The Missing Link of Jewish European Ancestry

Most Jews belong to the Ashkenazim (~11 m) out of a total of ~ 15 m. Since the time of publication of Abraham Polak's seminal work [Khazaria—the history of a Jewish kingdom in Europe (in Hebrew), 1951 Tel-Aviv (Israel), Mosad Bialik and Massada Publishing Company] and later Arthur Koestler's controversial book - The thirteenth tribe: the Khazar Empire and its heritage, 1976 New York, Random House  - where they showed that the Ashkenazim may have been descendants of Khazar Jews of the Caucasus who had converted to Judaism (as the '13th tribe) in the 8th century, the world Jewry has been trying to debunk the Khazarian theory fearing that their claim to Jerusalem as being outsiders and not being part of Children of Israel would be diluted by such research findings. 

A DNA study by a Jewish scholar Eran Elhaik: "The Missing Link of Jewish European Ancestry: Contrasting the Rhineland and the Khazarian Hypotheses", Genome Biology and Evolution, Volume 5, Issue 1, 1 January 2013, Pages 61–74; https://doi.org/10.1093/gbe/evs119 - proves once again the validity of the Khazarian theory.

Here is the link: https://academic.oup.com/gbe/article/5/1/61/728117 whose abstract reads:

Abstract

The question of Jewish ancestry has been the subject of controversy for over two centuries and has yet to be resolved. The “Rhineland hypothesis” depicts Eastern European Jews as a “population isolate” that emerged from a small group of German Jews who migrated eastward and expanded rapidly. Alternatively, the “Khazarian hypothesis” suggests that Eastern European Jews descended from the Khazars, an amalgam of Turkic clans that settled the Caucasus in the early centuries CE and converted to Judaism in the 8th century. Mesopotamian and Greco–Roman Jews continuously reinforced the Judaized empire until the 13th century. Following the collapse of their empire, the Judeo–Khazars fled to Eastern Europe. The rise of European Jewry is therefore explained by the contribution of the Judeo–Khazars. Thus far, however, the Khazars’ contribution has been estimated only empirically, as the absence of genome-wide data from Caucasus populations precluded testing the Khazarian hypothesis. Recent sequencing of modern Caucasus populations prompted us to revisit the Khazarian hypothesis and compare it with the Rhineland hypothesis. We applied a wide range of population genetic analyses to compare these two hypotheses. Our findings support the Khazarian hypothesis and portray the European Jewish genome as a mosaic of Near Eastern-Caucasus, European, and Semitic ancestries, thereby consolidating previous contradictory reports of Jewish ancestry. We further describe a major difference among Caucasus populations explained by the early presence of Judeans in the Southern and Central Caucasus. Our results have important implications for the demographic forces that shaped the genetic diversity in the Caucasus and for medical studies.

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Explaining the reason for the DNA study, Dr. Eran Elhaik says, "The original project aimed to trace live descendants of Khazars, however it was since expanded to develop tools and study the origin of populations from the Caucasus and Near East, including Jews.

The project traces the origin of populations by searching for their particular DNA signature in the genomes of other populations. Sounds like searching for a needle in a sack of hay? It’s somewhat similar, but imagine that you have a magnet!

What can DNA tell us? Our DNA is like a history encyclopedia. It tells us the stories of our forbearers from the first human who walked on the earth to YOU. Different DNA regions can tell us whether you ancestors interbred with Neanderthals, while other regions tell us about the path your ancestors took out of Africa. It all depends on what you want to know and your ability to interpret the genetic code. We are interested in identifying populations around the world the carry the Caucasus signature. Because Caucasus people remained largely confined in the Caucasus, finding populations who carry these signature is the first step in relating them to the Khazars.

Why Khazars? Why now? Unlike the famous Greek, Roman, and Persian Empires, the history of the Khazar’s Empire remained a mystery, known only to very few people. The main reason was that the study of Khazaria was forbidden in the Soviet Union, where the major sites reside. Dr. Satanovsky, director of the Middle Eastern Institute in Moscow, said that Josef Stalin detested the idea that a Jewish empire had come before Russia’s own. He ordered references to Khazar history removed from textbooks because they “disproved HIS theory of Russian statehood.” Only now are Russian scholars free to explore the Khazar culture, and they are doing a tremendous job. The Itil excavations, for example, sponsored by the Russian-Jewish Congress, recently revealed one of the three Khazar capital cities. While archeologists and historians are making their contribution to our knowledge of the Khazars, so should geneticists. Using genetic data we can unravel some of the mystery around these people who built their Empire of the basis of harmony and peace and later on joined the Jewish faith and perhaps contributed to Eastern European Jewish culture.

Our knowledge of the ancient Khazars is based almost entirely on the writings of educated, wealthy, elite men who often contradicted one another. The Soviet Union did its share of spreading fear and prejudice around about the Khazars that still prevails among many people and hinders studies in the field. It’s time to change our approach to Khazar history by harnessing genetics and combining it with archeological and historical knowledge.

The possibility to reveal the genetic background of these mysterious people through genetic data is one of the most exciting ventures now available with Next Generation Sequencing data."

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As expected, since the publication of his work on European Jewish DNA, Eran  Elhaik has been targeted by others who wanted to debunk his work. However, his latest work once again proves that he has been right on his conclusion. He says, "When compared with non-Jewish populations, all Jewish communities were significantly (P < 0.01, bootstrap t test) distant from Middle Eastern populations and, with the exception of Central European Jews, significantly closer to Caucasus populations (table 1, right panel). Similar findings were reported by Behar et al. (2010) although they were dismissed as “a bias inherent in our calculations.” However, we found no such bias. The close genetic distance between Central European Jews and Southern European populations can be attributed to a late admixture. The results are consistent with our previous findings in support of the Khazarian hypothesis. As the only commonality among all Jewish communities is their dissimilarity from Middle Eastern populations (table 1, right panel), grouping different Jewish communities without correcting for their country of origin, as is commonly done, would increase their genetic heterogeneity."
He continues, "Both mtDNA and Y-chromosomal analyses yield high similarities between European Jews and Caucasus populations rooted in the Caucasus (fig. 7) in support of the Khazarian hypothesis."
He further writes, "The religious conversion of the Khazars encompassed most of the [Khazar] empire’s citizens and subordinate tribes and lasted for the next 400 years (Polak 1951; Baron 1993) until the invasion of the Mongols (Polak 1951; Dinur 1961; Brook 2006). At the final collapse of their empire (13th century), many of the Judeo–Khazars fled to Eastern Europe and later migrated to Central Europe and admixed with the neighboring populations.
Historical and archeological findings shed light on the demographic events following the Khazars’ conversion. During the half millennium of their existence (740–1250 CE), the Judeo–Khazars sent offshoots into the Slavic lands, such as Romania and Hungary (Baron 1993), planting the seeds of a great Jewish community to later rise in the Khazarian diaspora. We hypothesize that the settlement of Judeo–Khazars in Eastern Europe was achieved by serial founding events, whereby populations expanded from the Caucasus into Eastern and Central Europe by successive splits, with daughter populations expanding to new territories following changes in socio-political conditions (Gilbert 1993). These events may have contributed to the higher homogeneity observed in Jewish communities outside Khazaria’s borders (table 1).
After the decline of their empire, the Judeo–Khazars refugees sought shelter in the emerging Polish kingdom and other Eastern European communities where their expertise in economics, finances, and politics was valued. Prior to their exodus, the Judeo–Khazar population was estimated to be half a million in size, the same as the number of Jews in the Polish–Lithuanian kingdom four centuries later (Polak 1951; Koestler 1976). Some Judeo–Khazars were left behind, mainly in the Crimea and the Caucasus, where they formed Jewish enclaves surviving into modern times. One of the dynasties of Jewish princes ruled in the 15th century under the tutelage of the Genovese Republic and later of the Crimean Tartars. Another vestige of the Khazar nation is the “Mountain Jews” in the North Eastern Caucasus (Koestler 1976)."
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More info on the Khazar DNA project can be found in the link: https://khazardnaproject.wordpress.com/2017/08/29/shaming-23andme-works/