Here’s a brief look at the discussion of aDNA in Denisovan Origins and what Collins and Little got wrong.
In their book, Denisovan Origins, authors Andrew Collins and Greg Little appear to paint a picture of how giant Solutreans of “Denisovan origin” dominated less capable Native Americans of a more diminutive stature who arrived across the Beringian land bridge: showed them how to build mounds, established themselves as their “elite” leadership, and passed on their “advanced knowledge.” You know… because plain old Indians couldn’t possibly have figured out all the cool stuff.
The very notion is racist. Are Collins and Little racist? Probably not intentionally. But not all racists are card-carrying members of the KKK or NAZI’s or any number of other extreme notions you can think of. Simply not willing to afford an indigenous population the credit its due for its own accomplishments without injecting some silly notion of “elites” and “giants” is racist.
But perhaps it’s a racist notion arrived at innocently through fallacious thinking. Here are the problems with Collins’ and Little’s understandings of ancient DNA (aDNA).
Haplogroups X, X2, and X2a
In his section of the book, Little repeatedly states that Haplogroup X exists in the aDNA of Native American populations (chapters 23 and 26). Occasionally he rightly refers to the Native American haplogroup in question as X2a but sometimes he calls it X2.
These are three different haplogroups.
I’ll put some quotes from Collins and Little below followed by a critique:
Haplogroup X also is more problematical. While haplogroup X is present in two versions (X2 and X2a) in about 3 percent of living Native American tribal members, it is not evenly distributed.”Collins and Little: Denisovan Origins, Chapter 26
The only thing he really got right here is the last phrase of that sentence. Distribution is not even. The two X haplogroups found in ancient Native Americans are X2a and X2g. The latter is rare, but both are uniquely North American. They don’t show up in the aDNA of other populations in the world. Nor do other X haplogroups show up in the aDNA of North American populations, at least not in current data (it could all change in the future with better aDNA surveys of ancient populations. Regardless, there is no X2 or X in the current available data for ancient North American populations. Little is wrong about this.
“The X2 haplogroup found in the Altai Mountain regions in Siberia closely matches the X2 found in Native Americans. Of course, many archaeologists hailed this as proof that X2 also came into the Americas via Beringia.”Collins and Little: Denisovan Origins, Chapter 26
The haplogroup found among populations in the Altai Mountain region of Siberia is X2. But I’m not aware of any archaeologists that “hail this as proof” that the X2a haplogroup found in North America came via Beringia. Other lines of evidence are suggestive of this, however, which David Madsen (2015) lists in nice detail in the very reference Little cites for this next sentence.
However, the X2a version has also been found in heavy concentration in the Orkney Islands of Scotland.Collins and Little: Denisovan Origins, Chapter 26
For this he cites David Madsen (2015). First, there is no X2a haplogroup on Orkney. Not in among ancient populations and probably not among modern ones. There is, however, the X2 haplogroup present on Orkney Island. And this is what Madsen says: “although, as an aside, it is interesting that a modern population with one of the highest percentages of the X2 clade, higher even than Native American populations, is found in the Orkney Islands off the coast of Scotland.”
It’s important to note that Madsen isn’t saying that X2a is on Orkney. Nor is he saying that X2 is among Native Americans. He’s saying that the percentage of Orkney’s X2 is higher than the percentage of Native American X2a. If you’re not reading the entire paper carefully and if you don’t already have a very basic, working understanding of aDNA (either nuclear or mitochondrial), you might miss the context. But Madsen is assuming his readers know X, X2, X2a, and others are different haplogroups. And that X2a (along with X2g, X2j, X2b, X2c, …) is in the X2 clade.
The real question is this: is Little truly ignorant of what a haplogroup is and isn’t? Or is he intentionally conflating and confusing them for his readers. My suspicion is the latter. It’s useful for for the conclusions he and Collins began with when they started looking for data. By pseudoscientifically reducing the X2a haplogroup to the X haplogroup, they can fit data into the very conclusions they’ve both carried for years: giants dominated Native Americans, etc.
Maybe X2a did come to North America by way of an Atlantic crossing. The Solutrean hypothesis is science. But it’s an hypothesis. To date, the evidence stacks against it. And haplogroup X isn’t its savior because that haplogroup is not present in North America. Nor is hapogroup X2 (thehaplogroup found in a modern Orkney population). The haplogroup X2a lineage doesn’t simply fall from X to X2 to X2a. The X2a’j clade lies between X2a and X2-225 before stepping back to X2, along with nearly 10,000 years of mutations.
There’s no good reason to think an Atlantic arrival for X2a is more likely than the Beringia route. Little liked to suggest that since X2a was observed in North America’s northeast that this is evidence, but it really isn’t. X2a was observed in Kennewick man (8690-8400 cal yr BP), putting it about as early as any X2a samples. Little tries to cover this base:
Kennewick Man is one of the few haplogroup X skeletons found that far Northwest. Perhaps the greatest importance of Kennewick Man is that his lineage is haplogroup X2a. It is proof that X2a was in the Americas long, long ago, and not that he was from Asia.Collins and Little: Denisovan Origins, Chapter 26
At least Little acknowledges that the haplogroup is X2a and not X2 or X. But he’s dead wrong when he says its proof Kennewick was not from Asia. In fact, Kennewick showed many Siberian genetic affinities and no recent European ancestry.
Little isn’t the only one of the two authors to get all this wrong. Here’s Collins in chapter 10:
The closest source of haplogroup X outside of the northeastern and eastern coasts of North America is that present among modern populations in southwestern Europe, which just happens to be the very same territory in which the Solutreans thrived circa 20,000–15,000 BCE.Collins and Little: Denisovan Origins, Chapter 10
He is, of course, wrong. I’ve included a chart based on the one found in Raff and Bolnick (2015) to give you an idea. But suffice to say, Haplogroup X and its sub-clades are present in more places than Collins seems aware. Moreover, he’s also conflating haplogroup X with X2a. And they both occasionally conflate modern populations with ancient populations. As if the presence of haplogroups in modernity reflects the localities of antiquity. They both seem to have an affinity with the X2 haplogroup in modern Orkney populations which 1) is irrelevant to the X2a haplogroup in the Americas; and 2) representative of modern populations, not those of 14,000+ years ago.
Here’s Collins again in chapter 16:
The tribe possessing the highest level of haplogroup X is the Ojibwa. Up to 26 percent of its population’s mtDNA contains haplogroup X, while the Cree also possess haplogroup X, but, once again, at a slightly lower level than their southern neighbors, the Ojibwa.Collins and Little: Denisovan Origins, Chapter 16
For this, Collins cites Brown et al. (1998), referencing Table 3 on page 1858. You might be wondering why Collins and Little are citing a 20+ year-old paper when there are many more up-to-date sources. The reason, of course, is that within just a few years of 1998, sub-clades of X were being identified and understood. Collins and Little would have been better off citing Fagundes et al. (2008) in the very same journal. But the obfuscation of haplogroup X and ignoring the implications of how the sub-clade X2a is defined, makes it easier for Collins and Little to fit their narrative into the pre-conceived conclusion they already have.
Writing of haplogroup X in broad terms in a book that deals with the peopling of the Americas isn’t really wrong. Unless you’re trying to ignore the nuances and details that come along with its sub-clades. X2 in Orkney is a “modern population” (Madsen 2015: 213). X2a in North America is without a “clear record” of its evolutionary history “in any population” (Raff and Bolnick 2015: 298; see also Fernandes et al. 2012).
Wherever there’s a mystery in science, there will probably be someone ready and willing to pick it up and repackage it as proof of whatever silliness they’ve already concluded to be true. In this case, Collins and Little (among others, eg. Graham Hancock, Brien Foerster, etc) have quickly picked up on the fact that very little is known about Denisovans. With a handful of skeletal remains that point to individuals of large stature, they see the opportunity to display this as proof of their giants. With the mystery of the origin of the X2a haplogroup, this is now an opportunity to point to Solutreans, who are important for Collins and Little to get their giants across the Atlantic and into the Americas.
Never mind that there are literally only a handful of skeletal remains for the Denisovans: a piece of a finger, a tooth, a portion of a mandible, a few others… perhaps as many as seven pieces in all. You needn’t be a bioarchaeologist to realize only the more robust bones of the most robust individuals in the best of conditions will survive the tens of thousands of years these tiny fragments of even fewer individuals. It would be no surprise to me if, like my family, the Denisovan analog these remains are from included some very tall individuals and some rather small members.
And to suggest that because there are X2 haplogroups present in modern populations on Orkney (or even ancient populations for that matter) and therefore it’s more likely that X2a came from there is showing an extremely poor understanding of how haplogroups work, since X2a is not closely derived from X2.
References and Further Reading
Brown, Michael D., Seyed H. Hosseini, Antonio Torroni, Hans-Jürgen Bandelt, Jon C. Allen, Theodore G. Schurr, Rosaria Scozzari, Fulvio Cruciani, and Douglas C. Wallace (1998). mtDNA Haplogroup X: An Ancient Link between Europe/Western Asia and North America? The American Journal of Human Genetics, 63(6), 1852–1861.
Fagundes, Nelson J.R., Ricardo Kanitz, Roberta Eckert, Ana C.S. Valls, Mauricio R. Bogo, Francisco M. Salzano, David Glenn Smith, Wilson A. Silva Jr., Marco A. Zago, Andrea K. Ribeiro-dos-Santos, Sidney E.B. Santos, Maria Luiza Petzl-Erler, and Sandro L. Bonatto (2008). Mitochondrial Population Genomics Supports a Single Pre-Clovis Origin with a Coastal Route for the Peopling of the Americas. American Journal of Human Genetics 82: 583-592.
Raff, Jennifer A. and Deborah A. Bolnick (2015). Does Mitochondrial Haplogroup X Indicate Ancient Trans-Atlantic Migration to the Americas? A Critical Re-Evaluation. PaleoAmerica, 1(4), 297-304.