I usually don’t get that interested in human biodiversity stories, unless they are about me:

“[T]he great majority of Ashkenazi maternal lineages were not brought from the Levant, as commonly supposed,” Dr. Richards and colleagues conclude in their paper. Overall, at least 80 percent of Ashkenazi maternal ancestry comes from women indigenous to Europe, and 8 percent from the Near East, with the rest uncertain, the researchers estimate.

Dr. Richards estimates that the four major lineages became incorporated into the Ashkenazi community at least 2,000 years ago. A large Jewish community flourished in Rome at this time and included many converts. This community could have been the source of both the Ashkenazim of Europe and the Sephardim of Spain and Portugal, given that the two groups have considerable genetic commonality, Dr. Richards said.

This is not actually particularly newsworthy. We’ve known for a very long time that there were a large number of converts to Judaism in the heyday of the Roman Empire. We’ve also known that this pool of converts skewed heavily female, presumably in part because mobile Jewish males sought brides where they migrated, and in part because Roman and Greek cultures alike were disgusted by circumcision (not to mention the procedure is riskier when performed on adults), which was a serious bar to conversion for interested men. (Note, however, that circumcision was not a Jewish innovation; it was common to the ancient Levant. The Philistines are singled out as “uncircumcised” because, coming from Greece, they did not circumcise their males. They stood out in this regard not only from the Israelites, but from the other tribes of the region: Canaanites, Ammonites, Moabites, Assyrians, etc. – none of whom are called “uncircumcised.”)

Does it matter? Yes, it does – to understanding Jewish history, and European history. And it matters to understanding Jewish genetics, which has medical implications. And it is consistent with the Cochran hypothesis that Ashkenazi intellectual achievement is due in part to severe selection pressures on a small founding population in early medieval Northern Europe that resulted in a higher average IQ for that population and its descendants. (If the Ashkenazi population were substantially derived from, say, Kazar converts who migrated west to Poland, or, alternatively, were genetically indistinguishable from the Jews of Yemen, this would pose serious problems for his hypothesis.)

But it doesn’t matter for the question of whether the Jewish people are a “nation” and whether Israel is that nation’s homeland. Because all nationalism is a political fiction, including the romantic notion of the nation as an organic family. And debates about origins only matter to the narrative of nationalism inasmuch as they can be pressed into service for specific ideological debates.

Thus, whether the French think of themselves as the heirs of Vercingetorix or Clovis does not in any way turn on whether their genes are more Gaulish (Celtic) or more Germanic (Frankish). Rather, that debate is a proxy for the place of religion in the concept of the French nation: Clovis was the first Catholic king of a united Frankish kingdom. Similarly, if the fact that Ashkenazi Jews are substantially Italian were to matter, politically, it would be because there was already a live ideological debate within the Jewish community, and this fact could be pressed into narrative service within that debate as a proxy for the real question. So, if we imagine a future in which Israeli entry into the EU is a live question, it’s easy to see how this genetic evidence could be pressed into service – but it would be objectively a meaningless addition to that hypothetical debate, as the active debate about possible Turkish entry proves. The real issue would be the degree to which Israel should try to maintain a distinct society and control over their economy, a debate for which genes are substantively irrelevant.

Zionism – Jewish nationalism – was an ideological response to the material and spiritual condition of Ashkenazi Jews in the late 19th and early 20th centuries. As a matter of fact, Zionism created a state, and a nation, that did not previously exist, but it created them out of existing material: a people that understood itself to be an organic entity in spite of divisions of language, geography and culture; and a religious longing for a particular strip of land that had lasted two millennia. That’s what every nationalism does, everywhere it operates: creates something new by refashioning existing human material.