View Full Version : Questions on Autosomal DNA

Jack Johnson
10-03-2017, 07:46 AM
I am fascinated by the genetics of Jewish populations, primarily the Sephardic and Ashkenazi Jewish populations of Europe. Now I was on eurogenes, and someone brought up being of Polish descent and having Ashkenazi Jewish matches. He then said he had no Jewish ancestors, I also know that although historically, Jewish populations greatly discouraged mixing with non-Jews, and mixing between Jewish and non-Jewish populations did not take place often, a good portion of Jewish maternal lineages are of Southern and Eastern European origin. Male Jewish arrivals from the Middle East seem to have taken European brides. This is where my question finally comes in. Is there a way to tell through autosomal dna if one has Jewish ancestry? Because some Polish people and some Europeans (primarily Southern and Eastern Europeans) share ancestors with Jews, and because of those European women contributing to the modern European Jewish gene pool, doesn't that mean that said Europeans would receive a Jewish autosomal signature without actually having Jewish ancestry? Is there a way to tell if one actually has Jewish ancestors, rather than one simply sharing non-Jewish ancestors that contributed to the gene pool of modern European Jews?

10-04-2017, 01:19 AM
on GEDmatch, you can use the Eurogenes Jtest at least for Ashkenazi. If that score is much larger than the expected amount for one's ancestry (for example from the Jtest spreadsheet French tend to get ~4-5%) then it's a decent sign of actual heritage. DNAland and Gencove both have a tendency to "isolate" Ashkenazi from other possible sources and thus incorrectly report that as a component in a lot of people's admixtures.

10-04-2017, 06:32 AM
The story is a bit more complex: intermarriage was discouraged by both sides. We have historical traces that it happened anyway, as to be prohibited by authorities, the situation must have happened. And we have prohibitions edicted in the Rhône Valley (today in France) in the IXth and Xth centuries, among other prohibitions like for Christians to do Shabbat with Jews and so on. And we also know that some Jews converted to Christianism willingly or not (in that case, when they feared expelment). Studies are showing that half the Jewish community of Provence choose conversion instead of exile in the early XVIth century, but also that the converted were not "cryptic Jews", as their last wills (when known) showed commitment to Catholicism, and as their children or grandchildren married outside of the community.

Jack Johnson
10-04-2017, 07:07 AM
Thanks for the responses. That seems to clear things up a bit. Thanks to ffoucart for more info concerning this topic. I had just read an article about the history of Jews in Provence. It seems that those Jews that converted to Catholicism faced discimination even afterwards, as did their descendants. I wonder what families of Provence come from this background, for if discrimination continued even after conversion, the non-Jewish locals must have known which families/individuals had Jewish roots.

10-04-2017, 08:30 AM
I never said there was no discrimination. The converted were probably seen as bad Christians by "old Catholics", and often their children married children of other converted (néophytes) Statistically, it's clear. But, since we have data, it's relatively easy to follow those families, and grandchildren were married in "old Catholic" families in majority.
Now, it's easy to find some examples, as the wealthiest families were granted nobility at some point (some neophytes already in the XVth Century). Look at Hortie/Ortigue (descendant of Salomon de Beaucaire, neophyte under the name of Jean Hortie), Cipières (descendants of Astruc Nathan), Roquebrune (descendants of Josse de Lunel, néophyte under the name of Guillaume de Roquebrune), d'Orgon, d'Anjou (René d'Anjou, néophyte took the name of the count, his godfather), Silvecane (Vidal Cohen, néophyte under the name of Sauveur de Silvacane) and so on (examples are far too numerous).
Obviously it was not restricted to nobility. The example of the family of Nostradamus is quite clear: grandson of Crescas de Carcassonne, néophyte under the name Pierre de Notredame. Nostradamus did have several children, upon them Cesar, who qualified himself of "gentleman from Provence". Nostradamus descendants are known, and of various societal status. In 1700, some of them were nobles, other were humble plowman.
In fact, I think that neophytes of the early XVIth century in Provence have today at least hundreds of thousands, and probably millions, descendants.
Mind that there is no trace of crypto-Jews in Provence.

You should read the works of Danièle Iancu-Agou, THE specialist on the subject, given she has worked on marital contracts and last wills. It's far more reliable than other works, which are lacking this insider point of view. Last wills are especially interesting as you can see what was granted to who. So very informative. Often, you can use them to find "bad Catholics" (like protestants). It is clearly not the case here.

Jack Johnson
10-05-2017, 08:19 AM
Is there any data available pretaining to the genetic impact of the neophytes of Provence, or an estimation of how many French Gentiles have neophyte ancestry? All the genetic data I have read pretaining to France--including Provence--says that they are a mixture of the Mesolithic/Neolithic inhabitants of France, and Indo-European related peoples, starting with the bell beakers of Central Europe and continuing mainly with the celts, with minor contributions by Italic, Ligurian, and Germanic peoples. In the case of Provence there may also be some Greek related admixture, which goes back to when some areas of the south of France received Greek colonies and colonists.

10-07-2017, 07:24 AM
Is there any data available pretaining to the genetic impact of the neophytes of Provence, or an estimation of how many French Gentiles have neophyte ancestry?

There was probably no genetic impact on the overall genetic picture of Provence. And even if official sources were more preserved in Provence than in other parts of France, it is highly unlikely to have enough of them to be able to find all the descendants of people living 500 years ago, neophytes or not.

But if you look at the known descendancy of some neophytes (the ones with noble descendants), numbers must be rather high. Here the descendancy in paternal line only of some of them:


This is only partial figures, obviously. But since there was around 1000 neophytes in Provence around 1500 (source: Danièle IANCU-AGOU), and since it was between 15 and 20 generations ago, with a number of descendants doubling at each generation (obviously inaccurate), it would mean potentially at least 32 millions descendants today. Obviously, you must reduce the number as many descendants are marrying with other descendants (often without knowing it), and I took 1000 neophytes and 15 generations even if not all the neophytes did leave descendancy. But in any case, numbers are extremely high. And probably not restricted to Provence, as some descendants were Huguenots.

Another point must be highlighted: this is only about neophytes in Provence around 1500. It does not cover other neophytes who lived previously in Provence or in other parts of France. As a matter of fact, we know that the highest point of conversion was in the XIIIth century. A study has been made for Paris:

The results are contradictory with the ones find for England by Robert Stacey, who found some discrimination toward neophytes and their families. It was not the case in Paris. I find extremely interesting the examples of Philippe and Louis de Villepreux.

To me, it is clear that everybody as some jewish ancestry in Western Europe in the last 1000 years, except perhaps in some very remote or segregated populations.

Jack Johnson
10-08-2017, 08:33 AM
Thanks for the links. Is there a way to translate them? I'm guessing google translate would work. The only part of your post I question is the part about almost every Western European having Jewish ancestry. I have not read/seen any genetic data to suggest that many--let alone almost all--Western Europeans have Jewish ancestry. If anything it seems that practically no mixing occurred, and very few ethnic Europeans (especially Western Europeans like the English, Irish, Scottish, Welsh, French, Belgians, Dutch, or Germans) have any Jewish ancestors/ancestry. Some Western European countries such as Ireland, Sweden, Norway, and Iceland, have practically never had a jewish population until very recently, let alone a very large one. Jews were banished multiple times throughout Western European history from many different parts of Western Europe; one such case was Britain, where Jews were persecuted and expelled for a few hundred years. The amount of time Jewish populations spent settled in mostly major cities in said Western European regions, would not be enough time to leave a genetic impact; let alone the fact that Jews were heavily persecuted/discriminated against for the most part, and mixing was discouraged by both Jews and their ethnic European host populations. If there was such a massive amount of admixture between the two populations you think it would be reflected in excess middle eastern admixture in European autosomal DNA, with that admixture tracing back to the Roman/Medival/Middle Ages, yet it doesn't. Ashkenazi and Sephardic Jews have a distinctive autosomal structure, due to selective breeding within their respective Jewish populations, and practically no breeding with gentile populations. You would think such a structure would be observable in almost all Europeans. I recently read a paper where they compared the genetics of Ashkenazi Jews with that of those who had some Jewish ancestry, and with those who are completely of ethnic European background. Here is the name of the study: "Differences in Autosomal DNA Characteristics between Jewish and Non-Jewish Populations". It is quite an interesting read on Ashkenazi Jewish autosomal DNA, and the genetic relationship between European Jews and ethnic Europeans. Thank you again for providing the links.

10-08-2017, 06:14 PM
You should perhaps look at extended genealogical trees in relation to DNA. You've got the false impression that every ancestry we have is reflecting in our genome which is not the case. By the way, Jews were a small minority so any remote Jewish ancestry is very unlikely to show up. Moreover you must think again about the number of your ancestors at the 15th generation: 65536. Given that it's unlikely that a neophyte would appear more than one or two times, its genetic contribution would be null.

Obviously the likehood to have some Jewish ancestry arise at each generation you go back in time. At one point in the past, all people with a living descendancy today are our ancestors. No matter who they were. And given Jews were present in Europe (and probably already in Southern France from the 1st century), it is statiscally impossible that a modern European doesn't have some Jewish ancestry.

About relavent isolated countries or place, you should take into consideration the fact that no place was fully isolated (even Iceland wasn't). Merchants, monks, priests, pilgrims, crusaders, slaves travelled through Europe. Our ancestors weren't static. Most of them lived in their countryside, but others, a small minority travelled far away. And it is known that some well known families from Ireland or Norway were from abroad. Often German merchants in Norway and Normans knights in Ireland. If some of them did have Jewish ancestry, how many people today in those countries could have some?

You are also making a confusion about the way admixture occured. Even if some Jews admixed with Europeans (mt DNA and Y DNA (like a R1b L21 specific subclade), even autosomal DNA, are showing it occured), modern Jewish population is representative of the Jews who chosen to keep their religion. Not of the Jews who became Christians. And Ashkenazis are the result of a specific ethnogenesis, and are not representative of all Jewish populations which existed in Europe centuries ago. We could be surprised (even if they I don't think it could be outside the Jewish cluster).

My last point will be about the social changes which occured for Jews in medieval societies. The key century is the XIIth. Before, discrimination was limited, some Jews hold public offices, even prestigious ones like baillif. They were part of the feudal system. We know that some intermarriage occured (as we have various edicts prohibiting them, showing that the situation existed). After the XIIth century, situation changed, and Jews became more and more oppressed, with limitations to the possibilities to hold lands, public offices, or the places to live. So, there was no uniformity of Jews social situation in History. The change in the XIIth century means that many Jews choose to convert to Christianism in the XIIIth century, to keep their social situation, wealth...

Now a few thousands neophytes in France or England 750 years ago will hardly give any specific genetic signature today. Except for uniparental markers. I remember discussing some years ago with a French with the specific L21 subclade without any known Jewish ancestry. So more clues can be hiding.

The case of the neophyte Louis de Villepreux is interesting as he was baillif of Corentin, and did have sons. One identified, Simon, others unnamed. But perhaps they could be identified with Jean and Pierre, knights of the King in the early XIVth Century. You can bet that if Louis has left living descendancy today, they are tens of millions, probably living mostly in France, England and USA.

One last word: about Belgium, it is known that some Conversos families seek refuge in Low Countries in the XVIth century, and not only in Antwerp. I'm trying to find if one of my gf's ancestor is not one of them.