Posted by:
SL Cabbie
(
)
Date: February 10, 2018 12:57AM
Ouch!! What this is saying is that less than 10% of Ashkenazi maternal lines can be traced back to the Near East or Caucasus.
https://www.nature.com/articles/ncomms3543>>The origins of Ashkenazi Jews remain highly controversial. Like Judaism, mitochondrial DNA is passed along the maternal line. Its variation in the Ashkenazim is highly distinctive, with four major and numerous minor founders. However, due to their rarity in the general population, these founders have been difficult to trace to a source. Here we show that all four major founders, ~40% of Ashkenazi mtDNA variation, have ancestry in prehistoric Europe, rather than the Near East or Caucasus. Furthermore, most of the remaining minor founders share a similar deep European ancestry. Thus the great majority of Ashkenazi maternal lineages were not brought from the Levant, as commonly supposed, nor recruited in the Caucasus, as sometimes suggested, but assimilated within Europe. These results point to a significant role for the conversion of women in the formation of Ashkenazi communities, and provide the foundation for a detailed reconstruction of Ashkenazi genealogical history.
>>The Ashkenazim are thought to have emerged from dispersals north into the Rhineland of Mediterranean Jews in the early Middle Ages, although there is little evidence before the twelfth century. After expulsions from Western Europe between the thirteenth and fifteenth centuries, the communities are thought to have expanded eastwards, especially in Poland, Lithuania and then Russia.
>>We are then faced with several competing models for Ashkenazi origins: a Levantine ancestry; a Mediterranean/west European ancestry; a North Caucasian ancestry; or, of course, a blend of these. This seems an ideal problem to tackle with genetic analysis, but after decades of intensive study a definitive answer remains elusive.
My antennae perked up with that "maternal line" statement; this clearly pointed to mitochondrial DNA--inherited from one's mother--as the "source evidence" for this claim; however...
>>The maternal line has also been studied, and indeed Ashkenazi mtDNAs are highly distinctive, but they have proved difficult to assign to a source population. Some progress has been made by targeting whole-mtDNA genomes or mitogenomes, which provide much higher genealogical (and therefore geographical) and chronological resolution than the control-region sequences used previously...
>>Overall, we estimate that most (>80%) Ashkenazi mtDNAs were assimilated within Europe. Few derive from a Near Eastern source, and despite the recent revival of the ‘Khazar hypothesis,' virtually none are likely to have ancestry in the North Caucasus. Therefore, whereas on the male side there may have been a significant Near Eastern (and possibly east European/Caucasian) component in Ashkenazi ancestry, the maternal lineages mainly trace back to prehistoric Western Europe. These results emphasize the importance of recruitment of local women and conversion in the formation of Ashkenazi communities, and represent a significant step in the detailed reconstruction of Ashkenazi genealogical history.
>>Previous researchers proposed a Levantine origin for the three Ashkenazi K founders from several indirect lines of evidence: shared ancestry with non-Ashkenazi Jews, shared recent ancestry with Mediterranean samples, and their absence from amongst non-Jews, and this suggestion has been widely accepted. However, our much more detailed analyses show that two of the major Ashkenazi haplogroup K lineages, K1a1b1a and K2a2a1 have a deep European ancestry, tracing back at least as far as the early and mid-Holocene respectively.
>>The heavy concentration of Near Eastern haplogroup K lineages within particular, distinct subclades of the tree, and indeed the lack of haplogroup K lineages in Samaritans, who might be expected to have shared an ancestral gene pool with ancient Israelites, both strongly imply that we are unlikely to have missed a hitherto undetected Levantine ‘reservoir’ of haplogroup K variation.
>>Fewer than 10% of the Ashkenazi mtDNAs can be assigned to a Near Eastern source with any confidence, and these are found at very low frequencies...
Have fun...