Origins of R1a1a Ashkenazi Levites

The R1a1 haplogroup is very common throughout Europe and Western Asia. For this reason, and because the R1a1 haplogroup is found among R1a1a Ashkenazi Levites but is not commonly found in other Jewish populations and because the R1a1a Ashkenazi Levite progenitor was believed to have lived about 1,000 years ago, researchers have theorized that the progenitor may have been a Jewish convert from Khazaria or Adiabene. Other researchers, believing it unlikely that a convert to Judaism could have assumed Levite status, have suggested that R1a1a Ashkenazi Levites could be descended from (1) Nethinim of Iranian origin who returned to Jerusalem after the Babylonian Exile or (2) a member of a Levite tribe in Arabia who came to Spain with the Moors. A more recent analysis of STR data, posted here and summarized here, indicates that the ancestor of R1a1a Ashkenazi Levites was likely Jewish going back to the founding of Judaism, in Abrahamic times.

While the existence of a bottleneck / founder effect in the R1a1a Ashkenazi Levite population about 1,000 years ago appears at first glance to support the hypothesis that the R1a1a Ashkenazi Levite progenitor was a convert to Judaism, at least two other significant Ashkenazi Y-DNA clusters also have a Most Recent Common Ancestor ("MRCA") who lived at about that time; it appears that this may reflect the migrations that led to the foundation of the Ashkenazi population about 1,000 years ago.

Based upon recent Y-DNA testing and analysis, it is now apparent that the R1a1 haplogroup is quite old and quite diverse, and that any theory of the origins of R1a1a Ashkenazi Levites will need to take into account the Y-DNA SNPs that are found in R1a1a Ashkenazi Levites and their closest matches who are not R1a1a Ashkenazi Levites. 

Prior to December 2013, the
SNP data were consistent with each of these theories, as well as with a belief that R1a1a Ashkenazi Levites could be descended on their direct male line from a man who was part of the Jewish population three millennia ago.

In December 2013, Rootsi & Behar et al. published a paper that studied SNP data for R1a1a Ashkenazi Levites and other R1a1a men. S. Rootsi & D. Behar, et al., Phylogenetic Applications of Whole Y-Chromosome Sequences and the Near Eastern Origin of Ashkenazi Levites, Nature Communications 4, Article No. 2928 (2013). As discussed in more detail here, this paper establishes that R1a1a Ashkenazi Levites likely originate in the Near East, rather than Khazaria or Europe.   

In January 2014, Anatole Klyosov posted an article, originally in Russian, translated to English on this site, and summarized here, that concluded, based upon analysis of STR data, that the ancestor of R1a1a Ashkenazi Levites was likely a Jew who lived in Abrahamic times, when Judaism began.

Izrael Weksler (Isadore Wexler)

Izrael Weksler (Israel Wexler) (1891-1954)
Photograph taken in Lodz, Poland in 1912