypothesis. If it were true, we would expect to see ancestry from non-Siberian descended populations present in the genomes of ancient Native Americans. We don’t. All contemporary and ancient Native Americans, including the only known ancient individual buried in association with Clovis tools, show descent from an ancestral population with Siberian roots.

Raff’s does not cite the key relevant original published studies on nuclear autosomal DNA that she presumably refers to (e.g. Patterson et al. 2012; Raghavan et al. 2014; Rasmussen et al. 2015).

But there is a contradiction to her above dismissive assertion. These autosomal nuclear studies did, in fact, find evidence, both for significant unexplained ancient West Eurasian genetic admixture in First Nations people, as well as the expected larger East Eurasian component.

In the above papers, the mixed east and west Old World ancestries are both inferred, using tests for shared genetic genetic drift, to have occurred prior to recent European contact. A credible geographic source for the ancient West Eurasian component autosomal admixture in the New World is, however, not found now in modern East Eurasia/Siberia. The authors, however, still inferred, in their analyses, that this ancient West Eurasian admixture must have come via East Eurasia, but is just not there now (Patterson et al. 2012; Raghavan et al. 2014; Rasmussen et al. 2015). The ancient East Asian evidence for this ‘Ghost’ argument was based on a single ~24,000 year-old ancient DNA sample found in Mal’ta west of Lake Baikal, half-way to Western Europe, at the easternmost limit of the Ice Age West Eurasian Gravettian culture. Unlike the lack of evidence in modern Siberians for the source of New World’s ancient West Eurasian ancestry, there is, of course, good evidence found in modern East Eurasians for the predominant shared East Eurasian ancestry found in the New World, which did presumably arrive via the Beringian landbridge, and is not disputed by either side.

The Solutrean Hypothesis clearly allows a simpler and more direct explanation, than a ‘ghost’, for the West Eurasian pre-contact autosomal admixture (e.g. 14% to 38%: Raghavan et al. 2014) found in First Nations. I discuss these nuclear autosomal studies and others (i.e. those on mitochondrial DNA and the Y chromosome) in a joint review (Oppenheimer, Bradley & Stanford, 2014) on the Solutrean Hypothesis published in World Archaeology.

Unsurprisingly, our review is not cited by Raff in her online Guardian article. where her only genetics citation, is to her own attack on the same review (Raff & Bolnick 2015), and mainly addresses the mitochondrial DNA X group which is only found in West Eurasia and First Nations populations in the northern half of the New World. Curiously, Raff criticizes the documentary producers for the same bias of concentrating on one genetic region: mitochondrial DNA. Raff’s final couple of paragraphs also focus on the issue of First Nations mtDNA X2a and X2g lineages.

There were several potential production reasons I can see for that relatively higher emphasis on archaeology than on genetics in the Ice Bridge film. Firstly, documentary time and priority were important and the Solutrean Hypothesis is a cultural hypothesis. It explains the cultural ancestry and descent of the fine ancient biface spear-points in the New World, for instance Clovis Points appearing c.13,000 years ago, since they have no antecedents of appropriate antiquity in Siberia, but do have antecedents in southwest Eurasia (see Bruce Bradley’s section above). The new finds on Parson’s Island (Maryland), addressed in the film, have effectively provided a complete matching Solutrean toolkit (i.e. multiple different tool-type matches, thus excluding the possibility of random technical convergence on one tool type) with provisional dates of the predicted antiquity, leading several independent archaeologists who had seen the assemblages to be convinced. In other words, the Solutrean Hypothesis now has direct cultural proof and dates.

The anomalous X distribution pattern, i.e. excluding East Eurasia, is predicted by, and is consistent with, the hypothesis of an extra entry route from West Eurasia, i.e. more than one entry (contradicting the Clovis-First single entry theory) to the New World. The depth of the age of the West Eurasian branch ancestral to, i.e. leading to, the unique First Nations X2a and X2g branches is also consistent with the time prediction of the hypothesis. Finally, the UK research group based in Huddersfield University are not just looking at one part of the pre-contact genomes, they are currently looking at the Y chromosome and the rest of the ancient genomes using the samples we were given. Clearly, given the timescale, we did not have those results available for the film.


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(2015) Does Mitochondrial Haplogroup X Indicate Ancient Trans-Atlantic Migration to the Americas? A Critical Re-Evaluation. PaleoAmerica: A journal of early human migration and dispersal 1, 297-304.

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