Y6923: a season of breakthroughs

Last time I wrote about E-Y6923/Y6938, the Y-chromosome lineage carried by one in every 17 or 18 Ashkenazi Jewish males, signifying one shared early medieval ancestor, I had no idea when we’d be able to report back with any new findings.

As it turns out, not all that long. An early trickle of new data from Family Tree DNA’s Y-700 customers, read against some previously inscrutable data, has helped to shed light on several of the unknowns I spelled out in January. Among them:

Where did Y6923 originate, and what are its closest relatives?

As of the beginning of this year, as far as we could assume, the common ancestor of all Y6923 men, Ashkenazi and non-Ashkenazi, could be dated to roughly 400 CE, give or take a few hundred years—that is, the tail end of the Roman era in Western Europe.

But what about Y6923’s deeper origins? Unfortunately, the common ancestor of Y6923 and its closest relative, Y4972—found among Romaniote Jews, Mediterranean Europeans, Russians, Armenians, and Gulf Arabs—dates back to 3500 BCE, give or take, that is, right before the first pharaohs of Egypt and the first city-states of Sumer.

One day, population movements in the proto-historic Near East will be interpretable using contemporary Y-chromosomes, but until then, what about the gap between 3500 BCE and 400 CE? In the received history of Canaan, Israel, and the Jewish Diaspora, most of this period is surprisingly well-accounted for—but in the phylogeny of E-Y6923, this span of eras constitutes a yawning chasm.

Ladies and gentlemen, allow me to announce the first step in the closing of the gap. FTDNA has identified a marker downstream of Y4971 (Y6923’s most recent identified ancestor, until now), and upstream of Y6923, called Y6926. Someone who tests positive for Y6926, but negative for Y6923, could be said to be the ‘closest cousin’ of all Y6923 carriers.

Unfortunately, only one individual has been positively identified as Y6926+ and Y6923-, and he hasn’t included any information (even a name) to hint at his origins.

But! In examining the Y-STR data of potential distant Y6923 cousins in the E-M35 project on FTDNA, I caught a real break: it turns out that our unidentified Y6926+ Y6923- individual clusters—apparently within just a few hundred years—with a group of Emirati and Omani men from the same extended clan, along with a few other unidentified individuals.

An informed correspondent backed my assessment: this group of Gulf Arab men is very likely to be Y6926+ (we already know that they’re Y6923-; if they were Y6923+, we would have known by now). They are our closest cousins, and assuming that Latin American Y6923 is of converso origin, Y6923’s closest non-Jewish connection.

First of all, this link strengthens the case for a Middle Eastern origin of Y6923. Inferring beyond that is tough at this stage, but based on a preliminary account, Y6926 essentially ‘splits the difference’ between Y4971 and Y6923 in terms of distinguishing mutations, which suggests a common ancestor for Y6926’s Y6923+ and Y6923- descendants somewhere very roughly around 1600-1500 BCE, or in Levantine archaeological terms, the end of the Middle Bronze Age.

This was a time of upheaval in the region, and if we assume a Levantine, rather than Arabian, origin for Y6926, our tree would seem to correspond with the theory that it was also a time of proto-Arab migrations out of the Levant and into North and East Arabia. Again, this part is highly speculative.

How about Y6923’s big internal split?

In my last post, I wrote about the emerging picture of a split within Y6923 along pretty clean lines: Y6938 (now considered interchangeable with Y6940) characterizing all Ashkenazi members, and Y102667 being the signature of non-Ashkenazi members. We now have a few more data points, and in the broad sense, they appear to strengthen this paradigm.

First, one new individual of Tunisian Jewish origin has appeared on the YFull tree as Y102667+. His direct patriline, however, is said to be from somewhere in Turkey, having arrived in Tunisia in the early 19th century. This new cousin’s surname is attested in two different places: among Kurds in Turkey, and in elongated form, among Maghrebi Jews.

I am doubtful, however, about a Kurdish/Mesopotamian/Eastern Anatolian link: first of all, I don’t think Kurds had standard surnames 200 years ago, second, I don’t believe Jews were ever known to take on Kurdish clan names, and third, Jewish communities that far east were not part of the Sephardic network that would have linked, say, the Jewish communities of Istanbul, Izmir, and Tunis.

In addition, FTDNA has turned up a Y6923+ individual of Algerian (most likely Algerian Jewish) origin in its Y Haplotree; the individual does not appear on the list of Y6938/Y6940 downstream members (Y102667 doesn’t appear on the tree).

Finally, the E-M35 project has identified a Mexican and a Peruvian who are both estimated to be Y6923+, but Y6938/Y6940-, which would seem to make a pattern out of the one Puerto Rican individual who’s been known for a few years to be Y6923+ (now confirmed Y102667+). Given that all other known Y6923+ Y6938/Y6940- / Y102667+ individuals are Sephardic or North African Jews, a converso origin for these Latin American patrilines seems more likely than not.

While none of these new downstream findings changes the possibility space of the Y6938 / Y102667 split much, I’m inclined to say it slightly strengthens the case for an explicitly Sephardic origin of Y102667, and an identification of the split with the early branching of the late classical Western Roman Jewish community into proto-Ashkenazim and proto-Sephardim. That said, North African Y102667 might not have come from Spain, leaving other, less immediately legible possibilities open.

What we’re waiting on

  • More confirmed Y6926+ Y6923- individuals, for better ethnogeographical and chronological insights
  • Identification of sibling branches to Y6923, under Y6926
  • Confirmation of the Algerian individual’s Jewishness
  • Confirmation of the Peruvian, Mexican, and Algerian individual as Y102667+

Politifact rates your symphony false

This is one reason I respect Jordan Peterson’s pragmatism on a pragmatic level, even as I think it’s a crappy theory of truth. I can imagine a version of him saying (I don’t know if the real one does) “Look, I’m giving you all of these inspirational slogans. You can pick my science and philosophy and mythography apart if you really want, but are you sure you want to do that? You’ll just ruin my attempt to inspire you, and go back to lying on the couch all day wishing you had a reason to get up in the morning.”

Maybe aliens would view it as a tragic quirk of the human psyche that we have to conflate inspiration and truth. Maybe to them, inspiration is just another genre, closer to art or poetry than to an attempt to describe the world as it is. Maybe to them, if there’s an intuitively satisfying explanation of the meaning of life, asking “Is that really the meaning?” or “Is that really true?” would be just as stupid and annoying as nitpicking the lyrics of Ode To Joy. “Ode to Joy says ‘all creatures drink of joy’, but some creatures are unhappy, and joy is not a liquid! Politifact rates your symphony FALSE.”

— “Highlights from the Comments on Twelve Rules“, Slate Star Codex

You notice that vibrating soundless hum in the Socco? That means someone is making archetypes in the area and you’d best evacuate right now.

– “Lee’s Journals”, William S. Burroughs

Best Evacuate

The Litvak-Galitzianer divide: confirmed by genetics

Writing about something I haven’t covered at Whitmanic yet: the intersection of population genetics and history. If you know me, you know this is one of my favorite niche passions—and what a time to be passionate about it! We’re already at the point when pretty much all cultural and linguistic mysteries with population-level implications can be resolved with the help of genomic tools.

As my friend Razib Khan has lamented, despite the boom in published research and cumulative knowledge in this exciting, interdisciplinary space, very few people have joined him in blogging its discoveries.

Sometimes this means that an amateur like me will pick up on connections that no one in either a) the research field or b) semi-popular writing has pointed out. In these occasional cases, I’m going to do my best to communicate what I notice.

It happened a few months ago in the realm of Ashkenazi Jewish population genetics—one of those topics that’s been done to death, and yet still almost never done right.

I won’t rehash discourse or facts, but one new consensus opinion among people familiar with this field is that Ashkenazi Jews do not genetically differ along geographical lines. That is, as groups, German Jews, Polish Jews, Lithuanian Jews, Ukrainian Jews, etc., are not genetically distinguishable from one another.

This somewhat defies intuition: Ashkenazi Jews have been migrating out of their urheimat in Germany for at least 700-800 years, and there’s reason to believe that Eastern European Jews have other, minor sources of ancestry—both Jewish and non-Jewish.

But in fact, there’s good evidence from both Behar et al 2013 (“No evidence from genome-wide data of a Khazar origin of Ashkenazi Jews”) and samples provided by commenters on Anthrogenica that suggests that German Jews are on average distinct from Eastern European Jews—notable for their relative lack of Eastern European ancestry, which causes them to fall somewhere between European Sephardim and Italian Jews on one hand, and Eastern Ashkenazim on the other.

More research is needed to shore this up, but no one should be surprised.

What I haven’t heard people suggest, though, is the possibility of population structure among Eastern Ashkenazim. But a few months ago, I found it.

Let’s back up for context. In March, Ancestry rolled out “Genetic Communities”, a feature that makes use of information about DNA testers’ geographical origins and assigns them to ethno-geographical clusters of distantly related people. To my surprise, unlike component-based features employed by other DNA testing companies, “Genetic Communities” wasn’t totally uninformative for Ashkenazi Jews.

In fact, it revealed a hidden population structure that matches known patterns in Eastern European Jewish cultural and linguistic geography.

People familiar with Yiddish culture have surely heard yarns about “Litvaks” and “Galitzianers”—two subgroups of Eastern European Jewry set apart by geography, cuisine, dialect, and supposedly, temperament.

“Litvaks”, you might have guessed, are Lithuanian Jews—a well-defined group with a well-attested Yiddish dialect, with roots in Greater Lithuania, a territory encompassing modern Lithuania, Latvia, Belarus, and the northeastern corner of Poland.

“Galitzianers” are Jews from Galicia, the portion of southeastern Poland and western Ukraine ruled up until World War I by the Austro-Hungarian Empire. However, there’s no such thing as “Galitzianer Yiddish”, nor was Galicia a sovereign, well-defined cultural-political realm like Greater Lithuania. Instead, Galitizianers spoke either “Polish Yiddish”, a dialect common to Jews from most parts of Poland (save for its northeastern corner) or its very close cousin “Ukrainian Yiddish”, spoken in Western Ukraine, Moldova, and Romania.

Once we’ve dispensed with the mythology of Galicia (the part of Poland-Ukraine that happened to have the highest concentration of Jews in the early modern period), we can see that the main cultural divide among Eastern European Jews actually fell along a well-known non-Jewish boundary—the internal border within the Polish-Lithuanian Commonwealth between Greater Poland (which included core Ukraine) and Greater Lithuania (which included all of Belarus).

Back to genetics. In Ancestry’s published research, it identified three very closely related, but distinct, clusters of Ashkenazi Jews. One was much smaller than the other two, and exhibited no particular geographical pattern. As for the two major clusters, take a look for yourself.

Ancestry calls this one “Jews in the Russian Empire”:

And this one’s “Jews in Central Europe”:

The fact that each is divided into 3 subgroups is beside the point for now. What’s notable is that the distribution of the first cluster corresponds almost perfectly to “Litvak territory” i.e. Greater Lithuania, whereas the second cluster comprises all Eastern Ashkenazi territories other than Greater Lithuania—including the former Austro-Hungarian territories of Czech Republic, Slovakia, Hungary, and Austria, as well as Greater Romania (Romania and Moldova, whose Jewish populations, I recently learned, were mostly supplied by 18th-19th century migrations from Galicia and the Ukrainian region of Podolia).

So population structure among Eastern Ashkenazim (perhaps among all Ashkenazim, given the assignment of German Jews to the second cluster) falls along the lines of Litvak vs. non-Litvak. For a better illustration of the correspondence, and the cohesiveness of the Litvak concept, I refer you to two maps from Dovid Katz’s exceptional Atlas of Northeastern Yiddish.

The first is of Litvak cultural territory, which, you’ll notice, includes the northeastern corner of Poland and some border regions of northern Ukraine.

The second is of Litvak linguistic territory, which, you’ll notice, adds to the picture a swath running all the way down to the Black Sea through Ukraine’s midsection, supposedly the result of late settlement patterns.

Having studied those maps, let’s revisit Ancestry’s map of Litvak genetic territory:

The match is uncanny. The only real difference is that the “Litvak cluster” seems to spill over to include most of northeastern and north-central Poland (or rather, almost the entire north of historical Poland), as well as the entirety of northern and central Ukraine.

But: if you’ll take a look once again at the map of the non-Litvak cluster, you’ll notice that it also covers these very areas—which would suggest an overlap of the two population networks in these two regions. In the case of northeastern Poland in particular, this is interesting—the “Litvak cluster” predominance extends much farther west than someone would’ve guessed based on cultural and linguistic data. Perhaps this points to an origin of the Litvak population in northern Poland and an expansion into Greater Lithuania (in addition, all three Litvak sub-clusters extend into northeastern Poland).

As for historical explanations, I’m not familiar enough with the literature on Yiddish dialectology or medieval Ashkenazi migration patterns to offer a hypothesis. All that seems clear is that Litvaks (defined broadly), among all Central/Eastern Europeans Jews, have a distinct population history. I’d be curious to know if anyone can offer support for this.

Note: I would guess that the majority of present-day Ashkenazi Jews in America, Israel, and other parts have ancestors from multiple Eastern European Jewish cultural sub-regions. This means that individual-level PCA-based support for this cluster-driven analysis might be impossible.

Meeting George Harrison exactly where he is

Humans cannot be fully human if their focus is purely inward. It is not a question of choice, it is the way we are made. We always are in relation to the Other (which may be singular or plural.)  If that relationship is one where we reject every possible Other it still remains the thing which defines us and dominates our thoughts and actions.

The most perfect form, however, which that relationship can take is to love the Other for its own sake.

Via Tom Holland on Twitter, a lovely reflection on George Harrison’s “What Is Life” at Thoughtfully Detached. “What Is Life” is one of the better-known songs off All Things Must Pass, the most earnest collection of popular music that I know of.

Harrison’s knack for exuberant spiritual-romantic songwriting is all the more impressive given his ironic, dry, “bitch-wizard” manner.

1/Pyrrhic victory

Sunakkhatta left the order in disgust because the Buddha failed to defuse the crisis with Kosala and was forced into a humiliating retreat. Why, Sunakkhatta may have wondered, did he not multiply his bodies in a display of supernormal power before the awestruck troops? … On reaching his homeland, he spreads the news of the Buddha’s defeat and denounces him to the assembly: “The wanderer Gotama doesn’t have any superhuman states, any special knowledge or vision worthy of the noble ones. What he teaches is just hammered out by reasoning, following his own line of inquiry as it occurs to him. And all it leads to is the end of reactivity!”

— Stephen Batchelor in After Buddhism, quoting The Great Discourse on the Lion’s Roar

Summer reading list

If you’re interested.

So far:

Our Mathematical Universe by Max Tegmark
The Soft Machine by William S. Burroughs
Fooled By Randomness by Nassim Taleb
One Way Down (Or Another) by Calder Lorenz
The Map And The Territory by Michel Houellebecq
Meditations by Marcus Aurelius

In progress:

After Buddhism by Stephen Batchelor
The Gift of Fear by Gavin de Becker

On deck:

The Enigma of Reason by Hugo Mercier and Dan Sperber
Mindful Tech by David M. Levy
Ulysses by James Joyce

Perennial online favorites:

Gene Expression
Slate Star Codex
Qualia Computing

And—summer listening:

Offa Rex
Kacy & Clayton
Basement Signal
Led Zeppelin
Morrison Hotel by The Doors
No Blues
Bardo Pond
Hope Sandoval and the Warm Inventions
Amalia Rodrigues
Zeca Afonso