Excavating E-Y6923


Having just reformatted the website, I’d better get my money’s worth—what better excuse to rekindle my writing practice? But for the time being, it’s going to be easier to write about trivia than picking up the issues.

My latest trivial pursuit? Tracing my direct patriline all the way back to prehistory. Weird, right? Especially considering that the paper trail stops with my great-great-grandfather.

Turns out, there are thousands of people on the same sort of mission, a large share of them Jews with a limited paper trail. We live in the paradox of knowing (at least in theory) where our ancestors were in 1000 BCE and in 1000 CE, even if we can’t find documentation from before 1850.

Remarkably, genetic data have mostly confirmed the received narrative of Ashkenazi Jewish history: origins in Israel, classical-era migration to the West Mediterranean, emergence in Germany in the centuries following Charlemagne, and later diffusion into the Slavic lands.

In the last 7 to 10 years, the focus of Jewish population genetics has shifted from uniparental markers (especially Y-DNA) to autosomal DNA, giving a fuller picture of the mixed origins of European Jews. But with the help of better and cheaper sequencing technologies, hobbyists have honed in on the Y-chromosome, assembling a detailed catalogue of Ashkenazi patrilineages that for the most part date back to the Late Classical and Early Medieval periods.

Why does this matter? Well, as it turns out, rather than resorting to pie charts claiming that x% of Ashkenazim have Haplogroup J1, and y% have Haplogroup R1b, we can now make assertions like: 9 Early Medieval men account for the direct paternal ancestry of a full half of Ashkenazi Jews.

Courtesy of jewishdna.net.

For each of these 9 men, and for any other Ashkenazi Y lineages from the same time horizon (there are something like 100, but because of power laws, the vast majority of Ashkenazi men trace their direct patrilineages to the first few dozen), we can look at YTree, a tree of all charted human Y-chromosome mutations, check out its sister-lineages, and hypothesize about its classical, ancient, and ultimately prehistoric origins.

For some of the largest Ashkenazi groups (again, I mean specific Early Medieval subclades, like Q-Y2200, not “J1” or “J2”, each of which comprises about 20% of Ashkenazi Y-chromosomes, but across dozens of subclades), extensive work has been done to find non-Ashkenazi connections in the Jewish world, the Middle East, and beyond.

I’d like to do the same for E-Y6923, my own patrilineage, which holds the distinction of 5th largest Ashkenazi subclade, found in 5.6% of Ashkenazi men.

On E-Y6923: the big picture

For starters, consider that E-Y6923 represents a man who lived in the Late Classical or Early Medieval period, from whom 1 in every 18 Ashkenazi Jewish men directly descend on their direct male lines. Only four other men from this era contributed a larger share to the Ashkenazi gene pool.

Most Ashkenazim who belong to the Y6923 subclade don’t know it, even if they’ve tested their DNA before. Why? Because Y6923 wasn’t characterized until a few years ago, and 23andMe will still default to labeling a Y6923 man as “E-M34”, the macro-group under which Y6923 falls.

E-M34 is a geographically scattered, but well-characterized haplogroup with Paleolithic roots in either Northeast Africa or the Levant—its direct ancestor was found in human remains from Epipaleolithic Israel, and its earliest exemplar belongs to a man dug up in Neolithic Jordan.

Curiously, E-M34’s most famous member is Napoleon Bonaparte, whose membership speaks to the haplogroup’s low frequency in Mediterranean Europe. While not a member of the “classically Jewish” subclade Y6923, Bonaparte’s direct male-line relative did test positive for Y4972—which interestingly enough, is the closest sibling of the branch we’re discussing today, with representation among Europeans, Arabs, and Romaniote Jews.

A final note before we dive into the landscape of Y6923 itself: Y6923, as well as its Napoleonic sibling branch, descend from E-L791 (itself the main descendant of E-Z841), which appears to be the less successful son of E-M34, relative to E-M84.

M84 lineages account for 46% of Ashkenazi M34 (the majority belonging to Y6923), but they tend to outnumber L791 branches everywhere else that both are found. This is a question for another post.

Suffice it to say, L791, our intermediate father-clade, appears to have a most recent common ancestor ca. 3600 BCE—a date that falls smack in the middle of the Ghassulian period of the Copper Age, and seems to align with the dating of Proto-Semitic (or late pre-Proto-Semitic). Its descendants range across the Middle East and Europe, a saga that will one day hopefully be unrolled.

Y6923: the branch at hand

For now, our goal is limited to unrolling the saga of Y6923, which for at least the last 1,500 years (and in all likelihood, much longer), has been a Jewish saga.

First, one last technical clarification: we’ve been talking about Y6923, but we actually ought to be saying Y6938. Why? Because all Ashkenazim who’ve tested as members of Y6923 are also positive for Y6938, a downstream marker that’s only been discovered in the last 2 years.

As it happens, while Y6923 has a most recent common ancestor ca. 400 CE, Y6938 has a most recent common ancestor ca. 650 CE, which might be a helpful clue to tracking the origins and movements of this important line.

For what it’s worth, 650 CE dates a few centuries before the first attested, continuous Jewish settlements in old Ashkenaz, suggesting either a very early, pre-documentation origin in Germany, or more likely, an origin somewhere in France or Italy, in the generations prior to the foundation of the Rhenish Jewish community.

Until recently, the “closest relatives” of Y6923 Ashkenazim hadn’t been much help: E-Y6923 and E-Y4972, sister-descendants of Y4971, appear to have split during the Copper Age.

In the next few years, I expect the gap between Copper Age and Late Classical Period to narrow with& the detection of new markers and new branches, but who knows where and among whom.

The latest bombshell gives Y6923 a second child, and Y6938 a sibling: Y102667, exemplified by two non-Ashkenazi individuals—a Puerto Rican and a Libyan Jew. While we can’t make any detailed guesses about where Y6923’s direct ancestor was during the time of the Prophets, we now finally have a historical-era connection outside of the Ashkenazi community.

Courtesy of YFull.

On a fundamental level, these particular connections—Spanish and Libyan Jewish—should come as no surprise. We are talking about classical Mediterranean populations, which lived, along with the proto-Ashkenazi community, under Roman rule.

Nonetheless, a common Late Classical origin with these individuals rules out a few possibilities: namely, that Y6938 entered the Ashkenazi community via Rhenish or Khazar converts (given the heavily Levantine stamp of E-M34, these were never likely scenarios).

In addition, because the Puerto Rican and Libyan Jewish samples share a branch, we can rule out the possibility that Y6923’s presence in Spain is the result of an Ashkenazi back-migration to Spain. Y6938 is, to date, exclusively Ashkenazi, while Y102667 is, to date, exclusively non-Ashkenazi. This bifurcation also leads me to doubt the suggestion that Y6923 might have originated among Jews in Spain prior to arriving in Early Medieval Ashkenaz.

I am assuming that the Puerto Rican individual carrying Y102667 is of ultimately Jewish origin. While the simplest story would be an Early Modern converso introgression, we really can’t be sure of this—indeed, it’s possible that Jews were marrying out into the gentile Iberian community at a low rate for at least 1,500 years. Given the phylogeny and time depth of Y6923, a native Spanish origin for our Puerto Rican sibling seems very unparsimonious.

Wherever Papa Y6923 (or at least the most recent common ancestor of both Y6938 and Y102667) was located, it’s a safe bet that he was Jewish. Jewish, but not Ashkenazi, as the Ashkenazi community as such didn’t yet exist in 400 CE.

The puzzle of Y102667

By YFull’s estimate, the Puerto Rican Y102667 individual and the Libyan Jewish Y102667 individual share a most recent common ancestor dating to around 400 CE, contemporaneous with the split between Y102667 and Y6938. Superficially, this suggests no more recent affinity between the two individuals—but a more sophisticated reader might be able to correct me on this.

A disclaimer: the body of work on Late Classical/Early Medieval Jewish migrations around the West/Central Mediterranean, and on the origins of the Sephardic community of Iberia, is more diffuse (or possibly, more opaque to me) than that on the origins of Ashkenazi Jews in Italy and France. Either way, we’re dealing with a lot of conjecture and spotty sourcing.

My surface-level interpretation of the TMRCA date supplied by YFull suggests that Y102667 isn’t particularly likely to have originated in either Spain or Libya. That is, unless Jews were migrating from Spain to Libya, or from Libya to Spain, around 400 CE.

Rather, the common ancestor most probably came from an area that was supplying Jewish settlers to both Iberia and Libya during the Late Classical period. I will have to do some digging in my free time to find a country that matches this description (and I don’t expect a high-confidence answer), but off the top of my head, I can think of Northwest Africa and Italy as plausible candidates.

An alternative explanation dismisses the TMRCA, based on 2 samples, and narrows our theater of inquiry to Europe: since Late Medieval/Early Modern Sephardi Jews fled Spain for every possible Mediterranean shore, including Libya, it might be the case that Y102667 arrived in Libya in the last 500 years, via Spain. In this case, Y102667 would almost certainly have been born on European, likely Iberian, soil.

Wrapping it up: where Y6923 stands

There are other intermediate scenarios and timelines worth discussing, but the difference between these two theories of Y102667 presents a stark enough choice of possibilities for the origins of Y6923.

Flipping the order of the previous section, if Y102667 in the Libyan Jewish community is indeed of Sephardi origin (I asked Doron Behar for information on the sample’s origin, and no dice), then we can postulate that Y102667 is a marker of Iberian Jewry. Given that Y6938 is a bona fide marker of Ashkenazic Jewry, a common Late Classical origin would most likely trace back to some territory between Spain and Northern France/Germany—Southern France, but even more likely, Italy.

According to the most popular genetic models, both Ashkenazi and Sephardi Jews owe a substantial minority of their ancestry to Italy, a conclusion that is very much in step with the conventional historical narrative. In this case, Y6923 (or some downstream descendant of it, at least) is a Roman Jewish export from the Italian Peninsula, with likely Early Classical origins in Israel—for which no direct proof yet exists.

If on the other hand, Y102667’s Libyan connection has nothing to do with the Sephardi expulsion from Spain, we are left to ponder: where might the a most recent common ancestor of Ashkenazim, Sephardim, and Libyan Jews have lived, ca. 400 CE. Since we are only talking about one individual among many, rather than some averaged ‘central tendency’, the possibilities are various.

A piece of poorly-verified circumstantial evidence for this less-parsimonious path exists in the presence of a purported (via STR testing) Y6923+ Tunisian Jew in FTDNA and Semargl datasets, but until we can get ahold of him and test him for Y6923, Y6938, and Y102667 directly, it is too early to make any assumptions.

However, Y6923 in multiple North African Jewish communities, plus the Sephardi community, might suggest either a wide footprint of Y6923 across the Western Jewish world, or at the very least, some kind of Roman-era South or East Mediterranean origin for the common ancestor of Y6938 and Y102667. And either way, Italy remains an option.

Remember, at the end of the day we’re investigating the origins of 1/18 of all Ashkenazi patrilineages—not the Ashkenazi community at large. But maybe, just maybe, we can extend the reach of our family histories beyond our wildest dreams, and supply a new migration map for the next atlas of Jewish history.

Questions to pursue

What share of the Libyan Jewish gene pool is of Spanish Jewish origin? If 10%, it is not particularly likely that Y102667 arrived from Spain. If 30%, all bets are off.

Does the internal phylogeny of Y6938 (which is surprisingly well-characterized) offer any clues to origins, migration routes, and timing of the original Ashkenazi community?

Can we trust the TMRCA of 400 CE given for Y102667’s 2 individuals?

Are there any other non-Ashkenazi Y6923+ samples waiting to be catalogued?

What might’ve been a common source for Late Classical Jewish migration to both Spain and Libya?

What might’ve been a common source for Classical Jewish migration to Spain, France/Italy, and Libya?

One thought on “Excavating E-Y6923

  1. As a fairly close relative at Y44320, I commend your inquiry. We need this type of macro view so that dullards like me can make sense of it all.

    I do wonder how, or why rather, you assume that the Puerto Rican subject is not ashkenazi? Are the metrics involved genetic, family history, self identification or what?

Leave a Reply

Your email address will not be published. Required fields are marked *