Denisovan Origins and Ancient DNA

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.

Haplogroup X and its sub-clades
Chart showing some of the haplogroup X sub-clades. After Raff & Bolnick (2015)

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).

Mystery Mongers

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.

About Carl Feagans 380 Articles
Professional archaeologist that currently works for the United States Forest Service at the Land Between the Lakes Recreation Area in Kentucky and Tennessee. I'm also a 12-year veteran of the U.S. Army and spent another 10 years doing adventure programming with at-risk teens before earning my master's degree at the University of Texas at Arlington.

13 Comments

  1. From Wikipedia: “…in Intelligent Life in the Universe (1966) astrophysicists Iosif Shklovsky [Shklovskii] and Carl Sagan devote a chapter to the argument that scientists and historians should seriously consider the possibility that extraterrestrial contact occurred during recorded history; however, Shklovskii and Sagan stressed that these ideas were speculative and unproven.[20] Shklovskii and Sagan argued that sub-lightspeed interstellar travel by extraterrestrial life was a certainty when considering technologies that were established or feasible in the late 1960s;[21] that repeated instances of extraterrestrial visitation to Earth were plausible;[22] and that pre-scientific narratives can offer a potentially reliable means of describing contact with aliens…”.

    Apparently prior to 1968 when Chariots of the Gods was published, it was “cool” to inquire into the Paleo-Contact realm. There is no mention of the idea being pseudo-science, or that Sagan was using “pseudo-scientific methodology”; in fact I can’t find another scientist from that era denouncing Sagan as a fraud/quack/crank or maybe even a “closet racist” or possibly citing “racist sources” in his tome. Weird, isn’t it? The very pinnacle of pseudo-science, and the poster child for pseudo-science, is/was Eric von Daniken, and yet Sagan was there at the beginning. No doubt the reason for the lack of criticism was that other thing in the skeptics toolkit, that of special pleading and tribalism…oh well….

  2. By bringing up Von Daniken compared to Sagan in this way and basing your argument only on Wikipedia as a primary source you just managed to illustrate all of Susan Ford’s points without even realizing it.

  3. Fly on the Wall states: “…By bringing up Von Daniken compared to Sagan in this way and basing your argument only on Wikipedia as a primary source you just managed to illustrate all of Susan Ford’s points without even realizing it…”.

    If there is an error in the Wikipedia article, which is based on Sagan’s book, then by all means, point out the error. Or, if you like, I can quote from the actual book itself, if that is more to your liking. Which would you prefer? If you can’t point to a single error in the Wiki article, then you are, like a lot of others on here simply blowing smoke, without even realizing it. You are either unwilling or unable to actually engage with the argument (my guess is the latter)….

  4. Sagan made a proposition early in his career and he later modified his perspective. EVD continues to make an entire career out of slipshod research and misrepresentations that fall apart under close scrutiny. It doesn’t help his case that Von Daniken was convicted of fraud and embezzlement in relation to his career as a researcher. One could make fruit salad out of the apples and oranges logic being thrown about here.

  5. Magnus Canis: I stopped reading EVD in the very late 70’s because I became convinced that he’d produced no actual, verifiable evidence of Paleo contact. So, as to continuing career in that field, I’ll have to take your word for it. As for his prison record, none of it has any bearing on his central theory, that’s an ad hom attack on your part. Apples and Oranges logic? Don’t keep us waiting with your thoughts……:)

  6. Magnus Canis: A simple question that won’t require a long response from you; when Sagan, apparently in 1966, a full 2 years before EVD burst on the scene, first proposed the “Paleo-Contact” theory, was it then considered “pseudo-science”? Or maybe a “pseudo-scientific theory”?

  7. At the time Sagan began his career, it was just becoming clear that humans could develop the technology to travel to outer space. This raised the serious question of if there were beings from elsewhere who had the same or better technology and could have visited earth in the past. Sagan took this notion in one direction based on evidence at hand and EVD took it a very different direction form day one and has continued a pattern of bias confirmation and misrepresentation for nearly 50 years now. EVD actually confessed to forging artifacts to support his case. This confession appeared on the BBC broadcast “The Case of the Ancient Astronauts” which aired on March 8, 1978. So, his criminal conduct in matters of fraud do have direct bearing on his career. If you can’t grasp the distinction then I can’t help you any more with this and neither can anyone else.

  8. Magnus: I’m very aware of the distinction you’re making; I’m not “contesting” that issue. No one, absolutely no one, is somehow implying that Sagan and EVD, either in their training, education, career or morals are even remotely the same. For whatever reason you don’t want to address what I wrote/asked:

    “…A simple question that won’t require a long response from you; when Sagan, apparently in 1966, a full 2 years before EVD burst on the scene, first proposed the “Paleo-Contact” theory, (1). was it then considered “pseudo-science”? 92). Or maybe a “pseudo-scientific theory”?…”

    Do you see those questions? Neither of them have anything to do with what Sagan and EVD did *after* their theories were first proposed. If you can’t address that, there’s no reason to continue this thread

  9. Magnus states: “…so, his criminal conduct in matters of fraud do have direct bearing on his career. If you can’t grasp the distinction then I can’t help you any more with this and neither can anyone else…”.

    Again, I’m mot addressing EVD’s career, only his ideas; and no, they have absolutely no bearing on the truth of Paleo-Contact, you should be able to grasp that. As an example from history, Karl Marx was known to have, among other sins, neglected his wife and children, even to the point of abuse. In your mind, does that automatically invalidate Marxism?

  10. Another of Carl Sagan’s Pseudo-scientific moments:

    “…Sagan’s interest in UFO reports prompted him on August 3, 1952, to write a letter to U.S. Secretary of State Dean Acheson to ask how the United States would respond if flying saucers turned out to be extraterrestrial…”.

    I wonder if EVD did the same? Mmmmmmm?

  11. Lee Groff: I just bought “Denisovan Origins”; it’s sober, easily followed, and utterly unfantastic in it’s claims. I know most skeptics won’t read it, but after some of the commentary here I’m glad I purchased it to see what all the fuss is/was about (clue: you will be sorely disappointed, especially in regard to the charges of racism leveled at the authors)….

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