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View Full Version : Between .5-1% Ashkenazi in many Mexican 23 & Me results



digital_noise
04-12-2021, 04:54 PM
Hi all,
Iíve been meaning to inquire about this for a long time. I have noticed on Reddit that many (I would say 9/10 at least) people of Mexican descent have a small amount of Ashkenazi dna.

Where does this come from? Iím assuming itís correctly assigned because Ashkenazi has a high recall rate at 23 and Me. Someone mentioned something about a large amount of Jewish people immigrating to Mexico at some point in the past but the sheer amount of results shared with this makes me wonder if itís a misplaced signal somehow related to the Spanish side that is typical in people of Mexican descent.

I donít understand a lot about historic Jewish movements etc... so Iím curious about this. Apologies if itís been cover many times in the past.

passenger
04-12-2021, 05:13 PM
Almost certainly it's from remote Sephardic ancestry through conversos who migrated to many parts of Latin America in large numbers. That type of ancestry often shows up as Ashkenazi when it's in small percentages like that, even when the testing service has a Sephardic category (which 23andme doesn't). Of course there was also a fair amount of Ashkenazi immigration to Mexico in the late 19th and 20th centuries, but that wouldn't account for that population-wide impact.

passenger
04-12-2021, 06:29 PM
This link provides a nice overview of the history: https://www.jewishvirtuallibrary.org/mexico-virtual-jewish-history-tour

RCO
04-12-2021, 10:01 PM
It was a two-way street because Ashkenazi and Sephardi also have some autosomal Iberian (and Northern African, so three way) as we can also observe in some Y-DNA and mtDNA modern Jewish lineages, so Iberians and Latin Americans can find some matches, that's quite common.

leorcooper19
04-12-2021, 10:34 PM
It was a two-way street because Ashkenazi and Sephardi also have some autosomal Iberian (and Northern African, so three way) as we can also observe in some Y-DNA and mtDNA modern Jewish lineages, so Iberians and Latin Americans can find some matches, that's quite common.

I think it's much more reasonable to expect that segments that went from Iberian gentile > Sephardi Jew > Ashkenazi Jew and Iberian gentile > Mexican are vastly outnumbered by the segments that originate in a Sephardi that left descendants in both Mexico and among Ashkenazi Jews. The vast majority of West Med/North African ancestry in Ashkenazim and Sephardim come from the same classical and early Medieval Jewish sources, not something that would have happened so recently as to be the source of IBD segment sharing between the groups.

RCO
04-13-2021, 02:41 AM
What you call early Medieval Jewish sources also have substantial European origins. "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".
https://www.nature.com/articles/ncomms3543

Now we know they also have several European Y-DNA lineages just observe the closest matches and the phylogenetic structure in some haplogroups, so they were a new admixed Medieval population in Europe just like others. In the future we are going to know more about the sources of IBD segments, mtDNA and Y-DNA if Levantine, European or other.

passenger
04-13-2021, 04:10 AM
What you call early Medieval Jewish sources also have substantial European origins. "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".
https://www.nature.com/articles/ncomms3543

Now we know they also have several European Y-DNA lineages just observe the closest matches and the phylogenetic structure in some haplogroups, so they were a new admixed Medieval population in Europe just like others. In the future we are going to know more about the sources of IBD segments, mtDNA and Y-DNA if Levantine, European or other.

I'm not sure what the relevance of this is. We're not really talking about Ashkenazi DNA to begin with, but it's not a secret that most Ashkenazi mtDNA lines are "European" rather than "Levantine". At this point I don't think that's a common supposition at all among regulars in this subforum. Ashkenazi Y-DNA lines, on the other hand, appear to be majority Levantine.

The ongoing question is regarding the exact provenance and timing of that "European" ancestry in Ashkenazim and Sephardim, the bulk of which appears to come from a common Southeastern European (Southern Italian/Greek-like) source somewhere between Late Antiquity and the Early Middle Ages, rather than from admixture acquired from the majority non-Jewish populations in the areas where diasporic Jews lived in Medieval and Modern Europe, whether in Iberia or in Central/Eastern Europe.

Of course we really don't know what pre-1492 Iberian Jews' DNA looked like. If we're going by modern Sephardic groups, I'd hazard to say that they probably have less general Iberian admixture on average than Ashkenazi Jews have Eastern European admixture, but we also have to take into account that most modern Sephardim are heavily descended from other Mediterranean Jewish groups besides those that came out of Medieval to Early Modern Iberia.

BalkanKiwi
04-13-2021, 10:38 AM
My grandfather matches a few Mexicans on his Iberian segment. I can't check right now, but I believe one had minor amounts of Sephardic. This cluster includes mostly Spaniards with a few Brazilians and Puerto Ricans and an Algerian.

RCO
04-13-2021, 11:53 AM
Yes, we share small segments, in my FTDNA Family Finder I have a very small number of Ashkenazi and Northern Africans matches. The Iberian segments can have different origins.
Genetic genealogists know well the R1b>DF27>FGC20747, a very interesting branch and how they have Western European, Western Iberian origins and they also have Ashkenazi, Sephardic, Northern African sub-branches, so the same also happened with other segments as I wrote, it was a two-way or three-way street from different Ancestral origins.

Piquerobi
04-13-2021, 12:19 PM
What you call early Medieval Jewish sources also have substantial European origins. "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".
https://www.nature.com/articles/ncomms3543

Whether those four mtDNA lineages among the Ashkenazim are from the Near East as a result of Jewish migrations or predate them in Europe is still open to debate. That study provided no final answer at all. Clades of K are particularly common in the Near East and so are clades of N.

This is a rebuttal someone posted at the Family Tree DNA forum a long time ago:


Criticism of the article

Let’s start from the positive – as most paternal lineages carried by Ashkenazi Jews seem to trace back to the Levant, yet autosomal DNA tests reveal that Ashkenazi Jews have more European admixture than other Jewish populations, there is a strong assumption that the inflow into the Jewish community most likely occurred on the maternal side.

The problem is, reading through the article, that the authors with a predetermined conclusion in mind, seem to have set out to prove this despite not having sufficient data to do so.

Considering the K halogroups and K1a1b1a in particular (which is the most significant haplogroup making up 20% of total Ashkenazi lineages). As the authors state:

'These lineages are extremely infrequent across the Near East and Europe, making the identification of potential source populations very challenging. Nevertheless, they concluded that all four most likely arose in the Near East and were markers of a migration to Europe of people ancestral to the Ashkenazim only ~2,000 years ago'.

It is worthwhile repeating why Behar concluded that these haplogroups most likely originated in the Levant – the age of these maternal lineages (which are restricted to Jewish populations) exceeds 2,000 years. The authors admit the same: “K1a1b1a, K1a9 and K2a2a12. These three founder clusters show a strong expansion signal beginning ~2.3 ka” and furthermore “K1a1b1a (slightly re-defined, due to the improved resolution of the new tree) (Fig. 2) accounts for 63% of Ashkenazi K lineages (or ~20% of total Ashkenazi lineages) and dates to ~4.4 ka with maximum likelihood (ML)”. Just to place these results in their historical perspective 2,300 years predates the dispersal of the Jewish population from the Levant to Europe and 4,400 years predates the ancient Israelite kingdoms. Assuming that these haplogroups had originated in “Europe” many hundreds (or even thousands) of years prior to the establishment of the Ashkenazi Jewish community in Europe you would expect to find other non-Jewish individuals carrying ancient versions of these maternal lineages. The opposite is true – as the authors themselves admit those individuals in Europe carrying these maternal lineages nest within the Ashkenazi cluster and the geneflow is from the Ashkenazi community outwards rather than inwards.

In order to get around this problem what the authors do is make a false assumption – that it is possible to gain a better understanding of the origin of the haplogroup by looking at the lineages upstream – so in the case of K1a1b1a the authors examine K1a1b1. This is what they conclude: “The K1a1b1 lineages within which the K1a1b1a sequences nest (including 19 lineages of known ancestry) are solely European, pointing to an ancient European ancestry. The closest nesting lineages are from Italy, Germany and the British Isles, with other subclades of K1a1b1 including lineages from west and Mediterranean Europe and one Hutterite (Hutterites trace their ancestry to sixteenth-century Tyrol)”. There are a number of problems with this conclusion – I will focus on its age. K1a1b1 is by the authors own admission over 10k years old (Figure 2). Do the authors not consider that in the interim ~6,000 years between the appearance of K1a1b1 and the appearance of K1a1b1a the maternal lineage could have possibly migrated to and from the Levant? Since ancient times the Mediterranean basin has been the “central superhighway of transport, trade and cultural exchange between diverse peoples—encompassing three continents: Western Asia, North Africa, and Southern Europe”. During the timeframe in question the Western and Eastern Mediterranean were better connected than the Western Mediterranean was to North Western Europe and the British Isles. If K1a1b1 ended up in the British Isles there is no logical reason it could not have ended up or originated in the Eastern Mediterranean during the many thousands of years of its existence. If anything the paper shows the authors lack of knowledge of the ancient world and their inability to escape from the modern definition of Europe, which is completely irrelevant when looking at haplogroups thousands and tens of thousands of years old.

This is reinforced when the authors make the following statement: “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”. As the Samaritan population numbers 751 closely related individuals as of 2012 (and is actually a population of the verge of extinction) there is no reason whatsoever to think that it is in any way representative of the diversity of the ancient Israelite gene-pool.

This does not mean that K1a1b1a cannot have entered the Ashkenazi Jewish gene-pool in the Northern Mediterranean rather than the Levant, but the age of the haplogroup, and its apparent absence in non-Jewish populations indicates the opposite and until K1a1b1a samples are found amongst different ancestral populations or in ancient samples the fact that it originated in the Levant is the more logical conclusion.

Just to show the fallacy of this idea the authors promote that the geographical spread of a certain haplogroup has any implications for those downstream when looking at time frames of thousands of years let us examine HV1b2. The authors conclude that “HV1b2 mitogenomes, in particular, date to ~2 ka and nest within a cluster of Near Eastern HV1b lineages dating to ~18 ka”. However, HV1b is also found amongst Italians and other European populations, not just around Near Eastern populations. Here are a number of examples:

HV1b 12696
34. AY738942(Italy) Achilli HV1b 13-APR-2007 C150T A263G 309.1C 309.2C 315.1C A750G A1438G A2706G T3290C A4769G A5134G C6263T C7028T A8014T A8860G C9585T T12696C A15218G A15326G C16067T
35. EF657609 mtDNA44(Europe) Herrnstadt HV1b 14-JUL-2007 A750G A1438G A2706G A3547G A4769G G6023A C7028T A8014T A8860G T12696C A15218G A15326G
36. EF657676 mtDNA50(Europe) Herrnstadt HV1b 14-JUL-2007 A750G A1438G A2706G A3547G A4769G G6023A C7028T A8014T A8860G T12696C A15218G A15326G

Using this logic clearly HV1b1 (found amongst for example Yemenite Jews and Assyrians) and HV1b2 (which has recently been identified in a Kurdish individual as well as amongst Ashkenazi Jews) are also “European”.

The truth of the matter is that because of the incredibly ancient timeframes, it is not possible to reach any conclusion as to the origins of a mitochondrial haplogroup based on those halogroups upstream from the one in question and this is ignoring their “very superficial analysis of modern population distribution”.
https://forums.familytreedna.com/forum/general-interest/scientific-papers/13285-a-substantial-prehistoric-european-ancestry-amongst-ashkenazi-maternal-lineages?t=34338&page=2

leorcooper19
04-13-2021, 12:45 PM
Yes, we share small segments, in my FTDNA Family Finder I have a very small number of Ashkenazi and Northern Africans matches. The Iberian segments can have different origins.
Genetic genealogists know well the R1b>DF27>FGC20747, a very interesting branch and how they have Western European, Western Iberian origins and they also have Ashkenazi, Sephardic, Northern African sub-branches, so the same also happened with other segments as I wrote, it was a two-way or three-way street from different Ancestral origins.

I think you misunderstood my point. You're right that these classical and early medieval Jewish communities would have had considerable amounts of North African and Mediterranean European ancestry, as evidenced by many uniparental lineages, BUT the European or North African sources in these populations would not be the most likely source of any shared segments between modern Iberians, Western Jews, and Latin Americans. This is simply due to time; a 1500 year old Iberian segment shared by all groups are going to be incredibly rare compared to 500 year old Sephardi segments shared by all groups.

A simple inference from dating of admixture events and the rate of recombination can tell you that the DNA shared with your "very small number" of Ashkenazi matches is much, much more likely to originate from a late medieval Sephardi source than a classical or early medieval Iberian source.

RCO
04-13-2021, 08:37 PM
We have a genetic heritage from the Jewish populations and from the Islamic populations living in Iberia in the year 1000. We had the Christian frontiers with other populations and they were more or less related and mixed but they had their own genetic differences and genetic identities, we can find specific genetic clusters from different regions and religions, nowadays we can investigate high-coverage Y-DNA and mtDNA matches and phylogenetic structures to locate some origins of the communities. I think we have autosomal DNA from Jewish and Islamic populations but as I wrote the Jewish and Islamic populations also had Native Iberian of Hispanorroman genetic heritages as well, as we know conversions were generalized from all groups and populations to all others and I hope in the future we can get more ancient DNA to show that diversity. The Sephardic and Islamic Iberian populations were heterogeneous and the Reconquista War homogeneized the Iberian populations in meridians (East to West or West to East, so Iberia is not like Italy with a strong North to South genetic differences). Latin America is just an extension of the expansion with other genetic admixtures but in the case of the Portuguese Empire they had their own genetic profile. I have seen several results of Latin Americans and we share some matches as an expression of our History and war frontiers are always the biggest genetic mixer.

passenger
04-13-2021, 10:18 PM
We have a genetic heritage from the Jewish populations and from the Islamic populations living in Iberia in the year 1000. We had the Christian frontiers with other populations and they were more or less related and mixed but they had their own genetic differences and genetic identities, we can find specific genetic clusters from different regions and religions, nowadays we can investigate high-coverage Y-DNA and mtDNA matches and phylogenetic structures to locate some origins of the communities. I think we have autosomal DNA from Jewish and Islamic populations but as I wrote the Jewish and Islamic populations also had Native Iberian of Hispanorroman genetic heritages as well, as we know conversions were generalized from all groups and populations to all others and I hope in the future we can get more ancient DNA to show that diversity. The Sephardic and Islamic Iberian populations were heterogeneous and the Reconquista War homogeneized the Iberian populations in meridians (East to West or West to East, so Iberia is not like Italy with a strong North to South genetic differences). Latin America is just an extension of the expansion with other genetic admixtures but in the case of the Portuguese Empire they had their own genetic profile. I have seen several results of Latin Americans and we share some matches as an expression of our History and war frontiers are always the biggest genetic mixer.

No doubt that the general Iberian population acquired admixture from North Africans and Jews and that the flow from the Jewish/New Christian population to the general (Christian) population continued in colonial Latin America. It seems likely that Iberian Jews also acquired some admixture from the non-Jewish population in Iberia, but I highly doubt that this occurred at the same rate as Jewish genetic flow into the general Christian population. Jews were very insulated by numerous prohibitions of intermarriage enforced by both Muslim and Christian states as well as the social and religious laws and conventions of their own society. We know from the records that Jewish men in particular certainly had children with non-Jewish (especially Muslim) women, as this is frequently the subject of disputes and complaints, including from rabbis. However these children were most often the product of extramarital affairs - not legal marriages, as these would have been off limits under most Iberian states during most time periods - and we don't know to what extent such children were incorporated into Jewish society.

In terms of Y-DNA, I don't really see much overlap between modern North African and Eastern Sephardic populations and the general Iberian population. The patterns are very distinct. Again, we can't say that modern Sephardic populations are wholly representative of pre-expulsion Iberian Jews, since they are so mixed with other Mediterranean Jewish groups, but still, the difference is striking. There is more overlap of course, as is to be expected between Portuguese crypto-Jews (https://www.frontiersin.org/articles/10.3389/fgene.2015.00012/full) and the general Portuguese population, but there are still distinctions. On the other hand, there is a great deal of Y-DNA overlap between Ashkenazim and Sephardim.

As I understand it - and the more knowledgeable here will hopefully chime in - mtDNA is much more distinct between Ashkenazim and Sephardim than Y-DNA, and there is even more heterogeneity between different Sephardic subgroups. For modern Sephardic groups I believe there is more potential for overlap with non-Jewish Iberian haplogroups, but I really couldn't say.

Regardless, all of this may be moot since the issue at hand is about autosomal DNA, and I think leorcooper19's point about timing is an essential one. We can see segment sharing between Ashkenazim, Sephardim and Latin Americans which is consistent with those segments having originated as a result of the Early Modern Sephardic diaspora. These segments couldn't be much older than that since they simply wouldn't show up. And in any case, we're getting away from the main question here which is what would cause Latin Americans to show that "Ashkenazi" percentage.