Time and place of European admixture into the Ashkenazim-Xue et al

one majory counfusion in this thread for this whole discussion is the IBD sharing between Aj and the other ME and EU populations. When i was reading the study, when they were discussing IBD sharing between the populations it didnt seem to be an issue at all for the authors that AJ shared the largest IBD segments with Eastern europeans, then next with Iberians, then next with southern europeans, and then next with middle easterners. This makes total sense according to the evidence suggested in the study, that AJ had more recent ancestry from Eastern europeans then slightly older or pre bottleneck ancestry southern europeans, and then ancestry from the original levantine Jews. Obviously you will share the longest strands of your dna with recent people who admixed with you, so this makes total sense that if Eastern eurpeans mixed most recently with AJ that they will share the largest identical strands of dna with them. If admixture was from along time ago such as the ME admixture in AJ then you would expect for modern ME and AJ to share very little IBD segments as the length of Identically shared ancestry would be broken up thousands of times and would not remain identical anymore. Higher shared IBD with Iberia is easily explained away by the recent gene flow in Iberia from Sephardic Jews. The sephardic Jewish ancestry in modern Iberians is quite significant. Maybe I dont understand how it all works quite well enough but thats what I understood from it. I still do think its best to wait for ancient dna evidence.

Take a look at the graphic of the IBD sharing, and also read the caption:

IBD analysis of Ashkenazi Jews-Xue et al.PNG
Both the less than 7cm and more than 7cm sharing is highest with Eastern Europeans.

Also, the length of the segments is not the only important factor; one also has to consider the mean number of segments.
 
Srdceleva, that was absolutely brilliant. If you relate the order of the ibd lengths to the order of the proposed admixture events, you'll see how they match. The shortest is with levantines, but jews are from the Middle East, and derive from Bronze Age levantines. When they left, their Levantine cousins became Lebanese, etc and formed different sequences and eventually would drift from the jews overtime. Southern European (one that is about as southerly as south italians, not saying its from them) came next, and over time the south euro contributors drifted out genetically from European Jews so ibd got worse overtime. Pattern applies with the other contributors.
Not saying this happened for sure, we lack hard evidence but your idea is very interesting and makes a lot of sense.

thanks for the nice comments

Take a look at the graphic of the IBD sharing, and also read the caption:

View attachment 7878
Both the less than 7cm and more than 7cm sharing is highest with Eastern Europeans.

Also, the length of the segments is not the only important factor; one also has to consider the mean number of segments.

i still think it falls in line with what I said, and in the description above the graph it says also the same conclusion, that this shows that most of the recent genetic influence in AJ is from Eastern Europe.
 
thanks for the nice comments



i still think it falls in line with what I said, and in the description above the graph it says also the same conclusion, that this shows that most of the recent genetic influence in AJ is from Eastern Europe.

Yeah, they both show Eastern Europe>(Iberia or Western Europe-they seem to have different ranks in both charts, but they are somewhat close)>Southern Europe>MidEast
which makes sense given what we believe happened during the European journey.

And I don't know if we should say low ibd leads to not having any gene flow from a certain place. To say they haven't gotten any from Southern Europe is like saying they haven't gotten any from the MidEast, which is odd since that's where they are from...but we have the challenge of using modern populations for comparison, since Jews have been endogamous for centuries and other populations, even the ones where the Jews MAY have gotten what they got went their own separate ways genetically and drifted out. If they would be so kind as to replace the modern Levantines with Bronze Age Levantines, and the modern Southern Euros with ancient ones (Angela brought up the island types) the IBD should be higher between either of these populations or both. Jews descend from non-Jews. Period. It's not like they're a separate hominid species, or crash landed on Planet Earth from the outer reaches of the galaxy.

"We...bring...you...peace" (finger glows)

Let me know any issues you have with what I have said
 
Yeah, they both show Eastern Europe>(Iberia or Western Europe-they seem to have different ranks in both charts, but they are somewhat close)>Southern Europe>MidEast
which makes sense given what we believe happened during the European journey.

And I don't know if we should say low ibd leads to not having any gene flow from a certain place. To say they haven't gotten any from Southern Europe is like saying they haven't gotten any from the MidEast, which is odd since that's where they are from...but we have the challenge of using modern populations for comparison, since Jews have been endogamous for centuries and other populations, even the ones where the Jews MAY have gotten what they got went their own separate ways genetically and drifted out. If they would be so kind as to replace the modern Levantines with Bronze Age Levantines, and the modern Southern Euros with ancient ones (Angela brought up the island types) the IBD should be higher between either of these populations or both. Jews descend from non-Jews. Period. It's not like they're a separate hominid species, or crash landed on Planet Earth from the outer reaches of the galaxy.

"We...bring...you...peace" (finger glows)

Let me know any issues you have with what I have said

yes i think were on the right track. From my understanding IBD and proving recent genetic relatedness in general, for example between cousins or close family, is based on the fact that you share large portions of identical dna with that person, and as angela pointed out, the frequency of these segments. This proves that you have a recent genetic relationship. You may be almost one hundred percent of a different ethnicity as someone but if you have a recent common ancestor from not too long ago you will share higher rates of IBD with that person than with someone of your own ethnicity who isnt as close of a cousin because youve been seperated from them for a long time. The Jews have literally been seperated form levantine peoples for over 2000 years. As time goes on that dna gets broken up into so many parts that the length of identical dna becomes very small, though you are of the same ethnic group. This makes total sense. My overall genetic make up may resemble a guy from eastern europe, but because im a quarter american there maybe be many americans who i share more recent ancestry with than many eastern europeans.
 
I know, it makes total sense. They are descended from Bronze Age levantines and I bet if the calculator used in this student were used on the Bronze Age, they might not get any european. Maybe a small percentage of south european in the single digits. Ibd sharing with modern south Europe is small but it's certainly higher than with the modern Middle East.

Yeah ibd is "enough" sharing in a row as opposed to scattered short segments here and there, which admixture calculators go by (by state). The 47 percent Mideast is IBS sharing with the levant so 47 percent of the total genome is admired with levant, and one can be tricked into thinking that a gang of people who were 3/4 south italian 1/4 north euro mingled with a group of people who were of full Lebanese descent and together they formed Ashkenazim.

Also you said you are 1/4 American...you mean Native American ,colonial (English/german or some other northern descent), or having a grandparent born in the US of another background besides the colonial/native?
 
I know, it makes total sense. They are descended from Bronze Age levantines and I bet if the calculator used in this student were used on the Bronze Age, they might not get any european. Maybe a small percentage of south european in the single digits. Ibd sharing with modern south Europe is small but it's certainly higher than with the modern Middle East.

Yeah ibd is "enough" sharing in a row as opposed to scattered short segments here and there, which admixture calculators go by (by state). The 47 percent Mideast is IBS sharing with the levant so 47 percent of the total genome is admired with levant, and one can be tricked into thinking that a gang of people who were 3/4 south italian 1/4 north euro mingled with a group of people who were of full Lebanese descent and together they formed Ashkenazim.

Also you said you are 1/4 American...you mean Native American ,colonial (English/german or some other northern descent), or having a grandparent born in the US of another background besides the colonial/native?

Well I think to truely see how really middle eastern Ashkenazi Jews are we will have to wait for more ancient DNA to be sampled as many people on this website have said many times, modern populations are not always the best representation of ancient ones. Modern levantine people may have had alot of genetic influence from the Islamic arab expansions while ancient levantine people had more influence from southern european/ Mediterranean cultures ( possibly the philistines?). Well just have to wait.

My American grandmothers ancestry is very colonial after having done her family tree I can definitely say her family has been in the US in some places before the revolution. She does have more recent ancestry though ( but still a couple generations back) from Germany, Switzerland, and France . She didn't hsve any native American according to her DNA results.
 
It would really be great if they compare modern european jews with the philistines that were picked up about a week ago. I would definitely expect big ibd there and would explain the Southern European plotting that jews get. Using modern italians is pretty much a lost cause and I would be mad if I see a new study that uses them again. I would ask if they even bothered reading any other study that tries to figure out european admixture sources.
Not to mention Ashkenazim/sephardics score high european/Anatolian farmer, about on par with south euros unlike today's leventines who sit more with the Bronze Age leventines.
 
An Anthrogenica thread on the 23andMe results of 6 North African Jews gives Italian readings of 29pc, 17.5pc, 18.5pc, 25.1pc, 29.4pc and 23.8pc.Iberian readings were very low, generally 0.1pc with a single example reaching 2.2pc.
 
Genetic differences between Sephardi and Ashkenazi Jews are not great.
 
Whoa! I think 23 and me tests for ibd so that's freakishly high. 29 percent? That's insane! I think the jews who stuck around in italy picked up more recent Italiano blood and some moved to Africa. Or they're not fully jewish but mixed with italian.
I think I've seen maps where the researcher would pull some trick where Sephardim would still cluster with sicilans and cypriots whereas Ashkenazim would plot far from everyone and i think this is a result of testing longer ibd strands but i could be wrong.
Ashkenazim do have the greatest ibd with Sephardim
 
Uh it was redundant for me to say that they aren't fully jewish after mixing with italians because i already pointed out that they picked up more recent italian blood (those North African ones you posted). Lol. But yeah there's definitely recent italian in those, because most ashkenazi get 95 percent or more ashkenazi from 23and me, its own category.
I think if you take out all the jewish samples in 23andme I don't know if it would be able to figure out anything about a new ashkenazi customer.
 
Uh it was redundant for me to say that they aren't fully jewish after mixing with italians because i already pointed out that they picked up more recent italian blood (those North African ones you posted). Lol. But yeah there's definitely recent italian in those, because most ashkenazi get 95 percent or more ashkenazi from 23and me, its own category.
I think if you take out all the jewish samples in 23andme I don't know if it would be able to figure out anything about a new ashkenazi customer.


Where does that high Italian reading come from in these North African Jews on 23andMe?

These 6 samples also get 2 to 5pc of Ashkenazi.
 
Reference:
anthrogenica.com/showthread.php?5048-23andme-results-of-North-African-Jews/page3
 
2-5 percent means they and Ashkenazim drifted off genetically. Those high italian scores tell me that they have recent italian ancestry and i think they were more open to conversions. Ashkenazim who are full blooded shouldn't score much of any italian in this test, maybe 1-2 percent in an oddball.
What else did they score besides italian, Iberian, or Ashkenazim? Likely Mideast, but european jews left the Mideast long ago and are supposed to be drifted off, this is really strange. Ibd with Middle East can't be that high..,,
Or they're converts!
 
Oh I see you posted that thread. I'll read it later, but this is getting even more interesting. I love interesting.
 
Uh it was redundant for me to say that they aren't fully jewish after mixing with italians because i already pointed out that they picked up more recent italian blood (those North African ones you posted). Lol. But yeah there's definitely recent italian in those, because most ashkenazi get 95 percent or more ashkenazi from 23and me, its own category.
I think if you take out all the jewish samples in 23andme I don't know if it would be able to figure out anything about a new ashkenazi customer.

Yes, you finally got my attention. Don't expect it to continue, however, Sikeliot.

No, there isn't recent "Italian" in North African Jews. Please familiarize yourself with their history. You may also be confusing North African Jews with Sephardic Jews; they aren't the same even when they use the same religious rite and despite the fact that there was Sephardic migration into North Africa.
https://en.wikipedia.org/wiki/History_of_the_Jews_in_Algeria
https://en.wikipedia.org/wiki/History_of_the_Jews_in_Tunisia
https://en.wikipedia.org/wiki/Berber_Jews

Plus we have just finished discussing ad nauseam the fact that no academic study has found any appreciable IBD sharing between any Italians and any Jews. Certainly, it seems pretty settled that the only recent IBD sharing between Jews and European populations is with Eastern Europeans, and there isn't much of that.

I've urged you before to study the 23andme white paper in order to understand their proprietary algorithm.
https://www.23andme.com/ancestry_composition_guide/

Please familiarize yourself with the recall and precision numbers for "Italian" in 23andme results. It's in the white paper they've provided. Commenting without taking these things into consideration isn't very helpful.

As I've also told you many times, I put very little credence in posted results "supposedly" from 23andme, by people "claiming" to be all sorts of nationalities. They don't seem to have caught on at Anthrogenica that people posting there can claim to be all sorts of nationalities and there's no way to verify it, just as there is no way to verify the posted "results" are not doctored. Even if the posts are "honest", 23andme does not represent a randomly chosen, scientific set. It's all self selected people who may or may not be representative of their groups.

@Vallicanus,
Ah, our Iberian obsessed Scot is back. Perhaps you might consider contacting the authors of Xue et al and Behar and all the others who have looked at the issue of IBD sharing between Jews and Europeans and tell them that they're dead wrong; there is no IBD sharing between Jews and Iberians, and the proof is some unsourced individual sets of results from 23andme. Good luck with that, and please report back. I'm dying to hear the response.

Now, stop repeating the same things over and over again, and get back on topic.
 
Ok I appreciate the response, I just thought that non-Ashkenazic jews mixed more with their hosts and wasnt aware of 23-and me's quirks. It's my fault for not doing my homework, I'll admit. And I was aware from the beginning that Ashkenazim have no recent italian ancestry, this isn't anything new to me or anything I'm pushing to argue against. I mistakenly thought that North African jews were more open to mixing and incorporated italians into their troupe.

Try not to confuse me for someone else, please. I'm not sikeliot.
 
Sorry, everybody but I'm still in the dark why 23andMe's North African Jewish sample has such a high "Italian" reading.

What does "Italian" mean in 23andMe?

Remember Fiorito et alia (2015) found high IBD sharing between Italians, especially South Italians and Sardinians, and Northwest Africans.
 
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Sorry, everybody but I'm still in the dark why 23andMe's North African Jewish sample has such a high "Italian" reading.

What does "Italian" mean in 23andMe?

this thread is getting too confusing for me, i think angela was right earlier, we have to wait for the ancient samples. The ashkenazi have to complex of a history it seems, I also dont understand why those people from 23 and me show such high italian. Maybe because they are new york AJ and are a quarter Italian haha who knows, or maybe when europeans mix with middle easterners some parts of their dna can be easily confused with Italians lol. Im just gunna wait for the ancient DNA
 
Ok I appreciate the response, I just thought that non-Ashkenazic jews mixed more with their hosts and wasnt aware of 23-and me's quirks. It's my fault for not doing my homework, I'll admit. And I was aware from the beginning that Ashkenazim have no recent italian ancestry, this isn't anything new to me or anything I'm pushing to argue against. I mistakenly thought that North African jews were more open to mixing and incorporated italians into their troupe.

Try not to confuse me for someone else, please. I'm not sikeliot.

I apologize, Davef. The preoccupations are his, and indeed some of the arguments echo things he has posted on 23andme, so the name just floated to the surface of my mind I guess. I'll be more careful in the future.

Again, sorry.
 

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