Saturday, December 12, 2015

How Little We Know About Ancient DNA - Part II

Earlier this year, I posted a series of maps graphically depicting the (at that time) exhaustive list of Ancient DNA finds, mapped out for both time and space.

The post, while now a bit dated due to additional finds, is still worth examining.  When reading it, it should becomes very apparent to you, the concept in the title of this post: How Little We Know About Ancient DNA.

As you can see from the maps, it appears that people bearing certain Y Chromosome haplogroups "flew" across time and space.  And that certain parts of Europe had nobody in them until someone flew across the distances.  

Of course, this is impossible.  It simply reflects the fact that we continue to have immense gaps in skeletal finds and in our knowledge.

Most importantly, it shows that today's conventional wisdom, popular at echo chambers like the Anthrogenica boards, will certainly change tomorrow -- revealing the adherents to such theories to be akin to arrogant fraudsters, peddling certainty where none is scientifically warranted.

Recently, a poster at Anthrogenica, with the handle Tomenable, posted an excellent visualization of the same gaps in knowledge that I referenced.

You can view a list of aDNA finds here, in chart form, courtesy of Tomenable.

And even better, here is a chart, in chronological order, showing the same.

What does the chart show?   By applying *scientific* methods of taking things to their logical conclusions, and reducing our knowledge to a set of provable statements, you can easily see how little we know.

For starters, based on these chrono maps, it looks like Haplogroup C1 made it to Europe after I2.  Yet almost everyone, from the scientific community to the "citizen" scientists (their term) on Anthrogenica, agree that C1 is a rare, likely "Cro-Magnon" marker, that represents the very first humans out of Africa and into Europe.  On the other hand, it has been accepted for over a decade that Haplogroup I, notably I2, represents the second (or third) wave of the population of Europe, associated with the Gravettian dispersions.  

But again, this is *not* "what the aDNA shows."

Ask the wiseguys on Anthrogenica, or search their posts.  They express with certainty that C1 came first, followed by I2.  And it probably is true.  But it is NOT born out by the aDNA evidence.  (Yet).

However, the same group of people turn to the aDNA evidence (blindly) to express 100% confidence in other theories, for example, everything from the notion that R1b xV88 couldn't be found west of modern Poland until the Indo-European expansions.  (I find this notion laughable.)  

They also rely on the aDNA evidence to express 100% confidence in wild notions of sex selection that have more in common with dimestore novels than anything scientific.  The proponents of said theories also happen to be mostly males bearing R1b.  Yes folks, in a world where racial identity is taboo, any sense of ingroup-outgroup dynamics for Western Europeans has simply been transferred to tiny markers on one chromosome.

In other words, many of these folks blindly turn to our meager aDNA evidence to justify their pet theory du jour, but choose to ignore what the aDNA evidence shows, when convenient.  

They cite gaps in data (i.e., a lack of samples) as evidence for proving a negative, as if that was possible -- when they want to.

But they ignore the lack of samples when convenient, if it doesn't fit in their narrative for that time or place.  

Doubt them, they revert to the argument "well, the aDNA shows..." but they are more than willing to fill in gaps in aDNA when convenient.

It's already been a rough year for the arrogantly certain in Ancient DNA.  Notably, past theories on the dispersion of Haplogroup J2 have fallen by the wayside.  Theories posted on Anthrogenica just a couple months ago, and accepted by the echo chamber as gospel fact, have been called into serious doubt by recent academic papers.  

I've also posted repeatedly on how difference in culture and hyperlocal topography can affect what aDNA survives into modern times.  The easiest example is one tribe burying their dead, while another tribe cremates it.  Anyone who knows anything about written history understands that the reason why we don't have m(any) ethnic Roman skeletons is because they cremated their dead.  To those who don't grasp this concept, it would be as if the Romans, a powerful, numerous, colonizing, widespread, important society -- didn't exist.  

I can just see Anthrogenica in the year 2515: "but there are no Roman samples in aDNA," they would maintain adamantly.  Yes, you would reply.  But the Romans existed.

The point is simple: approach any theories explaining what happened before written history with caution.  There are major gaps in the record, and it is far, far too early to approach things with the smug certainty one sees on these boards.  

Look at the samples across time and space (geography).  Don't hide behind relative, subjective terms like "Mesolithic" and "Neolithic."  Instead, look at how Europe was populated, the way it was populated --- in gradations, over (real) time.  You, too, will notice "How Little We Know (Still) About aDNA."

10 comments:

  1. You've taken a good opinon and went too far. We do know a lot about aDNA. For the most part we now know where Europeans come from. There are ethnoccentrics out there and miss interpretations of aDNA. However it isn't as bad as you say.

    There's no other way to explain R1b-P312's popularity except some type of selection for R1b-P312 men. How else do you explain its absence until 2600 BC in over 100 samples and modern dominance? The majority of West European men trace their father line to a single man who probably lived no more than 6,000 years ago. Nothing else can explain this except selection for R1b-P312 men.

    Admitting this doesn't make you an R1b supremacist. I'm pretty sure at some point R1b-P312 men one way or another made it so hardly anyother male's lines survived. 'm simply stating what the evidence suggests.

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    1. Clearly you know little of mathematics and history. And within genetics, you never had the Genetics 101 Lesson on Pitcairn Islanders. Look them up. Learn how patrilines disappear over time. Without "selection…"

      Let's model another scenario, shall we?

      Imagine a 100-acre parcel. At first, it is a hunting preserve of sorts. It is inhabited by 5 families who own 20 acres each. They love the deer and geese they harvest from said land.

      Next some farmers move in. 50 acres are used for farming. They support 10 farming families, who each have 5 acres.

      The land is supporting 5 hunters and 10 farmers. Have the farmers been "selected for?" I think not.

      Finally, some refugees land in this area. There are 100 refugee families, and they squeeze into one acre of the land. They have metals, which they trade for food, so they are able to live in a much smaller parcel.

      I suppose you, Krefter, would say that the refugees were "selected for" genetically? Get a clue!

      I just described something that has happened in recorded history several times, and surely in prehistory too.

      Older, less numerous populations will appear to be drowned out, unless you are careful. But it's just simple math, and your theories of selection are meaningless fantasies.

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    2. I understand the concept. But it doesn't work for R1b-P312 in West Europe. Your theory proposes autosomal and Y DNA replacement. We don't see that with R1b-P312 or any Steppe related Y DNA.

      Each sub-region in West Europe has its own subgroup of R1b-P312. Wherever R1b-P312 went new lineages were favored and 99% of R1b-P312 went extinct. This is selection or certain lineages. There's no other explanation.

      There's no argument at all. Agreeing with this doesn't make you an ethnocentric. My ancestors and all West Europeans were if anything mostly on the losing side. This happened a gazillion years ago, was barely noticeable(gradual), and means nothing to who we are today.

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    3. I forgot to explain to mention: West Europe is autosomally diverse but dominated by R1b-P312. Your model only works if both autosomal DNA and Y DNA become the same in West Europe. They didn't, and so there must have been sex-biased admixture.

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    4. I don't mean to be harsh. But did you ever read those, "to be a X, you have to believe Y, plus Z, which conflicts."

      Well, to adhere to these crazy R1b theories, you have to believe that I2-M26 (WHG) populated Sardinia because of chance drift by a group of EEFs -- BUT -- that R1b-P12 populated other regions because the males were sex-favored. It's insanity.

      You are a smart guy. Think of other examples where Hgs spread for reasons other than sex selection. Drift, Founder Effect, Overpopulation, etc.

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  2. Some good points

    But out of interest, how would you explain the current frequencies of R1b in western Europe ?

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    1. http://snplogic.blogspot.com/2015/12/a-review-of-all-theories-on-why-r1b-is.html

      Ask and ye shall receive.

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  3. This comment has been removed by the author.

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  4. This is all so true, and not only of commenters in Anthrogenica. Haak et al found that the handful of known corded ware specimens were more similar to Siberian Yamna than to their limited sample of European specimens and concluded that the bearers of corded ware culture MUST be steppe pastoralist immigrants. They simply assumed that Ukrainian Yamna must have the same profile and that nobody anywhere else outside Europe at that time or earlier could. And so, big surprise, at the same time they make it to print, so does new evidence disproving their conclusion, revealing that at least on the mtDNA side the modern European profile was present in Romania two millennia earlier: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0128810

    But of course, fans of the Kurgan theory only reported the Haak paper and ignored the Hervella paper.

    And it goes on and on. It's astonishing how many illiterate prehistoric cultures are allegedly known to be Indo-European or Iranian, or how certainly Phrygian language is categorized with Thracian when we know extremely little about Phrygian and practically nothing about any Thracian languages.

    Re: R1b and related, you may need to add one: since the R1b marker is clearly associated with superior abilities to fake historical evidence, they cleverly wrote all the other Europeans out of history.

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    1. I have not seen Phrygian being associated to Thracian lately, but rather to Greek. And I think enough is known of Phrygian to make such a link.

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